LMR-400 vs LMR-600 Coaxial Cable: Which Should You Choose?

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 vs LMR-600 coaxial cable cross-section comparison drawn to scale — showing outer jacket, copper braid shield, aluminium tape, foam dielectric, and CCA center conductor for both cables — 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-400 vs LMR-600 signal attenuation comparison chart — dB loss per 100 feet from 100 MHz to 2500 MHz, showing LMR-600 delivers approximately 35% less signal loss at all frequencies — 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.

Decision guide flowchart for LMR-400 vs LMR-600 cable selection — three questions: run length over 30m, frequency above 1 GHz, or high-power BUC system — 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.