Dave Plowman wrote:
I collect old test gear as a hobby, and like to have it working too. I
recently bought a 110v valve sig gen in very nice condition and it works
fine off a 110 supply.

Looking inside - as you do - I noticed that the transformer primary was
two windings in parallel. This, of course, is common these days - parallel
operation for 115 volts and series for 230.

So I removed the transformer, and series the windings. On UK mains, under
500mA load, the heater volts are 7 volts rather than 6.3 which makes sense
if the windings are 110 volt. Will this matter?


Just a bit more that +10%, I suspect it could shorten the life of the
valves a bit. How many valves and what are they, 500ma is less that two
ECC83's (for example) would take, it may be that under actual use the
voltage would be lower that that. HT will I guess be a bit high as well,
but 10% shouldnt make that much of a difference.

Other option (as I am sure you know) would be to measure the primary
current and add a small dropper resistor.

Having wrote all that, I am tempted to say, no it probably won't matter.

--
Nick