Motorola CT250 Radio Problem

[MtnBiker81]

I am using a Motorola CT250 handheld, 16 channel variety, that has been working fine. Recently, the radio has audio on start-up and when selecting scan or de-selecting scan. However, it doesn't have any audio during transmissions. The indicator light flashes as it should. If pushing the side button above the key-up button, transmissions can be heard if red light flashes, otherwise open squelch. Not sure why this just started all of a sudden. Any help would be greatly appreciated.

NOTE: System was recently switched to narrowband and this radio has not been reprogrammed yet? It worked fine Friday/Saturday and not now. Thanks,

 

[cabletech]

If you can hear them with the monitor button engaged, then it is possiable that when the system was changed to narrow band, the CTCSS/DCS was changed at the same time.

As far as your radio not being in narrow band mode, the only thing that will be differant is the audio will sound differant from your radio to another user and the same coming back to you.

But you also need to change your mode so that you will not cause any problems down the line.

Check with system radio tech and see if they changed the PL codes.

 

[MtnBiker81]

PL tone hasn't changed. Radio just isn't working correctly. Any other suggestions? Thanks.

 

[R8000]

Simple answer :

When a radio system narrowbands, the system audio (and other things) is basically cut in half. The same also applies for the system PL encode. The PL your system was sending you should have been around .7 khz. Now with narrowband, the system PL encode going to your radio is around .350 khz. Your radio's PL decoder is expecting to see PL in the range of .700 khz.

Some radios are more tolerant than other on PL deviation....and some are not. It could be that your radio's PL decoder just isn't seeing enough PL from the radio system to properly unmute.

Having your radio programmed to narrowband should help with this.

 

[MtnBiker81]

Is the CT250 capable of narrowband frequencies? Secondly, a Motortrbo UHF moble radio hasn't been reprogrammed since this problem developed and still operates as normal. Is that due to the Motortrbo radio being newer or could it have been programmed in narrowband earlier in the year to work properly with the then forthcoming change? One person told me that the CT250 was capable of being reprogrammed for the recent change as the radio isn't capable of the narrowband requirements. Thanks.