SOV - PAR-7 (přívodná letecká radiostanice)

PAR-7 radio homing station



This high power (1,100 - 1,200 W) radio station is used to homing aircraft equipped with a radio compass to a designated area. In the OSP-48 system, it is used as a VPRS ("long-range") and can be used for one-way communication with aircraft.



Composition of the PAR-7 radio feeder system:


1. ZiS-150/ZiL-150 instrument box car:
The radio was delivered in a KUNG-1 superstructure on the chassis of the ZiS-150/ZiL-150 car.


- Some rdst were delivered to Czechoslovakia without a chassis - only a complete enclosure in the KUNG-1 cabinet and were used for "reassembly" into buildings as stationary ( in r. In 1958 at the 5th company of PZN Žatec),
or to be built into the body of a box car P V3S (PAR-7).



2. The PAR-7 transmitter and antenna system:
The PAR-7 transmitter operates in the frequency range 150 - 1000 kHz

Types of operation:
A 1 (unmodulated telegraphy),
A 2 (modulated telegraphy)
A 3 (phonics)


Accessories of the radio included:
- APS-2 automatic key
- telegraph key
- microphone
- earphones

In "Supply" mode, the call sign in Morse code is keyed by the APS-2 automatic key.(Apпарат Подачи Cигналов (/ АПС),
(An electric motor via worm gear "drove" the disc on which the mark was set. The switching contacts were then "keyed" via a relay during A 2 operation.
(The station could be used for so-called one-way communication with the aircraft - in case of a failure of its on-board radio station, the "feeder" operator could "communicate" instructions from the VS or flight controller to the pilot via a microphone. (The on-board radio compass had an "eavesdropper").


The antenna system uses the so-called ship's antenna "T". (3 wires 70 m long, on masts 20 m high). The system is complemented by a network of 16 counterweights, 50 m long and stretched in a beam pattern from the car, (or fixed masts or buildings).
A space of 110 x 110 m is required for deployment.
There is a 90 minute limit for deployment. ( 110 minutes at night, 120 minutes in winter)


3. VPU remote control console:
Used for remote control over a three-wire line up to a distance of 3 km.


4. Wavemeter:

Used to check the radio signals of the set frequency of the transmitter.


5. US-P or US-9 receiver:
Used to control the listening of the transmitter itself. The basic receiver was US-P with headphones. It was gradually replaced by the US-9 type.


6. MRM-48 radio beacon transmitter with antenna

The radio beacon transmitter MRM-48 ("Marker") was used to mark/mark the passage of the radio station (among others. It was also used to alert the pilot that after crossing the "far" he was about 4 km before the VPD threshold and to switch the radiopilot or automatic radiopilot (e.g. ARK-5) to the "near", after crossing which he was about 1 m before the VPD threshold.
The antenna consisted of a dipole with a reflector "on the ground" and provided directional knockout of radio waves in a narrow upward cone. It was folded on the roof of the car when moved.


7. The TAI-43 field telephone
The TAI-43 (or later TP-25) was used for telephone communication between the PAR-7 crew and the air traffic control office, the command post of their own unit, etc.


8.) ZiS-150/ZiL-150 resource box car:
When delivered from the USSR, it was in a KUNG-1 body on the chassis of the ZiS-150/ZiL-150 car.
It served as its own power supply, which consisted of 2 ZES-9K power generators (3x 220V; 9.2 kVA) for the possibility of AC operation.
The ZES-9K power generator consists of a gasoline, liquid-cooled L-12/4 engine and a three-phase synchronous SG-9S generator with an output of 9.2 kVA.
(similarly to the instrumentation part, it was delivered to the Czechoslovakia without a chassis - only a complete installation in the KUNG-1 cabinet, and were used as stationary (e.g. in 1958 at the 5th company of PZN Žatec they were reinstalled in the basement of the building ), or for installation in a trailer A 3S, as part of a set with P V3S.
Alternatively, a trailer-mounted power station EC 15 kVA(3x 380V; 15 kVA) was used
The total power input of the station was 6 kVA (transmitter 4.5 kVA) and was adapted to be powered from either 3x 220V, 3x 380V power stations or from the 3x380V/50 Hz mains.


The crew consists of.

Photo from the archive

Anténní systém PAR-7 (schéma z předpisu Let-51-70)