[Boatanchors] TCS Coax Mods & TN-233/SRC

[WA5CAB at cs.com]

Groups,

A list member (of one of these lists) recently acquired a TCS transmitter 
on which the Cannon K-series power connector had be replaced with an MS one 
and the antenna push posts with Type N connectors.  In private correspondence 
about both mods, I recalled in the dim past seeing photos of an "official" 
mod (for submarine installations) where the antenna posts had been replaced 
with N connectors.  After several false starts, I turned up the NAVSHIPS 
wherein I had seen it.  The manual is NS 92794 dtd 20 June 1956 on TN-233/SRC.  
It contains information on the tuner and on how to modify the receiver and 
transmitter.  It turned out that the list members transmitter was a ham mod 
but I thought that while I had the manual out I would post how the mod was 
done and what the tuner looks like.  In case a tuner or an "officially" 
modified radio ever turns up (none have that I'm aware of).

The tuner looks somewhat like the standard 47205 except that the front 
panel is square (taller than standard) instead of rectangular.  The box might be 
a little deeper, too.  The lower half of the panel looks like the standard 
unit (the loading coil and rotary switch are the same as in the standard 
one).  Above is a knob for another rotary switch and some N chassis connectors 
for input, frequency meter, and external dummy load.  Inside is a phantom 
antenna (resistor in series with either of two capacitors) and a pickup link 
for the LM.  The upper switch selects either phantom, the external load, or 
the antenna.  The coax connector going to the antenna is on top of the box 
and the coax looks from the photo to be 2" or maybe a little larger hard line. 
 No information on the antenna given.

Directions for modifying the transmitter and receiver are in the manual.  
Basically, the push posts are removed, the holes reamed out to 5/8", and 
using a connector as a guide, the panels are drilled and tapped for #4-40.  The 
connectors, which are UG-58A/U, are attached to the rear (inside) of the 
panel with four (three in the case of the one next to the RF Ammeter) #4-40 x 
1/4" binding head machine screws with lock washers.  The original wires are 
reused.  The original power connectors are not changed.  The cable used is 
RG-9/U.

If anyone ever turns up a tuner or a radio modified in this was, I would be 
interested in hearing of it.

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480