On 31 Dec 2016 02:03, "Bob Stewart" <b...@evoria.net> wrote: > > If you can touch the heat sink for 2 seconds, you're made of sterner stuff than I am! They run very hot. It's a good idea to get a GPIB extender so your GPIB cable can clear the heat sink. Somebody, can't remember who, worked up a nice looking conversion to a pair of switching supplies.
SMPSs tend to be less clean than a linear supply. I would be somewhat reluctant to take that route on test equipment. But I will search for the conversion. I have a 13 A variac sitting around that's not been used in the last 25 years. I think as a short term measure I will drop the voltage to a few bits of the equipment with linear power supplies. The spectrum analyzer has linear supplies and puts out a lot of heat. As someone else said, a 20 V transformer would work. Adding the variac will take me 5 minutes to do, which has an advantage over anything I need to build. I will also log the mains voltage over a period of a few weeks and see if it high enough to ask the electricity supply company to do something about it. I do know someone that measured his voltage and found it was outside the legal limits. He advised the electricity supplier, they agreed, but said that they were not going to do anything about it. He wired his whole house on an auto transformer. I would be speaking to my Membrr of Parliament (MP) if it was outside the legal limits. I don't know what legal limits exist in the UK for voltage, but I can find out. It is unusual in the UK for a domestic property to have a phase supply, but mine does. I don't know whether any one phase is consistently lower than any other. If so phases could be switched. But given my close promptly to the 11 kV transformer, I doubt it. I know at one point I had a dispute with the electricity supply company as the 415 V overhead power lines used to be regularly hit by farm vehicles down a private road where my property is. This would pull the cables away from my house and make a mess of the house. The electricity supplier would always repair the damage, but after this happened a few times I complained. I was initially told they would do nothing as it is not a road. But I discovered that the cables needed to be a minimum height if there was vehicular access. So whether the electricity supplier considered it a road or not was irrelevant. Eventually they extended a pole and raised the cables up, which appears to have solved the problem. Whether I can convince them to move the transformer taps is another matter. I suspect that it might be hard if my supply is consistently high, but not outside the legal limits. 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.