[Elecraft] K3 ANT1 / ANT2 switching

[Keith Trinity WE6R]

Hi Tim;
We have seen the KAT3 circuit board touch the threads on the AUX BNC and 
short which burns some traces.
Check for that, you can put a washer on the mounting stud to lean it away.
Also there are some fine traces along the perimeter of the board that 
are delicate and can easily get cut by rough handling.
Keith WE6R K3/K4 Tech

Hi there Tim,
I have the same problem, I did some thinks at the back site changing the 
2 meter antenna, I think I touch the 12 volt power supple and then the 
K3 went to the same as you describe. When I press the ANT button with 
the AUTO ATU in Bypass, there's a click, and the annunciation changes 
from ANT1 to ANT2, but I can still hear signals just as loud, even 
though there a dummy load on ANT2. Also If I transmit, it doesn't matter 
whether I have ANT1 or ANT2 selected, RF always comes out of ANT1 
socket. If I have the ATU activated, the symptoms are exactly the same.  
What was your solution ??  I think it's in the software, but where as 
far as I know it only went of.. and I turned it on again which I doe 
every day.
Regards William
========================
PE1BSB @ zendamateur.nu
Stommeerkade 65
1431EL  Aalsmeer
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-----Original Message-----
From: elecraft-bounces at mailman.qth.net <elecraft-bounces at 
mailman.qth.net> On Behalf Of Tim Raven via Elecraft
Sent: Saturday, 10 July 2021 13:37
To: elecraft at mailman.qth.net
Subject: [Elecraft] K3 ANT1 / ANT2 switching
Hi,
I have acquired a second-hand K3/100 with the Auto ATU and 2nd receiver, 
which I have been checking out, calibrating and installing extra filters.
Everything has worked exactly as expected, until I tried to use an 
antenna connected to ANT2 socket.
I have a fan dipole connected to ANT1, and a 50 Ohm dummy load to ANT2. 
When I press the ANT button with the AUTO ATU in Bypass, there's a 
click, and the annunciation changes from ANT1 to ANT2, but I can still 
hear signals just as loud, even though there a dummy load on ANT2. Also 
If I transmit, it doesn't matter whether I have ANT1 or ANT2 selected, 
RF always comes out of ANT1 socket. If I have the ATU activated, the 
symptoms are exactly the same,
except when I switch from ANT1 to ANT2 there's no click.
The Auto ATU works fine, and I have the KRX3 "ANT=bnc" set.
I can also hear stations on the 2nd receiver through the  ANT1 socket or 
via AUX antenna socket.
The firmware has been updated to the latest versions for MCU, FPF, and 
both DSP units.
Any help would be most welcome.
73 de Tim G4ARI