On phone Absolutely repair you can do numbers of things to isolate the short by floating it Far to much for a phone
On Saturday, May 6, 2017, Ulf Kylenfall via time-nuts <[email protected]> wrote: > HP 5065A S/N 0048-00131 > Repairing the heater... > I was able to get my hand on a faulty 5065A > that was left for dead. > The date codes on the semiconductors says 1968 > so this unit is 50 years old... This instrument > has some provenance as it was > used in the European end during the very first > trans-atlantic VLBI (Radio Astronomy) > experiments between Sweden and the USA. > The unit has the known problem with one of the > rubidium unit (s/n 05065-6001) > heater wires shorted to GND. > This failure was the cause of the decomissioning. > I managed to salvage:The transmitter lamp (fires up within seconds when > connecting it to a 20V DC source),The Rubidium glass cavity, The photo-cell > at the receiving end. > Having downloaded the "First-aid" documents > from KO4BB, I read a quote from Corby Dowson > regarding this problem and what to do about it. > I have been able to separate the TX/Rb/Rx assembly from > the magnetic shields but after this, I hesitate > about how to proceed. (why did not HP put more energy > in trying to isolate the magnetic winding from the shield? > Any scratch on the enameled copper wire and a short > circuit will be the result here as well?) > As far as I can see, the magnetic > winding has to come off. The rest of the > polyurethane (?) structure has to be removed > after which that structure has to be rebuilt > using some other material (PTFE?). > One other reason why I hesitate is that this unit is > v e r y old. It uses regenerative dividers > instead of binary (etc) and a lot of other > obsolete components. > I could use some suggestions about what to do next. > One other question is of course if it is worth > putting a lot of energy trying to repair > a 5065 as old as this. Perhaps easier to go > look for a working modern 5065A on the open market? > Comments invited. > Ulf Kylenfall > SM6GXV > _______________________________________________ > time-nuts mailing list -- [email protected] <javascript:;> > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
