Inhaltsverzeichnis
AN/GRC-19 : T-195 / R-392
Radio station consisting of transmitter T-195 and receiver R-392, developed by Collins, produced by various manufacturers, including Collins, Stromberg-Carlson, Stewart-Warner.
To replace the medium-power radio stations from the Second World War, the stations SCR-299 or SCR-399 (in the shelter) based on the BC-610/HT-4 transmitter and the BC-312/BC-342 receivers, Collins was commissioned in 1951 to develop a medium-power radio station that could be used for mobile operation and parachute dropping. Under the direction of Fred Johnson, Collins' chief development engineer, the automatically tuned T-195 transmitter and the R-390-based R-392 receiver were developed.
Variants:
- T-195 transmitter, original version, power supply with dynamotor (rotary converter)
- T-195A transmitter, solid state power supply
- T-195B transmitter, solid state power supply
Technical data
- Principle: Radio station with separate transmitter and receiver; receiver - IF 9.5 - 18 MHz / 3 - 2 MHz / 455 kHz
- Frequency range: SW (1.5 - 20 MHz)
- Frequency display: mechanical digital display, 1 kHz
- Frequency memory: seven transmission frequencies
- Transmit power: 80 - 100 W
Power supply
- Rechargeable battery / battery operation: (24 -) 28 V DC (40 Amp.!)
Dimensions
- Transmitter: 560 x 290 x 360 mm, weight 55.4 kg
- Receiver: 275 x 360 x 275 mm, weight 23.7 kg
Accessories
- Power supply cable CX-2583/U
- Connection cable to receiver CX-1599/U, HF cable CG-1127/U for the HF signal to the receiver antenna input
- Handset H-33, loudspeaker LS-166 or headphones H-301
- Control box C-822 with microphone M-29/U or button KY-116; headset CW-49507 or H-33 handset
- for radio teletype operation modulator MD-203, FSK converter CV-278 and teletypewriter TT-76
- rod antenna or dipole antenna for stat. use
- MT-925 mounting frame (transmitter only) or MT-851 (with receiver as AN/GRC-19)
- Remote operating equipment AN/GRA-6
Operation
The T-195 is a CW/AM/FSK transmitter that covers the shortwave range 1.5 - 20 MHz and delivers 80 - 100 W of power to the antenna. It has electromechanical tuning with 7 transmitter memories and automatic antenna tuning.
The first obstacle to operation is the supply of the necessary operating voltage. To start the dynamotor, the rotating converter for generating the anode voltage, a power of 40 amps is required, which can now be supplied by a powerful power supply unit or a car battery. For operation, the various covers must be removed from the ventilation openings, the fan and the dynamotor generate a loud operating noise, so that headphones on the receiver are recommended for operation.
Operation is described in TM 11-806, seven frequencies can be preset and recalled electromechanically, the tuning knobs turn „as if by magic“ using servomotors. In position „M“ for manual tuning, a further frequency can be set. When a frequency is recalled, an automatic tuning process begins and the aerial is adjusted fully automatically; the transmitter must not be operated without an artificial aerial. For the automatic tuning process, the BAND SELECTOR and TUNING CONTROL buttons must be locked and the red mark must disappear. As long as this is visible, you must not switch from tuning position M to fixed frequency mode. The band range set with BAND SELECTOR is displayed to the left in a small window, above which the memory location number is displayed in fixed frequency mode. The frequency display is designed as a mechanical digital display as on the R-390 or R-392, depending on the band, the aperture reveals one of four windows with the frequency display.
The automatic tuning process is triggered with the TEST switch (and the transmitter emits HF, so an (artificial) antenna must be connected). When tuning to a new frequency, you will hear the motors of the antenna tuning network; when the TUNING INDICATOR indicator lights up, the tuning process is complete. To avoid overheating the transmitter tube, it is best to press the test switch for only 20 seconds and watch how the anode current decreases and the transmission power increases during the tuning process. After a short pause, activate the TEST switch for another 20 seconds and only leave it in the ON position when the anode current has reduced and the tuning process is almost complete. In the event of overheating, with the switch for dial illumination in the OVERHEAT CHECK position the red lamp lights up, the set must be allowed to cool down for a few minutes until the tuning process is restarted.
The R-392 receiver is technically related to the top-of-the-range Collins R-390 receiver, which is also equipped with a mechanical digital display, but battery tubes with an extremely low anode voltage of 28 V are used, so that the power supply can be used directly for the anode voltage without up-transforming. For this reason, the receiver delivers a significantly better reception result with an anode voltage of 28 V than with the minimum 24 V required.
The receiver can be operated standalone or can draw its operating voltage (in addition to the T-195 a further 3 - 4 amperes, which load the power supply) and antenna signal directly from the transmitter.
In contrast to the R-390, three IF coil filters with nominal 2, 4 and 8 kHz are used.
Technical principle
Radio station with separate transmitter and receiver
- Receiver R-392: triple conversion superhet
- Transmitter T-195: fully automatic tuning
Components
The set is tube-equipped.