Started by gil, March 15, 2014, 10:40:13 PM

Previous topic - Next topic


How long of a cable can i run before any signal drop occurs?  I'm considering using the same setup you had....  depending on cost.  My mast/antenna would be about 80 feet away.  also, would mounting a scanner antenna around the ham antenna cause any interference?


Coax Cable Loss Chart

The 2nd chart shows dB of loss in 100' of cable.  As you can see, loss gets pretty bad at the higher frequencies.  For HF frequencies you can get away with RG58, but at 146MHz the loss is 6dB (4X reduction in power).  Then again, don't forget that 6dB is only 1 S-unit, so with 6dB of loss you only go from S9 to S8.

At VHF frequencies most people use RG8 or LMR400 for long runs.  Some use RG8X.  With it your losses will be 4dB (2.5X reduction).  That sounds like a lot but is about 1/2 an S-unit.