K2 s/n 4276
Original Issue: Reported in March 2003.
"VCO Alignment (p61)
VFO set at 4000 kHz
@R30 left side = 0.018 vdc
L30 verified as a 4.7 uH "T005Z"
C72 verified as a 270 pF "271"
Rewound T5
verified primary = 16 turns
verified secondary = 4
Adjusting L30 has no effect on R30 voltage reading."
*************************************************
VCO Alignment issue solved!!
Family responsibilities had the project in the shelf for over 2 years. I finally was able to continue construction this past summer. I discovered after studying the circuit diagram and other details that I had a possible problem with U6. Specifically with U6B. When checking inputs and outputs, U6A's inputs and output were all as the DC Voltage Tables predicted. On the otherhand, U6B had good inputs but the output was almost non-extistant. After checking other components (that could be loading down the circuit).
As my K2 is no longer under warranty, I made a quick call to Mouser and a few days later, I had a replacement part in hand. After installation, L30 now adjusts the voltage reading at R30.
Construction then proceeded at a rapid pace, such that all that is left is final alignment and test.
Amazing how a 40 cent part can stop the train in it's tracks.
As I have the KPA100, construction has begun and proceeds at a steady pace.
Thanks to all those who responded to my original request for help. :-)
73's
William Smith
KC4WVL
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