A pic of a new deck

[N9NEO]

Hope this works.




73
NEO

[N9NEO]

[img]http://mysite.verizon.net/vze6qsvc/sitebuildercontent/sitebuilderpictures/brick3.jpg
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[frank carcia]

Bob,
I wonder if you put any juice to it yet?

[N9NEO]

Yea, put 25v/8a on it the other night. Got about 200w carrier out.

Running a pair of 200v size 4 fets with case soldered to pc board on each side - push_pull. Board is screwed directly to the heatsink, with fets soldered to board smd style. They ran very cool with 200w carrier.

You may recall seeing that the output transformer was wound 2:4 on a pair of cores. I decided to use 4 cores and wind 1:2. Bought some braided sleeving off the net and wound the 2 turn secondary inside primary. I figured leakage inductance was gonna kill me.

The boards hanging off the side have LM317 regulators with 10t pot to bias up the sinewave gatedrives. Gets rid of the commutation narleys. Boards also have transorbs and some loading resistors. The bias supplies are run off tertiary windings on the input drive core - simple.

Running a bunch of 300pf silver mica caps across the drains.

I don't know if I will be able to get full strap out of the thing or not.

This is last push-pull rig I will build using sinewave drive. I've got extra board sets if anyone wants. They were free. I had extra room on a prototype flyback pc board for work, so just tacked em on to artworks. I would like to pass them on (with parts) to anyone who would like to experiment.

73
Bob


73
Bob

[frank carcia]

Bob,
I have considered running a bit of bias so would be interested in your DC voltage coming out of the 317. I only have to unsolder 1 jumper to add bias to the drive center tap. The extra winding on the drive transformer
goes dead without drive which is a good thing. I would suppose you have a bleeder to discharge things during RX. I would be interested in any observations in the drain circuit as the duty cycle changes with positive bias voltage. fc














dc