b. Ensure the right equipment is available. To install a TD-1234/TT at the maximum distance
from the AN/TRC-173, eight 14-mile reels of CX-11230A/G are needed. That will provide a distance of
2 miles. A source of power, power cable, and plug is also needed. The equipment does not get its
power from the CX-11230A/G. Ensure the ground rod, ground cable, and a hammer or mallet are
available, and don't forget to protect the eyes with goggles. Ensure there is at least 1/4 mile of WF-16/U
telephone cable to go from the TD-1233/TT to the 4-wire telephone. Any 4-wire telephone TA-838(
)/TT, TA-954/TT, or TA-341/TT will work on this equipment. The TL-13 is needed to prepare the wire
ends to fit into the TD-1234/TT and the telephone.
45. In the old days, the Army used large switchboards in an area and all telephones were wired
through it. Now the units are dispersed and only a few telephones go into an area. The TD-1234/TT
will permit the use of up to eight telephones. The TD-1234/TT will accept the signal from the telephone
and mix it or multiplex it to be technical, and send all signals out as one signal to the van where it is sent
on its way.
46. The TD-1234/TT will also provide remote power to another piece of equipment-the TD-1233/TT.
This unit can handle four telephones at one time and can be placed up to 2 miles from the TD-1234/TT.
The telephones can also be up to 1/4 mile from the TD-1233/TT.
47. Both units, the TD-1233/TT and TD-1234/TT, will provide the installer with an analog order wire
system. Using the test set telephone TS-3647/G, the installer can then troubleshoot the system from the
TD-1233/TT all the way back to the van.
48. The TD-1234/TT requires 115 V AC. It has an internal power supply to change it to the proper
operating voltages needed for the circuit cards. It also has another power supply to provide the remote
voltage needed for the TD-1233/TT. The TD-1233/TT will operate on voltages of 28 V DC or 180 V
49. The front panel controls are used to turn the unit on and to let the installer know when there is a
problem. There is an ALARM SMY indicator, ALARM LOI indicator, ALARM POWER SUPPLY
indicator, ALARM TEST pushbutton, a main POWER BREAKER circuit breaker, a power lamp, a
REMOTE POWER OUT ON/OFF toggle switch, power ON/OFF toggle switch, and a REMOTE
POWER OUT indicator.
50. There are up to 16 circuit cards inside that do all the work. They provide power, remote power,
and process the telephone signals. In positions A9 through A12, you can interchange the cards. If you
are installing digital telephones such as TA-954/TT or KY-68, you need a loop modem (LP MDM) card.
If you are installing a TA-341/TT or a TA-838( )/TT, you need an analog applique unit (AAU) circuit
card. You can mix or match the cards depending on the telephone. (See Figure 1-30 for circuit card
locations. Note that positions A9 through A12 can handle two telephones that are the same.)