After two
weeks of having my PLL oscillator problems I finally cracked it and thankfully
the “Alignment test part 2” is now completed. I have to give a huge thanks to
Don Wilhelm from the K2 forum, without his help I would still be tearing out what
little hair I have!
As usual with these things it was something small, a resistor or to be precise
a resistor network that wasn’t playing ball. After replacing various components
we narrowed it down to this resistor pak and in the end I replaced the pak for
two separate 10k resistors as suggested by Don and it worked.
From removing and
replacing the pak a number of times I managed to damage one of the patches off
the PCB but thankfully it wasn’t required so I was extremely lucky.
The PLL oscillating area is the top right of the PCB, you can see in the picture below where I've replaced the resistor pak with two 10k single resistors, that finally did the trick and got it running. You can see the 6th patch is damaged but luckily is now not used.
I must
admit I was beginning to lose hope and my confidence was getting low, I really thought I wasn’t going to get the old K2 working. It’s an amazing feeling
when it all comes together and you realise you are not a solder wavering madman who mucked everything
up.
The good news is I have had a listen to 40 meters CW and the
radio sounds great, the filters are really good and first impressions are that
it needs a slight tweak here and there but all in all it’s a very good
receiver.
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