RadioReference on Facebook   RadioReference on Twitter   RadioReference Blog
 

Go Back   The RadioReference.com Forums > Commercial and Professional Radio > Motorola Forum

Motorola Forum For general discussion of Motorola land mobile radio equipment and their trunking technologies.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1 (permalink)  
Old 10-10-2013, 10:45 PM
centuryvrproductions's Avatar
Member
   
Join Date: Jun 2010
Location: milford
Posts: 208
Default Does my maxtrac have a bad Crystal?

One day I turned on the 2M Maxtrac to do some simplex, Powerd up, BEEP, seems fine, Transmit, Herd fine over the air. NO RX AUDIO!

It knows when theres a signal there, will know when theres a signal even if its real weak. When there is a transmitting station on the frequency, Busy light flashes, I hear a click when the squelch opens but no audio at all after that.

Is this what would be a simple Crystal Replacment, an adjustment, or time for a new RF Board?

ive done my searching and ofcourse it sounds to be the 44.645 crystal. But Ive had the issue in the past where it does this but the audio instantly begins to fade in. ???


I would just replace it and see if it works but im unsure if its the issue, have no spare RF Boards and will appreciate any input before I go and order a crystal ...

Last edited by centuryvrproductions; 10-10-2013 at 10:48 PM.. Reason: clarifying
Reply With Quote
Sponsored links
  #2 (permalink)  
Old 10-11-2013, 7:26 AM
RKG's Avatar
RKG RKG is offline
Member
   
Join Date: May 2005
Posts: 928
Default

Just a guess, but be sure that radio isn't programmed for an Rx PL/DPL different from the one that the radios you're trying to listen to send.
Reply With Quote
  #3 (permalink)  
Old 10-11-2013, 10:43 AM
ramal121's Avatar
Member
  Shack Photos
Shack photos
Premium Subscriber
Premium Subscriber
Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2008
Location: Sonoma, CA
Posts: 1,127
Default

If the 2nd LO crystal was bad you would not get a received signal indication (busy light). Since the radio responds (the pop in the speaker is the audio PA being enabled) I'd say the RF is working just fine and the problem is in the audio chain. If you had some kind of audio tracer, I'd be looking for detected audio. That would narrow things down considerably.
Reply With Quote
  #4 (permalink)  
Old 10-11-2013, 3:56 PM
cmdrwill's Avatar
Member
   
Join Date: Mar 2005
Location: So Cali
Posts: 667
Default

Check for audio, press and hold the Mon button, squelch should open and get noise in the speaker.

Also check at the mic jack on the headset pin for RX audio.
Reply With Quote
  #5 (permalink)  
Old 10-16-2013, 8:57 PM
centuryvrproductions's Avatar
Member
   
Join Date: Jun 2010
Location: milford
Posts: 208
Default

When I press and hold the Mon to open the squelch, I hear the button press Tone come out of the speaker, the Bsy light flashes as it is recieveing, but no audio at all comes through.

just a click when the squelch opens thats it.
Reply With Quote
Sponsored links
  #6 (permalink)  
Old 10-17-2013, 3:34 PM
cmdrwill's Avatar
Member
   
Join Date: Mar 2005
Location: So Cali
Posts: 667
Default

Did you HOLD the MON button......... takes a few seconds for the squelch to un mute the audio.

The BUSY indication IS a good thing, says the receiver is working.

Last edited by cmdrwill; 10-17-2013 at 3:36 PM..
Reply With Quote
  #7 (permalink)  
Old 10-17-2013, 7:21 PM
ramal121's Avatar
Member
  Shack Photos
Shack photos
Premium Subscriber
Premium Subscriber
Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2008
Location: Sonoma, CA
Posts: 1,127
Default

Quote:
Originally Posted by centuryvrproductions View Post
When I press and hold the Mon to open the squelch, I hear the button press Tone come out of the speaker, the Bsy light flashes as it is recieveing, but no audio at all comes through.

just a click when the squelch opens thats it.
When you power up the radio or press a button and hear a strong beep as normal, this indicates the audio PA amp is OK. By pressing and holding the monitor button you see a flashing "busy" light but no open squelch audio out the speaker.

OK, the audio starts at the detector chip on the RF board. This is raw detected audio, unsquelched and unfiltered. It is then passed over to the logic board where the squelch gate lives and the filters are that shape the audio. Not much on the logic board to oops on. If there is a problem there it would be at the component level and you would need a schematic and test equipment to troubleshoot.

I'd say you are missing the detected audio or the squelch indicator from the RF board to the logic board. This is a common problem with this era radio, a bad connection between the two boards. Easy fix though if this is the problem. Remove several torx head screws from the RF board and lift it out. Use a pencil eraser and some contact cleaner to scrub the pin connectors that go between the two boards.

This usually fixes most problems....
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 3:23 PM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
All information here is Copyright 2012 by RadioReference.com LLC and Lindsay C. Blanton III.Ad Management by RedTyger
Copyright 2011 by RadioReference.com LLC Privacy Policy  |  Terms and Conditions