| Author |
Message |
    
Cdn_superpower
New member
Username: Cdn_superpower
Post Number: 6
Registered: 6-2005
| | Posted on Tuesday, May 09, 2006 - 3:42 am: | 
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I am in great need of help here, I was playing with my cb while using a dummyload, I didnt notice that that tip of the pl259 was so "centered" that it was not making contact........
To make a sad story short my radio started back swinnging and a squeal when I talk and the finals are getting red hot so I unplugged it.
It is a Cobra 135XLR with 2 1173's and a 1307......
Did I pop a final or what.
Please anyone that has had this unfortunate situation, please reply......
Also when i plug it in and turn it on the finals get hot on recieve....and when I turn up the volume the speaker gets compressed sound the louder I turn it up and starts to make a squeal too
http://img97.imageshack.us/img97/6381/screenshot0327ik.gif |
Tech237
Moderator
Username: Tech237
Post Number: 331
Registered: 4-2004
| | Posted on Tuesday, May 09, 2006 - 4:07 pm: |
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What exactly do you mean by "playing with my CB"? Were you tweaking things, or just plain transmitting into the dummy load?
While I suspect you have damaged something it's hard to say what. Some radios have the finals wired so that they always have 12V on them whenever the radio is turned on, and I am not sure if yours is one that is wired that way.
Some more information would certainly help. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1544
Registered: 9-2004
| | Posted on Tuesday, May 09, 2006 - 4:53 pm: |
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im gonna guess that its the AM regulator that went, and took the audio chip with it.
not familiar with this chassis at all though.
to be safe, i would replace the AM regulator, and the audio chip first, and see if it is at least ok on receive, and the final and driver are not heating up.
if that works, then replace the driver(s) and final.
remember, i am just guessing here, and some second opinions would be good before proceding.
matt |
Cdn_superpower
New member
Username: Cdn_superpower
Post Number: 7
Registered: 6-2005
| | Posted on Tuesday, May 09, 2006 - 6:41 pm: |
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I was wiring up a turner +3 and doing a little whistling but, ya i feel real upset I tried to find this radio for years and i go and ruin it........anyways i hope its the regulator the audio is there but the heat builds rapidly.
I have 4 transitors together the are the ones that get hot, then the PS will heat up.
I think the green 2SB435 is the regulator, ?
Of all radios to wreck.......
Also 1307 is the one that gets hot on recieve and then the PS gets hot the green regulator has 12 8 12 volts on the pins,there is no "up in smoke" components yet, I want to keep it that way.
hope that helps with any answers you can give me.
http://img299.imageshack.us/img299/3686/picture293fd.jpg
http://img308.imageshack.us/img308/5529/picture289li.jpg |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1550
Registered: 9-2004
| | Posted on Tuesday, May 09, 2006 - 10:30 pm: |
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i think i have the sams manual for that radio.
i'll look tonite and see if i can find some voltage charts for you to check.
for now, just keep the radio off, and when checking the voltages i give you, keep it short, and turn the radio off and let it cool often.
matt |
Cdn_superpower
New member
Username: Cdn_superpower
Post Number: 8
Registered: 6-2005
| | Posted on Wednesday, May 10, 2006 - 1:56 am: |
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Yes thanks, I just bought sams 181 off an internet site. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1626
Registered: 9-2004
| | Posted on Wednesday, May 17, 2006 - 7:54 pm: |
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well, im glad you are getting the sams manual, becuse there is just too much there to type.
the voltages you want to check are on page 56.
would you list the transistors you have in the pics?
i cant make them out and i want to make sure that there is not a typo in the sams book.
better list any and all transistors with heatsinks on them.
ex:
Q502 is 2SC235
etc...
im going to give you cross referrences for parts you can get these days, as some of those you cant.
my bet is that we will just replace all of them, as we are talking about less than $20.00 worth of parts.
good luck and let me know when you get your book,
matt |
Wildrat
Advanced Member
Username: Wildrat
Post Number: 883
Registered: 12-2003
| | Posted on Wednesday, May 17, 2006 - 9:00 pm: |
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The radio can be fixed but if I were you if you like this radio that much, I would bring it to a good shop and not try and fix it myself not unless you just made one of those mistakes everyone makes at sometime or another. Sorry it died, I know how you feel, because I know how I feel when one of my radios go north, as a matter of fact my laptops hard drive just went north about 2 hours ago. I lost a lot of good CB, Amp, and antenna data from the past month. I'm hoping that once it cools down it might boot long enough for me to back up to dvd. |
Cdn_superpower
Junior Member
Username: Cdn_superpower
Post Number: 41
Registered: 6-2005
| | Posted on Wednesday, May 24, 2006 - 1:01 pm: |
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GOOD NEWS !!!!!!!!!!!
I fixed the radio !!
Replaced 1307 and whammo !!
1 down 1 to go....
I used a mica insulator instead of the gray rubber, hope thats ok....
http://img69.imageshack.us/my.php?image=picture427wq.jpg
http://img69.imageshack.us/my.php?image=picture413uh.jpg
http://img308.imageshack.us/my.php?image=picture289li.jpg |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1686
Registered: 9-2004
| | Posted on Wednesday, May 24, 2006 - 5:47 pm: |
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go ahead and replace the driver too.
they work together.
then adjust R86 and R89 for max. on SSB while saying "ahhh" into the mic.
nice job!!!
what a feeling of relief!
matt |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1687
Registered: 9-2004
| | Posted on Wednesday, May 24, 2006 - 5:48 pm: |
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mica insulator is better.
again, nice job!
matt |
