On Fri, 06 Mar 2009 19:39:10 -0500, K3HVG wrote:

SX-25 wrote:
I've got a receiver that has no identifiable markings and I wonder
if anyone can assist me in learning what it is?

The receiver can be viewed at

http://img.villagephotos.com/imageview.aspx?i=24536290

It is 10-inches wide, 8-inches deep and 8-inches high.

It contains two tubes and I presume it to be a regenerative. The
two
tubes are a 6J5 and a 6J7. Since the receiver has such
a cloak of mystery surrounding it, I have no way of knowing if
those
were original tubes or substitutions. The 6J5 may
very well have been a substitute for an original 6C5. The 6J7 may
have been a substitute for a 6W7.

At first I believed the receiver to be a derivation of either a
National SW series or possible a homebrew Frank Jones regen. However
the die cut of the cabinet and extrusions are too professional to
be
a homebrew nor does the wiring job underneath suggest a factory
made unit.

The two pointer knobs were on the receiver when I bought it
although, to me anyway...they look too modern for the rest of
the vintage of the receiver. Band is selected with a plug in coil.
The coil that was included was homebrewed and without marking.

The style, circuit and tube choice suggests a vintage of very late
1920s or 1930s era.

If any of you have any ideas or guesses I would welcome them.
Thanks.

WA9VLK

Looking at the photos, I'll vote for homebrew or, possibly, a rough kit
of parts supplied by a wholesaler of the period. The fact that the rear
of the cabinet reveals a too large opening for the chassis and its
lopsided sort of bodes homebrew, too. Tube vintage is.. what.. octals,
late 30's or 40's? The underside may well be the answer.... Nice find,
though.

de K3HVG

Those particular metal-octal tubes came out in '36 or '37 -- I have a
1940 RCA tube manual reprint, which was already touting the virtues of
the internally shielded versions.

That doesn't mean the receiver wasn't _designed_ in the late '30s, and
not _built_ until much later, of course.

I'd love to see a pic of the underside -- a really tidy job won't rule
out a really tidy homebrew, but a really messy job would certainly weigh
heavily against factory-made.

--
http://www.wescottdesign.com