The TG-5 came out in the mid 1930s,
more than a decade after the
Fuller Phone.
It uses an interrupter that is essentially an earphone with a carbon
contact type switch driven by the diaphragm. The TG-5 must be
operated with the bottom of the case level for the interrupter to work
properly. It runs at about 1 kHz.
The signal sent over the wire is a DC level, not an audio tone.
There's a sensitive relay that detects this DC current and when it
closes sounds the tone (if the hi impedance headphone is physically
plugged into the jack-switch) or sounds the door bell if the plug is
removed.
The interrupter is a cleaver way to generate a 1 kHz tone without any
tubes or transistors.
This
is not 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. Uses 2
ea. BA-30
"local batteries" and one each (or more if needed) BA-2 22.5 Volt
"line Battery". The 22.5 Volt BA-2 has wire leads to connect to
the binding post. The two BA-30 "D"
flashlight cells go in a compartment on the back of the box. Uses
a single earphone (HS-32) that stows in the top right of the box.
The top left is the larger battery compartment.
These work with a single wire line and a ground return path, similar to
the Fuller phone using a 1,000 Hz tone generated by in
interrupter BZ-7-N.
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" versions
caused by the box being made of steel instead of Aluminum on the n.c.
and "A" versions. There are also newer versions of the
interrupter (BZ-7-N) and relay (BK-7-B) in the "B" version The
n.c. and "A" versions have adjustments "spring" and "gap" while the "B"
version has a single "adjust" for relay optimization.
If you have a CS-49-A canvas case please
let
me know.
I have scanned, cleaned about 95% of
the
prior copy curd, added some color photos, extensive bookmarks and
internal links for paragraph and figure references as well as in the
Table of Contents. TM 11-351. The manual was written for the TG-5
and TG-5-A and the two changes add information for the TG-5-B, BUT the
changes then were not done are complete pages that could be inserted,
but rather as comments, making it very difficult to actually change the
manual. This idea was to just keep the change pages with the
manual and refer to them. Not a very practical system, and that's
probably why it was changed to the current method of changes. So
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:
Brooke Clarke
3425 Deerwood Dr.
Ukiah, CA 95482
USA
This
is not 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. Uses 2
ea. BA-30
"local batteries" and one each (or more if needed) BA-2 22.5 Volt
"line Battery". The 22.5 Volt BA-2 has wire leads to connect to
the binding post. The two BA-30 "D"
flashlight cells go in a compartment on the back of the box. Uses
a single earphone (HS-32) that stows in the top right of the box.
The top left is the larger battery compartment.
Line Battery