• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • Click here to find out how to win free radios from Retevis!

Maximum Coax Length?

160 feet will be about 1.2 dB loss, not much choice if that is the distance to bridge.
Get a good antenna up, see forum here, and it will work fine.
3dB loss is just noticable, so don't sweat.
Is there lower loss cable out there? yes, but the price and connectors will be a LOT more expensive.
When the antenna is good i dont see chance on interference, good brand/quality coax can last decades.
Yea, connectors are the killer. I run lmr600, cost? No big deal. The 50 ohm 10kw connectors for it? $$$$$ ouch! I almost fell over when i saw the price...
 
  • Like
Reactions: Slowmover
Mustang 131 wrote: "350 foot plus of lmr 600". 3dB. of line loss attenuation results in a 50% reduction in power delivered to the antenna load. 350 "plus" feet of LMR600 results in a 25% reduction in power delivered to the antenna load. These losses will be higher depending upon values of inductive or capacitive reactance, impedance mismatch and any ground return losses present at the load.

https://www.w4rp.com/ref/coax.html
 
Last edited:
If you want to bury the coax I've been very impressed with the Davis RF Bury Flex. It lived underground for years and when I dug it up and washed it off the jacket still looked excellent. I should mention it also worked great :)
 
  • Like
Reactions: secret squirrel
Better grade coax,from point A to point B. But huge long runs will show loss. But thats part of radioing
TEST,IS THIS THING ON? SQUEEEEL CAN YOU HEAR ME NOW SQUEEEEL TEST?
lester roadhog n his cadallac cowboys
 
Grandpap wrote, "I have not decided on an antenna yet, but about the only place I have to set up my tower gives me a run of about 160 feet from my shack...."

assuming a perfect load, (R=50, jX=0) 160 ft. of LMR400 @ 27.385 (channel 38) will have an amount of line loss due to attenuation of 1.030 dB.. with 100 watts input to the line, 78.9W/% will be delivered to the load (antenna) while 21.1W/% will be dissipated in the line.

as to what part of the 78.9W/% will actually be radiated by the antenna depends on the radiation efficiency of the antenna.

any deviation from perfect load conditions above will result in increased power losses.
 
Last edited:
Bringing any feed line thru the attic or any part of a home without a way too disconnect it outside of the home during severe weather is a Bad Idea.I have seen first hand what happens to the coax from a lightning strike & it could very easily result in your home burning down.Lighting should not be taken lightly.Give it the respect that it deserves & don't lose your home or life for a radio.

SIX-SHOOTER
Good Wisdom
 
  • Like
Reactions: W4KVW and Rwb

dxChat
Help Users
  • No one is chatting at the moment.
  • dxBot:
    Greg T has left the room.
  • @ BJ radionut:
    EVAN/Crawdad :love: ...runna pile-up on 6m SSB(y) W4AXW in the air
    +1
  • @ Crawdad:
    One of the few times my tiny station gets heard on 6m!:D
  • @ Galanary:
    anyone out here familiar with the Icom IC-7300 mods