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THE AM BULLETIN BOARD => Technical Forum => Topic started by: Opcom on July 04, 2011, 10:45:29 PM



Title: BC-375 modulation transformer
Post by: Opcom on July 04, 2011, 10:45:29 PM
I'm wondering what a BC-375 modulation transformer will do. I am thinking 100W should be no problem. It's also made for 1000 B+.
pri DCR 120CT
sec DCR 100
ACV test pri 100V sec 73V so that is a 1.37:1 ratio.

Maybe it is about 6700 Ohms secondary based on the PA running 1KV/150mA. If so, primary would be about 12K or so which would explain using two VT-4's to modulate only one, they'd run at the high voltage but a lower current. The VT-4 is like the 211, a 100W tube, a pair will do 200W of audio. I think the BC-375 can do 60 to 100W carrier. so it makes sense. It might be good for any 1000V tube like the 811, 813, 572B, or even 4X150's.

Has anyone used one of these transformers?


Title: Re: BC-375 modulation transformer
Post by: WD5JKO on August 06, 2011, 02:05:08 PM

Patrick,

  I see no one answered this post. Maybe they did at the other place. I don't go there much anymore. If you did get an answer elsewhere, maybe share that with us here.

Jim
WD5JKO


Title: Re: BC-375 modulation transformer
Post by: Opcom on August 06, 2011, 05:43:34 PM
There was an opinion that it inherited a bad reputation from the design and operating characteristics of the transmitter it was used in, not the transformer's fault. Not many people seem to have used the transformer.
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands