Question about Cobra Mr Hh425li Vp Marine Hand Held Dual Band Transceiver
I have two Cobra MR HH425LI. After 5 minutes from power up, the radio stop to transmit or received.
On first 5 minutes all MR HH425LI work well (received and transmit ok with the same cobra radio and with other model).
After 5 minutes from power up, the radio stop to transmit or received.!!!:
When I press TX on the screen appared the TX indicator but I don't received anything on all other station on this chanel (on bouth band).
When I press Tx on other model station (I have many other station) all MR HH425LI don't received the signal (but all other station receiv all ok).
When I press Tx on Cobra MR HH425LI other station don't received the signal.
If I power off the Cobra MR HH425L and Power Up this radio work ok again for only 5 minutes!!!
What can I do to resolvate the problems?
SOURCE: cobra 148gtl
tomcat 1 back ...i have found the fault no modulation on am/usb/lsb.tr -23 a bc458 transister .replaced this transister and wow modulation on all 3 modes thanks zeppfrog for telling me where to look .
Posted on Mar 01, 2007
The problem is most likely the audio ic . open the radio and see if the diode 44 is blown or see if you see anything that looks like it got hot around the plug area. if not contact me and i will buy it. is it an old or new 148 gtl.Read more
Posted on Dec 06, 2008
SOURCE: Have Cobra 29 LTD CB
Sounds like the PLL circuit....... no channel synthesizer will kill the transmit and receive...... bad crystal or IC could be at fault or if someone has attempted to add more channels could also be cause.
Posted on Dec 22, 2008
There is a relay in side of the cb that might be sticking. The problem is that this situation might be environmental. You say that you sent it back to Cobra twice for repairs. I think that the place you are sending it to differs enough environmentally so that the problem does not manifest itself. You can test this by exposing the unit to different temperatures, to determine if the internal relay is sensitive to variations in temperatures.
If you do find that the relay has become tempurature sensitive, you can order the part from Cobra, or strangly enough from Radio Shack, since they do carry the same part just by a different part.
I hope this helps,
Posted on Mar 11, 2009
SOURCE: Cobra 148GTL can't TX on USB
Its the cap that feeds the first transistor to the first of the finals. It is either shorted or burned out.
Or the audio IC. It could be putting just enough out on AM to seem like its working, and then not enough for side band.
look at the caps near the finals. Look for a burn one, or one that could be twisted, or shorted in any way.
Posted on May 05, 2009
Tips for a great answer:
Nov 29, 2014 | Cobra Mr F45-d Marine Class-d Dsc...
Nov 10, 2013 | Cobra Radio Communications
Dec 04, 2011 | Galaxy Radios DX-959 40-Channels Base CB...
Jun 19, 2011 | Cobra MRF55 2-Way Radio
Mar 31, 2011 | Cobra MR- F55 Base CB Radio
Dec 30, 2008 | Cobra MR- F55 Base CB Radio
Dec 21, 2008 | Magnum 257 CB Radio
Oct 22, 2008 | Cobra Mr F75b Marine Vhf Radio Fixed Mount...
39 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: