[Elecraft] K3 Transverter drive problem

[Alexandr Kobranov]

Hi Mike,

your problem is in SSB or also in CW mode or in both?

There are no visible spikes on DB6NT 144MHz transverter/25W out.
Firmware 2.10 now implemented.

73!
Lexa, ok1dst

AD6XY - Mike napsal(a):
> Thanks for the Email suggestions. 
> 
> Setting tune power back to normal did not fix it. It fixed it for one cycle.
> I also had my K3 lockup in the config menu. I suspect some problem with the
> new beta firmware to be the cause, possibly corrupted memory or something
> like that. I have gone back to the old firmware and the system is working.
> The overshoots are still there as you adjust the power control but they are
> much smaller.
> 
> Mike
> 
> 
> 
> AD6XY - Mike wrote:
>> I have come across a problem with my K3 driving an XV50 converted to
>> 70MHz. 
>>
>> The K3 low level output from the KXV3 produces high power spikes before
>> settling to the correct level - which it then holds until you change mode,
>> or power setting. It also produces spikes at full power ( a few mW) as you
>> turn the power knob. When I originally tested the transverter interface, I
>> used an analogue power meter, so I would not see these spikes. I can see
>> them clearly on my oscilloscope for a few fractions of a second before the
>> ALC acts.
>>
>> The effect is of course for the transverter to over drive and then settle
>> back. Obviously I am doing something wrong here but I am not sure what it
>> is. The K2 does not do this but it is making transverter operation
>> impossible with my K3 until I can find out how to fix it.
>>
>> The curious thing is the way the spikes appear as you adjust power. It is
>> like the CPU is forgetting the ALC setting, reading the op-amp output,
>> thinking for a bit and then setting the correct gain. I must have some
>> setting set incorrectly.
>>
>> Mike
>>
>> PS
>>
>> The K3 also suffers from the same transverter failure mode as the K2 - if
>> you power off the radio in a transverter band, the transverter stays on in
>> transmit mode because of the way the PTT works and because the K3 does not
>> send an "off" command on the auxbus before shutting down. The result is a
>> very hot transverter power amplifier module the next morning. Perhaps we
>> could fix this using one of the digital outputs?
>>
>>
>>
>