Hi Dave,
Years ago when we were doing a fair amount of contesting at my Dad's
place, W6KUT, we had some front end overload problems with our TS930's.
The station had fairly good sized monobanders and a KT34 (60' away). The
tribander, being resonant on any of the three bands picked up enough
energy to knock out the PIN diodes that switch the 930's bandpass
filters.
We were using receive bandpass filters, and 2 pole stubs on the
transmitters.
We managed to knockout both of our transcievers. We got upgraded PIN
diodes from Kenwood, and it happened again.
Finally, Kenwood came up with a tech bulletin, that installed a zener
diode across the RF input to ground, ahead of the bandpass filters. The
mod was said to make the front end capable of taking 50W. We made this
mod and the radios have been bombproof ever since. Still got'em both. I
once got to try the 50W test, getting ready for a M/M. No problem.
73, Kurt, K7NV
"Curtis, David B" wrote:
>
> Both the Force 12 catalog and recent posts suggest that the multiple
> feedline multi-band antennas can be used simultaneously by different
> operating positions as long as appropriate filters are in place. Clarifying
> example: a 10/15 dual band antenna with two feedlines, being used
> simultaneously by different M/M ops, both running the legal limit.
>
> Have you tried this? And did it toast any receivers? Or is overload a
> problem?
>
> Seems kind of marginal to me. 1500W - 40db = .15W
> 150 mW directly into the antenna terminals seems a lot. I'd be interested in
> hearing how this as worked out for anyone who has tried it.
>
> 73, Dave N6NZ
>
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