Kenwood TS-870S FM Transmission, FM Repeater Operation, Press RX B or RX a, Press RX a or RX B

6 COMMUNICATING

FM TRANSMISSION FM REPEATER OPERATION

FM operation on HF frequencies solves the problem of how to have long distance voice communication with the finest audio quality. When combined with the full-quieting aspect of FM signals that suppress background noise on the frequency, FM can be the best method for maintaining regular schedules with friends. And when conditions are unusually good allowing simplex FM contacts over intercontinental paths, you may feel as though you are using your local VHF repeater to talk across town instead of using the HF spectrum for multi-hop communication.

Refer, if necessary, to ÒOPERATING BASICSÓ beginning on page 19 for complete receiving details for any mode.

Note: Switch ON Menu No. 12 (FM.S-MET) if you prefer. This function applies a correction for the S-meter when operating on FM. This correction will adjust S-meter readings to be equal with other KENWOOD HF transceivers.

1Select the operating frequency.

2Press [FM/AM] to select FM mode.

AGC AUTO

FM

3Press [MONI] to switch the Monitor function ON.

Compared to the usual simplex method of FM communications on HF, which is radio to radio with antennas at or slightly above average terrain, you can often transmit much farther through repeaters.

Repeaters are typically located on a mountain top or other elevated location. Most often they operate at a higher ERP (Effective Radiated Power) than the average mobile or fixed amateur station. This combination of elevation and high ERP allows communications over wider and longer distances than can be achieved by the average station.

HF repeaters operate only in the 29 MHz FM sub-band. This special service combines the advantages of FM operation, good fidelity with noise and interference immunity, with the excitement of HF DX (long distance) communications. Even on a quiet day, 10 meter FM provides reliable around-town communications with the potential for sudden DX from across the country or around the world.

Note: Switch ON Menu No. 12 (FM.S-MET) if you prefer. This function applies a correction for the S-meter when operating on FM. This correction will adjust S-meter readings to be equal with other KENWOOD HF transceivers.

29.520 MHz
88.5 Hz	29.620 MHz

¥ÒMONIÓ lights.

4Press and hold down the Microphone [PTT] switch, or press [SEND].

¥The ÒON AIRÓ indicator lights.

¥Refer to ÒVOXÓ {page 45} for information on automatic TX/RX switching.

5Speak into the microphone.

¥FM microphone gain can be switched between low (L) or high (H) via Menu No. 61 (FM MIC). The default is low (L). Low is usually appropriate; however, select high if the monitored audio or reports from other stations indicate that your audio is weak. The Front Panel MIC gain control has no affect in the FM mode.

¥Speak in a normal tone and level of voice. Speaking too close to the microphone, or too loudly, may increase distortion and reduce intelligibility.

¥The CAR control does not need to be adjusted since the carrier level is fixed at the best setting for the FM mode.

6Release the Microphone [PTT] switch, or press [SEND] again, to return to the receive mode.

¥The ÒON AIRÓ indicator goes out.

Note:

◆When using the optional MC-90 in FM mode, the microphone sensitivity is low, and this may cause insufficient modulation. Use Menu No. 61 to select high microphone gain.

◆When the target station is using FM wide-band deviation, you also must select wide-band deviation (Menu No. 60). If you transmit using the narrow band against this rule, the target station will receive your audio less clearly.

29.620 MHz	29.520 MHz
	88.5 Hz

1Press [RX B] (or [RX A]).

¥The VFO selected in this step will be used for the transmit frequency.

2Select the transmit frequency.

3Press [FM/AM] to select FM mode.

AGC AUTO

FM

4Press [A=B].

5Press [RX A] (or [RX B]).

¥This must be the VFO that was not selected in Step 1.

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