TS-790A Satellite Communications Addendum

The information in paragraph 4-9 of the TS-790A Instruction Manual has been revised to explain the satellite operating procedures.

Satellite communications utilize numerous frequencies and modes in a pre- assigned band plan. Transponders are used to control the contact. For example, part of the band plan of OSCAR 13 utilizes a frequency arrangement known as mode B. In this mode, you would transmit to the satellite (uplink) in the set frequency range of 435.425 - 435.575 MHz. Your signal will be processed by the transponder and re-transmitted back to earth (downlink) in the frequency range of 145.975 - 145.825 MHz. The TS-790A is capable of allowing the uplink and downlink frequencies to track simultaneously by storing the sum of the two frequencies in memory. Memory channels 0-2 are programmed by the factory for FO-12 and OSCAR 10. The remaining memories are user programmable. To operate the TS-790A in the satellite mode, proceed as follows.

Entering Data

Determine the uplink and downlink frequencies of the satellite you are tracking

Add the two frequencies together. The sum can now be placed in memory as follows:

  1. Press the F key and then the SAT key.
    Note: This function is inoperative when SUB is selected.
  2. Rotate the Tuning knob to select the desired satellite memory channel.
  3. Press the ENT key and then enter the frequency using the numeric keypad. The frequency will be automatically stored after the seventh digit has been entered.
Recalling Data

The satellite memory channels can be recalled in the following manner.
  1. Press the F key and then the SAT key.
    Note: This function is inoperative when SUB is selected.
  2. Rotate the Tuning knob to select the desired satellite memory channel.
  3. Press the SAT key to recall the initial mode setting.
Operating Procedure:
  1. Recall the desired satellite memory channel as described above.
  2. Select the SUB function.
  3. Use the TUNING knob to select the desired downlink (receive) frequency.
  4. Press the SAT key. The MAIN display will shift to the correct uplink frequency.
  5. Each time you change the SUB frequency, press the SAT key twice in order to update the MAIN display. The first time SAT key is pressed, the transceiver goes out of the satellite mode. The second time it is pressed, the transceiver goes back into the satellite mode and updates the MAIN display. An alternative method is to press and hold the SAT key when going into the satellite mode. While the key is held, the TUNING knob can be rotated and both displays will track simultaneously.

Note:In step 2, the SUB key was pressed to allow the TUNING knob to control the downlink (receive) frequency. If the MAIN key is pressed, the tuning knob will control the uplink (transmit) frequency.

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