K2 PLL

[Rolf-Dieter Schmidt]

Hi all,

I am Rolf, DK8SJ, a new member of this list. 3 weeks ago I got my K2 SN
5218.
Now I am in the stage "Alignment and Test, Part II".
All tests are within the range and I receive strong and stable signals
on 40m.

But I have a problem:

Tuning on the main-knob I have a continuous frequency readout on the
display, but the actual frequency makes alternating steps of  abt 0.200
kHz and 3.8 kHz. The VCO-Voltage shows according steps.
During "VFO Linearization" nothing happens until the end of the test
after 8 minutes the frequency drops down abt 15 kHz and "END" is
displayed. No letter "d" appears during the test.

Solder joints etc. are triple-checked. Who can help? Thank you in
advance.

73 de Rolf, DK8SJ

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Don Wilhelm-3]

Rolf,

>From your symptoms, it would appear that the EEProm is either not being
written or not being correctly read, or that the PLL is not properly
responding to the control voltages being fed to it.

First, re-check the PLL range to be certain it is correct - if it is
correct, then the PLL itself is likely not the source of your problem, so
proceed as follows:

Re-check the VFO Range selection voltages at the end of RF Board R30.  If
all voltages are not within the specified range, VFO linearization may fail
to produce expected results.

Check and re-check the soldering at RF Board U6 and U5, then check the
soldering at RF Board connector J8 - epecially pins 16, 19 and 20.  Check
the same pins on the mating Control Board connector P3.

After that, check the soldering at Control Board U7 and U6 pins 22, 23 and
24.

If everything is good at all those locations and it still does not work, you
may want to try an email to Gary mailto:[hidden email] to see if he
has any additional suggestions.  If the problem should be in the EEprom or
the signals that drive it, that area is very difficult to troubleshoot and
Gary's expertise will be needed.

73,
Don W3FPR

> -----Original Message-----
>
> I am Rolf, DK8SJ, a new member of this list. 3 weeks ago I got my K2 SN
> 5218.
> Now I am in the stage "Alignment and Test, Part II".
> All tests are within the range and I receive strong and stable signals
> on 40m.
>
> But I have a problem:
>
> Tuning on the main-knob I have a continuous frequency readout on the
> display, but the actual frequency makes alternating steps of  abt 0.200
> kHz and 3.8 kHz. The VCO-Voltage shows according steps.
> During "VFO Linearization" nothing happens until the end of the test
> after 8 minutes the frequency drops down abt 15 kHz and "END" is
> displayed. No letter "d" appears during the test.
>
> Solder joints etc. are triple-checked. Who can help? Thank you in
> advance.
>
> 73 de Rolf, DK8SJ
>
>

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com