The Maycom AR-108 and the identical Commtel COM307 and Albrecht AR106 are usually marketed as an 'airband scanner'. In spite of that, the European version covers 108-180 MHz, so it can be used for AIS and VHF paging reception.

If you have the US version, you should bridge the solder pads marked 'OP 4'. This changes the FM reception range from WX channels only into full VHF (136-180 MHz). [Thank you, Jon Z. for pointing this out].

The discriminator IC is a TK10930.

AR-108 / COM307 / AR106

The discriminator IC is located at the back of the PCB in the scanner's top half. The board can be disassembled in three steps:

1. Remove the volume- and squelch knobs and remove the washer from the potentiometer with a pair of fine tip pliers.
2. Remove the solder of the antenna plug's ground and inner conductor. Use desoldering braid or a desoldering pump.
3. Remove the three screws that connect the board to the housing.

The top half of the scanner

The discriminator IC, a 10930, is a VSOP (Very Small Outline Package) IC. Its pins are spaced 0,5 mm (0.02''). A 'normal' SMD in SOIC (Small Outline IC), like the MC3361, uses a spacing of 1,27 mm (0.05''). The discriminator signal can be found at pin 12, on a corner of the IC.

Pin 12 contains the baseband signal

A piece of wire is soldered to pin 12

A piece of wire is connected to pin 12 of the receiver IC. The wire can be fixed to the IC by a drop of glue from a glue gun.

After leading the wire to the other side of the circuit board next to the volume- and squelch potentiometer, the board can be mounted in the case again.

A 3.5 mm chassis socket is mounted in the scanner's other half. The signal lug is connected to the wire running from the receiver IC through a 10 k resistor.

The socket's ground lug is connected to a blank piece of copper clad nearby by a small piece of wire. You can see this wire running left of the resistor.

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