Topband: Coupling between bev and other antennas

[Joe Reisert]

Hi Earl et al,

There maybe some hidden coupling between Beverage and transmit antennas.

While the coupling from a nearby TX antenna to a Beverage antenna on RX may 
not seriously degrade receiving performance, watch out for coupling between 
the Beverage and TX antenna while transmitting. I blew the front end right 
out of a brand new IC-775DSP with only 300 Watts to a nearby dipole (100 
feet away). It also caused the IC-775DSP final power transistors to blow! 
Needless to say, ICOM was not happy to fix it.

We know that the answer is to decouple or short the input to the RX during 
RX by a switch (such as the ones from KD9SV?), but I had not yet installed 
mine at the time. It seems that the input protection diodes on some HF 
transceivers use very low power fragile diodes!

73,

Joe, W1JR

At 08:57 PM 9/8/2002 -0700, k6se@juno.com wrote:
>When I had about five Beverages, they all came to within 20 to 50 feet of
>my 160m towers.  All of them had good F/B and F/S ratios, so there wasn't
>any apparent coupling to the towers and resultant degradation of the
>performance of the Beverages.
>
>73, de Earl, K6SE
>_______________________________________________
>Topband mailing list
>Topband@contesting.com
>http://lists.contesting.com/mailman/listinfo/topband