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Cobra 2000 gtl reads 92.0000

jerzeyj420

Member
Nov 10, 2009
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I bought a cobra 2000 the other day, hooked it up and it reads 92.0000 on every channel??? Anyone know what this is about? Also, it doesnt receive or TX from channels 2-8. Thanks!!
 

there is a technical service bulletin for this problem.

it is #1232

you might have to replace IC512 also.

sorry i cant find the bulletin itself to tell you what to do, but at least you know what to look for now.
hopefully it can be found online.
LC
 
Must be a glitch in the PLL section you hadda scratch your head when seeing that on the readout :confused::blink::eek::w00t:
 
at least the freq counter is fixable with the update , module needs to come out , in your case , you will be very lucky if you can find a new IC for that )-: if you do the cap/resistor fix and it doesn't change ? You need to change the IC.

Now your other problem with not getting channels 2 thru 8 , this would not have anything to do with the FC. PLL related issue. Does this 2000 have channel upgrades ?does it have the pll that is not the 8719 ?

I feel your pain 420 . These darn radios have become antiques. There surely not bad radios but some are even older then others . they first came out in 1979 and ended in 1993. so they are 30 to 17 years old.

That FC fix came out from cobra in the early 80s , so it applied to the much older units I would believe. The serial nember on your 2000 should give you the date of your unit , but it sounds like a older one. (especially if it has the other pll other then the 8719)

Like many radios over the years , they had there issues. (all were pretty much fixable) One of the other more popular problems was the AM voltage regulator going out on them (was the same for many 148s as well) easy fix all the same.

The money guys put out for these things nowadays is ridiculous as far as IM concerned. Especially if there looking for a everyday radio that will last from here to eternaty (if there's even such a thing ?) Parts are even harder and harder to get on top of everything else cause they don't make them anymore.

Good luck 420 , I hope you didn't pay to much for your new used 2000. I say If guys are looking for a everyday radio for a base use , Go with a late 80s early 90s 148 GTL (or chassis like that) , put a FC-390 on it and a nice 20 amp power supply . (same as the 2000) but I would bet to say it will out live the 2000 in the long run on performance reliability.

Oh yeah , the power supplies in the 2000s surely could and would get week over the years. )-:
 
I bought a cobra 2000 the other day, hooked it up and it reads 92.0000 on every channel??? Anyone know what this is about? Also, it doesnt receive or TX from channels 2-8. Thanks!!
I have seen several posts that have shown the readout on the counter with essentially the same display as yours, and the fix in all cases was replacing all the electrolytic caps on the counter driver pcb. Hope this helps.
 
I have seen several posts that have shown the readout on the counter with essentially the same display as yours, and the fix in all cases was replacing all the electrolytic caps on the counter driver pcb.

I agree. I had the same problem with my unit. I did not implement bulletin 1232. You have to cut a trace. I replaced the electrolytic's in the module and did the VCO alignment and all was well.


PS. I have a replacement kit of electrolytics available for the complete unit available at Electrolytic capacitor kit for Cobra 2000GTL - eBay (item 140522349636 end time May-09-11 21:11:18 PDT) Send me a PM and I'll give you $1 off.
 
Frequency counter cap kit needed. HELP! Thanks Ron

I agree. I had the same problem with my unit. I did not implement bulletin 1232. You have to cut a trace. I replaced the electrolytic's in the module and did the VCO alignment and all was well.


PS. I have a replacement kit of electrolytics available for the complete unit available at Electrolytic capacitor kit for Cobra 2000GTL - eBay (item 140522349636 end time May-09-11 21:11:18 PDT) Send me a PM and I'll give you $1 off.
 

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No substitute for a 'scope.

Lost track of how many different points of failure cause this particular one symptom.

The symptom tells you that the counter has lost the 35 MHz input from the radio's PLL.

Doesn't tell you where the signal is getting lost. Somewhere between J412 pin 4 and IC506 pin 9.

A 'scope will narrow this down.

Does selecting USB or LSB change the reading? You didn't say.

73
 

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