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: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of RoadKing > Sent: Thursday, February 26, 2004 7:02 PM > To: [email protected] > 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 > > > > > > > --- StripMime Report -- processed MIME parts --- > text/html (html body -- converted) > The reason this message is shown is because the post was in HTML > or had an attachment. Attachments are not allowed. To learn how > to post in Plain-Text go to: http://www.expita.com/nomime.html --- > _______________________________________________ > AMRadio mailing list > [email protected] > http://mailman.qth.net/mailman/listinfo/amradio
