[Drakelist] Test
-- Nigel A. Gunn, 1865 El Camino Drive, Xenia, OH 45385-1115, USA. tel +1 937 825 5032 Amateur Radio G8IFF W8IFF (was KC8NHF), e-mail ni...@ngunn.net www http://www.ngunn.net Member of ARRL, GQRP #11396, QRPARCI #11644, SOC #548, Flying Pigs QRP Club International #385, Dayton ARA #2128, AMSAT-NA LM-1691, AMSAT-UK 0182, MKARS, ALC, GCARES, XWARN. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] AC-4 / R-4C Voltage Questions
Jon - See below ... kilo4wit wrote: I'm in the process of getting some c-lines back to life. Befor I even started to delve into these boxes, I am making the assumption that I will need to replace electrolytics. I ordered all new single value cans of near values from Mouser. I have a few questions on voltages: AC-4 Pin #10 is showing 717VDC verse 650VDC Pin #11 is showing 292VDC verse 250VDC These are OK, just at peak because bleeder current only. Pin #9 showing -60VDC - OK This voltage is adjustable with the BIAS pot on the side. Should vary from -50 to -100 VDC with no load. This is the most critical voltage. If this fails, it can cause catastrophic damage to the transmitter, even if it has been left in STANDBY. These filter caps should be replaced, regardless. Watch polarity, as they are "upside down". Pin #6/#4 showing 14VDC - OK This should be ~ 14 V AC between these two pins. This is the "12.6VAC" filament supply, at no load. No hum is observed with 0 load. What would cause the higher than spec voltages? Should I replace caps on general principal? Best is to use the AC-4R upgrade kit from heathkitshop.com. It replaces all but a couple of components and puts them on one PC board. I think the transformer, fuse and BIAS pot are about all that is not replaced. R-4C Unit burnt transformer on start-up. I don't know the history of this unit. I received a replacement transformer. What would cause it to burn up? Capacitors in the power section? Most likely cause is shorted filter caps. Drop-in replacement caps are available from hayseedhamfest.com, although currently there may be a supply problem. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line& TR-4/C Service Supplement CDs ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] UV3 Parts request
A friend passed along to me that Terry, N7BDL, was looking for UV3 parts. There was no direct contact information, so I am pinging this list. I have the meter, and may have the black plastic piece that he wants. You can contact me via this list...I just became a subscriber! Regards, Tom Holmes, N8ZM Tipp City, OH EM79xx ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Wanted: SP-75
Looking for a working SP-75. If you have one send me an email and pictures (if possible). 73 W5BXE ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
