| Author |
Message |
    
Plano
Junior Member
Username: Plano
Post Number: 12
Registered: 6-2004
| | Posted on Monday, March 13, 2006 - 10:47 pm: | 
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I HAVE COBRA 2000 THATS HAS NOT BEEN TOUCH. (I MEAN BEEN TAMPERED WITH NO MOD STOCK CLEAN RADIO THATS THE WAY I LIKE MY 2000.) THE ONLY THING THAT I DID DO IS ADDED UPPER AND LOWER CHANNELS ABOUT 2YEARS AGO. THE RADIO HAS BEEN WORKING FINE. I DIDN`T TALK ON IT BUT A COUPLE OF TIMES IN THE LAST COUPLE MONTHS. TURN IT ON THE OTHER DAY AND IT ONLY KEYS 1 WATT AND SWINGS 1 1/2 TO 2 WATTS. ANY IDEAS WHAT IT COULD BE. ANY SUGGESTIONS WOULD BE GREATLY APPREC.
THANKS IN ADVANCE |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1294
Registered: 9-2004
| | Posted on Monday, March 13, 2006 - 11:33 pm: |
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im going to guess that the problem is not in the radio, but in the way it was hooked up or what it was hooked to that day that is making the difference.
thats where i would start my troubleshooting.
matt |
Plano
Junior Member
Username: Plano
Post Number: 13
Registered: 6-2004
| | Posted on Tuesday, March 14, 2006 - 8:01 am: |
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THANKS Kid_vicious BUT THE STATION HAS BEEN HOOK UP THE SAME AS ALWAYS, NEVER DISCONNECTED IT. JUST BEEN REAL BUSY AND HAVEN`T TALK ALOT LATELY. BUT I WILL RECHECK EVRERYTHING. THANKS |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1059
Registered: 1-2005
| | Posted on Tuesday, March 14, 2006 - 9:11 am: |
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Check your vswr. I had a Cobra 148 do the same thing and discovered a bad final. IMHO the Cobra 2000 has the best sounding audio over any other cb in its class. Nice to have one thats not all chopped up like so many are these days. Good luck Plano! 73 |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1299
Registered: 9-2004
| | Posted on Tuesday, March 14, 2006 - 10:44 pm: |
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ok, it sounds to me like the radio is just showing signs of aging.
just so you know, when this starts happening, its better to replace all the electrolytics in the radio rather than have them go out one by one when you least expect it, and you spend the next hour scratching your head. IMO!
the electrolytic caps are the most prone to going bad due to old age, dont worry so much about the disc and tantalum caps.
to try and fix your immediate problem, try transmitting on SSB, does it work?
do the radio checks come back "scratchy"?
if so, try removing one leg of C95.
does the power return?
if yes, good! replace that cap. its 47uF 10 volts, but should be replaced with a 16 volt cap, as should ALL of the electrolytics in the radio that are rated at 10 volts.
didnt work?
there is another elec. cap near the final that will kill the bias current to the final which would cause the low power output.
try replacing any caps that are near the final, unless you can trace which one is going into the final bias pot.
and last, try replacing TR 41. the AM power reg.
if its a 2SC1419 use an NTE152
if its a 2SD1135 use an NTE291
(it really doesnt matter which one you use, but those are the best subs, unless you can find a GE-66)
this part should be replaced even if it wasnt your problem. (there is another on the small power supply board. replace it too)
lots of mods for this radio.
do a search on this forum for "my 2000gtl"
or "2000gtl modulation mods"
you'll find good stuff!
hope this helps,
matt |
Chad
Advanced Member
Username: Chad
Post Number: 729
Registered: 11-2004
| | Posted on Wednesday, March 15, 2006 - 12:18 am: |
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If you replace the 'lytics do so with ones rated at 105 Deg C. I prefer Panasonic or Nichicon. The price difference is moot compared to shipping for such a light weight order. I have found them to last the longest in black, Live Audio consoles baking under a hot sun for years. Should be Ok in a Cobra 
Doing outdoor festivals as a "soundguy" for a long time, this initial parts cost has brought my shop time down by an amazing amount!
Chad |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1301
Registered: 9-2004
| | Posted on Wednesday, March 15, 2006 - 12:30 am: |
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"cool" idea chad!
although you coulda' told me about this BEFORE i replaced ALL the electrolytics in my 2000!
just kidding!
how've you and the family been?
havent talked to you in a while,
matt |
Plano
Junior Member
Username: Plano
Post Number: 14
Registered: 6-2004
| | Posted on Wednesday, March 15, 2006 - 9:11 pm: |
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THANKS FOR INFO IT`S NOT SHOWING ANY WATTS ON SIDE BAND EITHER. I`LL DIG IN THIS WEEKEND AND FIND THE PROBLEM I HOPE
PLANO |
Plano
Junior Member
Username: Plano
Post Number: 15
Registered: 6-2004
| | Posted on Wednesday, March 15, 2006 - 9:45 pm: |
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IT DOES HAVE A LIKE A BAD CIRCIUT HUM JUST SITTING THERE, GETS LOUDER WITH VOLUME BUT IT STILL RECIEVED FINE. OH WELL I GUESS IT TIME TO GO WORK.
PLANO |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1305
Registered: 9-2004
| | Posted on Wednesday, March 15, 2006 - 10:45 pm: |
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good info plano!
was the hum there before the radio went weak on you?
or did it start the day you turned it on and noticed the low output?
im thinking that the main filter cap in the power supply may be the culprit.
if you have an external power supply, try running the radio off of it and see if the power returns.
if not, just replace the cap.
its on the bottom side of the chassis, all by itself under a little clip.
its the biggest cap in the radio by far.
replace if with one of larger value for some added "breathing room". (better for high modulation peaks)
replace it with a 5600-6800uF @50volts cap.
hope this helps,
matt |
Chad
Advanced Member
Username: Chad
Post Number: 733
Registered: 11-2004
| | Posted on Thursday, March 16, 2006 - 9:23 am: |
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Doing good kid, been really busy around the house, never got to do my ERF experiment like I was talking about, should soon though eh? MaMa's kept me busy around the house and I've been tinkering with automobiles. Spring is around the corner and rock shows have increased. PA maintainence is done, bathroom remodel should be done in a week, so I should have time to tinker again soon!
Chad |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1310
Registered: 9-2004
| | Posted on Thursday, March 16, 2006 - 6:41 pm: |
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cool deal chad!
sounds very familiar!
i too have been redoing a bathroom here at the home 20, and am about to tackle the brakes on one of the vehicles. also turning my music room and CB room into one CB/jam room to give the YL a room for exercize equip. and her art supplies.
so are you going on the road soon?
with who?
coming anywhere near vegas?
just worked with a guy who used to mix for Bon Jovi for years. have you ever worked with them?
matt |
Plano
Junior Member
Username: Plano
Post Number: 16
Registered: 6-2004
| | Posted on Thursday, March 16, 2006 - 11:03 pm: |
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HEY KID
CHECK MAIN CAPS ALL ARE GOOD. STILL NO WATTS HOOK UP ON DC STILL NO WATTS. I`M GOING TO TACKLE IT SOON.
THANKS PLANO |
Chad
Advanced Member
Username: Chad
Post Number: 740
Registered: 11-2004
| | Posted on Friday, March 17, 2006 - 10:02 am: |
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KV:
Man, bathrooms are tough! I just took my first shower tonight in over 2 weeks! I HATE taking baths so I'm a pretty happy camper!
Now that I am at the University I don't do long term touring. Although I miss it greatly, wife Ver2.0 would have my head I do work with a local band doing weekend things and I will work a few local festivals. I'm supplying PA for a couple biker rally’s this summer, that should be a hoot!
I was almost going to be in Vegas like... NOW at the NCSA show but they pushed up a few construction deadlines here so I stayed to work over spring break with my head buried in AV racks.
I have never worked with Bon Jovi but I may have worked with your aquatince. When tours end most of us went out with other acts. I was fortunate enough to have 3 legs of tours in the summer planned out perfectly then home in the winter working in repair/broadcast/local venues. Pretty nice IMHO.
Chad |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1320
Registered: 9-2004
| | Posted on Saturday, March 18, 2006 - 10:14 pm: |
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name was pete. last name sounded a lot like "guess".
who knows.
just know that if you ever do get a chance to come to town; give me a weeks notice.
i'll have tickets waiting for you to come see the show, and i'll show you around backstage afterwards.
open invitation.
plano, how do you know that the caps are good?
checking them with a capacitance meter is not enough.
that will only tell you that they are working, not how well they are working.
as for the AC hum, just try replacing that big cap and see if it doesnt go away.
the caps are sort of like batteries, you can check them on the meter and they show 9 volts, but put them in the mic and they sound like crud.
no more current! battery is dead.
try the cap replacements. then we'll go from there.
matt |
