RACAL RA-237B
Gerry O’Hara
5
Where rubber
threads were
present in inductor
slugs, I removed
these and added a
spot of ‘Kilopoise’
high-viscosity
lubricant to
prevent movement
due to vibration
whilst allowing
easy adjustment.
A couple of the
ferrite shrouds for
the inductors had
come loose and
these were re-
attached with a
spot of superglue.
Cosmetically, I
simply vacuumed-
out the dust, cleaned-up the knobs, removed some minor scratches and paint chips from the front
panel, and dusted the scale drum.
Testing and Aligning
The RA-237B really
needs the unit to be
connected to the RA-
117 to make it work
properly and to allow
set-up and test,
however, my RA-117 is
located at one end of the
basement and I don’t
have enough room in
my miniscule workshop
(at the other end of the
basement) for it in its rather bulky desktop cabinet. So, after a couple of basic checks (HT line
resistance to ground and filament continuity), I connected it up to the RA-117 (note: when it is
connected and switched to ‘10kHz to 980kHz’, the Wadley Loop and entire front-end of the RA-
117 is disabled and the RA-117 becomes simply a tuneable 2 to 3 MHz IF for the LF converter).
Connecting entails a couple of coax links (1MHz output from the RA-117 and output of the RA-
237B to the 2 to 3MHz ‘RF in’ socket on the RA-117), plus HT and AGC lines. Switching the
RA-237B on and the unit to LF, I heard a little hiss but other than that …. not a ‘sausage’!
