Re: LF: JT9-1 questions

[DK7FC <selberdenken@posteo.de>]

Am 05.12.2018 21:23, schrieb Chris Wilson:
> I  have  got  the  photos of the bridge amp, very useful, will collect
> bits! Could the choke wound on the iron core of a transformer be wound
> on  a  scrap  mains  transformer toroid instead Stefan?
Hi Chris,

Yes of course. I took a 50 VA transformer core. Of course it can be a 
bigger core. The idea is to reduce the mains current spike when charging 
the caps. Depending on your mains impedance that peak current can be 
very high, a factor 10 above the rms value maybe. WIth the series L you 
can reduce that a bit.
A more professional way would be to build a PFC supply, as used in most 
modern high power SMPS. But this is a project on its own. I didn't start 
it yet because it was not necessary.
OK, i'll take the photos from the server again.

73, Stefan