Thursday, June 18, 2026
24 check-insThis Week's Question
“Do you have a preferred coax manufacturer — who is it, and why?”
Coax Choices — Brands, Specs, and What Works at Your Station
Coaxial cable is one of those things hams tend not to think about until something goes wrong — a feedline that's been on the tower for fifteen years finally shows its age, a new antenna goes up and suddenly the old RG-8 in the attic looks pretty sad, or someone at a hamfest hands you a sample of something you've never heard of and you spend the drive home wondering whether to switch. The reality is that the cable between your radio and your antenna matters. Loss is loss. Once RF turns into heat inside the feedline, you're not getting it back.
But it's not just about loss numbers on a spec sheet. Flexibility, jacket material, direct-burial rating, connector compatibility, and the price per foot all matter just as much for many real-world installations. Tonight we want to know: what are you running, who makes it, and why did you choose it?
HF vs. VHF/UHF — Why Frequency Changes Everything
HF (1.8 – 30 MHz)
Coax loss at HF is relatively low even in thinner or older cable. A 100-foot run of decent RG-8X might cost you less than 2 dB at 14 MHz, which is acceptable for most HF work. That said, longer runs and higher-power stations still benefit from .400-class cable. The savings in feedline loss become real watts on the antenna.
VHF (50 – 148 MHz)
Loss roughly doubles compared to 14 MHz for the same cable. A run that's fine on 20 meters starts to sting on 6 meters and 2 meters. This is where hams moving from HF to VHF/UHF often get their first surprise. Upgrading feedline is frequently the biggest single improvement available for a VHF/UHF base station.
UHF (430 – 450 MHz)
Loss is significantly higher again. Thinner cable that's perfectly usable on HF becomes a serious liability at 440 MHz. For 70 cm satellite work, weak-signal SSB, or a long vertical run to a UHF repeater, the cable choice starts to directly impact whether you can make the contact or not.
The Portable and Mobile Exception
For portable ops, POTA, rovers, or vehicle installs, the lowest-loss cable isn't always the right answer. Stiff .400-class cable is miserable to route through a door gasket, coil on a rotor loop, or stuff into a pack. Many operators intentionally choose a more flexible cable that's slightly higher loss because it survives repeated bending, fits the install, and is still far better than standard RG-8X. The right cable is the one that actually works in your specific situation.
Common Ham Coax Comparison
All attenuation values are in dB per 100 feet at the stated frequency. Values marked (cp) are the closest official published frequency when an exact frequency is not in the manufacturer's table. Values marked (est) are interpolated estimates — not directly published by the manufacturer. Manufacturer specs were sourced from official datasheets and product pages; see links in the Further Reading section. Times Microwave official datasheets were unavailable for direct retrieval; LMR figures below reflect widely published values consistent with Times Microwave documentation.
| Manufacturer | Model | OD | Impedance | Vel. Factor | ~10 MHz (dB/100ft) | ~50 MHz (dB/100ft) | ~146 MHz (dB/100ft) | ~440 MHz (dB/100ft) | Flexibility / Use | Outdoor / Burial | Best Use Case | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ABR Industries | ABR240‑UF | 0.242" | 50 Ω | 84% | —1 | 2.1 | 3.6 (cp: 150 MHz) | 6.3 (cp: 450 MHz) | Flexible; PE jacket | Outdoor; not rated direct burial | Portable, mobile, jumpers, rotor loops | 19-strand TC center; dual foil + braid; .240-class alternative to RG-8X with PE jacket |
| ABR Industries | ABR400 | 0.405" | 50 Ω | 86% | —1 | 0.9 | 1.5 (cp: 150 MHz) | 2.7 (cp: 450 MHz) | Low flexibility; stationary runs | Outdoor; PE Type 3A jacket | Base station long runs, HF through UHF | Solid CCA center conductor; designed for stationary installations; foil + 95% braid shield |
| ABR Industries | ABR400‑UF | 0.405" | 50 Ω | 84% | —1 | 1.1 | 1.8 (cp: 150 MHz) | 3.3 (cp: 450 MHz) | Flexible; 19-strand copper center | Outdoor; non-contaminating PE jacket | Rotor loops, portable ops where .400-class flexibility matters | 19-strand copper center vs. solid CCA in ABR400; slightly higher loss tradeoff for flexibility; foil + 95% TC braid |
| Times Microwave | LMR‑240 | 0.240" | 50 Ω | 83% | 0.8 (est) | 1.3 | 2.1 (est) | 3.9 (est) | Semi-flexible; standard jacket | Outdoor; UV-rated jacket | Short HF through UHF runs, portable, vehicle | Industry benchmark .240-class cable; widely distributed; UltraFlex variant available (~15% higher loss, better flex) |
| Times Microwave | LMR‑400 | 0.405" | 50 Ω | 85% | —1 | 0.7 | 1.5 (est) | 2.7 (est) | Semi-flexible; standard jacket | Outdoor; UV-rated jacket | Base station runs HF through UHF; the classic low-loss .400 benchmark | Industry-standard reference cable; bonded foil + braid; UltraFlex variant is ~15% higher loss but far more flexible |
| Messi & Paoloni | Ultraflex 7 | 0.287" | 50 Ω | 83% | 0.6 | 1.2 | 2.1 | 3.6 (cp: 430 MHz) | Highly flexible; designed for tight bends | Outdoor UV PVC; not direct burial (EXTRAFLEX BURY 7 variant for burial) | Portable, patch cords, jumpers, vehicle, rotor loops | 19-strand copper center; 83% vel. factor; lighter than .400-class; won't tolerate direct burial without burial variant |
| Messi & Paoloni | Ultraflex 10 Competition | 0.405" | 50 Ω | 87% | 0.4 | 0.8 | 1.4 | 2.5 (cp: 430 MHz) | Highly flexible for .400-class | Outdoor UV PVC; not direct burial (AIRBORNE 10 or EXTRAFLEX BURY for burial) | Best flexible .400-class; rotor loops, portable, long-run with tight routing | Replaces discontinued Hyperflex 10; 7-strand copper center; foil + braid; 87% vel. factor; best attenuation in M&P .400 flexible line |
| Messi & Paoloni | Hyperflex 10 Discontinued | 0.405" | 50 Ω | 87% | 0.4 | 0.8 | 1.4 | 2.6 (cp: 430 MHz) | Extremely flexible; reactive braid with spring action | Outdoor UV PVC; not direct burial | Tight rotor loops, vehicle routing, repeated flexing; replaced by Ultraflex 10 Competition | Discontinued by M&P; replaced by Ultraflex 10 Competition (slightly better specs). 19-strand copper center; reactive CCA braid. If you have it, it's still excellent cable. |
| Davis RF | Bury‑FLEX | 0.405" | 50 Ω | 82% | 0.6 (cp: 10 MHz) | 1.1 | 2.0 (cp: 200 MHz) | 2.8 (cp: 400 MHz) | Flexible for .400-class; 2" min bend radius | Outdoor and direct burial; UV-resistant PE jacket | Underground feedline runs, rotor loops, long outdoor runs where burial is needed | PE jacket (not PVC) extends outdoor life; 9.5 AWG stranded bare copper center; bonded foil + 97% TC braid; gas-injected foam PE dielectric |
| Belden | 9913 | 0.405" | 50 Ω | 84% | 0.6 (est) | 0.9 (est) | 1.7 (est) | 3.0 (est) | Semi-flexible; stiff by ham standards | Outdoor; PVC jacket (standard) | Base station HF and VHF, classic low-loss fixed installation | Long-standing ham favorite; solid bare copper center; air dielectric construction; well-known connector fitment with standard PL-259 |
| Belden | 9913F7 | 0.405" | 50 Ω | 84% | 0.5 (est) | 0.9 (est) | 1.6 (est) | 2.9 (est) | More flexible than 9913; 7-strand center | Outdoor; PVC jacket (standard) | Fixed installations needing slightly more flexibility than 9913; HF through UHF | 7-strand bare copper center vs. solid in 9913; slightly more flexible; comparable loss; same family, easier to work with |
| 1 No 10 MHz data point published in the manufacturer's official datasheet; closest available was 30 MHz. ABR sources: official product datasheets (Oct 2023 / Nov 2018). M&P sources: official datasheets from messi.it. Davis RF source: davisrf.com product page. LMR figures: widely published values consistent with Times Microwave documentation (timesmicrowave.com PDFs were inaccessible for direct retrieval at time of publication). Belden figures: estimated from Belden 9913/9913F7 product family data; belden.com product pages did not expose structured spec tables for direct extraction. All (est) values are interpolated; treat as approximate. | ||||||||||||
Understanding the Specs — What the Numbers Actually Mean
The table above is only useful if you know what you're looking at. Here's a plain-language breakdown of each column.
Velocity Factor (VF)
Radio signals don't travel through coax at the speed of light — the dielectric material slows them down. Velocity factor is that speed expressed as a percentage of c. A cable with 84% VF means the signal travels at 84% of the speed of light through that cable.
Why it matters: the electrical length of a cable is not the same as its physical length. A 100-foot cable with 84% VF is electrically 119 feet long. This matters any time you're cutting cable to a specific electrical length — phasing lines, matching stubs, antenna feed points, or delay lines.
For everyday point-to-point feedline, VF doesn't directly affect loss — but higher VF generally means a better dielectric, which tends to correlate with lower loss at high frequencies.
Attenuation (dB / 100 ft)
Attenuation is how much signal the cable absorbs and turns into heat over a given length. It's expressed in decibels (dB) per 100 feet, and it goes up as frequency goes up — which is why the table has separate columns for HF, VHF, and UHF.
The decibel is logarithmic, not linear. A few key reference points:
| Loss | Power remaining | Practical feel |
|---|---|---|
| 1 dB | ~79% | Barely noticeable; roughly one S-unit on receive |
| 3 dB | 50% | Half your power gone; clearly audible on SSB |
| 6 dB | 25% | Three-quarters of your power lost |
| 10 dB | 10% | Nine out of ten watts never reach the antenna |
Example: a cable rated at 1.5 dB/100ft at 146 MHz means a 100-foot run from a 100-watt radio delivers about 71 watts to the antenna. A 200-foot run doubles the loss to 3 dB — only 50 watts makes it through. That's a lot of power to leave in the feedline.
Impedance (50 Ω)
Impedance is the characteristic resistance of the cable to RF energy. All ham radio coax is 50 ohms. The antenna, radio, and feedline all need to be the same impedance for maximum power transfer. Mismatches cause reflections, which show up as SWR on your meter.
Don't confuse ham coax with TV coax. Cable TV and satellite dishes use 75-ohm coax (RG-6, RG-11). It looks similar and even takes the same connectors in some cases, but putting 75-ohm cable in a 50-ohm system causes an impedance mismatch. At HF the effect is mild; at UHF it causes real loss and elevated SWR.
Outer Diameter (OD)
The physical diameter of the cable. This affects connector choice, routing difficulty, bend radius, and weight. It also directly drives loss — larger cables are almost always lower loss.
Ham coax broadly falls into three size classes: .100-class (RG-174, tiny jumpers), .240-class (RG-8X, LMR-240, ABR240-UF, Ultraflex 7 — the flexible mid-size group), and .400-class (RG-8, RG-213, LMR-400, ABR400, Bury-FLEX, Ultraflex 10 — the low-loss standard for base-station runs). Above .400 are .500 and .600-class cables, which are mostly found on towers and commercial installations.
Why Cable Diameter Matters More as Frequency Rises
The single most important physical fact about coax loss is this: loss goes up with frequency, and it goes up faster in smaller cable. That thin RG-58 you've been using for HF starts to become a serious liability the moment you move to VHF — and on UHF it can be genuinely ugly.
Here's why. RF current doesn't flow through the entire conductor — due to the skin effect, it flows only in a thin layer on the surface. As frequency rises, that skin depth gets shallower, and the effective resistance of the conductor goes up. A larger conductor has more surface area, so the resistance stays lower. That's why .400-class cable is meaningfully better at 440 MHz than .240-class, even if the difference looks modest at 14 MHz.
The table below shows typical attenuation for common size classes at ham frequencies. These are representative values for standard (non-low-loss) cable in each class; modern low-loss cables like LMR-400 and ABR400 do significantly better than classic RG equivalents in the same diameter because of their improved foamed-PE dielectric. Values are typical published industry figures; treat as approximate.
| Size Class | Typical Example | OD | 14 MHz (dB/100ft) | 50 MHz (dB/100ft) | 146 MHz (dB/100ft) | 440 MHz (dB/100ft) | 100W in → at 100ft, 146 MHz | Comment |
|---|---|---|---|---|---|---|---|---|
| .100-class | RG-174 | ~0.100" | ~3.5 | ~6.5 | ~12.0 | ~22.0 | ~6 W | Jumpers and internal wiring only; do not use for feedline |
| .195-class | RG-58 | ~0.195" | ~1.8 | ~3.3 | ~5.8 | ~11.0 | ~26 W | Passable for short HF runs; gets painful fast on VHF/UHF |
| .240-class | RG-8X / LMR-240 | ~0.240" | ~0.8 | ~1.4 | ~2.5 | ~4.5 | ~56 W | Good all-around; popular for portable and vehicle; solid for 2m |
| .400-class (classic) | RG-8 / RG-213 | ~0.405" | ~0.4 | ~0.9 | ~1.8 | ~3.4 | ~66 W | Traditional base-station standard; good at HF, decent through UHF |
| .400-class (low-loss) | LMR-400 / ABR400 | ~0.405" | ~0.2 | ~0.7 | ~1.5 | ~2.7 | ~71 W | Best practical choice for most base-station installs; foamed PE dielectric is the key difference vs. classic .400 |
| All values are typical representative figures for the size class; individual cables vary. "100W in → at 100ft" shows how many watts reach the antenna from a 100-watt radio through a 100-foot run. | ||||||||
Legacy RG-Series Reference
“RG” stands for Radio Grade — a military specification system dating back to World War II. Most hams know these designations even if the original mil-spec documents are long retired. The cables themselves are still widely sold and perfectly usable; just know where each one fits in the performance ladder.
Attenuation values below are typical published figures for standard-quality cables in each designation. Exact numbers vary by manufacturer and construction; treat these as reference ballparks, not precision specs.
| Designation | OD | Impedance | Vel. Factor | ~50 MHz (dB/100ft) | ~146 MHz (dB/100ft) | ~440 MHz (dB/100ft) | Center Conductor | Typical Ham Use | Notes |
|---|---|---|---|---|---|---|---|---|---|
| RG-174 | ~0.100" | 50 Ω | ~66% | ~6.5 | ~12 | ~22 | Solid or 7-strand | Internal patch cords, short jumpers inside equipment | Too lossy for any external run; used inside rigs and for short test leads |
| RG-58 / RG-58A | ~0.195" | 50 Ω | ~66% | ~3.3 | ~5.8 | ~11 | Solid or 7-strand bare copper | Short HF runs, dipole balun tails, HT patch cords | Cheap, lightweight, widely available; fine for short HF jumpers but unacceptable for real VHF/UHF feedline beyond a few feet |
| RG-8X (Mini-8, RG-8/Mini) | ~0.242" | 50 Ω | ~82% | ~2.0 | ~3.6 | ~6.5 | Stranded TC | HF portable, mobile, short VHF runs, older all-in-one installations | A solid middle-ground cable; flexible enough to route easily, significantly lower loss than RG-58, outclassed by modern .240-class low-loss cables but still widely trusted |
| RG-8 / RG-8/U | ~0.405" | 50 Ω | ~66% | ~0.9 | ~1.8 | ~3.4 | Solid bare copper | Traditional base-station HF feedline | The original full-size 50-ohm ham cable; stiff and heavy; replaced in most new installs by modern low-loss .400 cables but still perfectly functional at HF |
| RG-213 / RG-213/U | ~0.405" | 50 Ω | ~66% | ~0.9 | ~1.8 | ~3.4 | Solid bare copper | Base-station HF; mil-spec quality step up from RG-8 | Military-grade version of RG-8 with tighter construction tolerances; arguably the most common base-station cable in the hobby for decades; still a solid choice for HF |
| RG-214 | ~0.425" | 50 Ω | ~66% | ~0.9 | ~1.8 | ~3.5 | Solid silver-plated copper | Commercial, military, and surplus hamfest finds | Double-shielded RG-8 family with silver-plated center; excellent shielding; heavy and expensive new; common as hamfest surplus |
| RG-393 | ~0.390" | 50 Ω | ~69% | ~0.9 | ~1.8 | ~3.4 | Silver-plated stranded | Military surplus, high-flex commercial | MIL-C-17 double-shielded; shows up as hamfest surplus; high shielding effectiveness |
| RG-6 | ~0.275" | 75 Ω | ~82% | Not for ham radio | Solid copper-clad steel | Cable TV, satellite dish, CATV — not amateur radio | 75-ohm cable — causes SWR and mismatch loss in 50-ohm systems; easily confused for ham coax; reject it on sight for RF feedline | ||
| RG-11 | ~0.405" | 75 Ω | ~78% | Not for ham radio | Solid copper-clad steel | Long-run cable TV drops — not amateur radio | 75-ohm cable — looks like .400-class cable and even fits PL-259 adapters; check the label before buying surplus | ||
| All attenuation values are typical published figures for standard-construction cables in each designation. Individual manufacturers vary. Key takeaway: modern low-loss .400-class cables (LMR-400, ABR400, Bury-FLEX) beat classic RG-213/RG-8 by roughly 40–50% at 146 MHz and above because of their foamed polyethylene dielectric — same size, notably less loss. | |||||||||
Why Modern Low-Loss Cables Beat Classic RG at the Same Diameter
RG-8 and RG-213 use solid polyethylene dielectric. Modern low-loss cables like LMR-400, ABR400, and Bury-FLEX use gas-injected foamed polyethylene. Foaming the dielectric introduces tiny air bubbles, which lowers the dielectric constant and reduces the energy lost to dielectric heating — especially at higher frequencies where the signal is cycling the dielectric millions of times per second.
The result: a foamed-PE .400-class cable is roughly 40–50% lower loss than classic RG-213 at 146 MHz, in the same physical footprint. Same connectors, same routing space, noticeably better performance. That's the upgrade that makes the most sense for anyone replacing old RG-213 on a VHF/UHF base station.
Things Members Might Mention on the Net
Coax preferences are personal. Here are some of the reasons hams pick a favorite and stick with it:
Connector Fit & Installation
Some cable is easy to prep and terminate; others fight you every step. A cable you can actually put a clean PL-259 or N connector on correctly is worth something all by itself.
Rotor Loops & Repeated Bending
A cable that cracks, kinks, or work-hardens at the rotor is a ticking clock. Operators with beam antennas care about this more than almost any other spec.
Lower Loss at UHF
Hams who work 70 cm — satellites, weak-signal SSB, linking — feel feedline loss much more than HF operators. A 1 dB improvement at 440 MHz is noticeable and worth paying for.
Direct Burial Suitability
Running cable underground to a remote antenna is clean and durable — but only if the jacket survives. PE jackets hold up far better than PVC in buried applications.
Jacket Quality Outdoors
UV, temperature extremes, and moisture are the enemies of outdoor coax. PE outperforms PVC over the long haul; jacket color can affect solar heat loading as well.
Vehicle & Portable Routing
Getting coax through a door gasket, around a trunk hinge, or coiled in a field bag requires genuine flexibility. The stiffest low-loss cable in the world is worthless if it won't fit the install.
Value for Money
The performance per dollar varies widely. Some operators want the absolute best cable regardless of cost; others want a solid performer that doesn't require financing a new rig to afford a 100-foot run.
Availability & Shipping
Some cable is easy to get at the local ham radio shop or next-day from a distributor; others ship from overseas or require planning. When your antenna goes up this weekend, that matters.
Trust Built Over Time
Some hams have been buying the same brand for twenty years because it's never failed them. That kind of track record matters more than any spec sheet number for a lot of operators.
Manufacturer Resources
Official spec sources used for tonight's topic. Worth bookmarking if you're shopping for cable.
ABR Industries
ABR240-UF and ABR400-UF product overview pages with specs and application notes.
ABR240-UF ABR400 ABR400-UF DatasheetTimes Microwave (LMR)
Official datasheets for LMR-240 and LMR-400 from the originator of the LMR standard.
LMR-240 Datasheet LMR-400 DatasheetMessi & Paoloni
Italian manufacturer with a detailed comparison chart and individual product datasheets.
Comparison Chart Ultraflex 7 Ultraflex 10Davis RF — Bury-FLEX
Direct-burial flexible coax from Davis RF with full specs and pricing on their product page.
Bury-FLEX Page Bury-FLEX DatasheetTimes Microwave LMR Reference Chart
Side-by-side LMR product family comparison chart from Times Microwave.
LMR Reference ChartBottom Line
There's no single right answer here — the best coax is the one that fits your installation, survives your environment, and gets signal from your radio to your antenna with acceptable loss. The specs help, but trust built over years of real-world use often weighs just as heavily as the numbers. Tonight, we want to hear what's working at your station.
Check-In List
| # | Call Sign | Name | City | Member |
|---|---|---|---|---|
| 1 | N8VDZ | Mike | Warren | Member |
| 2 | KE8WUO | John | Warren | Member |
| 3 | WS6O | Michael | Chesterfield | — |
| 4 | W8VOX | Jon | Macomb | Member |
| 5 | 27/N8BZR | Brian | Harrison Township | — |
| 6 | 26/N8CAF | Cliff | Clinton Township | — |
| 7 | 32/KF8FGS | David | Utica | — |
| 8 | 6/N8WCB | Dave | Sterling Heights | — |
| 9 | WC8E | Jeff | Sterling Heights | Member |
| 10 | 43/KE8RUH | Anthony | Grosse Pointe Woods | — |
| 11 | 18/WA4MLD | Ray | Warren | — |
| 12 | 35/AD8MP | David | Saint Clair Shores | — |
| 13 | 38/N8KJV | Jason | Warren | — |
| 14 | K8WA | Bill | Warren | Member |
| 15 | 25/N8KNS | Don | Sterling Heights | — |
| 16 | 12/N8HLY | Tom | Sterling Heights | — |
| 17 | 9/W8VD | Wally | New Baltimore | — |
| 18 | 46/K8ACW | Arthur | Utica | — |
| 19 | 15/N8HAP | Joe | New Baltimore | — |
| 20 | 10/N8WRO | Tim | Richmond | — |
| 21 | 14/KC8KJO | Tom | Memphis | — |
| 22 | KF8ETQ | Darren | Fraser | Member |
| 23 | KF8DRC | Jack | Rochester | — |
| 24 | KE8WOJ | Rickie | West Bloomfield | — |