[MRCA] T-195 Power Supply Options

[Mike Murray]

Hi again, Dennis!
Well, your supply of Ted's worked great on my T-195, and it was a very nice piece of craftsmanship. Well done!

For my T-195, I have a good ol' fashioned mechanical dynamotor. At least, I am 99.999% sure I do.
Is that good or bad, I wonder? Have thought about conversion to solid state. Possible?

OK on the batteries. This sounds like what I should do.
Will keep you all updated as we formulate our next steps.

TNX es 73!
Mike
KW4HF


--- On Sat, 10/31/09, mac <w7qho at aol.com> wrote:

> From: mac <w7qho at aol.com>
> Subject: Re: [MRCA] T-195 Power Supply Options
> To: "Mike Murray" <mmurray377 at yahoo.com>
> Cc: MRCA at mailman.qth.net
> Date: Saturday, October 31, 2009, 5:42 PM
> Mike,
> 
> First of all, which power supplies do you have in your
> T-195, i.e, mechanical dynamotors or the later solid state
> replacements.  If the latter your switcher may work OK
> without any capacity or other assist.  Many T-195s I've
> seen have one of each, usually solid state HV and mechanical
> for +250, -45 & 115V-400 cps. which still requires some
> surge capability but not as much as the 1000 volt unit.
> 
> DO NOT try to hang a bunch of caps across the output of
> your switcher.  Better way is to shunt  a couple
> of seriesed 12 volt car batteries across your supply through
> an isolating diode to prevent a reverse current flow back
> into your PS.  Adjust your PS voltage to give 2-3 amps
> charging current to the battery under no-load condx and
> connect the -195 across the battery terminals.  The
> diode should have a rating of 200 A or so, no problem these
> days.
> 
> You can  also use a pair of smaller power supplies to
> run the T-195.  The load is split almost perfectly
> 50-50 at the primary power input connector, see your manual
> for the pin-out.
> 
> I built the supply that Ted uses.  It's simply an old
> garage Hot-Shot charger with the selenium rectifier replaced
> by a solid state bridge and something more than 100,000 mfd
> (I don't remember exactly) hanging across the output. 
> No regulation but not needed with the -195.  Have since
> duplicated this circuit in a nice cabinet with a variac,
> meters, etc. and use this for my GRC-19s.
> 
> Dennis D. W7QHO
> Glendale, CA
> 
>