Batboard

I am doing work for a city south of me, they have Minitor 5's installed and the audio out goes into a amplifier to alert the station when a call comes in. The problem i am having is the pager acts like a microphone when it receives a 2 tone call. You can actually pick up the base off the pager and talk into the pager and hear youself softly come out of the speakers. Also there is a 60Hz humm only going off when the pager is opened, the buzz is coming out of the audio. I called M, and they said they would open a ticket. Anyone have an idea how to get rid of the buzz. I have used several audio transformers and ground lifts and everything my 28 years of audio taught me. I am lost....

Unless someone here has access to the internal details of the Min V(which I doubt...they're too new) your best bet may be to switch rather than try to depend on Motorola to find out what the source of the problem is. CM200s with a smallish power supply probably wouldn't cost any more than the Min V setup that you're trying to get to work, and you'll have no problems with microphonics, hum etc. Unless you have the requirement for alerting on multiple sets of tones, if it was programmed for QCII with only one set of QCII tones it should replace the Min V acceptably.

Thanks, for the response, but as you figured out, this city went with the M5 because it allows them to be dispatched on diffrent tones and diffrent freqs. I have never scene a pager become a microphone before, I am trying to talk them back to thier M2's, but the new captian thinks new technology is better, which sometimes is not always true. If any see any bullentins from the big M on the M5's issues please let me know.

O.K. I just plugged computer speakers in to the bottom of my M5 and I hear the hum comming out of my pager too, so the hum must be comming from the output audio of the pager. Do you have just the pager plugged in or an amplified charger with the house amp plugged into that. I have no clue about the microphone thing though try a different pager or amp charger.

I tried several pagers and the noise is coming from the audio output. I have the M5 in the amplified charger an then the audio output from the charger going into a line level input on an amplifier. I tried both the 6 pin plug and the remote speaker plug for audio, both produce a hum. As for the mic issue, I do not know how to explain it, the pager when it gets a 2 tone activation, turns into a mic and if you tap the pager while in the charger you can hear the tapping coming out of the sprakers. I tried holding the diffrent pager in my hand and set it off, and while turing up the volume, i could tap on the bottom of the pager and you could hear it come out of the pagers speaker. M created a pager and micorphone all in one (hahaha).