TG-5 Telegraph Set
© Brooke Clarke 2004
CS-49 Canvas Carry Bag
The TG-5 came out in the mid 1930s,
more than a decade after the Fuller Phone
interrupter that is essentially an earphone with a carbon
contact type switch driven by the diaphragm. The TG-5 must
operated with the bottom of the case level for the interrupter to
properly. It runs at about 1 kHz.
The signal sent over the wire is a DC level, not an audio
There's a sensitive relay that detects this DC current and when it
closes sounds the tone (if the hi impedance headphone is
plugged into the jack-switch) or sounds the door bell if the plug
The interrupter is a cleaver way to generate a 1 kHz tone without
tubes or transistors.
a phone, but a Morse code set that works
with a pair of field wire or more commonly with a single wire (or
phantom wire) and an Earth ground. 4 x 7 x 5" high.
"local batteries" and one each (or more if needed) BA-2 22.5
"line Battery". The 22.5 Volt BA-2 has wire leads to connect
the binding post. The two BA-30 "D"
flashlight cells go in a compartment on the back of the box.
a single earphone (HS-32) that stows in the top right of the
The top left is the larger battery compartment.
These work with a single wire line and a ground return path,
the Fuller phone using a 1,000 Hz tone generated by in
TM 11-351 Telegraph Sets TG-5 and TG-5-A, Sep 22, 1941.
Change 2, dated 22 July 1943 adds the "B" revision. The "B"
version weight 7 lbs, compared to 6 lbs for the n.c. and "A"
caused by the box being made of steel instead of Aluminum on the
and "A" versions. There are also newer versions of the
interrupter (BZ-7-N) and relay (BK-7-B) in the "B" version
n.c. and "A" versions have adjustments "spring" and "gap" while
version has a single "adjust" for relay optimization.
If you have a CS-49-A canvas case please let
There are two batteries needed.
A BA-2 dry battery is used for
normal line battery applications, but
for long lines additional batteries can be connected in
Each BA-2 supplies 22.5 Volts. It may be that the TG-5
application is the reason these were still being made.
Freeport, Illinois, U.S.A.
3 3/8" wide (3 5/8 counting bulge) x 2 1/2" tall (excluding wires) x
15/16" deep. 12.6 oz. DMM shows 22.97 Volts open
You could use three each 4 cell AA battery holders in series with a
cell AA battery holder (15 cells total or about 22.5 Volts total)
A couple of BA-30 (common "D" cells) are used for local power.
CS-49-A Canvas Carry Bag
Bag photos from John Forster.
Manual TM 11-351 w/ Changes 1 & 2
I have scanned, cleaned about 95% of
prior copy curd, added some color photos, extensive bookmarks and
internal links for paragraph and figure references as well as in
Table of Contents. TM 11-351. The manual was written for the
and TG-5-A and the two changes add information for the TG-5-B, BUT
changes then were not done are complete pages that could be
but rather as comments, making it very difficult to actually
manual. This idea was to just keep the change pages with the
manual and refer to them. Not a very practical system, and
probably why it was changed to the current method of
you need to read the changes on this manual.
TM 11-351 on CD-ROM to U.S. mailing address $11.50.
You can use your charge card by means of PayPal
or send a cashier's check or money order to:
3425 Deerwood Dr.
Ukiah, CA 95482
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