[Elecraft] Diversity receive with ant1 and ant2?

[Don Wilhelm]

Turning the sub off is not going to prevent damage to it.  With your 
configuration, the sub AUX ANT input is connected at all times to the 
non-TX antenna.  Protecting the RX input is the purpose of the COR 
relay, and it will do the job in most cases, although continually having 
the COR activated is not a great idea either.

I am sorry that I did not think that you were using both antennas for 
transmit.  You only indicated that you had the RX antenna connected to 
ANT2, now "the rest of the story" becomes apparent.

You could use a relay in each antenna line that is capable of handling 
the 100 watt TX power.  Connect it so the non-energized path connects 
the two coax leads.

Now, you will have to manually steer the "activate the relay when 
transmitting" to the non-TX antenna.
You could use the NO contacts to connect to two dummy loads just in case 
you forget to operate the manual switch properly - the K3 TX signal will 
always see a decent load.

Sure, there may be automated ways to do that task like 'read the AI data 
that can be made to flow over the RS-232 signal lines', but that would 
take some intelligent processing.  Alternately, you could mod the KAT3 
to bring out the signal that activates ANT2 for transmit - that would 
take some logic too, but it is more straightforward than attempting to 
read the RS-232 data.

I have not done any similar design work, I am simply throwing out ideas 
about how it *could* be done.

It might just be easier to separate the antennas than to do it the 
clever and automated way..

73,
Don W3FPR

On 10/9/2011 5:30 PM, tomb18 wrote:
> Ok that's a good idea but it raises another question!
> What about just having two antennas connected to the K3 as I do, when I
> don't use the sub?  Isn't this exactly the same thing?  Wouldn't this also
> potentially cause a problem too?  Please keep in mind I am not using the rx
> antenna port but rather the sub receiver is connected to the ATU.  Is this
> not a good idea even if it is off?
>
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