Motorola PX300-S (MX300 in a box) Question
Posted: Sun Dec 07, 2014 6:45 am
i picked up a PX300-S lunchbox radio. (former navy unit)
the radio was missing the usual Secure module, and Prom, common with military decommissioning of MX gear but also missing a variety of other modules.
i transferred my C revision EEPROM to it, the DES NLD7900D board so all the audio paths work, transferred all the other missing boards and the stuff tuned for ham such as the Preselector from my working HAM/BIZ MX360
the radio comes to life now with several issues, 1. there's a Ticking sound thru the speaker, like a helicopter and its not Receiving a signal from one of my other radios, but it does hear static when i open squelch (with the helicopter ticking mixed in there) and 2. the PL decode doesn't work.(even in Decode mode i still hear static)
this PX300-S radio has an MPL option with a rotary for 8 PL selections. this knobs wires go to an option board on the bottom of the MX radio circuit board with a part number of something like PLN74X3A (where X is i cant tell the number and the last digit looks like the upper half of a 3) unfortunately this option boards daughter boards or modules have been removed.
also, i have placed a PL module in the normal place on the MX main board, but it has no effect. i dont really need the MPL option so if i could disable it to use the one pl that plugs into the main MX board, im ok with that too
anyone have any ideas on what the ticking is, and boards or modules go on that PLN board or how to get the MX not to use the MPL circuit?
wazz
the radio was missing the usual Secure module, and Prom, common with military decommissioning of MX gear but also missing a variety of other modules.
i transferred my C revision EEPROM to it, the DES NLD7900D board so all the audio paths work, transferred all the other missing boards and the stuff tuned for ham such as the Preselector from my working HAM/BIZ MX360
the radio comes to life now with several issues, 1. there's a Ticking sound thru the speaker, like a helicopter and its not Receiving a signal from one of my other radios, but it does hear static when i open squelch (with the helicopter ticking mixed in there) and 2. the PL decode doesn't work.(even in Decode mode i still hear static)
this PX300-S radio has an MPL option with a rotary for 8 PL selections. this knobs wires go to an option board on the bottom of the MX radio circuit board with a part number of something like PLN74X3A (where X is i cant tell the number and the last digit looks like the upper half of a 3) unfortunately this option boards daughter boards or modules have been removed.
also, i have placed a PL module in the normal place on the MX main board, but it has no effect. i dont really need the MPL option so if i could disable it to use the one pl that plugs into the main MX board, im ok with that too
anyone have any ideas on what the ticking is, and boards or modules go on that PLN board or how to get the MX not to use the MPL circuit?
wazz