LMR-400 vs RG-8X for ham radio comes down to loss versus flex. LMR-400 loses far less signal at 70cm and handles much more power while RG-8X stays thinner and easier to route in tight spaces. Pick LMR-400 for runs over 25 feet, RG-8X for short jumpers and portable setups.
LMR-400 vs RG-8X for Ham Radio: Key Differences at a Glance
Both are 50-ohm coax built for VHF/UHF feedlines. The gap widens hard at 70cm: over 100 feet, LMR-400 still delivers about 54% of your power to the antenna at 440 MHz. RG-8X delivers only about 15%. A real gap.
At 440 MHz, LMR-400 loses 2.7 dB per 100 feet versus 8.1 dB for RG-8X (Universal Radio, 2026).
| Cable | Diameter | Loss/100ft @146MHz | Loss/100ft @440MHz | Power handling | Flexibility | Approx. cost/ft | Best use case |
|---|---|---|---|---|---|---|---|
| LMR-400 | 0.405 in | 1.5 dB | 2.7 dB | ~550W @ 450MHz | Stiff, solid core | $1-$2 | Long runs, base/tower feeds |
| RG-8X | 0.242 in | 4.5 dB | 8.1 dB | ~80W @ 450MHz | Very flexible | $0.30-$0.60 | Jumpers, portable, mobile |
Which One Should You Choose
Length over price. Match the cable to the run length not the sticker price.
Choose LMR-400 if…
- Your feedline run is longer than 25-30 feet
- You're feeding a tower mounted antenna or repeater
- You run higher power and don't want to lose it in the cable
Choose RG-8X if…
- You need a short jumper or portable go-kit cable
- Weight and bend radius matter more than the last dB
- Your run stays under 20-25 feet
Both cables commonly terminate in PL-259 or Type-N connectors though RG-8X needs a reducer adapter to fit a full size PL-259 shell.
💡 Pro Tip: Many stations run RG-8X as a short jumper from the radio then switch to LMR-400 for the long outdoor run to the antenna. You get the flex where you need it and the low loss where it counts.
Bottom Line
RG-8X earns its place for short, flexible jumpers where weight and routing matter more than the last decibel. No contest at 70cm though. Weighing LMR-400 vs RG-8X for ham radio on loss, LMR-400 wins by a wide margin at 70cm.
Now that you know your feedline loss (2.7 dB for LMR-400 or 8.1 dB for RG-8X at 440 MHz), plug it into our amateur radio antenna gain and link budget calculator to see your exact margin before you climb the tower. Calculate your antenna gain and link budget
Other Common Amateur Radio Questions: How to Improve Simplex Range on Ham Radio: 6 Step Guide
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