Licensed Amateur Radio operator in 1996 as IW5EDI, active member of ARI Firenze and ARRLĬlass 1970, married with two childrens, love experimenting and antenna home-brewing. Use a 4060 IC and a 455khz filter with minimum of parts. Very simple and stable circuit to produce 1750Hz tone from 12Volt single supply. The circuit has a total rangeÂ of 2-15% of band and isÂ suited for CW-decoders,AFSK-RTTY, TV sync-decoder. This plan is the ideal solutio to remote control ATV station or repeatersįor good sensitivity only minimum of input AF-Voltage is recommended. Pin TOE is useful to enable 3 Sate output of MT8870.Ĭombine this circuit with CD 4028 decoder or 4514 demultiplexer.

Resistor R at the input is dependent on input voltage. Max current on each output of 74LS154 is 20mA.

Pin DV (data valid) enables a demultiplexer. This circuit is capable of decoding 16 different pairs of tones. In order to monitor RX signals transmitting with no tone, you have to use pin ( open to listen) OTL You can find aÂ filter this embebbdedÂ (0-300Hz) to haveÂ low tones off the speaker. In this project The IC detects 39Â tones in theÂ Â 67 Hz – 250 Hz range This plan is an ideal mod for old FM tx, without Tone Sqelch. Sub – audible tone decoder based on aÂ a MX165CP from MX-com

Ham radio deluxe for raspberry pi