Is RG-8X good enough for an HF antenna?

Yes, for runs under 75 feet it is all you need. RG-8X loses only about 0.3 dB at 14 MHz over 50 feet, which you cannot hear. It is flexible, easy to route through walls, and takes PL-259 connectors with an adapter. The author feeds a 20m dipole with 45 feet of RG-8X that cost $22 for 50 feet with connectors, and recommends putting the savings into antennas.

Should I use LMR-400 for a VHF or UHF antenna?

Yes, for any permanent installation above 50 MHz. LMR-400 is double-shielded with a low-loss dielectric and has roughly half the VHF loss of RG-213, at 0.9 dB per 100 feet on 144 MHz and 1.5 dB on 440 MHz. The author replaced 80 feet of RG-58 feeding a roof antenna with LMR-400 and immediately worked repeaters he had never heard before.

Why should I never use RG-58 as a permanent feedline?

Because its loss is the worst of the common cables, at 2.8 dB per 100 feet on 144 MHz and 5.2 dB on 440 MHz, which means 100 feet on 70cm consumes about 70 percent of your power. RG-58 is fine for bench jumpers and 3 to 6 foot portable hookups where loss does not matter, but better cable is available at nearly the same price for permanent runs.

What is the difference between RG-8X and RG-213?

RG-213 is mil-spec and roughly twice the diameter at 0.4 inches, and it accepts PL-259 connectors directly with no adapter, giving modestly lower loss, for example 0.4 dB versus 0.6 dB per 100 feet at 14 MHz. For HF the improvement is small enough that it rarely justifies the extra bulk and harder routing, though RG-213 fills a niche for VHF runs needing more sturdiness than RG-8X at less cost than LMR-400.

What coax mistakes cost the most signal?

Running RG-58 to a rooftop VHF antenna, which loses about half your power, and failing to weatherproof outdoor connectors so water causes corrosion and a sudden SWR spike later. Also avoid sharp bends or kinks that permanently disturb center conductor spacing, leaving excess cable coiled instead of cutting to length, and inserting a barrel connector mid-run rather than using one continuous piece.

Should I learn to solder PL-259 connectors?

Yes. It is about a 10-minute skill that saves $10 to $15 per connector compared with pre-made cables and lets you build exact-length runs, which matters because extra coiled cable is extra loss. Remember that PL-259 and SO-239 are not truly weatherproof, so seal outdoor connections with self-amalgamating tape or Coax Seal, and consider Type N for VHF and UHF.

Coax Cable for Ham Radio: RG-8X vs LMR-400 vs RG-213

Coax is the boring part of your station that quietly eats your signal if you choose wrong.

I lost almost 3 dB on 70cm running 80 feet of RG-58 to a roof-mounted antenna for my first year of ham radio. That's half my power — gone in the cable before it ever reached the antenna. Replaced it with LMR-400 and immediately hit repeaters I'd never heard before.

The cable matters. Not as much as the antenna, but more than most people think.

Why Cable Type Matters

Every foot of coax loses signal. How much depends on:

Frequency: Higher frequency = more loss per foot
Cable type: Thinner/cheaper = more loss
Length: Every foot adds up

At HF (3-30 MHz) with runs under 50 feet, the differences between cables are minor. A few tenths of a dB. You won't notice.

At VHF/UHF (144-440 MHz) with runs over 50 feet? Cable choice is the difference between solid repeater access and marginal signals.

Loss Per 100 Feet (The Numbers)

Cable At 7 MHz At 14 MHz At 144 MHz At 440 MHz RG-58 0.5 dB 0.8 dB 2.8 dB 5.2 dB RG-8X 0.3 dB 0.6 dB 2.0 dB 3.7 dB RG-213 0.2 dB 0.4 dB 1.3 dB 2.5 dB LMR-400 0.1 dB 0.3 dB 0.9 dB 1.5 dB

Put another way: 100 feet of RG-58 on 70cm eats 70% of your power. Same run with LMR-400? Only 30%. That's the difference between hitting a distant repeater and not.

The Cables

RG-58 — Don't Use for Permanent Installs

Thin, flexible, cheap. Great for bench jumpers and portable setups where you need 3-6 feet of cable and don't care about loss.

Never run RG-58 as a permanent feedline to an antenna. I don't care if it's "just HF" — there are better options at nearly the same price.

RG-8X — The HF Workhorse

Half the diameter of RG-213 but surprisingly close in performance on HF. Flexible, easy to route through walls, takes PL-259 connectors with an adapter.

For HF runs under 75 feet? This is all you need. Loss at 14 MHz over 50 feet: 0.3 dB. You literally cannot hear that difference.

I run RG-8X to my 20m dipole (45 feet). Works perfectly. Cost: $22 for 50 feet with connectors from DX Engineering.

RG-213 — The Traditional Choice

Mil-spec, thick (0.4" diameter), directly fits PL-259 connectors without adapters. Marginally better than RG-8X.

Honest opinion? For HF, the difference between RG-8X and RG-213 is so small it rarely justifies the extra bulk and routing difficulty. But for VHF runs where you need something sturdier than RG-8X and cheaper than LMR-400, it has a niche.

LMR-400 — The Performance Pick

Genuine Times Microwave LMR-400 is the standard for VHF/UHF base station feedlines and long HF runs. Double-shielded, low-loss dielectric, significantly better than RG-213.

About half the loss of RG-213 on VHF. For any permanent antenna installation above 50 MHz, LMR-400 is the right call.

Warning: cheap "LMR-400 equivalent" or "LMR-400 type" cable from random vendors often doesn't match genuine Times Microwave specs. Buy name brand or from reputable ham radio dealers (DX Engineering, Ham Radio Outlet). The difference shows up on a VNA.

Hardline / Heliax — Overkill for Most

Rigid or semi-rigid cable used in commercial installations. Virtually zero loss. Also expensive, hard to route, and requires special connectors.

Used for tower runs to large yagi arrays. If you're reading a beginner article about coax, you don't need hardline yet.

Connectors

PL-259 / SO-239 — The ham radio standard on HF. Every HF radio uses SO-239 jacks. Not technically weatherproof — seal outdoor connections with self-amalgamating tape or Coax Seal.

Type N — Better for VHF/UHF. Truly weatherproof when tightened. Lower loss than PL-259 at high frequencies. Used on many VHF/UHF base antennas.

SMA — Small, for handhelds and SDR dongles. Not for feedlines.

Learn to solder PL-259 connectors. It's a 10-minute skill that saves you $10-15 per connector over pre-made cables, and you can make exact-length runs.

What to Buy

HF station, run under 75 feet: RG-8X. Done. Save money for antennas.

VHF/UHF base station, any length: LMR-400. Worth every penny.

Portable/field: RG-8X or even RG-58 if runs are under 15 feet and weight matters.

Tower installation (100+ feet): LMR-400 minimum. LMR-600 if budget allows. Hardline if you're serious.

Mistakes That Cost Signal

Running RG-58 to a rooftop VHF antenna (half your power gone)
Not weatherproofing outdoor connectors (water = corrosion = sudden SWR spike next spring)
Sharp bends or kinks (permanently damages center conductor spacing)
Excess cable coiled up (just cut it to length — extra cable is extra loss)
Using a barrel connector mid-run instead of one continuous piece (every connector adds loss and a potential failure point)

One More Thing

Shorter is always better. A 25-foot run of cheap cable beats a 100-foot run of expensive cable every time. Route your coax the shortest path from radio to antenna. Don't follow walls for aesthetics. Don't loop excess behind a desk. Cut it to length.

The antenna gets the glory. The coax just needs to not waste what the antenna captures. Pick the right cable for your frequency and distance, install it properly, and forget about it.