Radio collector Tom Brent provides some supplemental notes
on the TE-236B receiver.
" The TE-236B is another radio that appears to have only been used by
the RCN. I've had three or four of them and inside one there is a
label which states "Manufactured for the Royal Navy". I followed up on
that a few years ago, but nobody was aware of the TE-236B being used by
the Royal Navy nor could any documentation be found to support it.
The TE-236B was used at some of the D.O.T. marine radio stations on
the British Columbia coast but I'm quite sure this was war surplus equipment,
as hand-me-downs were plentiful after 1945. Except for minor differences
in some of the trimmer capacitor values, all fixed capacitors are identical
in both the RAK and TE-236B receivers and have the same part number assignments
on the schematic. Likewise,, the list of resistors is identical except
for R128 to R131 which are used in the output metering circuit and thus
are not used in the TE-236B. It would appear that when the the TE-236B
manual was ready for publication , RCA simply copied the existing RAK manual
since there is a blank space where R128 to R131 were omitted.
The TE-236B power
supply, like the receiver, appears to be a cost reduced version of
the RAK version. The TE-236-B and the RAK receivers both operated with
180 volts B+ from the AC power supply. The TE-236B-1 was designed to operate
from batteries only with a 144 volt B+ supply and two resistors (R104
and R-117) were substituted to enable this. I wonder why they (RCN and/or
RCA) felt it necessary to add this complexity? The RAK could also
be operated from a battery supply (which the manual refers to as "emergency
operation") but it still required 180 volts B+. This would also apply to
the TE-236B.
A few collectors I know have gone to the trouble of supplying DC to
the filaments in an effort to cure 60 Hz hum. I have a US Navy technical
bulletin that advises that only RCA 6D6's should be used for the detector
and first audio stages. Ken-Rad and Tung-Sol brands could used only
in the first and second RF stages. The hum was caused by the
construction of the filament in the 6D6 tube.
Note that the audio output transformer has a grounded center tap and
plugging a single circuit phone plug into the jack will result in half
of the secondary being shorted to ground. Use a 2-circuit plug to avoid
this problem ".
