[ICOM] Pro II vs. Pro III RX-ANT input circuit (was "Smoked ProII")

[Augie (Gus) Hansen]

On 2/6/06 8:08 PM, "Larry Benko" <w0qe at bnk.com> wrote:

> While the Pro3 protection circuitry did the job in a single transmitter
> environment it unfortunately won't help if another radio in your shack
> is the transmitting and going to damage the Pro3.  Even an external
> relay won't help in the case of a second transmitter.  In that case you
> need some external circuit that is not based on the Pro3 transmitting
> for protection.  Heck in the case of a second transmitter being the
> problem both the standard antenna and the RX antenna inputs are
> susceptable.  Of course this is why contesters use single band filters
> external to radios and 1/2 and 1/4 wave coax stubs.  What I wish Icom
> would do is to publish a maximum spec that will not cause damage such as
> +30 or +35dBm.

Hey Larry,

Great to hear from you.

Of course, my comments relate to my small city lot QTH. However, having
worked in a few multi-multi contest situations, I fully appreciate your
concerns. I haven't dealt with an SO2R setup yet, but expect to have to slay
some dragons when I do.

Anyone dealing with a multi-transmitter configuration would do well to read
W2VJN's book, "Managing Interstation Interference", which is available from
George's company, INRAD (www.qth.com/inrad).

Cheers,
Gus, KB0YH