Stealth Coax Routing: Getting the Feedline From the Antenna to the Shack Without Anyone Noticing
How to route feedline invisibly for restricted-space ham installs: coax selection, buried yard runs, existing wall penetrations, grounding at entry, and weatherproofing every connector.
The antenna is not the hard part. Running the feedline without creating a visible cable that draws a neighbor's attention or an HOA board's curiosity: that is the part most stealth installs get wrong.
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The cable is what people see. Get the feedline path right and the whole install becomes invisible. Get it wrong and a single curious neighbor undoes months of careful antenna placement.
The coax choice: loss vs. diameter on a short run
Most coax guides are written for hams with a tower and 100 feet of feedline. That is not your situation. A stealth run from a yard vertical or a roofline-mounted wire to a shack window is often 20 to 60 feet. At that length, cable diameter matters more for routing flexibility than for loss.
Thicker coax has lower loss per foot, but on a 40-foot run the difference is a fraction of a dB that will never matter. What does matter is whether you can bend it around a foundation corner without kinking it, or tuck it under a fascia board without a visible bulge.
| Coax type | Loss at 14 MHz (per 100 ft) | Diameter | Burial-rated version | Best use in stealth runs |
|---|---|---|---|---|
| RG-58 | ~2.5 dB | 0.20" | No (avoid for outdoor use) | Skip for outdoor runs entirely |
| RG-8X | ~1.0 dB | 0.24" | Some versions, check jacket | Tight routing, flexible, under 40 ft |
| LMR-240 | ~0.77 dB | 0.24" | LMR-240-UF (underground/outdoor) | Flexible, burial-rated, the right choice for most stealth runs |
| LMR-400 | ~0.44 dB | 0.405" | LMR-400-DB (direct burial) | Long yard runs, 50+ ft, where loss would actually add up |
For most stealth feedline runs, LMR-240-UF from Times Microwave or sourced via DX Engineering is the right answer. It is flexible enough to route along a foundation, UV-rated for exterior exposure, and burial-rated for yard runs. The "-UF" suffix means the jacket is rated for direct burial without conduit. That rating matters because of the mechanism that kills buried coax, which I will explain below.
If you are running a longer yard span (say, 80 feet from a remote vertical back to the shack), step up to LMR-400-DB (direct burial). At that distance the loss difference starts to be audible on the bands. DX Engineering sells it cut to length, which means you can have a single clean run with factory connectors on both ends and no field-crimped joints buried in the ground.
Making the exterior run invisible
The key principle is to route the coax along lines that already exist on your house. Every exterior run should shadow something structural.
Along downspouts. Coax cabled to the back face of a downspout, held with staples painted to match, disappears at ten feet. Nobody looks at a downspout. Put the cable on the back face (the face against the house) and it reads as nothing from the yard.
Along the fascia and soffit. The horizontal joint where the roof meets the wall is full of shadow. A coax run tucked into that corner, stapled to the fascia, reads as trim from ground level.
Paint-matching. Black coax against white trim is visible. LMR-240-UF will take Rust-Oleum exterior primer and a matching color. Do a test section first.
Along the foundation. A run flush against the foundation below the siding is below eye level and behind the sight line of anyone walking by. This works for the last few feet before the cable enters the ground.
Direct-burial across a yard. For a remote vertical or a stealth wire anchored to a fence post, bury the run rather than routing it across the surface. The mechanism that matters: what kills buried coax is not the soil. It is UV degradation and water ingress. A standard PVC jacket cracks after a season or two of freeze-thaw cycles. Water wicks through any micro-crack and travels down the coax by capillary action, leaving oxidized braid a foot from the original entry point. That is why burial rating is a jacket specification, not a marketing claim.
Bury the cable 6 to 12 inches: shallow enough to lay with a flat spade, deep enough to survive normal yard work. Conduit is optional; LMR-240-UF and LMR-400-DB are both rated for direct soil contact. Sweep the cable around the edge of the yard so it is never in the path of anyone digging.
Getting through the wall: work with what is there
Almost every house already has exterior penetrations from cable TV, a removed satellite dish, a dryer vent, or a gas line. You do not need to drill a new hole.
The cable TV entry plate (the round white or gray cover on the exterior wall) is designed to open. Remove it, fish your LMR-240 through the existing hole, seal around the cable with weatherproof caulk, and replace the plate. The entry looks exactly as it did before.
For owners who can drill, a bulkhead entry panel is the cleaner permanent install. It is a small plate carrying one or more SO-239 or N-type connectors that mounts to the exterior wall: outdoor run on one side, shack run on the other. DX Engineering and ABR Industries both sell them with mounting hardware and weather boot seals. The connectors stay accessible and the plate seals cleanly against the wall.
The window-crossing approach (flat jumpers and feedthrough panels) is covered in detail in the renters ham radio setup article. The window approach is the right choice for an apartment or any situation where drilling is off the table entirely.
The entry must be grounded
This is not optional. A coax run from an outdoor antenna into your shack is a direct conductive path from whatever lightning or static the antenna collects straight to your radio. The fix is a lightning arrestor at the point of exterior entry, bonded to a ground rod.
The mechanism is simple: the arrestor gives surge energy a path to ground before it reaches the shack. Without an arrestor, a nearby strike sends the surge down the coax to the first piece of equipment it reaches. With a properly bonded arrestor at the entry point, the surge current sees a lower-impedance path to ground and takes it instead of continuing into the shack.
The two products I would use here are the Alpha Delta ATT series lightning arrestors from Alpha Delta Communications and the PolyPhaser IS-B50LN-C2 available through DX Engineering. Both mount in-line in the coax run at the wall entry. Both require a low-impedance bond to a ground rod: a short run of #6 copper wire from the arrestor body to a ground rod driven near the entry point. Keep it short. Every foot of wire between the arrestor and the ground rod adds inductance, and inductance limits how fast the surge can drain. Keep the bond wire as straight and short as the installation allows.
The ground rod is a standard 8-foot copper-clad steel rod. Bond it to your existing electrical ground if the run is practical. The NEC requires it, and it is also good engineering. Separate grounds can create a potential difference that makes lightning damage worse, not better.
Common-mode choke at the feed point
Put a common-mode choke at the antenna feed point. Not at the shack end, not in the middle of the run: at the antenna itself. This prevents common-mode current from riding back down the coax shield and into the shack. A clamp-on mix-31 ferrite at the feed point is the quick field solution. A purpose-built 1:1 current choke from Balun Designs is the cleaner installation.
The grounding and counterpoise details (why common-mode matters for RF safety, how to size radials for a vertical, what the coax shield does in an unbalanced system) are covered in the RF grounding and counterpoise guide. I am not going to re-derive that here.
Weatherproofing every outdoor connector
Every outdoor connector will eventually leak water. The mechanism: water wicks in through the connector body and travels down the space between the braid and the center conductor by capillary action. You will not see it happen. You will notice SWR creeping up over a year, and when you finally cut the connector off you will find green oxidized braid for six inches back.
Two-layer weatherproofing on every outdoor connector. First, self-amalgamating (self-fusing) tape: the rubber tape that bonds to itself and creates a waterproof seal. Start below the connector, overlap onto the cable jacket, work up over the connector body, overlap back down. Then a layer of standard electrical tape over that to protect against mechanical abrasion. Coax-Seal is a putty-type alternative from Ideal Industries that molds around odd-shaped connectors; it is a commodity item carried at most electrical and ham suppliers.
Do this at every connector: the antenna end, the lightning arrestor, the wall entry, any barrel connector in a junction box. Every unsealed connector is a potential water entry point.
What I would run
Typical suburban lot, stealth vertical in the back corner, shack on the first floor:
Coax: LMR-240-UF from DX Engineering, cut to exact length with factory PL-259 connectors. No field-crimped joints buried in the ground.
Route: 6 inches below grade across the back yard, up the foundation line, along the back face of the downspout (stapled every 18 inches), along the soffit at the rear wall, and through the old cable TV entry.
Entry: Bulkhead panel from DX Engineering, Alpha Delta ATT lightning arrestor inline on the exterior side, bonded to a ground rod with 18 inches of straight #6 wire.
Weatherproofing: Self-amalgamating tape plus electrical tape over every outdoor connector. Fresh wraps every three years or when SWR starts drifting.
Common-mode choke: 1:1 current choke from Balun Designs at the antenna feed point. One mix-31 clamp-on ferrite where the coax enters the shack.
If you are crossing a window rather than a wall (apartment, rental, no drilling), read the renter setup guide for the flat jumper and feedthrough panel detail. The grounding and weatherproofing logic above still applies to everything on the outdoor side of whatever crossing you use.
The feedline path is boring engineering. It is also what separates a working stealth install from one that gets noticed, leaks RF into the shack, or corrodes into failure after one wet winter. Get the cable rated right, route it along existing lines, ground it at the wall, seal every connector, and the antenna you spent the weekend hiding will actually stay hidden.