[Elecraft] Alignment of VCO - Problem

[Don Wilhelm]

David,

All those voltages are about right for a VFO that is not oscillating.  Do
not be concerned about a voltage that is only a few 10s of millivolts
different from the chart.  Actual readings will vary a bit from DMM to DMM.

The important voltage now is the gate of Q18 - it should go negative once
some RF is developed in the gate circuit.

The best I can tell you right now is to turn to the schematic - RF Board
Sheet 1 of 4 and look at the VFO components in the upper right quadrant of
that page.  Check the placement and value of each of those components.  If
you have trouble physically locating any component, the Parts Placement
diagrams can be helpful.  Be certain the diodes are oriented correctly.
Re-check T5, or even rewind it.  Be certain the T5 leads are well tinned and
soldered.

73,
Don W3FPR

> -----Original Message-----
>
> Double-checking DC voltage measurements on 3 transistors.
>
> Item Measured  Chart
> Q18
> ---
> G:   0.00      -1.0     !!
> S:   1.97 **    2to3
> D:   7.97       6.3     !
>
> Q17
> ---
> G:   2.16 *     2.2
> S:   0.00       0.0
> D:   1.97 **    2to3
>
> Q16
> ---
> E:   0.00      0.0
> B:   0.55      0.6
> C:   2.16 *    2.2
> --
> David Dawson
>