Diagram of the remote setting frequency transceiver

Because not always PC is next to the transceiver, DM2AUO have proposed the remote setting frequency transceiver For fans to work PSK31, SSTV or FAX manual frequency setting is very often a problem can be remote control transceiver, independent of the computer. Modern transceivers the frequency of transmission and reception can be changed in steps of 10 Hz using keys that are controlled by buttons "Up" and "Down" through the microphone connector. If the buttons are pressed momentarily, the frequency changes steps, and more long press causes a smooth change in frequency. If the control input these keys will be commenced by a short sequence of button presses, you can get a continuous and slow change of frequency.

The author has solved this problem electronically, using for communication with the transceiver's microphone connector, especially because through it is fed with supply voltages from 5 to 12 In the possible consumption 10...40 mA (depending on the model of the transceiver).

Fig.1

Universal 4047 chip can operate as a monostable or astable multivibrator. Its power lies in the range 5... 15 V, and the current is negligible. In the scheme of Fig.41 IC 4047 is used in the function astable multivibrator. If the jumper JP1 is inserted, the multivibrator operates. When the button is pressed "Up" or "Down" are controlled by respective transistors Ts1 or Ts2 that through an open transition collector-emitter connect the corresponding pin of the transceiver with the common wire. Consumption of the device in working condition is 0.5 mA (u pit.=5 In.), 0.8 mA (u pit.=8); 1,4 mA (u pit.=12). With R4 set the speed adjustment from 1 kHz/min to 6 kHz/min.

Author: Max Perner (DM2AUO); Publication: N. Bolshakov, rf.atnn.ru