[Amps] Xmtr output impedance?

StephenTetorka@cs.com StephenTetorka at cs.com
Tue Sep 6 10:47:12 EDT 2005


Hello Karl-Arne:

Nice to hear from you again...how are things.

The tank final has the B+ for the 1625's coming into the center tap of the B&
W coil.
Each 1/2 coil from center tap has one section of the same variable across it.
The link attached to the antenna terminals has 3 links in the physical center 
between the B+ coil halves.
This is the traditional 1940's - 1950's set up per QST et al.

I have an RF ammeter & Pi tuner & SWR meter prior to my antenna.

Fortunately, I get good reports, esp. on the audio ( again per QST 1947 ), on 
80 meters.

But - and this is my reason to delving into this matter...my output on 20 is 
surprisingly low for 2 x 1625's...even after trying several pairs.

Your insightful remark about tuning via the link displacement is very much 
what I had in mind.

And yes, I do get 'focused'  on what I'm doing when I put my hand into the RF 
deck area from behind the tight space of the 6 foot rack door & wall when I 
change BOTH the grid tuning coil and the RF output coil on this great vintage 
rig.

Found out the bleeder for the high voltage modulator power supply doesn't 
bleed toooo quickly when I made sure to ground it out...and heard a Loud crack! 
when it sparked.

PS...weren't you putting an 813 rig together??

Warm regards,
Steve
WA2TAK


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