Maxon Radio

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Maxon SD125

These tune from 144 - 178 MHz and work great for APRS stuff. See image to the right for the pinout.


I got several of these off ebay used for cheap, but the power supplies were damaged. It appeared like someone had hooked the power up backwards as several of the reverse polarity protection diodes were blown off the board. Several tantalum caps were also damaged. Replacing those fixed one of the radios, but the other one had the switching power supply chip damaged as well as the buck regulator FETs shorted out. That was more work to replace and required removing the shielding can from the logic board - see the pictures.

Removing the damaged components.
New chips soldered on.

Squelch programming cable Icon-pdf.gif

Programming Cable Icon-pdf.gif

Service Manual Icon-pdf.gif

SD125E Programming software