Many Amateur radio operators, no matter what transceiver they have, try in one way or another to improve the quality of the transmitted signal. Someone has a timbre coloring of a voice "wrong", another ones has a microphone unsuitable. In home-made transceivers the correction is usually achieved by selecting the values of capacitors and resistors in the corresponding circuits of microphone amplifiers, or the frequency response is corrected by simple timbre regulators; the owners of "branded" units have to buy expensive Studio microphones and equalizers, the use of which in Amateur radio is rather unjustified than necessary.
Anyway, the use of the equalizer very often allows you to improve the signal, and you can do it almost for free, if you have a couple of hours and make the proposed device yourself. The signal quality will not be worse than when using a “branded” expensive equalizer. The five-channel equalizer for the transceiver is developed on the TA7796P (KA2223) chip, which was designed for home appliance applications. We have added an amplifier on the JFET to make it using the equalizer in the microphone amplifier path.
- Chip TA7796P-5 band audio mono equalizer:
- Power supply 4 - 16V; Current 6 mA;
· Input and output voltage from unit 0.775 V (0dB);
· Amplitude Frequency Response: 20 Hz-20 kHz, 1.5 dB;
- Voltage of noise 3 µv;
- Correction depth ± 11.5 dB;
- TA7796p analogues: KA2223, DBL1046, M5226P, LA3600.
- Regulator: 250 Hz, 500Hz, 1 KHz, 2 KHZ, 4 KHz
After installation, the device starts working immediately. No adjustment required.