question about my new coax

[hotrod]

Might help prevent common-mode current from flowing on the outside of the shield; therefore it might help with RFI.

However, with LMR-400, you don't want to coil it in "small loops". First, it's pretty inflexible, what with having a solid center conductor. Easier would be to take either RG-213 or LMR-400xf (extra flexible) and form it into coils no less than 8 inches in diameter. Don't use zip ties; they tend to crush the cable, forcing the shield closer to the center conductor. Use UV-resistant tape.

You can use a "barrel connector" to connect the stiff LMR-400 to the flexible coax. Be sure to weather-seal all the connectors.

if i using lmr-400 can i use lmr240uf or lmr195uf

 

[Captain Kilowatt]

Ive always put large loops in my feedlines (coax) befor it enters the house. Reason being is lightning as we all know has massive force and likes fastest path to ground and doesnt like sharp bends and corners so its always been said that a few coils may help due to the lightning blowing through the coax loop to ground.

Theres no gurantee but I was told this years ago by a antenna tower company so Ive always done this. I also disconnect all feedlines from the house if weather shows storms coming.

Something those loops of cable do is act like transformer windings and couple the energy from a nearby strike into the house. A nearby strike causes a massive electromagnetic wavefront that spreads out. As this wavefront spreads out it couples into conductors and if those conductors are in loops they act as transformer windings and readily couple the energy back into the house.The very small inductance offered by he loops is minute compared to that needed to choke off induced currents.

 

[BOOTY MONSTER]

I can't speak for LMR400, as I run RG8X (which is far more flexible). What I can tell you is that I'm not splattering on either myself or my neighbors (believe me, I've tried, and I've asked). I have an RF Choke directly below my feed-line (5 turns @ 4 1/4 inches diameter) and I've been doing just fine for years on 11 meters.

Here's a picture of my RF Choke. I actually wrapped it around my washing machine's agitator (which just happens to be 4 1/4 inches in diameter, lol -- no, I'm serious).

so what did the better half say when she saw you walking around measuring round stuff and you told her you were trying to find something 4 1/4 inches in diameter ?

nice job BTW