In today’s modern world, communication is key to success. It is essential to stay connected with colleagues, friends, and family members. With the rise of mobile technology, cell phones have become ubiquitous, and people rely on them to communicate. However, in some situations, 2-way radio communication can be a better option. Here are the top advantages of 2-way radio communication over cell phones:
Instant Communication
One of the most significant advantages of 2-way radio communication is the ability to communicate instantly. With a 2-way radio, you can transmit and receive messages with the push of a button. There is no need to dial a number, wait for someone to pick up, or navigate through menus on a touch screen. This feature makes 2-way radios ideal for emergency situations or any other scenario that requires quick communication.
Greater Range
Another advantage of 2-way radios over cell phones is their greater range. Two-way radios use radio frequencies to transmit and receive messages, and their range can reach several miles. This makes them an excellent choice for use in remote or rugged environments where cell service may be spotty or nonexistent. With the help of repeaters, 2-way radios can extend their range even further, making them suitable for use in large facilities like hospitals or shopping malls.
2-way Radios
Cell Phones
Greater range
Limited range
Can be used without cellular network
Require cellular network
Work in remote or rugged environments
May not work in remote or rugged environments
Use a closed network for private communication
Use public networks for communication
Less expensive with no monthly fees
May require contracts and monthly fees
Durability
Two-way radios are designed to withstand harsh conditions. They are built to endure extreme temperatures, dust, water, and shock. They are less likely to break if dropped or bumped, making them a more reliable choice in high-stress situations. In contrast, cell phones are delicate devices that can easily break if dropped or subjected to harsh conditions.
Privacy
Two-way radios use a closed network, which means that conversations are private and cannot be intercepted by outsiders. This is especially important in situations where sensitive or confidential information is being shared. Cell phones, on the other hand, use public networks that can be hacked or intercepted by unauthorized individuals.
Cost-Effective
Two-way radios are often less expensive than cell phones. They are a one-time investment with no monthly fees or contracts required. This makes them a cost-effective solution for businesses, organizations, and individuals who need reliable communication without breaking the bank. In contrast, cell phones require monthly fees, contracts, and may even come with hidden charges.
If you’re interested in learning more about 2-way radio communication and how it can benefit you, check out BravoSatCom.com. We offer a wide range of 2-way radios and accessories to meet your communication needs. With our products, you can stay connected in any situation, whether you’re on a job site, camping in the wilderness, or responding to an emergency. Browse our website today to learn more about our products and services.
In conclusion, 2-way radio communication offers a reliable, instant, and cost-effective way to stay connected in a wide range of situations. With its greater range, durability, privacy, and cost-effectiveness, 2-way radios are an excellent choice for emergency responders, construction workers, outdoor enthusiasts, and many other applications.
When planning a satellite, VSAT, or telecom installation, one of the first decisions you face is cable type. Fiber optic and coaxial cable both carry signals from point A to point B — but they work in completely different ways, and choosing the wrong one means poor performance, expensive rework, or a system that won’t scale.
This guide breaks down everything you need to know: how each cable works, where each excels, and how to make the right call for your specific project.
Left: Coaxial cable carries both RF signal and DC power through a copper center conductor. Right: Fiber optic cable carries light only — no DC power capability.
What Is Coaxial Cable?
Coaxial cable carries RF signals as electrical waves along a center copper conductor, insulated from a surrounding braid or foil shield by a dielectric foam core. The shield keeps the signal contained and reduces external interference. An outer PE or PVC jacket provides mechanical and weather protection.
In VSAT and satellite applications the most common types are LMR-400 (standard Ku-band IFL, runs to ~30m), LMR-600 (medium runs to ~60m), LMR-900 (long runs to 80m+), and legacy RG-214. For broadcast and CATV distribution, 75Ω RG-6 is standard.
The capability that makes coaxial indispensable for satellite work: it carries DC power alongside the RF signal. The same cable that carries your IF signal from modem to LNB also delivers the 13V or 18V DC that powers the LNB — plus the 22 kHz polarisation tone — and the 24–48V DC that drives the BUC. No other single cable can do this.
What Is Fiber Optic Cable?
Fiber optic cable carries signals as pulses of light through a glass core, surrounded by cladding (a lower-refractive-index glass layer that traps light inside by total internal reflection), a protective buffer coating, and an outer jacket. There are no copper conductors — signals travel at the speed of light with virtually no attenuation over distance.
Two main types exist: single-mode fiber (SMF, OS1/OS2) for long-distance runs up to 40+ km, and multi-mode fiber (MMF, OM3/OM4) for shorter data links up to ~300–550m. For telecom backhaul and building-to-building links, SMF OS2 is the current standard.
The defining advantages: attenuation of just 0.2 dB/km at 1550 nm (versus approximately 6.6 dB/100m for LMR-400 at 1 GHz), complete immunity to electromagnetic interference, and effectively unlimited bandwidth. The defining limitation: fiber cannot carry DC power. Any powered equipment at the far end requires a separate power cable.
Signal Attenuation: The Numbers That Decide Everything
Signal loss — attenuation — is the single most important factor in cable selection. Here’s how the main cable types compare at 100 meters:
Signal loss per 100m at 1 GHz. Fiber OS2 loses virtually nothing over any practical run. RG-58 and RG-6 are unsuitable for any professional RF application beyond short jumpers.
At Ku-band frequencies (12 GHz), coaxial losses are significantly higher still — LMR-400 loses approximately 30 dB per 100m at Ku-band, which is why VSAT IFL runs must be kept short or upgraded to larger cable (LMR-600 or LMR-900).
Fiber Optic vs Coaxial: Full Comparison
Feature
Coaxial Cable (LMR-400)
Fiber Optic (SMF OS2)
Signal medium
Electrical (RF waves)
Light (photons)
Attenuation @ 1 GHz
6.6 dB / 100m
0.02 dB / 100m
Attenuation @ Ku-band (12 GHz)
~30 dB / 100m
N/A — not RF
Max VSAT IFL run (Ku-band)
30m (LMR-400) · 60m (LMR-600) · 80m+ (LMR-900)
Not suitable for IFL
Max data run (1 Gbps)
~100m (Cat6 Ethernet)
10+ km (SMF)
EMI immunity
Partial — braid reduces, does not eliminate
Complete — light is unaffected by EMI
DC power over cable
✓ Yes — LNB 13/18V + BUC 24–48V
✗ No — separate power cable required
RF signal (native)
✓ Yes
✗ No — requires optical conversion
Bandwidth
DC to 40 GHz (LMR-600)
Practically unlimited (>100 THz)
Field termination
Easy — crimp tool + N-type / SMA / BNC
Requires fusion splicer + cleaver
Security
Can be passively tapped
Tap causes detectable signal loss
Ground loop / surge risk
Yes — copper conductor
None — glass is non-conductive
Weight
Heavier
Very light
Cable cost
Lower
Moderate to high
Equipment cost
Lower
Higher (transceivers, media converters)
Typical connectors
N-type, F, BNC, SMA, TNC
LC, SC, ST, FC
When to Use Coaxial Cable
✓ Coaxial is the right choice for:
VSAT and satellite IFL runs — Mandatory. Your satellite modem must deliver DC power to the LNB (13V/18V + 22 kHz polarisation tone) and BUC (24–48V) through the same cable that carries the IF signal. Use LMR-400 up to 30m, LMR-600 to 60m, LMR-900 to 80m+ at Ku-band.
Antenna feedlines — VHF/UHF, cellular base station, and microwave antenna connections are always coaxial. LMR-400 is the standard for fixed base station feedlines; LMR-600 for tower runs over 20m.
RF signal distribution — Splitters, combiners, amplifiers, RF patch panels: anywhere you’re routing a live RF signal, coaxial connections are required throughout the chain.
CCTV and analog video — Analog camera systems (HD-CVI, TVI, AHD) use RG-59 or RG-6. Still widely deployed throughout the GCC due to existing cable infrastructure.
Remote DC power delivery — Any equipment that needs power over the cable (BUC on a tower, LNB on a dish) requires coaxial IFL. There is no alternative.
Field installations — Coax connectors are field-terminable with a hex crimp tool. Fiber fusion splicing requires capital equipment and a clean environment — coax wins on field flexibility every time.
When to Use Fiber Optic Cable
✓ Fiber optic is the right choice for:
Long data backbone runs (>100m) — Any network link over 100 meters at Gigabit speeds or higher should be fiber. SMF supports 10G Ethernet over 10+ km without amplifiers.
Building-to-building links — Outdoor aerial or buried runs between buildings need fiber for ground-loop isolation and lightning surge protection. Copper cable between separate structures can conduct a surge that destroys equipment at both ends.
High-EMI environments — Generator rooms, industrial motor drives, high-voltage transformer enclosures: fiber is completely immune to electromagnetic interference regardless of the surrounding electrical noise.
High-bandwidth data (40G / 100G / 400G) — These speeds require fiber. Not achievable over coaxial cable at any practical distance.
Security-critical links — Fiber cannot be intercepted passively. Any physical tap causes a measurable signal loss that optical monitoring can detect and alert on.
Harsh or marine environments — Fiber is immune to salt air corrosion, moisture ingress effects on signal quality, and temperature-driven impedance changes.
Why VSAT Always Uses Coaxial — Without Exception
In a VSAT installation, coaxial cable (LMR-400/600/900) is mandatory for the IFL between the outdoor unit and modem — it carries both the RF signal and DC power to the BUC and LNB. Fiber or Cat6 handles the IP data backbone from modem to the office network.
In any VSAT installation — from a single maritime terminal to a large teleport earth station — the IFL between the satellite modem and the outdoor unit must be coaxial cable. The reason is simple: the modem or ODU controller delivers DC power to the LNB and BUC through the same coaxial IFL that carries the IF signal. Fiber optic cable cannot carry DC power.
Fiber-based IF extension systems do exist. They use optical modulators and demodulators with separate power injectors to extend IFL runs beyond 100 meters in large earth station facilities. But these are expensive, complex installations reserved for sites where very long cable runs make standard coax impractical. For any typical VSAT site, coaxial cable is the correct and only practical IFL solution.
Can I replace my VSAT coaxial IFL with fiber optic cable?
Not without additional equipment. The BUC and LNB require DC power that can only be delivered over coaxial cable in a standard installation. Fiber-based IF extension systems exist for very long runs (>100m) in large facilities, but they require optical modulators and separate power injectors — significant cost and complexity. For any typical VSAT installation, coaxial cable is the correct IFL choice.
Which has less signal loss — fiber optic or coaxial?
Fiber wins by a dramatic margin for data. LMR-400 loses approximately 6.6 dB per 100 meters at 1 GHz — and ~30 dB per 100m at Ku-band (12 GHz). Single-mode fiber OS2 loses just 0.2 dB per kilometer at 1550 nm. Over a 100m run, fiber loses roughly 0.02 dB versus LMR-400’s 6.6 dB — about 330× less attenuation. However, this comparison only applies to data signals. For native RF signals (satellite IF, antenna feedlines), there is no “fiber alternative” without conversion equipment.
Is fiber optic cable more expensive than coaxial?
Fiber cable typically costs more per meter, and field termination requires a fusion splicer — significant capital equipment. However, for long data backbone runs where coax would require inline amplifiers or multiple segments, fiber often becomes cost-competitive overall. For short RF applications under 50 meters, coaxial cable is almost always the lower-cost total solution.
Can fiber optic cable be used as an antenna feedline?
No — not without conversion equipment. Fiber carries light signals, not analog RF. An antenna feedline must be coaxial to carry the raw RF signal between the antenna and the radio or satellite modem. Any fiber in an RF path requires RF-to-optical conversion at both ends, adding cost and complexity that makes it impractical for standard installations.
What coaxial cable should I use for Ku-band VSAT?
Use LMR-400 for IFL runs up to 30 meters at Ku-band, LMR-600 for 30–60 meters, and LMR-900 for runs beyond 60 meters. All outdoor sections should use weatherproof N-type connectors with proper sealing tape. Never use RG-6 or RG-58 for VSAT — their attenuation at Ku-band is far too high even for short runs.
Need coaxial cable for your VSAT or satellite installation?
BravoSatcom stocks LMR-400, LMR-600, LMR-900 and IFL cables. We ship across the GCC.
Shop Cables →
When someone says “LMR cable” on a VSAT or radio installation, they almost always mean Times Microwave Systems’ LMR series — the industry standard for low-loss 50Ω coaxial cable. The range runs from the 2.79mm LMR-100 pigtail all the way to the 22mm LMR-900 long-haul run, and choosing the wrong model either wastes budget or degrades your link.
This guide covers the full LMR lineup: what each model is, where it belongs, connector compatibility, and how to specify correctly for VSAT IFL, two-way radio feedlines, and general RF installations.
LMR Series Attenuation at 1 GHz (dB/100m)
Lower bar = less signal loss = better long-run performance
LMR-100
35.4 dB/100m
LMR-195
18.7 dB/100m
LMR-240
12.8 dB/100m
LMR-400
6.6 dB/100m ← Standard VSAT IFL
LMR-600
3.6 dB/100m
LMR-900
2.4 dB/100m
Times Microwave LMR Series | Approx. values @ 1 GHz | bravosatcom.com
What Does LMR Stand For?
LMR stands for Low-loss Microwave RF. Times Microwave Systems introduced the LMR series as a direct replacement for legacy RG-series cables (RG-58, RG-8, RG-213) — cables designed in the 1940s that hadn’t kept pace with modern RF requirements.
The number after “LMR” is roughly the outside diameter in hundredths of an inch: LMR-400 is ~0.405″ OD, LMR-600 is ~0.590″ OD. The larger the number, the thicker the cable and the lower the signal loss per metre. All LMR cables are 50Ω and use foam polyethylene dielectric with a bonded foil + braid shield — the combination that gives them their attenuation advantage over solid-PE RG cables.
LMR Series: Full Specs at a Glance
Model
OD (mm)
Atten @ 450 MHz
Atten @ 1 GHz
Atten @ 5.8 GHz
Vel. Prop.
LMR-100
2.79
23.0 dB/100m
35.4 dB/100m
~98 dB/100m
83%
LMR-195
4.95
12.8 dB/100m
18.7 dB/100m
~52 dB/100m
83%
LMR-240
6.10
8.9 dB/100m
12.8 dB/100m
~36 dB/100m
84%
LMR-300
7.62
6.6 dB/100m
9.8 dB/100m
~27 dB/100m
83%
LMR-400
10.29
4.9 dB/100m
6.6 dB/100m
~15.7 dB/100m
85%
LMR-500
12.70
3.6 dB/100m
4.9 dB/100m
~11.8 dB/100m
85%
LMR-600
14.99
2.9 dB/100m
3.6 dB/100m
~8.5 dB/100m
86%
LMR-900
22.10
1.8 dB/100m
2.4 dB/100m
~5.6 dB/100m
87%
All values approximate. Refer to Times Microwave datasheets for exact published specifications.
LMR vs Legacy RG Cable: The Real Difference
The most common question when switching to LMR is: “is it really that much better than RG-213?” The answer is yes — by a significant margin:
Cable
Attenuation @ 450 MHz
Attenuation @ 1 GHz
RG-58
~54 dB/100m
~79 dB/100m
RG-213
~15 dB/100m
~22 dB/100m
LMR-400
4.9 dB/100m
6.6 dB/100m
On a 20m antenna feedline at 450 MHz, RG-213 loses ~3 dB — LMR-400 loses ~1 dB. That 2 dB difference is real link margin, and it can be the difference between a reliable radio network and intermittent dropouts on a fringe site.
Which LMR Cable for Which Application?
LMR-100 — Equipment Jumpers and Pigtails
LMR-100 is the thinnest and most flexible cable in the range. At 2.79mm OD it’s used for very short equipment connections: jumpers, test leads, and patch leads inside enclosures where flexibility is critical and run length is under 1–2 metres. Not suitable for outdoor runs or anything beyond short internal connections.
LMR-195 — Short Patch Cables and Radio Leads
At 4.95mm OD, LMR-195 is the best replacement for RG-58 — same size, dramatically lower loss. Well suited for patch cables on equipment racks, short antenna leads on mobile radios, and general RF connections where RG-58 is currently used. Keep runs under 15m at VHF/UHF.
LMR-240 — VHF/UHF Short Feedlines
LMR-240 (6.10mm OD) suits short base station antenna feedlines up to ~20m at VHF/UHF, or comms room rack cabling where some flexibility is needed. The 25mm minimum bend radius makes it reasonably easy to route through tight spaces and conduit.
LMR-400 — VSAT IFL (≤30m) and Radio Base Station Feedlines
LMR-400 is the workhorse of the range. At 10.29mm OD it’s the standard cable for VSAT IFL runs up to 30m at Ku-band, two-way radio base station antenna feedlines up to 50m at VHF/UHF, and the majority of outdoor RF installation runs. It’s the default choice when no other constraint applies.
For a full head-to-head on LMR-400 vs LMR-600, including attenuation charts and VSAT run length guidance, see the LMR-400 vs LMR-600 guide.
LMR-600 — VSAT IFL (30–60m) and Long Radio Feedlines
When your IFL run exceeds 30m but stays under 60m at Ku-band, LMR-600 (14.99mm OD) is the correct cable. Its attenuation at 5.8 GHz is ~8.5 dB/100m vs LMR-400’s ~15.7 dB/100m — a significant advantage for longer satellite runs. It’s less flexible (minimum bend radius 38mm) and requires more planning during installation, but there’s no alternative when the run length demands it.
LMR-900 — Long IFL Runs (60–100m+) and Earth Stations
LMR-900 (22.10mm OD) is used for long IFL runs in large VSAT earth stations, broadcast uplink facilities, and teleports where cable runs exceed 60–80m. Attenuation at 1 GHz is just 2.4 dB/100m — about one-third of LMR-400. The trade-offs are stiffness (100mm minimum bend radius) and cost. Requires appropriately sized N-type or 7/16 DIN connectors.
Application Quick-Select
Application
Recommended LMR
Max Run (Ku-band)
Max Run (UHF/VHF)
Equipment jumpers / pigtails
LMR-100 / LMR-195
<2m
<5m
Handheld radio patch lead
LMR-195
—
<10m
Short base station feedline
LMR-240
—
<20m
Standard VSAT IFL
LMR-400
~30m
~50m
Long VSAT IFL
LMR-600
~60m
~80m
Earth station / very long run
LMR-900
~100m+
>100m
Connector Compatibility
LMR cables use standard 50Ω connectors — but you must match the connector body to the cable series. Using an LMR-400 connector on LMR-600 cable will result in a poor crimp and intermittent contact in the field.
LMR Model
Standard Connectors
Notes
LMR-100
SMA, MMCX, MCX
Small-body connectors only
LMR-195
SMA, BNC, TNC, N-type
Specify LMR-195 body size
LMR-240
SMA, N-type, BNC, TNC
N-type standard for outdoor use
LMR-400
N-type, 7/16 DIN
N-type is standard for VSAT IFL
LMR-600
N-type, 7/16 DIN
Larger N-type body — do not mix with LMR-400 connectors
LMR-900
N-type, 7/16 DIN
7/16 DIN preferred for high-power applications
Field note: Always specify connectors by cable model, not just connector type. “N-type for LMR-400” and “N-type for LMR-600” are different parts. Using the wrong body size is one of the most common installation errors.
LMR vs LMR-DB (Direct Burial)
Times Microwave offers a -DB (Direct Burial) variant for most LMR models — LMR-400-DB, LMR-600-DB, etc. The DB variant adds a gel-filled or solid PE jacket designed for direct burial in soil without conduit. Electrical specifications are identical to the standard version. If any part of your cable run is underground, specify the DB variant — standard LMR jackets are not designed for prolonged soil contact.
Frequently Asked Questions
Is LMR-400 suitable for outdoor installation in the UAE?
Yes. Standard LMR-400 has a UV-resistant black polyethylene outer jacket rated for outdoor exposure. For direct underground burial, specify LMR-400-DB.
What’s the difference between LMR-400 and LMR-400-UF (Ultra Flex)?
LMR-400-UF uses a stranded centre conductor instead of solid copper, making it significantly more flexible for routing in tight spaces. Attenuation is marginally higher (~5–8%) but negligible for most applications. Both use the same connector bodies and termination tools.
Can I use LMR-600 everywhere instead of LMR-400?
You can, but it costs more per metre, is stiffer to route, and the performance gain on runs under 30m is small. LMR-400 is the correct choice for standard VSAT IFL runs. Reserve LMR-600 for runs that genuinely exceed 30m at Ku-band.
Do LMR cables work at Ku-band (14 GHz)?
LMR-400 and larger models are rated for Ku-band frequencies. At 14 GHz, LMR-400 loses approximately 30 dB/100m, limiting practical IFL runs to ~30m. LMR-600 extends this to ~60m and LMR-900 to ~100m+.
Are LMR cables 50Ω or 75Ω?
All LMR cables in this guide are 50Ω — the standard for VSAT, satellite, and two-way radio applications. Times Microwave also produces 75Ω LMR variants for broadcast/CATV distribution. Never mix 50Ω and 75Ω cables in the same RF path without an appropriate matching network.
Shop Times Microwave LMR Cables at Bravo Satcom
Bravo Satcom supplies the full Times Microwave LMR series across the UAE and GCC — including LMR-400, LMR-600, and LMR-900 in standard and direct-burial variants, cut to length with factory or field-fitted N-type connectors.
Not sure which cable and connector combination suits your installation? Send us your run length, frequency, and application and we’ll spec it correctly. Contact us at sales@bravosatcom.com or +971 55 541 5892.
The cable run between your VSAT outdoor unit and your modem is called the IFL — Intermediate Frequency Link. It carries the satellite signal after the LNB has downconverted it from Ku or C-band to L-band (950–2150 MHz), and it carries the uplink signal from your BUC before transmission.
Get the IFL cable wrong — wrong type, wrong length, connectors not properly terminated — and your link budget suffers before a single packet reaches the satellite. This guide covers what the IFL is, how to choose the right cable, how to calculate loss for your specific run, and what maximum lengths apply to each cable type.
What Is an IFL Cable?
IFL stands for Intermediate Frequency Link. It is the coaxial cable connecting two points in a VSAT system:
🛰️ ODU BUC + LNB
IFL Cable L-band 950–2150 MHz + DC power + DiSEqC
📡 IDU VSAT Modem
The LNB downconverts the received satellite signal from Ku-band (10.7–12.75 GHz) or C-band (3.7–4.2 GHz) to L-band (950–2150 MHz). The BUC upconverts the transmit signal from L-band to Ku or C-band. The IFL cable carries both of these L-band signals simultaneously — receive down, transmit up — through a single coax run. The IFL also carries DC power from the modem to the LNB and, in most systems, carries the DiSEqC or tone commands that control LNB polarisation and band switching.
IFL Cable Specifications
Frequency Range
The IFL operates at L-band: 950 MHz to 2,150 MHz for most Ku-band VSAT systems.
System Type
IFL Frequency Range
Ku-band VSAT (standard)
950–1,450 MHz (low band) or 950–2,150 MHz (wideband)
Ku-band VSAT (wideband LNB)
950–2,150 MHz
Ka-band VSAT
950–2,150 MHz
C-band VSAT
950–1,750 MHz (typical)
Always check your modem and LNB specs. The IFL cable must have low attenuation across the full operating frequency range of your specific system.
Impedance and Connectors
All IFL cables are 50Ω. Do not use 75Ω cable (standard satellite TV cable) for IFL runs — the impedance mismatch introduces reflections and degrades signal quality. Both ends terminate in N-type connectors, the standard for VSAT IFL work. See the N-Type vs SMA vs BNC connector guide for a full comparison.
Attenuation at 2 GHz per 100m — visual comparison:
LMR-240
14.8 dB
LMR-400
8.0 dB
LMR-600
5.2 dB
LMR-900
3.5 dB
⚠️ Do not use RG6 for VSAT IFL. RG6 is 75Ω — not 50Ω. Impedance mismatch affects every interface. Higher attenuation at L-band, lower DC current capacity, less shielding. It is a domestic TV cable and does not belong in a professional VSAT installation.
Attenuation accumulates with distance. Every metre of cable, every connector, and every in-line component adds insertion loss.
Total loss (dB) = Cable loss (dB/m) × Run length (m) + Connector loss × Count + In-line component losses
A good N-type connector pair adds approximately 0.1–0.2 dB. Surge arrestors add 0.3–0.5 dB each.
LMR-400 Loss Reference
Run Length
Loss at 1 GHz
Loss at 1.5 GHz
Loss at 2 GHz
10 m
0.56 dB
0.69 dB
0.80 dB
20 m
1.12 dB
1.38 dB
1.60 dB
30 m
1.68 dB
2.07 dB
2.40 dB
40 m
2.24 dB
2.76 dB
3.20 dB
50 m
2.80 dB
3.45 dB
4.00 dB
60 m
3.36 dB
4.14 dB
4.80 dB
75 m
4.20 dB
5.18 dB
6.00 dB
100 m
5.60 dB
6.90 dB
8.00 dB
LMR-600 Loss Reference
Run Length
Loss at 1 GHz
Loss at 1.5 GHz
Loss at 2 GHz
30 m
1.08 dB
1.33 dB
1.56 dB
50 m
1.80 dB
2.22 dB
2.60 dB
75 m
2.70 dB
3.33 dB
3.90 dB
100 m
3.60 dB
4.44 dB
5.20 dB
150 m
5.40 dB
6.66 dB
7.80 dB
✅ Worked example 60m LMR-400, wideband Ku-band (to 2 GHz), 4 N-type connectors, 1 surge arrestor:
Cable loss at 2 GHz: 4.80 dB Connectors (4 × 0.15 dB): 0.60 dB Surge arrestor: 0.40 dB Total IFL loss: 5.80 dB
Maximum IFL Run Lengths
Cable Type
Practical Maximum
Notes
LMR-240
25–30 m
Short jumpers only
LMR-400
50–75 m
Standard for most commercial sites
LMR-600
100–130 m
Longer buildings, rooftop-to-basement
LMR-900
150–200 m
Large campus or remote antenna
For runs beyond 75m on LMR-400, move to LMR-600. For runs exceeding 150m, consider relocating the modem closer to the dish or using a fibre optic IFL.
DC Power and Voltage Drop on Long Runs
The IFL cable carries DC power from the modem to the LNB (typically 13V or 18V at up to 500 mA). LMR-400 centre conductor resistance: ~1.4 Ω per 100m. At 100m with 400 mA LNB current, voltage drop ≈ 0.56V — within tolerance for most systems. At 200m+ on LMR-400, verify LNB minimum operating voltage against actual delivered voltage before commissioning.
Weatherproofing the ODU Connection
Moisture ingress at the N-type connector where the IFL meets the LNB or BUC is one of the most common causes of IFL degradation in the GCC. Weatherproof every outdoor connection on the day of installation.
Terminate with an N-type crimp connector — see the LMR connector crimping guide for strip dimensions and tooling.
Mate the connector — N-type hex nut finger-tight plus a quarter turn with a 7/16″ spanner.
Wrap with self-amalgamating tape, starting below the connector body, 50% overlap, two full passes minimum.
Overwrap with PVC electrical tape for UV protection.
Secure the cable to the mount at regular intervals to prevent wind stress on the connector.
⚠️ Never use PVC tape alone. It lifts in heat, traps moisture, and degrades in direct sunlight. Self-amalgamating tape fuses into a waterproof seal — use it first, PVC over the top.
Common IFL Installation Mistakes
Mistake
Effect
Fix
Using 75Ω RG6 cable
Impedance mismatch, high attenuation, poor transmit performance
Use 50Ω LMR-series cable
Exceeding minimum bend radius
Kinked dielectric, local attenuation increase
Route through gentle curves; use conduit elbows
Unterminated cable ends during installation
Moisture ingress into dielectric
Cap unused ends with N-type terminator immediately
Outdoor connections not weatherproofed
Connector corrosion, rising insertion loss
Self-amalgamating tape every outdoor connection, same day
IFL run parallel to AC mains
RF interference pickup at L-band
Separate by 100mm minimum; use metal conduit
Sourcing IFL Cable in the UAE and GCC
For professional-grade IFL installations — Times Microwave LMR-400, LMR-600, with matched N-type crimp connectors — source from a distributor carrying genuine Times Microwave product. Off-brand cable with inconsistent impedance control introduces return loss problems that are difficult to diagnose without a VNA.
The IFL cable is a critical and often underspecified component in VSAT installations. Use 50Ω LMR-series cable — LMR-400 for runs up to 75m, LMR-600 beyond that. Calculate your total IFL loss including connectors and in-line components, weatherproof every outdoor connection, and verify DC voltage delivery on long runs.
LMR Cable for VSAT — Stocked in Dubai
LMR-400, LMR-600, and matched N-type connectors available for immediate supply across the UAE and GCC.
Pick the wrong RF connector and you create a mismatch that costs you signal, adds insertion loss, or fails mechanically in the field. N-Type, SMA, and BNC connectors are all used on 50Ω coaxial systems, they all look broadly similar to the uninitiated, and they are absolutely not interchangeable.
This guide covers the real differences — frequency limits, coupling mechanism, weatherproofing, size, and which connector belongs where — so you can make the right call on the next installation or procurement.
RF Connector Size Comparison — N-Type / SMA / BNC
N-Type
~23 mm hex
DC – 11 GHz
SMA
~8 mm hex
DC – 18 GHz
BNC
~15 mm bayonet
DC – 4 GHz
Relative sizes approximate — all 50Ω | bravosatcom.com
Quick Reference: N-Type vs SMA vs BNC
N-Type
SMA
BNC
Impedance
50Ω (or 75Ω variant)
50Ω (standard)
50Ω or 75Ω
Usable frequency
DC to 11 GHz
DC to 18 GHz
DC to 4 GHz
Coupling
Threaded (hex nut)
Threaded (1/4″-36 UNS)
Bayonet (quarter-turn)
Size
Large
Small
Medium
Weatherproof
Yes (with boot/seal)
Not inherently
No
Common use
VSAT IFL, antenna feedlines, base stations
Lab/bench RF, GPS modules, indoor radio
Test equipment, video (75Ω), legacy radio
Cable range
LMR-195 to LMR-900
LMR-100 to LMR-400
LMR-200 to LMR-400
Mating cycles
~500
~500 (precision: 1,000+)
~500
N-Type Connector
N-Type (or Type-N) was developed in the late 1940s for military communications — a lineage that tells you something about its design priorities. It is a large, threaded, weatherproof connector built for outdoor and high-power RF applications. The hex coupling nut locks securely and resists vibration, which is why it is still the connector of choice for antenna feedlines and VSAT installations decades later.
N-Type Specifications
Parameter
Value
Impedance
50Ω (75Ω variant available — not compatible with 50Ω)
Frequency range
DC to 11 GHz
Voltage rating
Up to 1,000 V peak (varies by manufacturer)
Interface standard
MIL-STD-348, IEC 169-16
Coupling
Threaded — hex nut, ~5/8″-24 UNS
Body material
Nickel-plated or stainless steel
Weatherproofing
Yes — gasket seal on mated pair; add self-amalgamating tape for outdoor installs
Where N-Type Is Used
VSAT IFL cable runs — The intermediate frequency link between the ODU and modem operates at L-band (950–2,150 MHz). N-type is the standard interface at both ends. At 1–2 GHz the connector’s 11 GHz headroom is irrelevant, but its weatherproofing and robust coupling are not.
Antenna feedlines and tower work — Any run from a base station radio to an antenna uses N-type. The cable is exposed to wind, UV, and rain; the connector needs to be too.
LMR-400 and larger cables — The physical dimensions of N-type suit the larger LMR cable families. An N-type crimp connector on LMR-400 is the most common termination combination in outdoor RF installations in the GCC.
High-power RF — When you are driving a power amplifier into an antenna and the cable carries high power, N-type’s voltage rating and low contact resistance matter. SMA and BNC are not appropriate at high power levels.
Watch for this: The 50Ω and 75Ω versions of N-type look almost identical. The 75Ω centre pin is slightly smaller and will fit loosely in a 50Ω socket — potentially damaging it. Always verify impedance before mating.
SMA Connector
SMA (SubMiniature version A) was designed in the 1960s for microwave frequencies where physical size affects electrical performance. It is significantly smaller than N-type, uses a precision 1/4″-36 threaded coupling, and is rated to 18 GHz in standard form — making it the default for microwave and laboratory applications.
SMA Specifications
Parameter
Value
Impedance
50Ω
Frequency range
DC to 18 GHz (standard)
Frequency range (precision/3.5 mm)
DC to 26.5 GHz
Voltage rating
Up to 500 V
Interface standard
MIL-STD-348B, IEC 169-15
Coupling
Threaded — 1/4″-36 UNS hex nut
Body material
Brass (gold or nickel plated) or stainless steel
Weatherproofing
No — indoor/bench use by default
Where SMA Is Used
GPS and GNSS equipment — Nearly all GPS receiver modules and antennas use SMA or RPSMA. If you are running GPS cables to a VSAT terminal, modem, or asset tracking unit, you are dealing with SMA.
Indoor radio and wireless equipment — Small form-factor radios, modems, and routers in the 2.4 GHz, 5 GHz, and sub-6 GHz bands use SMA or RPSMA.
Test and measurement above 11 GHz — For measurements in Ku-band and above, SMA is the only option among these three connectors.
Two things to get right with SMA: 1. Torque: Finger-tight plus a quarter-turn with a 5/16″ spanner. Overtightening deforms the centre pin interface and kills return loss. 2. Standard vs reverse-polarity (RPSMA): In standard SMA the male plug carries the centre pin. In RPSMA the male plug has the socket. Same thread, different gender — forcing them together causes expensive damage.
BNC Connector
BNC (Bayonet Neill–Concelman) is quick to connect and disconnect — one quarter-turn to lock — which is its main advantage. It was widely used in legacy radio, test equipment, and broadcast video. The bayonet mechanism is fast but does not thread, so it cannot be torqued down and provides no environmental sealing.
BNC Specifications
Parameter
Value
Impedance
50Ω or 75Ω
Frequency range
DC to 4 GHz (practical limit for 50Ω)
Voltage rating
Up to 500 V
Interface standard
MIL-PRF-39012, IEC 169-8
Coupling
Bayonet — quarter-turn lock
Body material
Nickel-plated or gold-plated brass
Weatherproofing
No
Where BNC Is Used
Test equipment and oscilloscopes — BNC is the standard probe interface on oscilloscopes and most benchtop instruments below 1 GHz.
Broadcast video (75Ω) — The 75Ω BNC variant is the universal interface for HD-SDI video cabling. These look identical to 50Ω BNC but are not electrically compatible.
Network timing and 10 MHz reference signals — GPS disciplined oscillators (GPSDO) and network timing equipment typically output 10 MHz reference on BNC.
BNC limitations to know: The 4 GHz frequency ceiling is firm — do not use BNC at Ku-band frequencies. And 50Ω vs 75Ω BNC look identical and are the most commonly confused connector variants in the field. Check impedance before connecting to test equipment.
How to Choose: Decision Guide
By Application
Application
Connector
VSAT IFL run (L-band, ODU to modem)
N-Type
Satellite antenna feedline (outdoor)
N-Type
BUC or LNB RF port
N-Type
Base station antenna cable
N-Type
GPS antenna cable
SMA (or RPSMA — check equipment port)
Indoor radio / WiFi equipment
SMA or RPSMA
Microwave test and measurement
SMA
Oscilloscope / signal generator under 1 GHz
BNC
HD-SDI broadcast video
BNC 75Ω
Network timing / 10 MHz reference
BNC
By Frequency
Usable Frequency Range
N-Type
DC — 11 GHz
SMA
DC — 18 GHz (26.5 GHz precision)
BNC
DC — 4 GHz
04 GHz11 GHz18 GHz
bravosatcom.com
By Environment
Environment / Requirement
Best Choice
Outdoor / weatherproof required
N-Type (with boot or self-amalgamating tape)
Indoor bench / lab
SMA or BNC depending on frequency
Quick connect/disconnect cycles
BNC (bayonet is faster than threading)
Vibration-prone installation
N-Type or SMA (threaded coupling holds; bayonet can work loose)
Adapters: When You Have the Wrong Connector
Adapters between connector types are available and widely used, but they add insertion loss and reflections at higher frequencies. Keep adapters to one per signal path and do not use them on a connector you mate and unmate frequently — the wear happens on the adapter body.
Adapter
When You Need It
N-Type Female → SMA Male
SMA-tailed GPS antenna to N-type modem input
N-Type Male → BNC Female
Interfacing RF equipment to legacy test instruments
SMA Female → BNC Male
Lab bench bridging
N-Type 50Ω → N-Type 75Ω
Do not do this. Centre pin sizes differ; mating them can damage the socket.
What Cables Work With Each Connector
For VSAT and radio installations, the Times Microwave LMR series covers most cable runs. Here is how the connectors map to common LMR cables:
Cable
N-Type
SMA
BNC
LMR-100A
Not standard
✅ Common
—
LMR-195
✅ Available
✅ Common
✅ Available
LMR-240
✅ Common
✅ Available
✅ Available
LMR-400
✅ Primary
✅ Available
✅ Available
LMR-600
✅ Primary
—
—
LMR-900
✅ Primary
—
—
See the LMR-400 vs LMR-600 comparison for guidance on which cable to specify for a given IFL distance and frequency. If you are terminating N-type on LMR cable yourself, the step-by-step LMR crimp guide covers strip dimensions, tooling, and common mistakes.
Summary
N-Type, SMA, and BNC serve different roles in RF systems. N-Type is the outdoor, high-power, weatherproof choice for antenna feedlines and VSAT IFL runs. SMA handles microwave frequencies up to 18 GHz and belongs on indoor equipment, GPS cabling, and test benches. BNC is a legacy quick-connect connector suited to sub-4 GHz test equipment and broadcast video. Using the wrong one means you are either over-specifying and paying for it, or under-specifying and paying for it later in a fault call.
Need cables or connectors for your installation?
Bravo Satcom supplies RF coaxial cables and connectors — N-type, SMA, BNC — for VSAT, radio, and satellite installations in the UAE and GCC.
If you’re comparing Newtec and iDirect satellite modems for a UAE, KSA, or wider GCC deployment, there’s one thing you should know before you decide anything: since 2021, they’re the same company.
Newtec was acquired by ST Engineering in 2020. Then in 2021, ST Engineering completed its acquisition of iDirect. Both are now part of ST Engineering iDirect — one manufacturer, one roadmap, one support organisation.
That doesn’t mean the modems are interchangeable. Newtec’s platform (called Dialog) and iDirect’s legacy platform (called Evolution) are still distinct networks with different modems, and buyers regularly have to choose between them. But framing the decision as “Newtec vs iDirect” is now like asking whether you want a Toyota Corolla or a Lexus — different products, same parent.
This guide breaks down what’s actually different, which modem fits which use case, and how the choice looks from the UAE distributor perspective.
The 2020–2021 merger: what changed for buyers
For years, Newtec (based in Belgium) and iDirect (based in Virginia, USA) competed head-to-head in the enterprise VSAT market. Newtec built the Dialog platform. iDirect built the Evolution and Velocity platforms. Buyers had to pick a side because networks were closed to each other.
Then Singapore-based ST Engineering completed both acquisitions and unified them into ST Engineering iDirect in early 2021. Since then:
Newtec’s modem line kept its Dialog naming — MDM2510, MDM3315, MDM6000, MDM9000, plus SMB board-level variants.
iDirect’s Evolution and Velocity platforms remain in service — iQ series, X7, X1, plus network hubs.
The product roadmap is now consolidated. New development happens under one engineering organisation, and platforms are progressively converging.
All modems are sold as “ST Engineering iDirect” branded products, though older Newtec-branded and iDirect-branded stock is still in the channel.
For a buyer, this means: if you’re already on a Newtec Dialog network, you continue with Dialog modems. If you’re on iDirect Evolution, you continue with Evolution — for now — but the long-term direction is clear.
The three platforms explained
Any modem you’re evaluating belongs to one of three network platforms. This is the actual decision axis — not the brand name.
Dialog (formerly Newtec)
Dialog is the flagship multi-service platform. It’s designed for enterprise VSAT, cellular backhaul, maritime, and government applications. Its signature is Mx-DMA® — a return-link technology that combines the flexibility of MF-TDMA with the on-demand bandwidth allocation of SCPC. In practice, Mx-DMA gives Dialog networks better link efficiency and higher availability than pure MF-TDMA.
Dialog supports DVB-S2X wideband forward carriers up to 500 Msps, so a single hub can deliver hundreds of Mbps to remote sites.
Evolution (legacy iDirect)
Evolution is the older iDirect platform. It’s proven, widely deployed across corporate VSAT networks in the Middle East and Africa, and still fully supported. Its return technology is A-TDMA and SCPC, without Mx-DMA. Evolution modems are typically simpler and less expensive at the low end.
Some Evolution modems (like the X7) are approaching end-of-life status and are being replaced by Dialog equivalents (the MDM3315 in the X7’s case).
Velocity (iDirect HTS/mobility)
Velocity is iDirect’s platform for HTS (high-throughput satellite) networks and mobility applications — think in-flight connectivity, cruise ships, oil rigs. It uses DVB-S2X adaptive modulation with global beam-hopping support. Most enterprise buyers won’t touch Velocity; it’s built for HTS operators and mobility service providers.
Modem-by-modem comparison
Here are the modems most UAE buyers actually encounter, side by side:
Modem
Platform
Origin
Target Use
Peak Data Rate
Return Tech
MDM2510
Dialog
Newtec
SOHO / SME, POS
150 Mbps fwd
Mx-DMA, MF-TDMA
MDM3315
Dialog
Newtec
Enterprise, maritime, backhaul
150/70 Mbps
Mx-DMA MRC, MF-TDMA, SCPC
MDM6000
Dialog
Newtec
High-end enterprise, DTH contribution
500+ Mbps
Mx-DMA, SCPC
iQ200
Evolution
iDirect
SOHO / SME
~50 Mbps
A-TDMA
iQ Desktop 200
Evolution
iDirect
Desktop SOHO
~50 Mbps
A-TDMA
X7
Evolution
iDirect
Enterprise (EOL – succeeded by MDM3315)
90 Mbps
A-TDMA, SCPC
X1
Evolution
iDirect
Low-cost remote
~20 Mbps
A-TDMA
A few practical notes:
The MDM2510 and the iQ200 target the same market — small offices, retail, banking, POS networks. If you have a choice, MDM2510 gives you more headroom and modern Mx-DMA efficiency. iQ200 is often cheaper on the ground and easier to deploy on existing iDirect networks.
The MDM3315 replaces the X7. If a client has an X7 fleet, MDM3315 is the natural upgrade path. It offers a dual receiver, higher throughput, and a 4-port Ethernet switch versus the X7’s single receiver and simpler I/O.
The MDM6000 is a different animal. It’s not a competitor to the iQ200 or X7 — it’s for high-end backhaul and DTH contribution where you need 500 Msps+ of forward capacity.
How to choose: a decision guide
The right modem depends less on brand preference and more on what network you’re joining.
If you’re joining an existing Dialog network (many enterprise VSAT operators in the Middle East run Dialog): you must buy a Dialog modem. Options: MDM2510 for SOHO, MDM3315 for enterprise, MDM6000 for high-throughput.
If you’re joining an existing iDirect Evolution network: you’ll typically buy an Evolution modem. Options: iQ200 or X1 for entry-level, X7 or MDM3315 for enterprise. Note that new Evolution deployments are becoming rare — most operators are migrating.
If you’re deploying a greenfield VSAT network (you’re setting up the hub too): Dialog is the strategic choice. Better roadmap, better return efficiency, aligned with ST Engineering iDirect’s future direction.
By application:
SOHO / retail / banking / POS: MDM2510 (Dialog) or iQ200 (Evolution). Both do the job. Choose based on the network you’re joining.
Enterprise fixed VSAT: MDM3315 on Dialog, or MDM3315 replacing X7 if you’re on Evolution and upgrading.
Maritime: MDM3315 or iQ200 with OpenAMIP support. Verify vessel-specific stabilization requirements.
Cellular backhaul: MDM3315 or MDM6000 depending on cell load.
Government / secure networks: MDM3315 with 256-bit AES option, or purpose-configured MDM6000.
UAE and GCC considerations
A few things matter specifically for buyers in the region:
TDRA type-approval. Any satellite terminal deployed in the UAE requires TDRA (Telecommunications and Digital Government Regulatory Authority) type-approval. All current ST Engineering iDirect modems have approvals in place, but confirm the specific model and firmware version with your distributor before shipping.
Regional satellite compatibility. Yahsat’s Al Yah 1, Al Yah 2, and Al Yah 3 (Ka-band HTS) are the dominant satellites for enterprise VSAT in the UAE. Dialog and Evolution modems both operate on these fleets — the network operator determines platform choice. Thuraya is a separate GEO/MSS system that doesn’t use these modems.
Support and lead times. Post-merger, spares and support for both Dialog and Evolution modems flow through ST Engineering iDirect’s regional partners. Working lead times from Europe or the US into JAFZA are typically 2–4 weeks for stock items, longer for configured modems that need factory provisioning.
Local availability.Bravo Satcom stocks the MDM2510, MDM3315, and iQ200 for UAE and GCC delivery, along with SMW LNBs, iLBs, ANT2025 and ANT2035 antennas from the wider Newtec/ST Engineering ecosystem. Contact us for current stock and lead times.
Frequently asked questions
Are Newtec and iDirect the same company?
Yes — since 2021. ST Engineering acquired Newtec in 2020 and iDirect in 2021, then unified them as ST Engineering iDirect. Both product lines continue under one brand.
Can iDirect Evolution modems work on a Newtec Dialog network?
No. Evolution and Dialog are separate network platforms. Modems are not cross-compatible. Choose the modem that matches your network hub.
Which modem is better for a UAE small-office VSAT?
The MDM2510 offers modern DVB-S2X and Mx-DMA return-link efficiency. The iQ200 is often cheaper and simpler to deploy on existing iDirect networks. If you’re joining a Dialog network, choose MDM2510. If you’re joining an Evolution network, choose iQ200.
What replaces the iDirect X7?
The MDM3315 is the direct replacement. It offers dual receivers, higher throughput, and a 4-port Ethernet switch while maintaining a familiar form factor for X7 users.
Where can I buy Newtec or iDirect modems in Dubai?
Bravo Satcom supplies both product lines to UAE and GCC customers with local warehousing and support. Contact us for a quote on MDM2510, MDM3315, iQ200, or any related VSAT equipment.
Is MDM2510 still in production in 2026?
Yes. It remains an active product in the ST Engineering iDirect Dialog portfolio for SOHO and SME deployments.
Bottom line
The “Newtec vs iDirect” question is now really “Dialog vs Evolution”, and increasingly the answer is Dialog for new deployments. But if you’re joining an existing network, the choice is usually made for you.
For UAE and GCC buyers, the practical shortlist is:
Small office / retail / POS: MDM2510 (or iQ200 if on Evolution)
Enterprise / maritime / backhaul: MDM3315
High-throughput / contribution: MDM6000
Contact Bravo Satcom for current stock, pricing, and TDRA-approval confirmation on any of these models.
A poorly terminated connector is the number one cause of signal degradation on an otherwise well-designed RF installation. LMR cables — particularly LMR-400 — are used on VSAT IFL runs, radio base station feedlines, and outdoor antenna installations where the connector is exposed to weather, vibration, and long-term stress. Getting the crimp right the first time saves you a troubleshooting call six months later.
This guide walks through the complete termination process for LMR-400 with an N-type crimp connector — the most common combination in VSAT and radio work — and covers the critical dimensions, tools, and mistakes that separate a reliable termination from a future fault.
LMR-400 Cable Preparation — Strip Stages
Jacket
Full length
Braid exposed
25.4 mm
(fold back)
Dielectric
12.7 mm
(stripped)
Centre pin
12.7 mm
exposed
Outer jacket (PE)
Braid + foil shield
Foam PE dielectric
Copper centre conductor
LMR-400 N-type crimp | Dimensions per Times Microwave spec | bravosatcom.com
What You’ll Need
Getting the right tools matters more than most people realise. Undersized or worn tooling causes crimp failures that are invisible to the eye but catastrophic for RF performance.
Tool
Purpose
Notes
Coax cable cutter
Clean, square cable cut
Never use wire cutters or a hacksaw — both distort the cable end
Rotary coax stripper
Strip jacket, braid, dielectric to exact dimensions
Set blade depths for LMR-400 specifically
Hex crimp tool + die
Compress ferrule onto braid
LMR-400 N-type typically requires 0.429″ hex die — check connector spec
Utility knife / deburring tool
Clean dielectric end, remove stray braid strands
Vernier calipers
Verify strip dimensions
Optional but recommended for critical installs
Multimeter
Post-crimp continuity test
Mandatory before putting the cable into service
Connector types: This guide covers crimp connectors — the most common in field work. Times Microwave also makes EZ-400 compression connectors (faster, single-action, requires the matching tool) and solder-type connectors. The cable prep dimensions are similar but confirm against your specific connector’s installation sheet.
Strip Dimensions for LMR-400 N-Type Crimp
These are the published Times Microwave strip dimensions for LMR-400 with a standard N-type crimp connector. Write these on your tool bag if you do this regularly.
Strip
Dimension
What It Exposes
Outer jacket removal
25.4 mm (1.00″)
Braid for fold-back
Braid fold-back point
12.7 mm (0.50″) from jacket end
Positions braid over ferrule
Dielectric removal
12.7 mm (0.50″) from fold point
Centre conductor
Centre conductor trim
Flush with connector pin face
Clean mating contact
Dimensions vary between connector manufacturers. Always cross-check against your specific connector’s installation sheet before terminating.
Step-by-Step: N-Type Crimp on LMR-400
1
Cut the cable square. Use a proper coax cutter. The cut must be clean, flat, and perpendicular. Inspect: jacket, braid, dielectric, and centre conductor must all be concentric and undamaged. Any burr or angle — cut again.
2
Slide on the crimp ferrule first. Before stripping anything, slide the crimp ferrule (small metal ring) onto the cable with the open end facing the cable end. This is the most commonly forgotten step. You cannot install it after the connector body is on.
3
Strip the outer jacket — 25.4 mm. Set your rotary stripper and rotate 2–3 times, then pull the jacket off cleanly. Inspect the braid — intact, no nicks, no cut strands. Remove any cut braid strands before proceeding.
4
Fold back the braid — at 12.7 mm. Comb the braid wires back evenly over the outer jacket. Spread uniformly around the full circumference — avoid bunching. Bunched braid concentrates crimp force on one side and reduces shield effectiveness.
5
Strip the dielectric — 12.7 mm. Remove foam dielectric to expose the centre conductor. The cut must be clean — no gouges or teeth marks on the copper. Even minor nicks increase PIM and create stress crack points under vibration.
6
Inspect before assembly. Blow out loose strands. Verify strip dimensions. Confirm no braid strands are on the dielectric. Check the centre conductor is round and undamaged. A 30-second inspection here prevents a re-termination in the field.
7
Install the connector body. Slide the connector body onto the cable. The centre conductor passes through the contact pin and protrudes slightly — trim flush with the pin face. The braid seats inside the connector’s braid seat area. Push fully home until it seats firmly.
8
Slide the ferrule into position. Slide the crimp ferrule forward until it butts against the rear of the connector body, sitting over the folded braid.
9
Crimp. Place the ferrule in the correct hex die. Close the handles with a single smooth, firm stroke until the ratchet releases. One complete ratchet cycle only — do not over-crimp (distorts the body) or under-crimp (ferrule slips).
10
Inspect the finished crimp. The ferrule should be uniformly hexagonal, no cracking or oval distortion. Firm tug — connector should not move. No braid strands protruding. Centre pin flush or just proud of the mating face.
Common Mistakes
Mistake
Consequence
Fix
Forgetting the ferrule before assembly
Must cut off connector and restart
Slide ferrule on as Step 2, every time
Nicked centre conductor
PIM, cracking under vibration, future open
Re-cut cable end and re-terminate
Stray braid strands on dielectric
Dead short centre-to-outer
Inspect under good light before inserting body
Wrong hex die size
Under-crimp — passes pull test, fails in field
Always match die to connector spec sheet
Bunched braid fold
Non-uniform crimp, reduced shield coverage
Comb braid evenly around full circumference
Centre pin too long
Bottoms out in mating connector, damages both
Trim flush with pin face
RG-8 connector on LMR-400
Wrong bore — mechanically and electrically poor
Always use connectors specified for LMR-400
Testing Your Termination
Every terminated connector should pass three checks before the cable goes into service:
① Visual Inspection
Ferrule uniformly hexagonal. No braid strands protruding. Centre pin flush. Connector firmly seated — no movement under hand tug.
② DC Continuity (Multimeter)
Centre pin to centre pin: continuity. Centre pin to outer body: open circuit. Any short = failed termination, re-terminate.
③ Return Loss / VSWR (if available)
Good LMR-400 termination: >25 dB return loss (VSWR <1.12:1) at 1 GHz. Worse than 20 dB (VSWR >1.22:1) indicates a problem.
Connector Compatibility Quick Reference
Always match the connector spec to your cable. Using an LMR-400 connector on LMR-600 is the most common ordering mistake.
Can I reuse an LMR connector after removing it?
No. Once a crimp ferrule has been compressed, it cannot be re-used. Cut the connector off, re-prepare the cable end, and use a new connector.
What’s the minimum pull-out force for a properly crimped LMR-400 connector?
Times Microwave specifies approximately 45 kg (100 lbs) minimum pull-out strength for a correctly crimped LMR-400 N-type. If yours pulls off with hand force, the crimp failed.
Can I use a standard N-type connector meant for RG-8 on LMR-400?
No. LMR-400 has a different OD, braid construction, and dielectric. Using an RG-8 connector produces a mechanically and electrically poor termination. Always specify connectors made for LMR-400.
How do I know if my crimp tool die is worn?
A worn die produces ferrules that are out-of-round or show uneven hex faces. Check with calipers — if in doubt, replace the die. A worn die is cheaper to replace than a failed installation.
What’s the difference between silver and gold centre pins?
Silver-plated pins are standard for VSAT work. Gold pins appear in some lower-frequency or high-reliability connectors. For LMR-400 N-type in VSAT IFL work, silver-plated is correct.
Need LMR Cables and Connectors?
Bravo Satcom supplies Times Microwave LMR cables and N-type connectors for VSAT and radio installations across the UAE and GCC. We stock LMR-240, LMR-400, and LMR-600 with matching crimp and compression connectors.
Five factors feed into your BUC power requirement. Antenna gain and satellite G/T work in your favour; rain fade and higher data rates work against you. The BUC power bridges the gap.
What BUC Output Power Actually Does
The BUC’s job is to amplify your uplink signal to a level the satellite can receive. The key metric is EIRP — Effective Isotropic Radiated Power — the combination of your antenna gain and BUC output power:
EIRP (dBW) = BUC Output Power (dBW) + Antenna Gain (dBi) − Feed and Cable Losses (dB)
The satellite operator specifies a minimum uplink EIRP your terminal must achieve to hold the link at the required carrier-to-noise (C/N) at the hub. Your BUC power and antenna size are interchangeable in the link budget — a larger dish needs less BUC power to hit the same EIRP, and vice versa. Understanding this trade-off is the key to smart BUC selection.
Factor 1: Antenna Size
This is the single biggest lever in the link budget. Antenna gain scales with aperture: doubling the dish diameter adds approximately 6 dB of gain — equivalent to quadrupling your BUC’s output power.
Antenna Diameter
Approx. Gain (Ku-band ~14 GHz)
Relative EIRP vs 0.75m
0.75m
~38 dBi
Baseline
0.9m
~40 dBi
+2 dB
1.2m
~43 dBi
+5 dB
1.8m
~47 dBi
+9 dB
2.4m
~50 dBi
+12 dB
A 2.4m dish achieves roughly 12 dB more EIRP than a 0.75m dish at identical BUC power — the same as multiplying BUC output by 16×. If you’re constrained on dish size (rooftop, aesthetics, vessel), budget for a higher-power BUC to compensate.
Factor 2: Frequency Band
The frequency band determines free-space path loss and rain fade sensitivity:
Band
TX Frequency
Rain Fade Risk
Typical VSAT Use
C-band
5.85–6.425 GHz
Very low (near immune)
Maritime, tropical, broadcast
Ku-band
13.75–14.5 GHz
Moderate
Standard enterprise VSAT
Ka-band
27.5–31 GHz
High (spot beams offset)
High-throughput broadband
For the same data rate and availability, Ka-band requires more power margin than Ku-band, while C-band needs less but uses larger antennas for equivalent gain.
Factor 3: Rain Fade Margin
Rain absorbs and scatters RF signals — the higher the frequency, the worse the effect. Rain fade margin is the extra power budget reserved to keep the link open during heavy precipitation.
Region
Rain Fade Margin — Ku-band (99.5% availability)
UAE / GCC (arid)
1–2 dB
Mediterranean / Southern Europe
2–4 dB
Sub-Saharan Africa
5–8 dB
Southeast Asia / tropical
8–12 dB
For a site in Dubai, 2 dB of rain fade margin is typically sufficient at Ku-band — often the difference between a 1W and 2W BUC. For a site in Lagos or Jakarta with the same link requirement, you may need 3–4× more BUC power just to cover rain fade.
Factor 4: Satellite G/T
Not all satellite transponders are equal. A high-power spot beam pointed at the Middle East (such as Yahsat Y1A) has a better uplink G/T, meaning the satellite is more sensitive to your signal — you need less transmit EIRP to achieve the same link quality at the hub.
A wide-area global beam covering multiple continents will have lower G/T, requiring more transmit power from your terminal. Always obtain a link budget from your satellite operator or service provider — they will specify the minimum EIRP your terminal must achieve, which determines your BUC power requirement given your antenna size.
Factor 5: Data Rate and Modulation
Higher data rates require more bandwidth or more efficient modulation. High-order modulation (16APSK, 32APSK) packs more bits per Hz but demands a stronger, cleaner signal — higher Eb/N₀ at the hub — which requires more transmit EIRP.
A low-data-rate monitoring link (64 kbps, QPSK) may work fine with a 1W BUC. A high-throughput corporate broadband link (10+ Mbps, 16APSK) may need a 4W–8W BUC on the same dish.
BUC Power Quick-Selection Guide
Starting-point guidance for Ku-band VSAT in the GCC/MENA region. Always confirm with a full link budget from your service provider.
Application
Antenna Size
BUC Power
Notes
Remote monitoring / IoT VSAT
0.75m – 0.9m
1W
Low data rate, QPSK
Small office broadband (TDMA)
0.9m – 1.2m
1W – 2W
Standard managed VSAT plans
Enterprise VSAT (SCPC)
1.2m – 1.8m
2W – 4W
Dedicated bandwidth
High-throughput / corporate
1.8m – 2.4m
8W – 16W
High data rate, tight SLA
Video contribution uplink
2.4m+
16W – 25W
HD/UHD broadcast
GCC region (low rain fade)
1.2m
2W
Typically sufficient for managed VSAT
Tropical climate (same link)
1.2m
4W – 8W
Additional rain fade margin required
C-band (large antenna)
2.4m – 3.7m
2W – 5W
Lower free-space loss, rain-fade immune
Ka-band (spot beam)
0.75m – 1.2m
1W – 2W
High satellite EIRP compensates
Don’t Overspec “For Headroom”
Common mistake: Specifying a 10W BUC on a 1.2m dish “just to be safe.” The dish is the limiting factor — a 1.2m antenna at Ku-band has a gain ceiling of ~43 dBi regardless of the BUC attached. Extra watts don’t compensate for inadequate aperture. If you need more EIRP, step up the antenna size before stepping up the BUC power — it’s almost always cheaper and more efficient.
The legitimate exception: a higher-power BUC on an existing installation can buy you additional rain fade margin or support a higher data rate without changing the dish. This is a valid upgrade path when the antenna is already correctly sized for the baseline link.
Always Specify PLL — Not DRO
Independent of output power, always specify a PLL BUC for professional VSAT. A PLL (Phase-Locked Loop) BUC locks its local oscillator to a stable crystal reference (±0.5–1 ppm), ensuring the uplink carrier stays on frequency across temperature changes.
DRO BUCs drift with temperature — acceptable for broadcast receive-only monitoring terminals, not for bidirectional VSAT links where the hub modem requires precise frequency accuracy.
For a full explanation of BUC specifications, see the BUC vs LNB guide.
Frequently Asked Questions
Is a 1W BUC enough for a VSAT installation in the UAE?
For a 1.2m Ku-band antenna on a standard managed VSAT plan in the GCC, 1W–2W is generally sufficient given the low rain fade environment. Confirm with your service provider’s link budget — they specify the minimum EIRP, and you can work backwards to the BUC power needed for your antenna size.
What’s the practical difference between 1W and 2W?
3 dB — which matters. A 2W BUC doubles your transmit power, giving 3 dB more uplink margin. That’s the difference between a link that holds through a rain event and one that drops. For a modest cost increase, the 2W unit is usually the better baseline for any outdoor installation.
Can I upgrade BUC power without changing the dish?
Yes. BUC upgrades are straightforward as long as the new unit is compatible with your feed/waveguide interface and the DC power supply can support the higher draw. A 4W BUC typically draws 40–50W DC vs ~15W for a 1W unit. Verify your IFL and power injector can handle it.
My link drops in rain — will a higher-power BUC fix it?
Likely yes, if rain fade is confirmed as the cause. A BUC upgrade from 1W to 4W adds ~6 dB of uplink margin and typically resolves moderate Ku-band rain fade in the GCC. Also check IFL cable and connector condition first — degraded cable can silently lose 3–5 dB before it shows visible damage.
Does BUC power affect download speed?
No. The BUC only affects the uplink (transmit) path. Download speed is determined by the satellite’s downlink EIRP, your antenna receive gain, and your LNB noise figure — none of which are changed by the BUC. If downloads are slow but the uplink is fine, the BUC is not the issue.
Shop BUCs at Bravo Satcom
Bravo Satcom supplies a full range of Ku-band and C-band BUCs from 1W to 25W — including Terrasat, NJRC, Actox, and Agilis. All units stocked for delivery across the UAE and GCC.
For NJRC BUCs — one of the most widely deployed PLL BUC brands in the MENA region — contact us for datasheets, pricing, and availability.
Not sure which BUC power suits your link? Send us your antenna size, satellite, and data rate requirement and we’ll run the numbers. Reach us at sales@bravosatcom.com or +971 55 541 5892.
Every RF and satellite engineer hits this fork eventually: you’re designing a cable run and someone asks, “should we go fiber?” The right answer depends almost entirely on what the cable is carrying. If it’s connecting a modem to a BUC or LNB, the answer is always coaxial — no exceptions. If it’s a data backbone between buildings, fiber is almost certainly the better call.
This guide breaks down the key differences between fiber optic and coaxial cable and gives you a clear framework for choosing the right one every time.
Fig 1. Cable cross-section comparison: coaxial (LMR-400) vs single-mode fiber optic (SMF OS2). The critical difference for VSAT installations — coaxial cable carries DC power to the BUC and LNB alongside the RF signal; fiber cannot.
What Is Coaxial Cable?
Coaxial cable carries RF signals as electrical waves along a center copper conductor, insulated from a surrounding braid or foil shield by a dielectric foam core. The shield keeps the signal contained and blocks external interference from entering. An outer PE or PVC jacket provides mechanical and weather protection.
In VSAT and satellite applications the most common types are LMR-400 (standard Ku-band IFL, runs to ~30m), LMR-600 (medium runs to ~60m), LMR-900 (long runs to 80m+), and legacy RG214. For broadcast and CATV distribution, 75Ω RG6 is common.
The capability that makes coaxial indispensable for satellite work: it carries DC power alongside the RF signal. The same cable that carries your IF signal from modem to LNB also delivers the 13V or 18V DC that powers the LNB — plus the 22 kHz polarisation tone — and the 24–48V DC that drives the BUC. No other single cable can do this.
What Is Fiber Optic Cable?
Fiber optic cable carries signals as pulses of light through a glass core, surrounded by cladding (a lower-refractive-index glass layer that traps light inside by total internal reflection), a protective buffer coating, and an outer jacket. There are no copper conductors — signals travel at the speed of light with virtually no attenuation over distance.
Two main types exist: single-mode fiber (SMF, OS1/OS2) for long-distance runs up to 40+ km, and multi-mode fiber (MMF, OM3/OM4) for shorter data links up to ~300m. For telecom and data center backbone, SMF OS2 is the current standard.
The defining advantages: attenuation of just 0.2 dB/km at 1550 nm (vs approximately 30 dB/100m for LMR-400 at Ku-band), complete immunity to electromagnetic interference, and effectively unlimited bandwidth. The defining limitation: fiber cannot carry DC power. Any powered equipment at the far end requires a separate power cable.
Fiber Optic vs Coaxial Cable: Full Comparison
Feature
Coaxial Cable (LMR-400)
Fiber Optic (SMF OS2)
Signal medium
Electrical (RF waves)
Light (photons)
Attenuation @ 1 GHz
6.8 dB / 100m
0.035 dB / 100m
Attenuation @ Ku-band (12 GHz)
~30 dB / 100m
N/A — light, not RF
Max practical IFL run (Ku-band)
30m (LMR-400) · 60m (LMR-600) · 80m (LMR-900)
Not suitable for IFL
Max data run
~50m (10GBaseT, Cat6A)
40+ km (SMF)
EMI immunity
Partial (braid reduces, does not eliminate)
Complete — immune to all EMI
DC power over cable
✓ Yes — LNB 13/18V, BUC 24–48V
✗ No — separate power cable required
RF signal (native)
✓ Yes
✗ No — requires RF-to-optical conversion
Bandwidth
DC to 40 GHz (LMR-600)
Practically unlimited (>100 THz)
Field termination
Easy — crimp tool, N-type / SMA / BNC
Requires fusion splicer + cleaver
Cable cost
Lower
Higher
Weight
Heavier
Very light
Minimum bend radius
25mm (LMR-400)
30mm (standard OS2)
Security
Can be passively tapped
Tap causes detectable signal loss
Ground loop / surge risk
Yes — copper conductor
None — glass is non-conductive
When to Use Coaxial Cable
✓ Coaxial is the right choice for:
1. VSAT and satellite IFL runs — Mandatory. Your satellite modem must deliver DC power to the LNB (13V/18V + 22 kHz polarisation tone) and BUC (24–48V) through the same cable that carries the IF signal. Use LMR-400 up to 30m, LMR-600 to 60m, LMR-900 to 80m+ at Ku-band.
2. Two-way radio and base station antenna feedlines — VHF/UHF antenna connections are always coaxial. LMR-400 is the standard for fixed base station installations.
3. RF signal distribution — Splitters, combiners, amplifiers, RF patch panels: anywhere you’re routing or processing a live RF signal, coaxial connections are required throughout the chain.
4. Short runs under 40–50 meters — For L-band and below, coax is simpler, cheaper, and easier to terminate. The attenuation penalty is manageable for short runs.
5. Remote RF power delivery — Any equipment at the far end that needs power over the cable (BUC on a tower, LNB on a dish) requires coaxial IFL — there is no alternative.
6. Field installations — Coax connectors (N-type, SMA, TNC, BNC) are field-terminable with a hex crimp tool. Fusion splicing fiber requires capital equipment and a clean environment.
When to Use Fiber Optic Cable
✓ Fiber optic is the right choice for:
1. Long data backbone runs (>100m) — Any Ethernet or network backbone link over 100m should be fiber. SMF supports 10G Ethernet over 10+ km without amplifiers. Coaxial cable would require impractically thick gauge (LMR-900+) and still fall short.
2. EMI-heavy environments — Generator rooms, industrial motor drives, high-voltage transformer enclosures: fiber is completely immune. Coax braid reduces EMI pickup but does not eliminate it — you’ll see interference on the signal.
3. Building-to-building links — Outdoor aerial or buried runs between buildings: fiber provides natural ground-loop isolation and is immune to lightning surges between structures. Copper cable between buildings can conduct a surge that damages equipment at both ends.
4. High-bandwidth data (40G / 100G / 400G) — These speeds are not achievable over coaxial cable at practical distances. Fiber is the only option.
5. Security-critical installations — Fiber signals cannot be intercepted passively. Any physical tap causes a measurable signal loss that optical monitoring equipment can detect and alert on.
6. Harsh or marine environments — Fiber is immune to moisture ingress effects on signal quality, salt air corrosion of conductors, and temperature-driven changes in impedance.
Why VSAT Always Uses Coaxial — Without Exception
In any VSAT installation — from a single maritime terminal to a large teleport earth station — the IFL between the satellite modem and the outdoor unit (BUC and LNB) must be coaxial cable. The reason is simple: the satellite modem or ODU controller delivers DC power to the LNB and BUC through the same coaxial IFL that carries the IF signal. Fiber optic cable cannot carry DC power.
Fiber-based IF extension systems do exist. They use optical modulators and demodulators with separate power injectors to extend IFL runs beyond 100 meters in large earth station facilities. But these are expensive, complex installations reserved for sites where very long cable runs make standard coax impractical. For any typical VSAT site — from a rooftop dish to a teleport hub — coaxial cable (LMR-400 through LMR-900 depending on run length) is the only practical and cost-effective IFL solution.
Can I replace my VSAT coaxial IFL with fiber optic cable?
Not without additional equipment. The BUC and LNB require DC power that can only be delivered over coaxial cable in a standard installation. Fiber-based IF extension systems exist for very long runs (>100m) in large facilities — they use optical modulators with separate power injectors — but they are expensive and complex. For any typical VSAT installation, coaxial cable is the correct and only practical IFL choice.
Which has less signal loss — fiber optic or coaxial?
Fiber wins dramatically. LMR-400 loses approximately 30 dB per 100 meters at Ku-band (12 GHz). Single-mode fiber OS2 loses just 0.2 dB per kilometer at 1550 nm — roughly 15,000 times less attenuation per meter. For data signals over any meaningful distance, fiber is the clear choice.
Is fiber optic cable more expensive than coaxial?
Fiber cable typically costs more per meter, and termination requires a fusion splicer — significant capital equipment. However, for long runs where you’d otherwise need thick-gauge LMR-900 coax plus inline amplifiers, fiber can become cost-competitive overall. For short RF applications under 50 meters, coaxial cable is almost always the lower-cost total solution.
Can fiber optic cable be used as an antenna feedline?
No — not without conversion equipment. Fiber carries digitised optical signals, not analog RF. An antenna feedline must be coaxial to carry the raw RF signal between the antenna and the radio or satellite modem. Any fiber in an RF path requires RF-to-optical conversion at both ends, which adds cost and complexity that makes it impractical for standard installations.
What coaxial cable should I use for Ku-band VSAT IFL runs?
Use LMR-400 for IFL runs up to 30 meters at Ku-band, LMR-600 for 30–60 meters, and LMR-900 for runs beyond 60 meters. All outdoor sections should use weatherproof N-type connectors with proper weatherproofing tape. Never use RG6 or RG58 for VSAT — their attenuation at Ku-band is far too high even for short runs.
Need coaxial cable for your VSAT or satellite installation? BravoSatcom stocks LMR-400, LMR-600, RG214 — weatherproof N-type connectors included. We ship across the GCC.
Ask any VSAT engineer and they’ll tell you: the two components most misunderstood by procurement teams are the BUC and the LNB. Both sit at the antenna, both deal with frequency conversion — but they do opposite jobs, spec differently, and fail in completely different ways. Understanding the BUC vs LNB difference is fundamental to specifying, installing, and troubleshooting any VSAT system correctly.
This guide explains what each component does, the specs that matter, and how they work together in a complete satellite link.
BUC handles the transmit (uplink) path; LNB handles the receive (downlink) path. Both mount at the antenna and connect to the modem via separate IFL coaxial cables.
What Is a BUC (Block Up-Converter)?
A BUC — Block Up-Converter — handles the transmit (uplink) side of your VSAT link. It takes the low-frequency IF signal from your modem (typically L-band: 950–1,450 MHz) and up-converts it to the satellite’s transmit frequency — Ku-band (13.75–14.5 GHz), C-band (5.85–6.425 GHz), or Ka-band (27.5–31 GHz) — then amplifies it to a level strong enough to reach the satellite.
In plain terms: your modem talks, the BUC shouts it toward the satellite.
Spec
What It Means
Typical Ku-band VSAT Values
Output Power
RF power delivered to the feed
1W, 2W, 4W, 8W, 16W
Frequency Range
TX frequency range
13.75–14.5 GHz
LO Stability
Phase noise / frequency accuracy
PLL: ±0.5 ppm · DRO: ±5 ppm
DC Power
Power consumption
12W–120W depending on output power
Power Supply
How it receives power
DC via IFL coax (24–48V) or external AC
P1dB
Max linear output before compression
Rated output power
Output power is the primary BUC spec. A 1W BUC is sufficient for many SCPC/TDMA VSAT links with a 1.2m antenna in good conditions. Move to a 4W or 8W BUC when you have longer hop distances, smaller antennas, or need rain fade margin in tropical climates.
What Is an LNB (Low Noise Block Downconverter)?
An LNB — Low Noise Block Downconverter — handles the receive (downlink) side. It captures the extremely weak satellite signal arriving at the antenna (typically −90 to −120 dBm at Ku-band), amplifies it with the least possible added noise, then down-converts it to L-band IF (950–2,150 MHz) for the modem to process.
In plain terms: the LNB listens to the satellite and whispers the signal to your modem.
Spec
What It Means
Typical Ku-band VSAT Values
Noise Figure
Added noise in dB — lower is better
0.3–0.7 dB
Noise Temperature
Equivalent noise in Kelvin — lower is better
~20–55 K
LO Stability
How precisely the LO holds its frequency
PLL: ±1–5 ppm · DRO: ±100–500 kHz
Frequency Range
RX frequency range covered
10.7–12.75 GHz (Universal Ku)
Gain
Total amplification
55–70 dB typical
Power Supply
Powered via coax from modem
13V (vertical pol.) / 18V (horizontal pol.)
For VSAT applications, always specify a PLL LNB over a DRO LNB. PLL (Phase-Locked Loop) LNBs have a local oscillator stability of ±1–5 ppm — critical for VSAT modems that use tight carrier spacing. DRO LNBs drift with temperature and cause demodulation errors on professional VSAT links.
BUC vs LNB: Side-by-Side Comparison
BUC
LNB
Direction
Transmit (uplink)
Receive (downlink)
Function
Up-converts L-band IF → satellite TX frequency; amplifies for transmission
Down-converts satellite RX frequency → L-band IF; amplifies with low noise
Critical Spec
Output power (Watts)
Noise figure (dB) / Noise temperature (K)
Power Consumption
High (12W–120W+)
Low (~0.5–2W, powered from coax)
Failure Symptom
No transmit / low Eb/N₀ at hub
No receive / low C/N at modem
Ku-band TX/RX Range
13.75–14.5 GHz
10.7–12.75 GHz
Connection to Modem
Separate IFL coax (IF signal outbound + DC inbound)
Separate IFL coax (IF signal inbound + DC outbound)
How BUC and LNB Work Together
In a typical VSAT installation, the signal flow is:
Transmit: Modem → IF coax → BUC (up-converts and amplifies) → waveguide/feed → reflector → satellite Receive: Satellite → reflector → feed → LNB (amplifies and down-converts) → IF coax → Modem
The modem supplies DC power to both the BUC and LNB via the IFL coaxial cables. In compact VSAT installations, the BUC and LNB are often integrated into a single ODU (Outdoor Unit) or transceiver — but they remain functionally separate components inside.
Important: The BUC and LNB use two separate IFL coaxial runs. Do not combine them without a diplexer — the TX and RX signals occupy different frequencies and the DC power requirements differ between the two paths.
Choosing the Right BUC: Output Power Guide
Application
Antenna Size
Recommended BUC
Small office VSAT (SCPC/TDMA)
0.9m – 1.2m
1W – 2W
Standard enterprise VSAT
1.2m – 1.8m
2W – 4W
High-throughput / redundant link
1.8m – 2.4m
8W – 16W
Broadcast / major uplink
2.4m+
25W+
For the GCC and wider MENA region, a 2W–4W BUC on a 1.2m–1.8m Ku-band antenna typically provides adequate margin for local rain fade statistics.
Choosing the Right LNB: What to Look For
Noise figure under 0.5 dB for any professional VSAT application — a 0.3 dB LNB gives meaningful link margin advantage over a 0.7 dB unit.
Always specify PLL for VSAT modems (iDirect, Newtec, UHP, Comtech) — DRO LNBs will cause link instability on any system using tight carrier spacing or high-order modulation (16APSK, 32APSK).
Match the frequency band to your satellite — confirm whether you’re on standard Ku (10.7–12.75 GHz universal) or a specific Ku sub-band that requires a dedicated LO frequency.
Frequently Asked Questions
Can a BUC and LNB share the same cable?
Not without a diplexer. The transmit and receive signals occupy different frequency ranges and the components have different DC power requirements. In some compact VSAT systems a diplexer is built into the ODU housing allowing a single IFL cable — but inside, the signals are always separated.
What fails more often — the BUC or LNB?
The BUC. It’s an active transmit amplifier running at meaningful power levels in outdoor conditions. LNBs are lower-power receive devices and tend to be more reliable, though noise figure degrades slowly over years. If receive C/N has dropped with no other changes, check the LNB first.
Is a BUC the same as an SSPA or TWTA?
Not exactly. A BUC combines an up-converter and an amplifier in one unit. A standalone SSPA (Solid State Power Amplifier) or TWTA (Travelling Wave Tube Amplifier) is a high-power amplifier only — it requires a separate up-converter. BUCs are the standard solution for VSAT; SSPAs and TWTAs are used in larger broadcast and teleport uplinks.
What’s the difference between a PLL and DRO LNB?
PLL (Phase-Locked Loop) uses a stable crystal reference to lock the local oscillator frequency to a precise value (±1–5 ppm). DRO (Dielectric Resonator Oscillator) relies on a temperature-sensitive ceramic resonator and drifts significantly (±100–500 kHz). For VSAT: always PLL. DRO is acceptable only for DTH (direct-to-home) TV reception.
Shop BUCs and LNBs at Bravo Satcom
Bravo Satcom supplies a full range of Ku-band and C-band BUCs from Terrasat, NJRC, Actox, and Agilis — and PLL LNBs from NJRC, Norsat, and Swedish Microwave. All units are stocked for delivery across the UAE and GCC.
For NJRC BUCs and LNBs — one of the most widely deployed brands in the region — contact us for pricing, datasheets, and availability.
Reach us at sales@bravosatcom.com or +971 55 541 5892 for a technical consultation or quote.
If you’re specifying cable for a VSAT antenna, two-way radio system, or any RF installation, you’ve likely hit the same question: LMR-400 or LMR-600? Both are Times Microwave Systems’ most popular flexible coax cables — low loss, UV-resistant, and built for outdoor use. The difference comes down to run length, signal loss budget, and how much space you have to work with.
This guide gives you the specs, the attenuation data, and a clear decision rule.
LMR-400 and LMR-600 cross-sections drawn to scale. The larger conductor in LMR-600 (0.176″ vs 0.108″) is the primary reason for its 35% lower signal loss.
Physical Specs: Side by Side
Property
LMR-400
LMR-600
Outer Diameter
0.405″ (10.3 mm)
0.590″ (15.0 mm)
Center Conductor OD
0.108″
0.176″
Center Conductor Material
Copper-clad aluminum
Copper-clad aluminum
Minimum Bend Radius
1.0″ (25 mm)
1.5″ (38 mm)
Weight
0.068 lbs/ft
0.131 lbs/ft
Impedance
50 Ω
50 Ω
Temperature Range
−40°C to +85°C
−40°C to +85°C
DC Resistance (center, per 1000 ft)
1.39 Ω
0.53 Ω
The bigger conductor in LMR-600 (0.176″ vs 0.108″) is the reason it outperforms LMR-400 on signal loss — lower DC resistance means less energy dissipated as heat per foot of cable.
Signal Attenuation: The Numbers That Matter
Attenuation is measured in dB per 100 feet — the lower the number, the better. Based on Times Microwave Systems official specifications:
Frequency
LMR-400
LMR-600
Improvement
100 MHz
~1.0 dB/100ft
~0.65 dB/100ft
~35% less loss
450 MHz (L-band)
~1.7 dB/100ft
~1.1 dB/100ft
~35% less loss
900 MHz
~2.6 dB/100ft
~1.7 dB/100ft
~35% less loss
1,500 MHz (VSAT IF)
~3.5 dB/100ft
~2.2 dB/100ft
~37% less loss
2,000 MHz
~4.2 dB/100ft
~2.7 dB/100ft
~36% less loss
2,500 MHz
~4.8 dB/100ft
~3.1 dB/100ft
~35% less loss
LMR-600 consistently delivers ~35% less signal loss than LMR-400 at every frequency. The gap compounds over longer runs.
LMR-600 delivers roughly 35% less attenuation at all frequencies compared to LMR-400. That gap compounds quickly over longer runs.
Real-world example: A 30-metre (100 ft) run at 1,500 MHz (typical VSAT L-band IF):
LMR-400: ~3.5 dB loss | LMR-600: ~2.2 dB loss | Difference: 1.3 dB — meaningful when your modem’s link budget is already tight.
When LMR-400 Is the Right Choice
LMR-400 is the industry standard for good reason. Choose it when:
Run length is under 30 metres (100 ft). At this distance, the loss difference between LMR-400 and LMR-600 is minimal and doesn’t justify the cost or weight difference.
You need flexibility. With a 1.0″ minimum bend radius, LMR-400 is significantly easier to route through conduit, around corners, and in tight equipment racks.
Weight matters. At 0.068 lbs/ft (vs 0.131 lbs/ft for LMR-600), LMR-400 is nearly half the weight — important for rooftop or tower installations where cable tray loading is a concern.
Budget is a factor. LMR-400 is meaningfully less expensive per metre than LMR-600, making it the practical default for short-to-medium runs.
LMR-400 is the cable of choice for most VSAT antenna-to-modem runs, two-way radio base station feeders, and short rooftop drops.
When You Should Upgrade to LMR-600
Move to LMR-600 when signal loss budget is tight:
Run length exceeds 30–40 metres (100–130 ft). Beyond this point, the accumulated loss in LMR-400 starts eating into your link margin — especially at higher frequencies (Ku-band IF at 950–1,450 MHz and above).
High-power applications. LMR-600’s larger conductor handles more RF power before thermal losses become a concern — relevant for high-wattage BUC installations where every dB matters.
You’re running at 1 GHz or above over long distances. Attenuation increases with frequency. A 60-metre Ku-band IF run at 1,500 MHz in LMR-400 loses ~7.0 dB. In LMR-600, the same run loses ~4.4 dB. That 2.6 dB difference can be the margin between a stable link and intermittent dropouts.
Maximum cable run distances: LMR-600 supports antenna cable runs up to 400 ft (120 m) without inline amplification. LMR-400 is typically limited to around 200 ft (60 m) before loss becomes unacceptable at Ku-band frequencies.
Cost and Installation
LMR-600 typically costs 30–50% more per metre than LMR-400. It’s also heavier and stiffer, requiring more careful routing and stronger support hardware — cable trays and support clamps need to account for the increased weight (0.131 lbs/ft vs 0.068 lbs/ft).
Connectors are cable-specific — don’t mix LMR-400 and LMR-600 connectors. If you’re terminating in the field, LMR-600 requires a larger stripper tool and more robust crimp or compression fittings. Both cables accept Times Microwave Systems EZ push-on connectors, which eliminates soldering on site.
Answer three questions — run length, frequency, and power — and you have your cable choice.
The Simple Decision Rule
Under 30 m and below 1 GHz? → LMR-400.
Over 30 m, or high frequency, or high-power BUC? → LMR-600.
If you’re ever in doubt, calculate your total path loss budget: add up the cable loss, connector insertion loss (~0.1 dB per connector), and any other passive components. If the total pushes you within 1–2 dB of your link margin, upgrade to LMR-600.
Frequently Asked Questions
Can I mix LMR-400 and LMR-600 in the same run?
Yes, but only with proper barrel adapters. Keep the LMR-600 section on the longer runs and use LMR-400 for short flexible jumpers at each end.
Are LMR-400 and LMR-600 connectors interchangeable?
No. Each cable requires its own connector size. LMR-400 and LMR-600 both accept N-type, TNC, and SMA connectors — but in their respective sizes. They are not physically compatible with each other.
Which cable is better for outdoor VSAT installations in hot climates?
Both use a black UV-protected polyethylene jacket rated for −40°C to +85°C, making them suitable for the UAE and GCC climate. For buried runs, specify LMR-DB (watertight/flooded version) from Times Microwave Systems.
Does LMR-600 need different support hardware?
Yes. At 0.131 lbs/ft, LMR-600 requires stronger cable trays and more frequent support points — approximately every 18–24 inches on horizontal runs vs every 24–36 inches for LMR-400.
Shop LMR Coaxial Cable at Bravo Satcom
Bravo Satcom stocks Times Microwave Systems LMR coaxial cable including LMR-400 and LMR-600, along with the full range of N-type, TNC, SMA, and BNC connectors for both cable types. Available for delivery across the UAE and GCC.
Contact us at sales@bravosatcom.com or +971 55 541 5892 for cut lengths, bulk pricing, or pre-terminated assemblies.
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