Topband: High performance RX antenna at T6LG

[N4IS]

Hi Arunas

>>>
I just wondering what is the reason to separate each of CAT5 pairs?
<<<

The main problem in high noise environment is common mode noise,  The unused
wires does not help to eliminate common mode noise. Actually the unused
pairs will deteriorate common mode isolation, The gain on the flag could be
-35db and a high gain preamp is necessary.

There is another reason, the unused pair can become an antenna too, and
interact with the vertical part of the flag. 

Check also the cross talk on CAT 6 or CAT 5 it is not that great. The 100
ohms impedance is excellent, and one single pair is very light., does not
load the flag, in special horizontal flags or square loops.

I had no success trying to use one cat 5 with a low gain antenna in one end
and a high gain preamp on the other end,  However I think it is possible to
use all pairs if the preamp is located near the flag, driving current into
the cable, and the common mode noise killed by chokes at both ends.

I do not recommend using the cable without stripping the pair you want to
use under high noise environments.

Regards
JC
N4IS