Building on the foundations of the APRS igate, the transmit side of the setup

In this video I show the transmit side of my potential igate now working, the circuit used is based around a version of the 555 timer IC that works as low as 2 volts, which is ideal because the Raspberry Pi GPIO does not like 5 volts on it, the circuit is available on the direwolf github page under the Raspberry Pi APRS document

As the radio has a transmit light I know by looking at it if it is in transmit or not, the transmitted audio leaves the speaker jack on the USB sound card on the Raspberry Pi, passes through a potentiometer with a tantalum capacitor on the wiper pin and out to the radio, the potentiometer is required to ensure transmitted audio is at the correct volume and is not over-deviating as a result of overdriving the radio.

The Pi also has a green LED on it to indicate data carrier detect.

#amateurradio #hamradio #aprs
Connect and chat with me:
I monitor the GB3IR and GB3HG repeaters (GB3IR is also on IRLP & Echolink), CB channel 19 mostly when mobile, the Hubnet and Network Radios channel 00.

You can now send me pager messages via the DAPNET from the DAPNET website or app or via SMS from a DMR radio via a gateway on the Brandmeister network on private call 262994 starting the message with 'M0WNU', I will receive these as long as I am in the range of my Jumbospot or a general pager transmitter that is part of the DAPNET