How much signal loss in 90 feet of coax? I'm in the planning stages of my station and antenna setup. I'm trying to figure out the shortest way to run my coax. I'm not through thrilled of anything longer than 75 feet because I was told the longer the run the more signal lost.
It is true that the longer the run of coax, the greater the loss. But that's only common sense. Its very easy to estimate coax loss. Just do a Google search on "coaxial cable loss comparison".
Coax, like the old standard RG-8, is pretty good and only has about 2db of loss per 100 feet at 100 MHz. But many users like the flexibility of RG-8x. But RG-8x will almost double your loss, for the same length. Its very nice for 1 and 2 foot interconnects, but not for long runs. Of course, the better the coax, the higher the cost.
If you want some good low loss cable, take a look at RG-6. Or better yet, RG-11. You can usually get RG-6 for free from your local cable or satellite installer. Both of those cables are 75 Ohm cables and may cause a little rise in SWR, but the loss due to SWR will be small and the overall loss will be lower. Adapters are available to go between the F-Type connectors and standard PL-259 style.
The drawback to low loss cable is that, it may show you antenna is not as good as you thought it was. If there is a bad mismatch at the antenna, high loss cable can hide the bad mismatch and show you a low SWR at the transmitter end. But with low loss cable, the bad mismatch is no longer hidden by cable losses. Many users mistakenly blame the cable.
Martin - K7MEM