Bob,
I assume you also have 8R active at the same time - that is the usual
case. I have encountered it a few times in the process of repairing
over 1000 K2s.
The problem source is usually on the Control Board. Check the voltage
on the gate of Q3 - it should be zero during receive.
Also check the gate of Q4.
If both gates are at about 5 volts, then you have a problem with the MCU
and it should be replaced. You could try a Master Reset, but it is
unlikely to correct the problem.
OTOH, if only one gate Q3 or Q4 is at 5 volts, then look for something
that is putting the K2 into transmit.
Should you find the gate of Q3 at zero volts, and you still have 8T
active all the time, either Q3 is not conducting when it should or there
is a problem with Q1 and the RP1 resistors.
73,
Don W3FPR
On 7/11/2020 12:57 PM, Robert Calver via Elecraft wrote:
> Hi Guys
>
> Anyone had a this fault? The radio was working fine until a day or so ago, now can hear noise, AF and RF gain pots work, but nothing from the antenna.
> If you inject signal at the anode of D6 RF board you can hear it, not on the cathode though - its being back biased by the permanent 8T volts?
>
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