Greetings. Having had my 5065 disconnected several months due to all sorts of things, and started it up yesterday. It was dead. "Pining for the fjords"
No 2nd harmonic. Just PhotoCurrent. Quick Phase Checkusing a scope in X/Y-mode returned a "U" instead of a bump And most of the rest was noise. I have previously replaced a number of transistors in A3 (5 -> 60 MHz Multiplier) during first attempts to resurrect this unit and it seems like the rest of them were gone (how come?) now. Many of them are 1855-0327 which I have replaced by 2N4416. Q7 by BC557 (!) and Q9 by 2N5109. After this, I have adequate regulation and an AGC of > 4V. All-in-all: Just about every transistor in A3 was bad. There were output at first ~ 10 dBm at J8 but it was not possible to increase the output by tuning. Also there was no AGC. I checked a second unit from a scrapped 5065 on my bench and the situation was the same with that A3. Low output power. No AGC. So now for the question before I put any more energy in trying to fix the rest of the old faithful: I checked the A1 syntesizer unit which did provide correct output frequencies but they were not as stable as the internal 5 MHz Osc. (10811) HP does not mention any stability/jitter data for A1. Using a 5370B and 1 second gating, the output fq was stable down to single kHz figures but jittered further down. The 5370B counter is locked to a GPS diciplined 105B and comparing with the 5065's internal 10811 (in OpenLoop mode), that oscillator is also very stable and settable within spec. I have two of these synthesizers, but they are both the 1st edition using TO packaged IC's that are unobtanium. One of my manuals shows a more modern unit with plastic DIP's. Some signetics and a one-shot that is unidentifiable. IF the A1's are bad - has anybody made some reverse engineering trying to fit the "DIP-version" with modern available IC's or modified it in a way that can be reproduced? Best Regards Ulf Kylenfall SM6GXV _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.