[Johnson] viking invader problerm

[David C. Hallam]

Ed,

I misspoke a little.  What I have is a modified way to align the 9MHz 
amplifier.

T2 Adjustment
a. Mode switch to CW
b. RF level to maximum clockwise
c. Connect vacuum tube RF voltmeter to pin_9_ of V3
d. Short out T5 trimmer
e. Adjust the slug of L3 so the top of the threaded rod is 9/16" above 
the metal cap of the coil (not the metal ears)
f. Bottom core of T2 should be at bottom limit of its travel and top 
core should be at top limit of its travel
g. Run top core of T2 through the first peak as evidenced on the 
voltmeter and adjust for peak reading at second peak reached
h. Adjust bottom core to second peak reached
j. Readjust top and bottom cores if necessary to obtain maximum reading
k. Remove voltmeter probe
l. Remove short from T5 trimmer
m. Set T5 trimmer at approximately 35-40 degrees from maximum capacity.

Actually whenever a RF VTVM is called for in the adjustments, I use my 
spectrum analyzer with a pick up made from a strip of copper sheet 
fashioned to slip around a tube envelope.  with this set up I can be 
sure that I am peaking on the correct frequency.  Or, you could use a 
scope with a frequency counter connected to the vertical signal output jack.

Some Invaders can be a little fussy about the tube in V3 (6CX8) first 
mixer/heterodyne oscillator.  You might try substituting tubes.  I have 
heard that Sylvania band works best but I have no direct knowledge of that.

David
KW4DH



On 11/19/2015 12:17 PM, ed wirtz wrote:
> Hi,
>
> I've got a cranky Invader 200. No output at all and the 9MHz amplifier 
> output is low. VFO output is normal and the het oscillators are 
> normal. T2 is good. The 9MHz crystal oscillator output seems low as 
> well. tubes are good and resistors seem to be reasonably in tolerance.
>
> Any ideas?
>
> Thanks and 73,
>
> Ed, KØBKA
>
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