[Elecraft] Failing K3 at 3C0L

[Ron D'Eau Claire]

I doubt if anyone expects the receiver to survive if you hook the output of
even a 10 watt transmitter directly to the receiver antenna connector. If
the layout of a multi-transmitter site does not include consideration for
substantial separation between antennas, there will be failures. 

The K3/K3S receivers (sub and main) are protected by carrier-operated relays
that shunt signals to ground in the event they are strong enough to cause
damage. Of course any protective device can be defeated (or destroyed) if
punished too hard. 

Successful multi-transmitter operation begins with a rational antenna layout
considering the power levels involved. IMX, we've always used at least one
wavelength between transmitters running 100 watts or so (250 feet on 80, 120
feet on 40, and so on) and we orient the antennas to minimize coupling. 

73, Ron AC7AC 

 

-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of brian
Sent: Friday, October 27, 2017 10:35 AM
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] Failing K3 at 3C0L

I'm going out on a limb. I've heard that some other DXpeditions had K3
failures in the RX section.  RX dead TX OK.  Apparently, the protection
circuitry was not enough in the close quarter multi-transmitter operations.
It would be nice to know the details or if this or is just rumor.  If this
is so what in the field fixes could be done? 
Alternatively, what additional steps in such contemplated operation could be
taken to further minimize such failures.

73 de Brian/K3KO