Michael Black wrote:
Scott Dorsey ) writes:

Primary 20,000 ohms single plate 10MA DC
Secondary 500 ohms

Ahh, wait, you DID give impedances!

What you want is a 20K to 600 ohm line output transformer. I bet a nickel
Hammond makes one.


There was a time when everyone made them. If you were making a phasing
rig, you'd need those to interface with the B&W phasing network (the
ones that came in a package like a metal tube). The B&W seemed to
be the most common, but I think the other similar networks (Central
Electronics was another manufacturer) used the same sorts of transformers.

So look for a phasing rig, and the transformers will follow.

Michael VE2BVW


Michael and Scott,

Thanks for the tips. I did check Hammond and did not find anything
suitable. The 51SB-B does use the B&W Model 350 (2Q4) audio phase shift
network. I suppose my best bet will be to look for a junk phasing rig
at a hamfest.

Gene W3PM