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Title: Heathkit AT-1 Power Supply Post by: W9ZSL on October 27, 2015, 10:09:48 PM I'm about to start the "rejuvenation" of the AT-1. Cid Vance K8JLY has a cabinet and Fred has one too so either way I'm escaping any metal work. I have a question about the power supply filter since that is #1 on the construction list. The sketchomatic calls for 4 x 8 MFD caps and 2 x 47K @ 2watt resistors in series for bleeders. Rather than use the 8 MFD caps in series for 4 MFD on each side of the filter choke, is there any reason why I can't use a single 10 MFD @500 VDC on each side and substitute something like a 100K bleeder? Of course, I can pick up 2 more 8 MFD caps (I have 2 on hand...Sprague Atoms) and have no problem with the 47K resistors.
Keep in mind this is NOT going to be a "restoration" in the strict sense, but a clone / restoration / modified re-build using all new caps and resistors on the original chassis. Title: Re: Heathkit AT-1 Power Supply Post by: N2DTS on October 28, 2015, 08:10:30 AM What is the voltage?
Series caps are used to increase the voltage rating. I really dislike series electrolytic caps and go oil filled when I can. You want at least 100 volts below cap rated voltage (unloaded power supply) so if the rig runs 400 volts a 500 volt cap should be ok. 600 volt oil filled caps are common and I could likely give you one. Title: Re: Heathkit AT-1 Power Supply Post by: W9ZSL on October 28, 2015, 12:57:56 PM I have a pair of new Sprage "Atoms" 10 MFD at 500 volts. I used this iron in another power supply a few years ago and it put out just under 400 volts, no load, so I'll be good to go. AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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