The MX-300S or Scorpio
Series
Notes on programming MX-300S.
MX-300S and MX-300R radio memory have a maximum of 48 channels, arranged in 4 zones of 12 channels. There are two kinds of memory, early ones that are EPROMs and can only be burned once, and EEROMs that can be reprogrammed. Both kinds can be programmed only with the R-1801A or R1821A suitcase programmer, with suitable adapter board and software (RTL5805C adapter and RTL4809C software). This version can program both the write-once and reprogrammable memories, but earlier versions can program only the write-once kind. The late version reprogrammable part is RPX4455A or NLN7302B.
If your radio has an old write-once memory but you aren't using all 48 channels, you can write the new frequencies to an unused zone in the memory and use that bank of 12 channels, and change the jumper on the flex print to select that zone of 12 channels instead of zone 1.
Henry Crun 97
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