[AMRadio] Need Variac

[Brett Gazdzinski]

Now, if you want to change voltages, there is
another way besides the variac setup.
I have two power supplies with variacs, they work well,
but there is loss in the variacs, more sag under load
than without one.
They also generate a large magnetic field, and can put hum
into the audio if its close.

So for the next rig, I used a transformer with a bunch
of primary taps, selected by relays hooked up to a rotary
switch on the front panel (low, med, high).
The trans has secondary taps as well, and I can get
all sorts of voltages.
900 1100 1300,
1100 1300 1500
1300 1500 1700

Or something like that.
 
No hum, and I can even switch it while its on.

Brett
N2DTS

> -----Original Message-----
> From: amradio-admin at mailman.qth.net
> [mailto:amradio-admin at mailman.qth.net]On Behalf Of RoadKing
> Sent: Thursday, February 26, 2004 7:02 PM
> To: amradio at mailman.qth.net
> Subject: RE: [AMRadio] Need Variac
> 
> 
> 
> At 06:34 AM 2/26/2004 -0600, you wrote:
> 
> 
> Tony,
> 
> 
>         A variac
> like what you are asking for is large, somewhat lossy, and usually
> 
> expensive. Variacs tend to be a little lossy as the voltage in/out
> ratio
> 
> i
> 
> :snip:
> 
> Wonderful Idea Jim!
> 
> 
> Thanks so much for the very astute, and experienced suggestion. 
> Much, better, less expense and certainly simple way to control and
> prevent another {quot}Wreck of the Old 97{quot}  I can simply look
> long and hard down the track and open 'her' up!  
> 
> 
> Man, there is truly such a {quot}GREAT{quot} bunch of AM ops 
> who are so
> willing to keep those of us still climbing the learning curve on the
> straight and narrow.  
> 
> 
> After assuming the worst Jim, I discovered with a great deal 
> of joy, that
> it was a mechanical problem.  The {quot}Disk{quot} holding the
> brushes, had slipped backward on the shaft, away from the Windings
> therefore, the Variac was fine it was just not able to Pass 'juice'..
> BOSEG  Now, the {quot}Total Output Performer{quot} is back up and
> Rolling out the RF at its usual rate.
> 
> 
> Should I ever need to replace, it, your note is now a 
> permanent part of
> the 304tl folder! !  Tnx....
> 
> 
> 73,
> 
> Tony/W5OD
> 
> River House Radio
> 
> Boling,TX
> 
> 
> 
> 
> 
> 
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