[Elecraft] Re: s/n 4276 VCO Alignment issue
kc4wvl
kc4wvl at peoplepc.com
Tue Mar 15 11:13:07 EST 2005
K2 s/n 4276
VCO Alignment (p61)
VFO set at 4000 kHz
L30 verified as a 4.7 uH "T005Z"
Adjusting L30 has no effect on R30 voltage reading.
*************************************************
At TP3, there is a 12100.93 kHz signal present.
At TP1, there is a 7717.86 kHz signal present.
R30 is only 0.019v
Visually inspected all components, verified that all are the correct values and no components are installed backwards. Solder joints look ok. No solder bridges or un-soldered connections found.
Changing bands does not change the reading at R30.
Visually inspected D16 and D17, both appear OK.
RFC15 is 8.5 ohms
U6-1 during PLL test, goes from 0.006v to 7.63v
U6-5 is steady at 4.004v
RFC14 leads look good and has 10 turns.
RFC15, C91 and C88 reinspected and appear ok.
T5 looks like the photo. Tried spreading and compressing the windings. No change in voltage readings at R30.
Other measurements:
U6-1 = 7.65v
U6-5 = 4.004v
U6-6 = 4.88v
U6-7 = 0.019v
U6-8 = 8.05v
U4-16 = 4.88v
Please advise.
Thank You
William Smith
KC4WVL
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