1942, U.S. ARMY, SIGNAL CORPS TG-5-B TELEGRAPH SET and CS-49-A Canvas Carry Bag, SERIAL NO. 7036
民國31年，美國陸軍，通信部隊，TG-5-B有線電報機及CS-49-A攜行袋，序號:7036號《Black Water Museum Collections | 黑水博物館館藏》
1. General
a. Characteristics. Telegraph Set TG-5-(*) is a portable, opencircuit, field set designed for telegraph communication over short lines. The set may be used on ground return circuits obtained by simplexing a telephone circuit, or on other ground return or metallic circuits. The range of the equipment will vary with the type of line wire used, the condition of the wire, whether the wire is wet or dry, and whether the wire is on the ground or in the air. The telegraph set will operate satisfactorily over field wire circuits of any length likely to be encountered within divisions or subordinate units, provided the lines are well constructed.
b. Nomenclature. Telegraph Sets TG-5, TG-5-A, and TG-5-B are referred to in this manual as Telegraph Set TG-5-(*). Such nomenclature refers to any one or all of the above three models. Similarly, Relay BK-7-(*) refers to Relays BK-7, BK-7-A, and BK-7-B; Case CS-49-(*) refers to Cases CS-49 and CS-49-A; Key J-41-(*) refers to Keys J-41 and J-41-A; Interrupter BZ-7-(*) refers to Interrupters BZ-7-A, BZ-7-C, BZ-7-J, and BZ-7-N; and Interrupter BZ-5-(*) refers to Interrupters BZ-5 and BZ-5-G.
2. Description
a. Case CS-49-(*) (fig. 2). The case is made of heavy olive-drab canvas with leather reinforced bottom and corners. The cover is hinged at the back, overlaps the sides and front, and fastens in front with a snap fastener. Sewed to the sides of the case is an adjustable carrying strap in approximately 2 inches wide and 85 inches long.
b. Box (figs. 3, 4, and 5). The box which contains the circuit elements of Telegraph Set TG-5-(*) is constructed of sheet metal and is approximately $ l / 2 inches high, 10 inches long, and 5 l / 2 inches deep. The box is provided with a hinged front and cover. When closed, the cover projects over the front edge of the box and holds the front in place. In the closed position a spring catch on the front engages with a hasp mounted on the cover and serves to hold the cover closed. When open, the front folds down to form a shelf upon which Key J— 41— (*) is mounted. A wiring diagram of Telegraph Set TG-5-(*) is mounted on the inside of the cover. On the inside of the box, near the back, a compartment is provided for installing one Battery BA-2. To the right of this compartment a space is provided for storing the headset when not in use. In the rear of the box, a hinged door, held in place by a locking screw, provides access to the battery compartment which is designed to hold two Batteries BA— 30. (See fig. 6.)
Section II. APPLICATION
5. General
Telegraph Set TG-5-(*) may be connected directly to each other by metallic or ground return circuits, or may be used in conjunction with existing wire systems to provide additional communication channels. In either case operation of the telegraph set is the same. The telegraph set can also be used as a tone keyer for voice-modulated radio sets, permitting transmission of International Morse Code over radio sets originally designed for voice operation only.
a. When used on metallic or ground return lines, two telegraph sets may be connected in series as terminal stations and one or more telegraph sets connected in series with them as intermediate stations. No more than three or four telegraph sets however, can be so connected and still operate properly.
b. When used in conjunction with existing wire systems, two telegraph sets may be connected in series as terminal stations or one or more connected in series with them as intermediate stations on a simplex, phantom,or simplex-phantom circuit by use of repeating coils contained in the equipment with which they are operated.
c. Telegraph Set TG-5-(*) will operate satisfactorily as a tone keyer with any Signal Corps radio using a standard carbon button microphone, such as Radio Sets SCR-300, SCR-508, SCR-510, SCR-608, SCR-610, and SCR-619. An adapter cord is necessary to permit the use of the telegraph set as a tone keyer. This cord consists of a two-conductor cord terminating in Plug PL-55 on one end and Plug PL-68 on the other. The cord is so wired that the tip and sleeve of Plug PL-68 are connected together and through the cord to the sleeve of Plug PL-55. The ring of Plug PL-68 is connected through the cord to the tip of Plug PL-55 in series with a 400-ohm, 1/2-watt resistor. The resistor is connected in the circuit to prevent r-f feedback which results in steady tone modulation in some cases.
6. Range
The range of Telegraph Set TG-5-(*) is dependent on the type, construction, and condition of the wire lines used, weather conditions, adjustment of the relay, condition of the battery in the set, and the type of telegraph sets working together. When the conditions given above are at their best, the following ranges can be expected on a simplex circuit :
a. Two Telegraph Sets TG-5-A working together will operate satisfactorily, at a speed of 20 words per minute (wpm), over 50 miles of wet Wire W-110-B. On dry Wire W-110-B the sets will operate satisfactorily when the total resistance of the line does not exceed 23,000 ohms.
b. Two Telegraph Sets TG-5-B working together will operate satisfactorily at a speed of 15 wpm, over 50 miles of wet Wire W-110-B. On dry Wire W-110-B the sets will operate satisfactorily when the total resistance of the line does not exceed 72,000 ohms.
c. Telegraph Set TG-5-A working with Telegraph Set TG-5-B will operate satisfactorily, at a speed of 20 wpm, over 30 miles of wet Wire W-110-B. Over dry Wire W-110-B the sets will operate satisfactorily when the resistance of the line does not exceed 26,000 ohms.
Comments