[GreenKeys] Model 28 Drive Voltage

[Bob Camp]

Hi

Well this is maybe the tenth time I've gone in for this and it's the 
only time I've actually considered keeping the stuff in the box rather 
than just stripping it all out an going direct to the magnets. I've 
always come down on the side of keep it really simple before. Fewer old 
wires and old terminal blocks = fewer problems to figure out. That goes 
double for a machine with a hacked up wiring harness.

Maybe I should strip them out and sell them as *RARE* on a certain 
auction site. Might pay off the mortgage ....

So the next question is - how common is the 0.1 uf cap across the 
magnets ?  It's certainly not common on a model 15. Obviously things 
are different on a 28.

	Enjoy!

		Bob Camp
		KB8TQ



On May 25, 2004, at 6:41 PM, Jack wrote:

> Bob,
>
> Those magnet drivers you have are definitely oddballs. Any
> "normal" 28 has a polar relay circuit keying an internal HV
> loop with the coils strapped for 20 or 60 ma. Most Hams just
> bypass the relay and wire to the magnets. It cuts down on
> the relay's contribution to distortion (if it's not perfectly
> adjusted). Your keyers obviously were a work-around for
> the relays and probably interfaced to a very low voltage
> external signal source for security (no HV pulses) reasons.
>
> Jack WA2HWJ
>
> NNNN
>
>