wrote:
hello,

After completing my AF amp and BFO, I'm in the process of doing IF/BFO
diode ring mixer.
I understood that it is a good idea (or even mandatory?) to follow DBM
with a diplexer.

I found one from http://www.qrp.pops.net/dip2.htm

My question is: how on earth should I wind those 10mH inductors? My
calculations show that I should wind 487 turns on FT37-43 (which is
obviously impossible), or 437 turns on FT50-43 (which is hard..but
should be possible).

Any other ideas how to make 10mH inductors for AF diplexer?

thanks!

The best solution is a pot core. A molded inductor is ok, too, but you
might have trouble with hum pickup -- the voltage produced by any field
coupled into the inductor will be amplified by the whole audio chain. A
pot core is self-shielding like a toroid.

Roy Lewallen, W7EL