RADISTA Radio-teleprinter set RTpS-100

To RTpS-100 description

Radio-teleprinter set RTU-100/V (1st version)

Radio-teleprinter set RTU-100/V was installed in the field vehicle Zastava AR-55V and trailer Zastava D-2V of 0.5 t payload capacity. The vehicle and trailer were produced at the automobile factory "Crvena zastava" Kragujevac in cooperation with the Italian company Fiat. In the same vehicle the station crew was also carried, consisting of three radio-teleprinter operators and a driver. The space with the driver and co-driver seats was separated by a canvas cover from the rest of the cabin. All parts of the system in the vehicle cabin were fastened to the steel frame, mounting frames, floor and cabin walls.

In addition to the vehicle and trailer, the Radio-teleprinter set RTU-100/V comprised:

Transceiver PD-6;
- it was built into a separate aluminium housing and is characterized by modular construction. The receiver and transmitter used common circuits, so it operated in simplex. In the transmitter, an output power of 150 W (PEP) was provided by 4 powerful pentodes QE 05/40, and in the modulator a mechanical filter at 455 kHz was used. Receiver selectivity was determined by 4 crystal filters at 455 kHz with selectivity of: 250 Hz, 700 Hz, 3000 Hz and 5000 Hz. The frequency was set in combination: with two switches in steps of 100 kHz and a variable oscillator 0–100 kHz. Frequency stability was 300 Hz, and this would later prove to be a major shortcoming for RTTY operation.

Antennas and antenna accessories;
- Antenna box KA-2 was also built into a separate aluminium housing and served for matching the transceiver to whip antenna AT-16.
- wire antenna AT-5 was used as a quarter-wave antenna for operation in the band from 1.5 MHz to 12.5 MHz. It was erected when the full range of the set was required and when frequent displacements were not planned. Its set comprised: an antenna mast of 8 tubular aluminium sections with a total height of 12 m, a joint with pin and antenna insulator, antenna wire 41 m long, 12 guy ropes for guy-ing, coaxial cable KK-10 12 m long for connection to the set, and other parts for erection and packing. On the march it was carried in the trailer in two packs. The sections and guys in a separate carrier-cover, and the smaller accessories in bag TB-21. The weight of the set was a full 34 kg, and its erection required a trained and well-drilled crew, so a more suitable solution was sought, but it nevertheless remained in the system set to the end.
- whip antenna AT-16 was used for transmit-receive at the halt and for receive on the move and consisted of an antenna base and five sections totaling 4.7 m in length, a guy rope and a packing cover. It was mounted on the rear left side of the vehicle cabin. When operating with it, the declared range was reduced by 20%.

Power sources;
- Mains rectifier MI-8 provided all voltages required for operation of transceiver PD-6 when RTU-100 was powered by AC 220/110 V. When a 12 V lead-acid battery was used as the source, it operated as a voltage converter and provided voltages for the receiver section of transceiver PD-6. It was housed in a separate casing closed with a cover.
- Battery charger rectifier MI-9 was housed in a separate box and served for charging the 12 V / 70 Ah lead-acid battery and for powering the remote keying and modulation unit UK-3. Powered by AC 220/110 V. Maximum battery charging current 6 A.
- Generator set AG-3 powered all consumers in the radio-teleprinter system with AC 230 V 50 Hz at a maximum power of 2 kW. Its set also included a 12 V / 135 Ah lead-acid battery. The same battery served for starting the generator set. It was topped up from the generator set itself with DC 14 V / 2 A. It used petrol as fuel and was transported in the trailer.
- 12 V / 70 Ah lead-acid battery powered the receiver of transceiver PD-6 when operating on receive on the move. It was placed in a housing under the driver's seat.
- distribution boxes KR-4 and KR-5 served for distributing voltages within the teleprinter system, and a 5-core power cable KE-6 30 m long brought AC 220/110 V from the generator set.

Equipment and accessories for radio-teleprinter operation and remote control;
Most of these sets are described on the page about telephone and telegraph equipment. They comprised: teleprinter Siemens T-68D or "EI" Niš ET-1, telegraph transceiver TG-2, telegraph transceiver TG-1, telegraph-telephone filter FL-1, Feld telephone M-63. For remote control with the magneto telephone M-63 or for keying the transmitter in continuous-wave telegraphy operation, in front of transceiver PD-6 it was necessary to connect the keying and modulation unit UK-3. Also for this purpose the system set included two reels of cable PTK-56 of 750 m each (total 1.5 km) and reel ML-1.

Operating accessories;
Operating accessories serve for keying and modulation on transmit or for converting the electrical energy of received signals into sound. The accessories comprised: telegraph key TS-1, handset MK-1, headphones SL-2 and loudspeaker ZV-1.

In addition to the above, the radio-teleprinter set RTU-100/V included accessories for mounting the equipment in the vehicle, auxiliary equipment for packing the gear and spare parts, various power and interconnecting cables, earth rod ZM-1, engineer tools (shovel and pickaxe) as well as a small staff tent for accommodating the crew.

HF radio teleprinter system RTpS-100/2 (2nd version)

Radio-teleprinter system RTpS-100/2 is a version that appeared in the mid-1980s and was mounted in the Pinzgauer 710K motor vehicle with 4x4 drive produced by the Austrian company Steyr-Puch. The designation "K" denotes a closed steel cabin (Kompaktwagen / hardtop). In addition to the equipment, all other parts of the system were also carried in the cabin: generator set, antennas, line cables... which makes this system more compact compared with the 1st version, which besides the vehicle also had a trailer for transporting the set.

Like RTpS-100/1, this system also operated in the HF frequency band from 2 MHz to 12 MHz. Modes of operation: SSB (LSB) and AM telephony, Morse-code telegraphy — CW, teleprinter telegraphy RTTY. The transmitter output power over the entire band is 120 W for CW and RTTY, 150 W PEP for SSB and 40 W for AM operation with 55% modulation. The other technical characteristics are completely the same as in the 1st version, with some improvements. The VFO frequency drift problem was solved by installing a direct frequency synthesizer, and some elements of the antenna system were replaced with newer ones made of more modern materials. The old generator set AG-3 was replaced by the domestic generator set AB-2.

System RTpS-100/2 was held on the establishment of an infantry regiment — brigade. In operation it was sited away from the command post so that it would not unmask it because of the transmitter power. The crew of this system consisted of four members: a driver and 3 soldiers of the radio-teleprinter specialty.

° Functional assemblies, equipment and component parts of the RTpS-100/2 set:

Transceiver, rectifiers and antenna matching	Transceiver PD-6/S built in vacuum-tube and transistor technology. Unlike the older transceiver PD-6, here instead of the VFO oscillator for selection from 0 to 100 kHz a direct frequency synthesizer was installed, and the exact frequency is set with switches. This eliminated the greatest shortcoming in teleprinter telegraphy RTTY operation — frequency drift. All voltages required for operation of transceiver PD-6/S and other equipment are provided by the voltage rectifier MI-8. When the system operates on receive on the move, rectifier MI-8 operates as a voltage converter and from the lead-acid battery provides voltage for the receive section of transceiver PD-6/S and 12 V for the VHF radio set RU-2/1 used for the service link. The 12 V / 135 Ah lead-acid battery was charged by the battery charger rectifier MI-9. Antenna box KA-2 (in some versions the antenna box KA-3 was installed) served for matching the transmitter output stage to the whip antenna. Antenna selection was made with the antenna selector, and the accuracy of the transmit frequency was checked with the frequency counter F4-3. Checks were made on a BIRD model 8141 dummy load.
VHF radio set	For official VHF communications the RTpS-100/2 set included the VHF radio set RU-2/1. (In some sets there was the VHF radio set RUP-12). The set was powered by 12 V DC from rectifier MI-8 or, when the system was operating on the move or when the generator set AB-2 was switched off, by 12 V from the 12 V / 135 Ah lead-acid battery.
Telephone and telegraph equipment and accessories	For receive and transmit of teleprinter telegraphy RTTY the electronic teleprinter ETL-1 manufactured by EI Niš was used. As the teleprinter modem the control unit UP-1 was used. On receive, error correction was performed by the telegraph error corrector TgKG-1. For receive and transmit of telephony and Morse telegraphy the following accessories were used: telegraph key TS-1, handset MTK-1, headphones SL2 and loudspeaker ZV-3. For the telephone wire service link the set included a Feld telephone set M-63.
Antennas	Wire transmit-receive antenna AT-5A was used as a quarter-wave antenna for operation in the band from 2 MHz to 12 MHz, transmit-receive whip antenna AT-25 and transmit-receive whip antenna AT-28 for the VHF radio set RU-2/1.
Power supply	The system was powered by 220 V / 50 Hz AC from its petrol generator set AB-2 or from the mains. Total power consumption of RTpS-100/2 for AC was 1.5 kVA, and the generator set AB-2 could provide 2 kVA in continuous operation. When the generator set was not running, the system was also powered by 12 V DC from the 12 V / 135 Ah lead-acid battery. It was charged via the battery charger rectifier MI-9. DC power consumption was 108 W.
Line accessories	Two-conductor field telephone cable PTK-56, 2 reels of 750 m (total 1,500 m in length), reel DB-3A. Cable winder ML-14, throwing pole MO-2 and line set TBv-28.
Other	Motor vehicle Pinzgauer 710K 4x4, 3 earth rods ZM-1 and cables: interconnecting, power and coaxial.