Remote Tuners: Stop Putting Them Where You Don’t Need Them
Let’s clear this up once and for all.
Remote tuners are not magic boxes that "solve" every antenna problem. In fact, in most situations, they’re unnecessary — and sometimes even counterproductive. At RF.Guru, we only recommend a remote tuner in one very specific situation: a center-fed doublet using open-wire line (600 ohm).
Here’s why — and when an indoor external tuner is actually the smarter move.
When a Remote Tuner Does Make Sense: The Classic Doublet
A doublet with a balanced feedline (like open-wire line) is an incredibly versatile antenna if you want coverage from 80m through 10m. But there’s a catch:
Its impedance varies wildly depending on band, length, and height. You can see anything from 10 to 2000 ohms.
Trying to run this into a tuner inside the shack over a long run of coax? Bad idea.
Mismatch + coax loss = heat instead of signal.
Solution: Add an antenna tuner between the open-wire line and our coax. This keeps the tuner from being hit by common-mode currents and makes its job much easier. Once you transition to coax, the coax length to the shack doesn’t matter anymore.
When a Remote Tuner Is Overkill
Got an end-fed half-wave, off-center fed dipole, vertical, multiband vertical, or even a long wire with an unun?
You do not need a remote tuner — if your SWR is under 5:1 and you’re using decent coax.
Why? Because the losses from mismatch at these levels are often dramatically overstated.
Let’s look at real-world numbers:
Real Numbers: Coax Loss vs. SWR
Let’s say you're on 20 meters (14 MHz) and using one of our ExtraFlex Bury coax cables:
| Coax Type | Diameter | Loss @ 14 MHz | Loss with SWR 5:1 (approx.) |
|---|---|---|---|
| ExtraFlex Bury 7 | 7 mm | 2.2 dB/100m | ~3.2 dB/100m |
| ExtraFlex Bury 10 | 10 mm | 1.5 dB/100m | ~2.4 dB/100m |
| ExtraFlex Bury 13 | 13 mm | 1.1 dB/100m | ~1.9 dB/100m |
Let’s assume a 20-meter coax run (typical for many setups). Even with SWR = 5:1, you're looking at:
- ExtraFlex Bury 7: ~0.64 dB total loss
- ExtraFlex Bury 10: ~0.48 dB total loss
- ExtraFlex Bury 13: ~0.38 dB total loss
That’s nothing. Less than 1 dB means less than 20% power lost, and that’s at a high mismatch on 20 meters. On 80 or 40 meters, the loss is even lower.
So unless you’re running 100 meters of coax made of spaghetti (RG58), you’re fine.
- Below 2:1: Your rig’s internal tuner probably handles it. Done.
- 2:1–3:1: Most radios start to strain. Use a decent indoor external tuner.
- 3:1–5:1: Use a wide-range external tuner. Keep your coax decent and short-ish. Still no need to go outside.
- Above 5:1: Now it depends — if you're feeding something like a doublet, this is where a remote tuner makes sense. For all other antennas, there's probably a solution to bring it down to a reasonable SWR so you can manage it. Moving to an external tuner will not solve your issue or give you better performance.
The Bottom Line
Don’t fall for the trap of remote tuners being a universal solution. They're only worth the hassle (weatherproofing, powering, control wiring, etc.) when:
- The antenna has wild impedance swings
- You’re using balanced line, not coax
- You can’t avoid a high SWR at the feedpoint
In all other cases — especially if your SWR stays under 5:1, and your coax isn’t junk
A well-placed indoor tuner is simpler, cleaner, and just as effective.
RF.Guru Recommends
Unless you're running a doublet with open line, spend your money on better coax, not remote tuners.
We stock:
- ExtraFlex Bury 7 (7mm): Great compromise between price and performance
- ExtraFlex Bury 10 (10mm): Excellent for longer runs
- ExtraFlex Bury 13 (13mm): For serious power and low-loss setups
All three are high rated — waterproof, rugged, and built to last.
And yes — we’ll help you figure out if you actually need a tuner outside, or if someone just told you so on Facebook.
Written by Joeri Van Dooren, ON6URE – RF, electronics and software engineer, complex platform and antenna designer. Founder of RF.Guru. An expert in active and passive antennas, high-power RF transformers, and custom RF solutions, he has also engineered telecom and broadcast hardware, including set-top boxes, transcoders, and E1/T1 switchboards. His expertise spans high-power RF, embedded systems, digital signal processing, and complex software platforms, driving innovation in both amateur and professional communications industries.