Ian Smith wrote:
Hi
I have a Heathkit IG-42 signal generator. The RF choke coils on the
power supply need replacing,however I can find no reference in the
manual as to their value. Can someone help with values, substitutions
or are the even necessary.

Many thanks
Ian

If you're referring to the two line filter chokes, they are to
prevent/reduce RF leakage from the generator onto the AC line. You can
wind new ones using about 18T of #16 wire on a 1/4" air core. Also, you
could simply bypass the internal chokes and use one of the new,
sandwich-type RFI/EMI toroid line filters, externally on the line cord.
I'm curious as to how the originals went bad?