Eduardo Araujo via Topband <topband@contesting.com> wrote:
> My two cents......It was interesting during the installation of
> the last beverage, we have only #31 core, so we placed it at the
> receiver side. Disconnecting the coax at the bev feed point and
> shorting the coax there, many AM broadcast stations could be
> heard and some of them strong, indicating that even though one
> choke was at the receiver side the coax was acting like an
> antenna. The coax was just lying on the ground and is 40/50 mts
> long.
> When we got more cores and placed one choke at that place close
> to the short, repeating the test before and after most broadcast
> vanished and only one could be heard very week.
This is exactly as expected.
In the first case you fed all the RF received by the outer surface of the coax
directly inside the coax, and directly to your RX input.
In the second case, a significant isolating impedance was added
and the said RF was attenuated.
73,
Sinisa YT1NT, VE3EA
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
|