K2 VCO Alignment - Low voltage

[Mark Yergin]

I'm getting 0.02 V at R30, not 6V.  Turns on T5 correct and wound per
image.  Reflowed the four solder joints and verified continuity between 1
and 2, 3 and 4. C72 is correct value (label 271) and reflowed.  L30 is the
correct value (large slot), and reflowed.  D21-26 confirmed as correct
values.  C71-74 confirmed as correct values.

Suggestions?

Mark W8EWH
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[Don Wilhelm]

Mark,

First check the DC voltage on U6 pin 5.  It should be near 4 volts - if
not, you have a problem on the thermistor board, likely a solder bridge.

Then recheck the PLL reference oscillator range at TP3 using CAL FCTR.
Tell me the high and low frequencies.

Then check the VFO frequency at TP1 (using CAL FCTR) when tuned to
4000kHz and again when tuned to 7100kHz.

73,
Don W3FPR

On 4/21/2019 1:43 PM, Mark Yergin wrote:
> I'm getting 0.02 V at R30, not 6V.  Turns on T5 correct and wound per
> image.  Reflowed the four solder joints and verified continuity between 1
> and 2, 3 and 4. C72 is correct value (label 271) and reflowed.  L30 is the
> correct value (large slot), and reflowed.  D21-26 confirmed as correct
> values.  C71-74 confirmed as correct values.
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[Mark Yergin]

U6 Pin 5 = 4.1v

PLL ref Osc range at TP3 = 12098.83 to 12084.95

VFO at TP1:
@4000kHz = 8077.0
@7100kHz = 11288.5

Mark

On Sun, Apr 21, 2019 at 6:02 PM Don Wilhelm <[hidden email]> wrote:

> Mark,
>
> First check the DC voltage on U6 pin 5.  It should be near 4 volts - if
> not, you have a problem on the thermistor board, likely a solder bridge.
>
> Then recheck the PLL reference oscillator range at TP3 using CAL FCTR.
> Tell me the high and low frequencies.
>
> Then check the VFO frequency at TP1 (using CAL FCTR) when tuned to
> 4000kHz and again when tuned to 7100kHz.
>
> 73,
> Don W3FPR
>
> On 4/21/2019 1:43 PM, Mark Yergin wrote:
> > I'm getting 0.02 V at R30, not 6V.  Turns on T5 correct and wound per
> > image.  Reflowed the four solder joints and verified continuity between 1
> > and 2, 3 and 4. C72 is correct value (label 271) and reflowed.  L30 is
> the
> > correct value (large slot), and reflowed.  D21-26 confirmed as correct
> > values.  C71-74 confirmed as correct values.
>

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[Don Wilhelm]

Mark,

See my prior email.

73,
Don W3FPR

On 4/21/2019 1:43 PM, Mark Yergin wrote:

> I'm getting 0.02 V at R30, not 6V.  Turns on T5 correct and wound per
> image.  Reflowed the four solder joints and verified continuity between 1
> and 2, 3 and 4. C72 is correct value (label 271) and reflowed.  L30 is the
> correct value (large slot), and reflowed.  D21-26 confirmed as correct
> values.  C71-74 confirmed as correct values.
>
> Suggestions?
>
> Mark W8EWH
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

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