Yes, I agree, go oversize if you can. I was lucky to get loads of great parts 20 years ago when no one wanted the stuff, it was all transistors they wanted. I got a load of UTC commercial grade chokes rated for 7000 volts 700ma ccs for $10.00 each! BC610 transformers were free if you would remove them, etc. Good deals can still be got sometimes, I got a nice Peter Dahl power transformer that gives 3000 volts out at 500ma for $75.00 at a fest. I got some nice oil filled caps a few years ago at Gaithersburg for $5.00 each.
The really big parts seem rare though... Brett N2DTS > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of ARS W5OMR > Sent: Wednesday, December 06, 2006 8:58 PM > To: Discussion of AM Radio in the Amateur Service > Subject: Re: [AMRadio] RF Amp > > > If you've got the iron, I'd build up a 2kVDC supply, to run at 250mA > > on the final, for 500w DC Input to the final. at those > voltages, you > > don't need nearly as big of value components as you would > if you were > > running 4kV on a pair of 450's in the final. > > Of course, build for reserve ;-) Variac the thing, make the current > handling capability double, and make it 2500v. Got an old BC-610 > plate transformer laying around? > > Double up on the modulator supply for the 450T's. You're going to > need 3 or 4kVDC. > Pay attention to your DC power supply, think about things like > critical inductance, capacitors rated for 1.5x the B+ level and so > forth I''ve just gone through all that here, trying to design a (yet > another) power supply for my rig. > > A Power supply for a Class AB(1) or AB(2) or Class B requires a -lot- > more thought be put into it, than say one for a Class C circuit, that > will -always- have a decent amount of current being drawn through it. > > Got any Swinging Chokes? ;-) > > -- > Operating your AM rig without a scope > is like driving our car at night without headlights.(~K4KYV) > > 73 = Best Regards > -Geoff/W5OMR > ______________________________________________________________ > AMRadio mailing list > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Partner Website: http://www.amfone.net > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected] > ______________________________________________________________ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:[email protected]
