Found one resitor, changed value and I can tx down to 8.75 volts

FYI
For 16 channel no display or DTMF you have to specify the part number.
reason- if the accessory jack is two piece or one piece.
if model number has ZPC or ZPD it has a two piece accessory jack and referb kit is HLN9632B while if model number has ZRC,ZRD,ZRF or ZRH it is newer and part number is ...

We have clients that are finding they cannot transmit from the PM400 while they can from the CDM series, the M1225, GM300 and so forth.

They can start a tandom truck, but cannot call for help if they run into problems. This is why I am looking for a work around.

In the CDM you can at least use ...

Has anyone had any experience with low battery alerts for the PM400. In particular I am looking for a work around for the transmit inhibit