Mains Transformer

[pre65]

hi-i am looking to purchase two mains transformers 310-0-310 for my amp rebuild and have found two 320-0-320 with 250 volt input.
my question is if i use uk mains @ 240 volt,which is 4% less will the output also be 4 % less ( ie 307 volt ) which would be ok.
or is it not that simple ?

regards Philip

[John Caswell]

Hi Philip,
Simple answer is yes it is that simple!
That having been said if your mains does drift up to 250Vac, you can always lose a bit of voltage by putting series resistors in the ht ac feeds from the transformer to the rectifier anodes.
You will also need to make sure that the various heater voltages come out correctly eg the 6.3Vac is +/- 10% max.
Also depending on the efficiency of your HT rectifiers you may also have to increase or add some resistance to keep the HT line voltages similar.

Regards

John aka Dr John