T-347/SRT Buoy, Radio Transmitting



© Brooke Clarke 2017
Background
Description
Photos
    Fig 10 Tube ID
Patents
Related
References
Links

Background

This appears to be a emergency transmitter buoy. Marked:
T-347A/SRT
Buoy, Radio Transmitting
Serial  A21
Navy Department
Bureau of Ships
Contractor:
Summers and Mills Inc.
Dallas, Texas
Contract NObar 875??

Description

2.985" dia x  " long.
Weight:
The four main sections are:

Top - Antenna

Has BNC-f connector.  BNC-m to BNC-m cable runs to transmitter output.
Not sure what metal part on outside of antenna cap (Fig 3) is.

Flotation

Radio and Code Wheel

The radio uses a 8113 tube and there are adjustments for oscillator and amplifier shown in the following table.

Osc.
Amp.
Freq.
1500
1040
111.80
1400
1023
112.38
1300
967
114.03
1200
900
115.98
1100
829
118.09
1000
763
120.30
945

742
121.58
122.13
900
693
122.62
800
630
125.04
700
560
127.61
600
498
130.35
500
431
133.23
400
366
136.40
300
300
139.64
200
239
142.78
100
181
145.28
0
152.
146.33

Note: Approach set-
ting from clockwise
direction (rotate
ccw to release
backlash.

Power Supply

Converts the battery voltage to 6.3 Volts for the tube filament and also generates the B+ (125 VDC) for the power amplifier tube plate which is probably dropped by a resistor for the screen grid.
The negative voltage  (-1 VDC) for the control gird is probably generated by using a resistor between the cathode and ground.

Water Activated Battery



Photos

Fig 1 Overall View
T-347/SRT Buoy,
                      Radio Transmitting

Fig 2 Opened to show code wheel and table
Pink crystals at right are battery compartment desiccant.  Are they removable?
T-347/SRT Buoy,
                      Radio Transmitting

Fig 3 Antenna at top.
What is "D" shaped metal plate with one large and 2 small screws?
Ans.  It connects to the BNC center terminal so is where a tape antenna used to be connected.
The metal body of the buoy is the ground for the antenna system.
T-347/SRT Buoy,
                      Radio Transmitting

Fig 4 Water Activated Battery on left, power supply and radio on right.
Arm is the vent access and probably was to be removed prior to launch.
Pin at left of battery compartment has hole for a cotter pin and maybe a "Remove Prior To Launch" flag?
The hole left after removing arm goes into battery compartment
T-347/SRT Buoy,
                      Radio Transmitting

Fig 5 the three straps came mangled, not sure how to replace them or what their function is.
Maybe to protect tube?
Note two adjustments, each with fine and coarse readouts.
T-347/SRT Buoy,
                      Radio Transmitting

Fig 6 Code wheel motor at top, code wheel below.
T-347/SRT Buoy,
                      Radio Transmitting

Fig 7 another view of adjustments.
T-347/SRT Buoy,
                      Radio Transmitting

Fig 8 Battery on left, bottom of Power Supply on right.
7uF 150 Volts 1963 date code
T-347/SRT Buoy,
                      Radio Transmitting

Fig 9 inside of Power Supply
I think the round 5 terminal device is a transformer used to make an oscillator using the pair of 2N1042 transistors.
The output of this transformer also drives the conventional transformer which generates the B+ for the tube.
T-347/SRT Buoy,
                      Radio Transmitting

Fig 10 Tube ID:  This is a VHF power amplifier operating between 111 and 147 MHz.
GE
8113 or 8116
USN-8?13
Made In U.S.A.
64-13    64-48/ 188-5 (date codes)
--------------------------------------------------------------------------
Probably equivalent to the 6CY5 (Radio Museum, Frank.pdf)
3 & 4: 6.3 V filament
2 & 7: Cathode (0 volts)
1: Grid (-1 Volt)
6 Screen Grid (80 Volts)
5 Plate (125 Volts)
Pout: 2 Watts max
T-347/SRT Buoy,
                      Radio Transmitting

Fig 11
T-347/SRT
                              Buoy, Radio Transmitting
Fig 12
T-347/SRT
                              Buoy, Radio Transmitting
Fig 13
T-347/SRT
                              Buoy, Radio Transmitting


Fig 14
T-347/SRT Buoy,
                      Radio Transmitting

Fig 15
T-347/SRT Buoy,
                      Radio Transmitting


Patents

Tube Shield + Heat Sink
2807659 Tube clamp and shield, Woods Leroy Ralph, Internat Electric Res Corp (IERC), Sep 24, 1957 - Shield AND heat sink
2899670 Tube shield attachment, Leroy R. Woods, International Electronic Research Corporation, Aug 11, 1959 - slots that match bumps in base shield 
2935549 Tube shield liner, Leroy R Woods, Int Electronic Res Corp, May 3, 1960 - mesh with many points of contact with tube for heat sink   

Related

Sonobuoys
CRT-1 Sonobuoy - First one used in W.W.II

References

2N1042 PNP Transistor (Texas Instruments)

20 Watts
Vcemax: 30 Volts
Icmax: 3 Amps
Ft: 225 kHz
Package: TO-31



Links

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Page Created 24 November 2017