[Elecraft] K2 PLL Range

John Heaviside John.Heaviside at care4free.net
Wed Nov 10 14:40:39 EST 2004


I am slowly building a K2 and have run into a problem:

PLL Reference Oscillator Range Test (page 57 of manual).
The 4 MHz osc has been calibrated to an external counter with known accurate reference.
In CAL FCTR the counter reads 12099.15 MHZ
Tap BAND+ there is no change to this reading.
Tap BAND- the reading briefly changes to 12079.?? (too fleeting to read decimals) and instantly reverts to 12099.15.

Are there 2 problems here?  a) the reading at BAND- should presumably remain steady.  b) The range, if 12079 is correct is way outside the specified 9.5-15kHz.

Proceeding beyond this point everything seems to work but the VCO voltage at 7.000MHz is only 1.08V (page 58). L30 must be adjusted to 7.5V at 4.000MHz to get the 7.000 MHz reading up to 1.5V.  This seems too close to the limits for comfort.

Testing fails at page 60 VFO Linearisation.  Definitely on 40metres but CAL PLL produces INFO 232.

Have checked the components and all seem OK.  L31 is 12 microH and thermistor board installed.

Any ideas?

Thanks in advance.

John G3NYX.


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