Coax attenuation due moisture

[radioman]

coaxial cable moisture attenuation

Has someone experience with coaxial cable (RG213) whose attenuation becomes less with more moisture due to rain. The cable stays 50 Ohms, so the impedance doesn't change.

Radioman

 

[sick_man]

rg-213 moisture

it is crap cheep nasty coax

use heliax and some plated connectors dress with self amalgamate tape

it is more likly the antenna has changed impedance or is affected by the moisture

some get better some get worse
becouse the Q changes with moisture level
quotiant of gain relative to humidity
much like tuning a guitar string
then moving the guitar to a damp room

it sounds off tune
but is this the room the moisture ??? or both

so when you move it back
its tuned again


but tune the guitar in the moist room and move it back
?? and
maybe better resonance is achived as your on the moisture side is better side ... tuning range


rg213 is ment for inside the building
it is sensative to uv and moisture as you have found out

heliax isnt ...


impedance is realy only a measure of resistance
and not at any given point in general

so at a "hot " spot
much like a guitar string with a knot in it
you can encourage harmonic content etc and funny parasitics
try it.//./

initinatiously this is quite a good way to get gain from the feeder

attached is a device to self tune a guitar i designed just now

you can build into it a micro for self retune etc
even retune on the fly

amazing how much it looks like the simantics of an atu
and wonderfull handy devices they are too

 

[sick_man]

ps japan men in music industry
people are sick of tuning there guitar

look to the bmp
and build simple project
on pic 84f few mechano and gear a set of min servo
send finished one to my cloud


thanks