CDM1550LS+ Transmit Problem

The General forum is where users can discuss any topic regarding Motorola communications equipment - hardware, software, etc. There are also several focused forums on this board, so please take the time to ensure that your questions doesn't fall into one of those categories before posting here!

Moderator: Queue Moderator

Post Reply
ffnremtwhitby
New User
Posts: 2
Joined: Thu May 08, 2014 10:12 am

CDM1550LS+ Transmit Problem

Post by ffnremtwhitby »

My CDM1550LS+ VHF radio receives very well, but transmitts very poorly. I have changed antennas with no change. There is a lot of crackling, static, and hum in the receiving radios when this one transmits. Sometimes, if you hold the transmit button for about 20 seconds or so, the problem goes away and transmission clears up. I have swapped mics as well with no change. I have also tried dropping transmission power without improvment as well. Any ideas?
User avatar
jackhackett
Posts: 1484
Joined: Tue Jun 10, 2003 8:52 am

Re: CDM1550LS+ Transmit Problem

Post by jackhackett »

Take the plastic cover off the radio chassis, and check that the bolts that hold the radio together are tight. You'll probably find that they're very loose.
ffnremtwhitby
New User
Posts: 2
Joined: Thu May 08, 2014 10:12 am

Re: CDM1550LS+ Transmit Problem

Post by ffnremtwhitby »

That was it. Thanks
mmckenna
Posts: 217
Joined: Wed Aug 28, 2002 7:01 pm
What radios do you own?: AM/FM with 8 track.

Re: CDM1550LS+ Transmit Problem

Post by mmckenna »

Wow, good timing. The CDM1250 in my wife's car was starting to make odd noises on TX. I replaced the mic, checked the power feed, and a few others. Was just about ready to pick up another one. Ran across this post just in time. Tightened the screws and it's working top notch again. Thanks.
"The nice thing about standards is that there are so many to choose from."
User avatar
Bill_G
Posts: 3087
Joined: Thu Sep 17, 2009 5:00 am

Re: CDM1550LS+ Transmit Problem

Post by Bill_G »

Usually it's the loose screw across the microphone, but not today ...

(big grin)
AEC
No Longer Registered
Posts: 1889
Joined: Wed Dec 22, 2004 7:56 pm

Re: CDM1550LS+ Transmit Problem

Post by AEC »

I despise that carbon/rubber pad on the CDMs, a loose cover places the radio into 'test' mode.
mmckenna
Posts: 217
Joined: Wed Aug 28, 2002 7:01 pm
What radios do you own?: AM/FM with 8 track.

Re: CDM1550LS+ Transmit Problem

Post by mmckenna »

Bill_G wrote:Usually it's the loose screw across the microphone, but not today ...

(big grin)
Ah yes, like the "loose nut behind wheel" issue that I see happen with cars.
"The nice thing about standards is that there are so many to choose from."
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Re: CDM1550LS+ Transmit Problem

Post by Will »

mmckenna wrote: Ah yes, like the "loose nut behind wheel" issue that I see happen with cars.
"the loose nut behind the microphone" for radio operators.... ...
User avatar
SteveC0625
Posts: 465
Joined: Sat Jan 01, 2011 9:46 am
What radios do you own?: CDM's, CP's, CM's, and more

Re: CDM1550LS+ Transmit Problem

Post by SteveC0625 »

Will wrote:
mmckenna wrote: Ah yes, like the "loose nut behind wheel" issue that I see happen with cars.
"the loose nut behind the microphone" for radio operators.... ...
The official term is "short between the headphones." :)
Post Reply

Return to “General Motorola Solutions & Legacy Radio Discussion”