http://elecraft.85.s1.nabble.com/K2-VCO-Alignment-T5-L30-tp7648249p7648422.html
> Don Et Al,
> So, It is with some embarrassment, and much relief, that I can report it
> was operator error and my BFO is now working perfectly.
> I got home from work and was getting ready to do some continuity checks to
> all the circuits surrounding and including U11, but decided I better check
> all the components again in that section with the RF board disconnected and
> out of the case.
> I found much to my chagrin I had not installed D37 and D38! I had them
> checked off in the manual as being installed, and I even wrote in pencil in
> the margin on the next step where you put the rest of the V149's in the RF
> board that I had 2 left over, but I failed to notice I had them left over
> because I did not put them in the step before!, good grief.
> Anyway I have a high BFO reading of 4917.60 and a low reading of 4911.98
> with a difference of 5.62.
> Thank you Don and to others that gave suggestions, and I do wish those
> having similar problems well in their trouble shooting.
>
> Upward and onward 73,
> Tom Bewick, K2BEW
>
>
> On Sun, Jan 20, 2019 at 8:22 AM Don Wilhelm <
[hidden email]> wrote:
>
>> Tom,
>>
>> Good work on the VFO.
>> Before you replace U11, measure the resistance from the wire on the
>> carrier board to the lead of the SMD IC. Do that for all pins. The PC
>> traces on the carrier board are not thru-plated holes and sometimes
>> become damaged with soldering.
>>
>> 73,
>> Don W3FPR
>>
>> On 1/19/2019 6:35 PM, K2bew wrote:
>>> Don et al,
>>>
>>> I tried a 15pf cap ( what I had on hand) at the source of Q19 to
>>> ground and I got .025v on R30 that did not change with the adjustment
>>> of L30, essentially no voltage.
>>> So, I took it off and it went back to 4.5 volts. So, then I tried
>>> Vicenç, EA3ADV's suggestion and I put 17 turns on the red wire of T5.
>>> That got me a voltage of 8.5V on R30 with L30 bottomed out that I
>>> was able to easily back off to a stable 6 volts.
>>> I went ahead and did the voltage tests on the other bands and had a
>>> nice range of 1.844 to 6 volts as my low and high on the VCO.
>>> So, that's all set.
>>>
>>> However, new problem. I went on to the test the BFO and I have 0000.04
>>> kHz. on TP2, so it's not working.
>>> I went to the trouble shooting guide and I have 0.058 Vrms on pin 6 of
>>> U11 with the RF probe.
>>> Looking at the archives of the reflector that would indicate that U11
>>> is bad and I need a replacement, correct? or are there other things I
>>> should look at first?
>>> The good thing is I'm becoming very accustomed to the radio and
>>> enjoying the trouble shooting.
>>> Thanks for all the help, I really appreciate it.
>>>
>>> 73,
>>> Tom Bewick, K2BEW
>>>
>>