John Sorry to hear of the problem. Agree with a digging in and others will give you good advice. However if it just comes down to the very very difficult job of digging in. Consider floating the heater with a isolated supply and optical switch driver. Because the lamp heater uses the same common supply you would need to do the same to that. Though perhaps the two heater +24V supply can be easily separated. The transistor may be operated in the linear mode at some point that adds a wrinkle. But heck if your in deep trouble then anything is reasonable. I have had to float heaters like this twice. It works. Though they were on xtal ovens. Same with a CRT short. Regards Paul WB8TSL
On Mon, Aug 20, 2018 at 1:50 PM, John Ponsonby <[email protected]> wrote: > My HP 5065 has developed a fault. The LAMP OVEN heater winding has > developed an internal short to ground. It is not a dead short (about 9 > ohms) and it is intermittent, developing when the oven is hot. I shall have > to open the RVFR to fix it. I don't know what I'll find. I have no drawings > to guide me. So I'd welcome any advice on what to expect, what precautions > to take and what I shall need to effect a repair. > John Ponsonby > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to http://lists.febo.com/mailman/ > listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
