Cobra 2000 GTL S/N 65001008 Refurb Project Log

[TheCBDoctor]

Hello Everyone,

While I can still remember this:

The last Cobra 2000 GTL came out of the Philippines April 1994.
The 1983 radio is made in Taiwan. The MB-8719 board was made first in Hong Kong and was the Cobra 148 GTL. When the Cobra 2000 GTL was developed the MB-8719 board was used.

The PLL, by enforcement of FCC regulations, was changed to an MB-8734 to limit out-of-band use. The Cobra 148 GTL continued using the Toshiba MB-8719 because it was Grandfathered. All Uniden/Cobra production from the Philippines ended in April 1994.

Then it went south when Uniden's Radio production moved to China. The Cobra 29 LTD's made in China are nothing like the early versions. I would not buy a new Cobra 148 or the New Grant made in China.

I have original Toshiba MB-8719 PLL chips, Toshiba MB-8734. Ranger 8719 PLL's are actually the same pin-out as the Toshiba MB-8734. If one were to ground pin 10 on the Ranger 8719 or MB-8734 the chip will fry.

I have a lot of parts. I just bought back my URL and will be developing a new Website. Ignore the current eBay page that Bozo was kind enough to find and upload.

[JimboBowie]

Well, this guy has the complete unit but, frustratingly, he's gone quiet. Very hard to keep up momentum on projects when you are stalled for parts.

[Island_0860]

Good day ...
PLL is Finally up and running with the 8719 !!
The resistor R207 which was simply supposed to be clipped for Digi scan install was missing.
New discoveries...
No Audio...but plenty of PA mod.
Freq counter...reading 92.200 and it's controls are DIRTY !
AM mode lamp out
Both meters not functioning.
Otherwise...We seem to be on freq from 1 to 40 with normal power out.
Looks like the rebuilding of the counter will be an event by itself..even if the 92MHZ is found to be aboard issue.
The adventures continue...Thanks Team for your help !

[Gold Diamond]

My hat is off to you for the commendable project. KE0UW

[JimboBowie]

Well, this guy has the complete unit but, frustratingly, he's gone quiet. Very hard to keep up momentum on projects when you are stalled for parts.

Finally, the guy gets back into contact with me and I'm now waiting for him to put the item into the mail -- which hopefully will be sometime in this decade.

[Island_0860]

Good deal Jimbo.!
Looks like we will both be rebuilding the headphone jack as my other 2k sure enough used that for an xtal switch.
New problem is now I have a bad 7 segment channel display..so since my color choice will be black green I'm looking for a green 7 segment common Cath display.
My other 2k will be restored to factory...
See you soon !

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Post Merge Complete

Added 7 days 22 hours 20 minutes 31 seconds after previous.
Welp...looks like we will open some windows and enjoy a cool down here in Mid-America tomorrow...Time to :
Replace the now bad channel display.
Troubleshoot the counter module.
Replace meter pair.
Enjoy the weekend !

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Post Merge Complete

Added 7 seconds after previous.
Welp...looks like we will open some windows and enjoy a cool down here in Mid-America tomorrow...Time to :
Replace the now bad channel display.
Troubleshoot the counter module.
Replace meter pair.
Enjoy the weekend !

[JimboBowie]

Well, this guy has the complete unit but, frustratingly, he's gone quiet. Very hard to keep up momentum on projects when you are stalled for parts.

Finally, the guy gets back into contact with me and I'm now waiting for him to put the item into the mail -- which hopefully will be sometime in this decade.

And now it's somewhere in the mail. Stay tuned ...

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Post Merge Complete

Added 1 month 8 days 21 hours 42 minutes 25 seconds after previous.

Well, this guy has the complete unit but, frustratingly, he's gone quiet. Very hard to keep up momentum on projects when you are stalled for parts.

Finally, the guy gets back into contact with me and I'm now waiting for him to put the item into the mail -- which hopefully will be sometime in this decade.

And now it's somewhere in the mail. Stay tuned ...

Well, 50 days after being posted, I have finally received the part. Now to blow the dust off this GTL and get back to the resto.

[Island_0860]

FINALLY Jim!
Im looking for the phones jack/PCB for the other 2k ..not having any success so far.
On the the custom 2K ..I ordered the Digi Max Platinum . which solves the channel LED display as well as adding many channels without any hacking.
The 3 digit display will matchup nice.
Im planning on changing the 3 digit channel LED 7 seg block (only available in red or blue) with a green one.
The Digi Max should be here today..ill post some install/build pics.
The MB 8734 will be removed and a socket with a 8719 should be completed today.

Onward & Upward

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Post Merge Complete

Added 1 day 5 hours 18 minutes 33 seconds after previous.
Ok....Out with the 8734...installed a new 1983 8719....heh
The 2k tested with the 8719 checks out fine.

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Post Merge Complete

Added 15 minutes 54 seconds after previous.
The Digi Max arrived today and looks to be of high quality with excellent documentation.

Jimbo ..here is the 8734 that someone went thru the labor to sand off the chip I.D ... I just don't get it.?





Next steps is to remove the old front panel crystal switch mod and test again.
If things check out... we will disassemble /modify the channel selector to accommodate the Digi Max.
Let me know if you locate the headphone PCB...
Thanks

[Island_0860]

Removed the crystal switch mod... and the 2K is back to stock except for an aggressive clarifier ( -15K ) TX RX...heh
Looks like there was a power supply problem in the past as there is unacceptable work on the bridge wiring,...added that to the LONG list.
Pre install of the DigiMax is done.
The 18 pin socket for the 8719 is going to make it easy with no chopping/cutting when the interface is installed
Hopefully tomorrow it will be fully operational ......
Have a great weekend !