The AM Forum

Has anyone tried running 600 ohm ladder line thru a metal building wall?  If so, how did you do it?  My shack is in a metal sided building and I would like very much to be able to run 600 ohm line all the way to a tuner within the shack.  Any comments? ???

    get a set of nice old-timey ceramic feed through insulators and just do it. failing that drill 1/2" holes in the metal wall, put grommets in the holes, run the wire through and fill the holes with silicone caulk. radio men have run balanced open wire and single wire unbalanced lines through steel bulkheads into shipboard radio shacks for about a hundred years. if you can't do that just run it through the nearest window. be sure to close the window on it nice and tight so you don't get a draft. I have open wire line going through an aluminum storm window at one of my HF stations. I use insulated wire for the feeders and it works just fine at legal limit with the storm window closed on it. I am using ladder line at two other locations with a similar entry method. above legal limit power, or in very high reactance situations it may arc over, but since the storm window is metal only the insulation on the feedline burns if it arcs over. of course this problem only occurs at high power. at DX-100 power you will never have a problem.

    just DO IT. this has never been an issue for me in over 30 years on AM. if i read one more post here, or in QST, CQ, QTH, QRZ,QRM etc. about being afraid to run open wire all the way into the shack my friggin' head is gonna explode!

 {get a set of nice old-timey ceramic feed through insulators} this is what I did also, I did angle them slightly down toward the outside, so the rain water did not come right in. Yes they are sealed also.

mike

Or for each feeder use a set of Dolly Parton insulators.

I would think actually that going through metal would be less likely to have losses at rf than would wood when it gets wet, or some type of  composition material, which might have poor dielectric characteristics, although I wouldn't think the loss would be significant even then.

or as said in other threads listed before by Derb and others ... use a pair of short LARGE coax lines .....beefus

Easy and no holes! Make a a 1 foot U cut in the metal wall and fill it with RTV. Now use the wall as a Faraday shield, coupling through with a balanced grounded center tap link arrangement. ;D