Steve, What kind of resistor do you use in this type of rectifier build to simulate the voltage drop?
Jim/W5JO ----- Original Message ----- > I've made my own solid-state plug-in replacement rectifiers for a > variety of tube types. I look up the tube specs and select > solid-state > diodes that stack up appropriately for current and forward and reverse > voltages. I usually end up using either 1N4007s or 1N5408s. From > on-lline sources like Digikey or Mouser or All Electronics the diodes > are very inexpensive, ten cents to maybe 30 cents each. > > I put the diodes on a rectangular piece of perfboard sized to fit > upright with its bottom end tucked within the sides of the base of the > defunct tube it is replacing. A small L bracket holds it in place. > > If you use diodes from the same "run" (which is easy if they are sold > on the paper tapes used by manufacturers today) then I find no > equalizing components are needed. I add a few more diodes than the > calculated voltage required for an extra measure of safety and have > never had a failure, even in broadcast rigs on the air 24/7 with lots > of lightning and power bumps to deal with. > > You can expect somewhat higher voltage from the new stack than the > original tube rectifier - if that is a problem for the rig, then add a > series power resistor to simulate the internal voltage drop of the > earlier tube. So far I've only needed to do that once when the new > higher B+ exceeded the rating of the by-pass caps in the other > sections > of the rig. Otherwise the rigs seemed to thrive on the higher > voltage. > > Steve WD8DAS ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
