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VSAT

Newtec vs iDirect Satellite Modems: A Complete UAE Buyer’s Guide (2026)

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Comparison of ST Engineering iDirect Dialog, Evolution, and Velocity satellite platforms

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

Decision tree for choosing between Newtec MDM2510, MDM3315, iDirect iQ200 and X7 satellite modems in the UAE

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:

ModemPlatformOriginTarget UsePeak Data RateReturn Tech
MDM2510DialogNewtecSOHO / SME, POS150 Mbps fwdMx-DMA, MF-TDMA
MDM3315DialogNewtecEnterprise, maritime, backhaul150/70 MbpsMx-DMA MRC, MF-TDMA, SCPC
MDM6000DialogNewtecHigh-end enterprise, DTH contribution500+ MbpsMx-DMA, SCPC
iQ200EvolutioniDirectSOHO / SME~50 MbpsA-TDMA
iQ Desktop 200EvolutioniDirectDesktop SOHO~50 MbpsA-TDMA
X7EvolutioniDirectEnterprise (EOL – succeeded by MDM3315)90 MbpsA-TDMA, SCPC
X1EvolutioniDirectLow-cost remote~20 MbpsA-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

Newtec and iDirect merged into ST Engineering iDirect in 2021 — visual timeline of the acquisition

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.
  • High-throughput DTH / broadcast contribution: MDM6000.
  • 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.

Cable

How to Crimp LMR Connectors Correctly: Step-by-Step Guide

Posted on by rai

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.

ToolPurposeNotes
Coax cable cutterClean, square cable cutNever use wire cutters or a hacksaw — both distort the cable end
Rotary coax stripperStrip jacket, braid, dielectric to exact dimensionsSet blade depths for LMR-400 specifically
Hex crimp tool + dieCompress ferrule onto braidLMR-400 N-type typically requires 0.429″ hex die — check connector spec
Utility knife / deburring toolClean dielectric end, remove stray braid strands
Vernier calipersVerify strip dimensionsOptional but recommended for critical installs
MultimeterPost-crimp continuity testMandatory 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.

StripDimensionWhat It Exposes
Outer jacket removal25.4 mm (1.00″)Braid for fold-back
Braid fold-back point12.7 mm (0.50″) from jacket endPositions braid over ferrule
Dielectric removal12.7 mm (0.50″) from fold pointCentre conductor
Centre conductor trimFlush with connector pin faceClean 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

MistakeConsequenceFix
Forgetting the ferrule before assemblyMust cut off connector and restartSlide ferrule on as Step 2, every time
Nicked centre conductorPIM, cracking under vibration, future openRe-cut cable end and re-terminate
Stray braid strands on dielectricDead short centre-to-outerInspect under good light before inserting body
Wrong hex die sizeUnder-crimp — passes pull test, fails in fieldAlways match die to connector spec sheet
Bunched braid foldNon-uniform crimp, reduced shield coverageComb braid evenly around full circumference
Centre pin too longBottoms out in mating connector, damages bothTrim flush with pin face
RG-8 connector on LMR-400Wrong bore — mechanically and electrically poorAlways 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.

LMR CableStandard ConnectorCrimp Die (typical)Notes
LMR-195N-type, SMA, BNCPer connector specCheck braid OD matches
LMR-240N-type, SMAPer connector spec
LMR-400N-type0.429″ hex (typical)Standard VSAT IFL
LMR-600N-type, 7/16 DINDifferent bodyDo NOT mix with LMR-400 connectors
LMR-900N-type, 7/16 DINLarge-body only7/16 DIN preferred for high power

For a full cable series comparison, see the Times Microwave LMR Series guide.

FAQ

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.

→ Browse cable products    → Request a quote

VSAT

How to Choose BUC Power for VSAT: A Practical Guide

Posted on by rai
Diagram showing five factors that determine VSAT BUC output power: antenna size, rain fade margin, frequency band, satellite G/T, and data rate
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 DiameterApprox. Gain (Ku-band ~14 GHz)Relative EIRP vs 0.75m
0.75m~38 dBiBaseline
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:

BandTX FrequencyRain Fade RiskTypical VSAT Use
C-band5.85–6.425 GHzVery low (near immune)Maritime, tropical, broadcast
Ku-band13.75–14.5 GHzModerateStandard enterprise VSAT
Ka-band27.5–31 GHzHigh (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.

RegionRain Fade Margin — Ku-band (99.5% availability)
UAE / GCC (arid)1–2 dB
Mediterranean / Southern Europe2–4 dB
Sub-Saharan Africa5–8 dB
Southeast Asia / tropical8–12 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.

ApplicationAntenna SizeBUC PowerNotes
Remote monitoring / IoT VSAT0.75m – 0.9m1WLow data rate, QPSK
Small office broadband (TDMA)0.9m – 1.2m1W – 2WStandard managed VSAT plans
Enterprise VSAT (SCPC)1.2m – 1.8m2W – 4WDedicated bandwidth
High-throughput / corporate1.8m – 2.4m8W – 16WHigh data rate, tight SLA
Video contribution uplink2.4m+16W – 25WHD/UHD broadcast
GCC region (low rain fade)1.2m2WTypically sufficient for managed VSAT
Tropical climate (same link)1.2m4W – 8WAdditional rain fade margin required
C-band (large antenna)2.4m – 3.7m2W – 5WLower free-space loss, rain-fade immune
Ka-band (spot beam)0.75m – 1.2m1W – 2WHigh 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.

Uncategorized

Fiber Optic vs Coaxial Cable: When to Use Each

Posted on by admin

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.

COAXIAL CABLE (LMR-400) 50Ω · RF + DC Power Center Conductor (Cu) Dielectric Foam Braid Shield Outer Jacket (PE/PVC) ✓ RF Signal + DC Power (BUC / LNB) FIBER OPTIC CABLE (SMF OS2) Single-Mode · Light Signal Only Glass Core (9 µm) Cladding (125 µm) Buffer Coating Outer Jacket (LSZH / PE) ✗ Light Signal Only — No DC Power
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.

See also: LMR-400 vs LMR-600: Which Should You Choose?

Frequently Asked Questions

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.

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VSAT

C-Band in VSAT Technology

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C-band is one of the oldest and most widely used frequency bands in satellite communication. It operates in the 4 to 8 GHz frequency range and has a wavelength of around 4 to 8 centimeters. The lower frequency range of C-band provides better penetration through obstacles such as rain, fog, and foliage, making it ideal for long-distance communication in areas with harsh weather conditions.

In VSAT technology, C-band is often used for applications that require long-distance communication, such as maritime and aviation. It is also used for remote sensing, meteorological observation, and broadcasting.

One of the advantages of C-band over other frequency bands is its wider coverage area. Due to its lower frequency range, C-band signals can be transmitted over longer distances, which means that fewer VSAT terminals are required to cover a large area. This makes C-band ideal for applications that require wide-area coverage, such as disaster relief, rural connectivity, and military communication.

Another advantage of C-band is its lower susceptibility to rain fade compared to Ku-band and Ka-band. Rain fade occurs when raindrops absorb and scatter the radio waves transmitted between the VSAT terminal and the satellite, which can affect the quality of the signal. Due to its lower frequency range, C-band signals are less affected by rain fade than Ku-band and Ka-band signals, making it more reliable in areas with frequent rainfall.

However, C-band has some disadvantages compared to Ku-band and Ka-band. One of the main disadvantages is its lower bandwidth capacity. Due to its lower frequency range, C-band has a lower bandwidth capacity than Ku-band and Ka-band, which means that it can transmit data at a slower rate. This makes C-band less suitable for applications that require high-speed data transfer, such as video streaming and cloud computing.

In addition, C-band has a higher susceptibility to interference from terrestrial microwave communication and radar systems. This is because the frequency range used for C-band overlaps with the frequency range used for some terrestrial communication systems. To mitigate this interference, VSAT terminals using C-band must comply with regulatory requirements and use interference-reducing technologies such as frequency hopping.

In summary, C-band is one of the oldest and most widely used frequency bands in satellite communication, and it is often used for applications that require long-distance communication in areas with harsh weather conditions. It has a wider coverage area than Ku-band and is less susceptible to rain fade, making it more reliable in certain environments. However, it has a lower bandwidth capacity than Ku-band and Ka-band and is more susceptible to interference from terrestrial communication systems.

VSAT

Is VSAT Still Relevant Today Now That Starlink Is Out?

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Yes, VSAT (Very Small Aperture Terminal) is still relevant today even with the emergence of Starlink and other satellite broadband services. While Starlink offers high-speed internet service using low-earth orbit (LEO) satellites, VSAT technology operates using geostationary satellites, which are placed at a much higher orbit.

VSAT technology has been around for decades and is used for a wide range of applications, including remote communication, distance learning, and disaster response. VSAT can be an effective solution for businesses, organizations, and individuals who require reliable and secure satellite connectivity in remote or underserved areas where traditional wired and wireless internet services are not available.

Additionally, VSAT can be more cost-effective for some use cases, particularly for small and medium-sized businesses or individuals who require moderate bandwidth usage. VSAT can also offer more stable connectivity and lower latency than satellite services that use LEO satellites like Starlink, which may be affected by atmospheric conditions and require line-of-sight access to the satellite.

Overall, while Starlink and other LEO satellite broadband services are exciting developments in the satellite internet industry, VSAT remains a relevant and important technology for many applications and use cases.

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