Hello:
I know this has nothing to do with Elecraft gear, but having built the 3 radios, I knew this is the place to come for experienced troubleshooters. I have an old JPS NIR-12 DSP unit, that, after applying power, decided to quit. The power lamp will not now light. This unit does not have a fuse. So I decided to get out the DVM and attempt to see what's going on. The DC power jack goes to a T-network consisting of two 0.1 uf caps with a bead inductor before going to a DPDT switch. Beyond this is a 0.1 uf cap in parallel to ground and then a series 1N4004 rectifier diode to a 1000 uf electrolytic capacitor in parallel to ground. From there it branches to a couple of voltage regulators to get different voltages. When voltage is applied, I get 13.7 volts on the cathode side of the diode, but zero on the anode side (and beyond). I initially thought that this diode was at fault and desoldered it and replaced it with another 1N4004. But, alas, this was not the culprit. I desoldered the 1000uf electrolytic, but my capacitance meter reads it correctly at 1000uf. Can somebody help shed some light - voltage ? - here ? Thanks - 73, Jamie WB4YDL _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
