Saber PSM nmn6154b

[r.a.p.d.explorer]

Hello,I have a Motorola public safety mic(#NMN6154B)that I bought for my Saber.When I connect the mic to the radio,the push-to-talk on the mic works,but when the radio recieves,no audio comes through the mic's speaker;only very low audio comes through the radio's speaker.I opened the mic's case,and saw that the green wire that is connected to the speaker was cut.I reconnected the wire,but I still get no audio.Is there anythig else that could be wrong with the mic?

[Tom in D.C.]

First question: With the speaker/mic disconnected do you get normal audio out of
the radio's internal speaker? If you do then the radio's audio output is okay, which
eliminates one area of possible trouble.

Next, does that 6154 have an auxiliary audio jack? If it does, try connecting an earphone
or other speaker to it to see if you can get normal audio via the jack. If you can then the
problem is with the 6154's innards.

The Saber has an internal, electronic, sensing circuit that switches the audio output to the
external device when the device is connected. It is not uncommon for this circuit to be
a problem, which is the reason I suggested the first question, above.

Last, if you can get hold of another speaker/mic that's known to be good that's probably the
best and fastest way to diagnose the problem.

[r.a.p.d.explorer]

Thanks for the reply.The radio's speaker works fine when the mic is not connected.My Jedi style mic works on the radio,so the connector on the radio must work.The earphone jack is threaded,and I do not have an earphone that fits.

[mike m]

Edited a 2nd time:
Looking at the info from the link below I see there isn't an option for external mic only so I jumped the gun but it's still worth the while to check your mics option select voltage just to see what it is.


The info below is correct for the PSM with ext antenna, ext mic and ext spkr.

The correct UDC voltage measured as below should equal 2.5 Volts DC For EXT MIC, SPKR and ANT.

It's possible that the Option Select line is set wrong but now it doesn't appear to be as there isn't a mic and antenna only option.

With the spkr mic connected up to the radio, and the radio powered on, measure the DC voltage from pin 7 of the UDC to ground of the UDC and it should be 2.5VDC for external antenna, external spkr and external mic.

Go to this link http://www.batlabs.com/saberacc.html to see the UDC pin numbers, UDC ground is taken from the ring around the external antenna connector BTW.

Since the above probably isn't your problem, then I have a dumb question. Have you checked the spkr in the PSM to see if it is good ?

Mike

[r.a.p.d.explorer]

Thanks for the reply.The speaker looks fine.What I'm wondering is how the green wire was cut in half.The seller let me trade it in for another mic,so hopefully the next one won't have the same issue.