First of all, many thanks to those who gave help, hints, ideas, and schematics (!) over the past eight months; all was appreciated!
The story: I was building a master power/timing module for my rack system, including a Z3801A in a snazzy pull-out configuration with a dist. amp. All was great until I did the final power on test... The Z3801A was dead and the external PS shut itself down for ~4 minutes every time I tried to power it up. I had forgotten that the unit was designed for a *positive ground* environment... oops! After a few half hearted attempts to get it going, I gave up for a while to work on other projects. Later, knowing I had to "thin out the herd" I asked for and got the schematics for the PS board. While not 100% accurate, they were good enough. The incorrect grounding had blown out Q3 and CR4. I took a long time to track it down because it was hard to isolate portions of the circuit, and I didn't want to cut any traces. Deciding I didn't need the input voltage envelope circuit anyway, I just bypassed Q2, reassembled everything, and it's now purring along. Not having much luck acquiring sats, but it's locked on to a few, not bad considering the antenna is indoors, leaning against a book case. This weekend, I'll give it a real test on the roof. One last thing; this was the first pcb I've really had soldering issues with. Sometimes it just wouldn't melt unless I used the big weller gun, sometimes the clearance in the holes was so tight that I had to pull parts through even when the solder was totally melted. The pcb laughed at both my solder-suckers. I even ended up making a tip to heat all 3 terminals of a TO-220 at once. That worked, but the 2" wide tip for the DC/DC conv. didn't.... Thanks again to all, -Dave _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
