The Sony Air-7 is a vintage receiver. Thanks to the spacious layout, it's not to difficult to equip it with a discriminator output.

This receiver uses a discriminator circuit with discrete components: a ceramic filter and two diodes. The unfiltered audio can be found on the cathode of diode D23.

The linearity of this discriminator circuit is poor and therefore less suited for AIS. However, the Air-7 performs well as a paging receiver.

Air-7

The cathode of D23 contains the unfiltered audio

The right pin of D23 is the cathode

The components for the discriminator output

These two wires need to be connected

The earphone socket can be reused.

• Follow the wires from the earphone socket to the bottom of the scanner
• Cut the wires
• Connect the red and yellow wires and isolate them with tape or shrink tubing. This reconnects the loudspeaker.
• Connect the red wire coming from the earphone socket to the positive lead of the electrolytic capacitor
• Solder the black wire running from the socket to ground