MX300 info-photo page

All of the radios here are MX300-s series which includes MX320, MX340, MX350, MX360

the-s on the number means that it is a synthesised radio. You can tell by the red MX300-s writing beside the antenna. The radio to the right below is a mx360 VHF radio with selcall and the lef one is a UHF converted to CB. If you can get any old un-synthesised radios it's a good idea as they have many interchangeable parts with the MX300-S. Of paticular value is the external squelch pot and knob.

The radios with DVP or "Digital Squench" have a zone switch marked AB or rotary witch marked ABCD and a switch to the right to disable DVP etc and revert to level squelch. The squelch control is located insid on the PCB. To place a squelch control externally requires it to be placed where the zone switch is located and reconfigure the other switch to be the zone switch "Damn tricky but what the heck we aren't doing it for the money!"

Here's the original Code Plug that is nearly impossible to get and just as hard to program without a field programming set.

Heres my codeplug to UV-Eprom adapter.

This is very troublesom to make. You would have to be crazy to do so (I AM)!. The stiffening bar that compresses the board against the synth module is actually out of a broken synth module. There are two of them in the synth module. The PCB is actually an original code plug that has been removed from the metal case and has had the bipolar prom removed. soldering ranges from a little tricky to almost impossible based on your equipment and experience

My Eprom adapter installed where the DPL (Digital Private Line) module used to be. There is a metal clip that slides over the VCO and synth module (Not shown here). It is very important as it seems to ensure the stability of the system. Make shure you have one installed.

MX350 with the codeplug removed from the synth module. You can see the connector to the rihjt of the synth where the DPL module used to be.

Heres the PCB from an old code plug.

IT is a 3 layer PCB and is topped by a 256 byte Bipolar PROM

Here is a VHF MX360 with the code plug installed and a selcall module beside it

Note the codeplug has 145.175 on it. Thats because it is my moble APRS (Automatic Position Reporting System)
radio which is interfaced to the well known Tiny Track TX only APRS Modem. Cool Hey !