Bottlehead Forum

General Category => General Discussion => Topic started by: Jim R. on December 22, 2009, 06:04:40 AM

Title: Dimensions of FC-1 choke?
Post by: Jim R. on December 22, 2009, 06:04:40 AM

I'm considering building an external choke-filtered DC supply for the filaments in the 2a3 amp I have but need to know the overall dimensions of the FC-1 choke.

Thanks,

Jim

Title: Re: Dimensions of FC-1 choke?
Post by: Paul Joppa on December 22, 2009, 06:22:59 AM

It's a horizontal channel frame with a 1" stack of EI-75 laminations. One side of the bobbin has solder lugs protruding. Overall dimensions are:

Mounting centers 2 13/16 inch
Weight 21 ounce (600 grams)
Height 2.00 inch
Width (outer edge of mounting tabs) 3.25 inch
Depth (bobbin plus solder lug) 2.125 inch

The core itself is 1.875 by 2.25 by 1.00 inch. The bobbin width is 1.75 inch and the solder lugs protrude another 0.375 inch on the one side.

Title: Re: Dimensions of FC-1 choke?
Post by: Jim R. on December 22, 2009, 06:29:04 AM

Thank you, Paul.  Now just have to find some suitable filament transformers for 2a3/45 and a schottky/stealth rectifier bridge no caps.)

-- Jim

Title: Re: Dimensions of FC-1 choke?
Post by: Paul Joppa on December 22, 2009, 09:03:55 AM

You may find a suitable 6.3vCT to use with two Schottky diodes - that's both more likely and a bit more efficient that a 4 or 5v transformer and a full Schottky bridge. There's someone over on the TubeDIY asylum looking into such transformers. We should probably have one made for us just so it is available...

Title: Re: Dimensions of FC-1 choke?
Post by: Jim R. on December 22, 2009, 10:21:59 AM

Make one and I'll buy it :-).

-- Jim