RF systems on the Proton booster

Picture from NASA's PAO FTP site

The table below is valid for the Proton-K/DM vehicle and is derived from the Proton rocket handbook published on-line by ILS and from data published by Keith Stein on the Hearsat-L listserver. I think all transmitters and antennas for the first three are mounted in the third stage, where the guidance avionics is located. The picture on the right shows the top of the third stage of the proton that launched Zarya, the initial element of the International Space Station

# Fx  
1 192 0.256 20.8 TM stage 1
2 136.75 3.0 11.8 TM stage 1
3 240 0.256 20.8 TM stage 2
4 232 0.256 20.8 TM stage 3
5 132.4 3.0 11.8 TM stage 3
6 923 0.5 9.0 Block DM Tx
7 769 0.5 - Block DM Rx
8 2805 40 20 Block DM radar Tx
  1. This is an extremely strong transmitter and the frequency is that used by Salyut 4, Soyuz 16, Soyuz ASTP, Soyuz 22. Proton handbook gives modulation as "PM", but this is the modulation also given for the radar transponder for Proton-M, so probably PM stands for "pulse modulation" as well as "phase modulation". The bandwidth is quite similar to that observed in VHF transmissions from Soviet/Russian satellites using both PPM-AM and PCM/FM.
  2. Decimals given by Keith Stein. The Proton manual says "137 MHz"
  3. This frequency has also been used by Yantar photo-reconnaissance satellites and the modulation in that case was PCM/FM.
  4. This frequency has also been used by Zenit photo-reconnaissance satellites and the modulation in that case was PPM-AM (and later PCM/FM when the frequency moved from 232.0 to 231.5 MHz).
  5. Decimals given by Keith Stein. The  Proton manual says "132 MHz"
  6. This is the typical downlink frequency for the command-verification and telemetry link used by Energia spacecraft and is probably more precisely 922.75 MHz.
  7. This is the coherent uplink coherent with downlink 6. The "turnaround ratio" is 126/105, so the exact uplink corresponding to 922.75 MHz is 768.96
  8. The frequency is an interpretation of Keith Stein's number 2800-2810 MHz. The bandwidth is taken from the figure for the "tracking" transmitter of Proton-M in the Proton manual.
A blow-up of the lower section of the picture above shows four types of antennas clearly. I have made educated guesses as to which antenna fits which frequency.The unknown antenna looks like the 630-640 MHz antennas on Mir and Zarya itself. It could be a feature specific for the launch of Zarya to transfer telemetry from Zarya to the ground also during the launch phase.
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