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VCO Alignment - HOW?

Posted by Fred (FL) on Apr 23, 2006; 1:52am
URL: http://elecraft.85.s1.nabble.com/VCO-Alignment-HOW-tp389069.html

I've gotten to Alignment & Test, Part II RF Board
build on my K2 # 5422.

I seem to be having problems with "VCO Alignment"
problems:

a. 4 Mhz Oscillator Calibration = gave a reading of
12099.35 - OK it appears.

b. PLL Reference Oscillator Range = 12099.32 high, to
12085.65 low - Range = 13.67khz - seems OK

c. VCO Test:  Frequency counter probe to VCO Test
Point TP1.  I got a frequency counter reading of
8913.18, seemingly stable - and OK.

I'm trying to do VCO Alignment, and adjust Inductor
L30 - to adjust and measure the VCO control voltage
for
proper range.

I'M NOT SURE WHAT THE RELATIONSHIP IS BETWEEN
"CHANGING BANDS" using the BAND+ and BAND- buttons, or
changing
the displayed frequency using the VFO KNOB?  Which am
I supposed to use?  

At one point, I could not get into the "80meter band"
with the BAND- button, without lowering the displayed
frequency down to near 40 meters or lower.

VCO Alignment - requires going from Band 80 to 40 to
30 to 20 to 17 to 15 to 12m to 10m.   DOES THIS MEAN
TO DO IT WITH THE BAND+ switch or with the VFO Knob?

I tried the VCO Voltage Readings - using
band/frequency changes with the VFO Knob.  But then
when I tried to get
the low freq and high freq voltage measurements - I
seemed to be getting a steady stream of "8 volts DC"?

HELP - can someone give me a hint on how to attack
these VCO ALIGNMENT FREQUENCY CHANGES and
measurements?

Thanks,
Fred Osborne N3CSY
FL
4/22

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