My Westinghouse Model WR-272 (circa 1937) requires an "orignal" design 6U5 tube
for the Tuning Indicator. The "original" design featured a glass bulb that was
shorter than the dimensions listed for the 6U5 in all of the online tube
manuals (RCA and Sylvania from 1943 on). In fact, the radio chassis is
designed so that the tube's maximum seated length (measured from bottom of base
to top of glass tube) can be no longer than 3 inches. The tube socket is loose
and connects to the tube base and the tube and socket can be adjusted back and
forth, in and out, from the hole in the backside of the tuning face of the
radio. Interestingly, the adjustment appears to accommodate tubes that are as
short as two inches.
I have purchased and returned a "modern" Sylvania 6U5 because it would not fit
into the space in the radio -- no matter what I tried. I have also called
several of the onlione tube merchants and the ones who have a 6U5 (or any of
the common substitue tubes) report that the base-to-top measurement is
typically 3 1/4 to 3 1/2 inches -- way too long for my radio.
Any help in locating an original, short version of the 6U5 (or substitute)
would be sincerely appreciated.


MDCalvert
Oak Ridge, TN