I have a problem? A friend of mine gave me about 50 feet of some "LOW LOSS" antenna cable that he said would improve my signal to my scanner! However after climbing on my roof and replacing my previous installed RG-8 cable with the above mentioned cable, I know have terrible signal to my scanner.Only receive local police on high band and some local UHF stations! Previously I was receiving good reception but thought I could improve it, I guess I outsmarted myself. Any suggestions?
outsmarted myself?
- Thread starter joec157
- Start date
- Status
K8PBX
Member
What kind of coax did your friend give you? Reply with what it says on the cable.
It has no number on it but he used some numbers that began with a 9, like 972 or something like that. It has a large center conducter. Could that be the problem?
n5usr
Member
If it has no markings on it, that may be your first clue... ;-) Most of the unmarked cable I've seen is pretty low-grade.
He didn't say it was 9913, did he? This would be same size as RG-8, with a solid-core center conductor.
A thick center conductor would be fine, low wire resistance, but you may still have lossy coax based on other factors. How thick is the coax overall? Same size as the RG-8, or smaller, or...? What kind of dielectric (the portion between the center conductor and the shield)? The most common ones are a spiral-wrapped "plastic" type (the 9913 would have that), a solid "plastic", or a foam "spongy" material. How good is the shield? The best are 100% shielding, perhaps a foil wrapped around the dielectric with the braid over that. Cheaper coax often has just the braid, and you can often see the dielectric through it (<100% shield, some as low as 50%!) which means you'll get more interference and leakage along the coax.
And were you using 50 feet of RG-8? (Or did you add a bunch of coax length?)
Assuming everything else is fine, the first thing I would check is the condition of the connectors on the coax. It's possible you have a bad one, perhaps a strand of shield braid touching the center pin, or a bad solder joint. You can check for the obvious with an ohmmeter, check for continuity between center-center and shell-shell on each end, then check you don't have continuity center-to-shell.
It is also possible there's a "bad spot" (or several) in the coax that is inducing a lot of loss. You would need something that can check the loss in the coax to find that, such as an antenna analyzer. (Mine will do this, anyway.)
He didn't say it was 9913, did he? This would be same size as RG-8, with a solid-core center conductor.
A thick center conductor would be fine, low wire resistance, but you may still have lossy coax based on other factors. How thick is the coax overall? Same size as the RG-8, or smaller, or...? What kind of dielectric (the portion between the center conductor and the shield)? The most common ones are a spiral-wrapped "plastic" type (the 9913 would have that), a solid "plastic", or a foam "spongy" material. How good is the shield? The best are 100% shielding, perhaps a foil wrapped around the dielectric with the braid over that. Cheaper coax often has just the braid, and you can often see the dielectric through it (<100% shield, some as low as 50%!) which means you'll get more interference and leakage along the coax.
And were you using 50 feet of RG-8? (Or did you add a bunch of coax length?)
Assuming everything else is fine, the first thing I would check is the condition of the connectors on the coax. It's possible you have a bad one, perhaps a strand of shield braid touching the center pin, or a bad solder joint. You can check for the obvious with an ohmmeter, check for continuity between center-center and shell-shell on each end, then check you don't have continuity center-to-shell.
It is also possible there's a "bad spot" (or several) in the coax that is inducing a lot of loss. You would need something that can check the loss in the coax to find that, such as an antenna analyzer. (Mine will do this, anyway.)
K8PBX
Member
It's odd that there isn't any marking on the cable. Hard to help without knowing what kind of cable you have.
- Status
