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Message |
    
Fusebreaker
Intermediate Member
Username: Fusebreaker
Post Number: 176
Registered: 3-2004
| | Posted on Wednesday, September 14, 2005 - 2:31 pm: | 
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I seen that you can ground pin 8 and pin 9 threw a switch you get the same freqs and a few more a channels with this version. |
Yankee
Advanced Member
Username: Yankee
Post Number: 900
Registered: 7-2003
| | Posted on Wednesday, September 14, 2005 - 7:13 pm: |
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Allen: Excuse me, Before someone corrects me Pin 9 is the B+, and pin 8 is the oscillator output. Therefore neither of these 2 pins of the MB-8719 PLL IC can be grounded. BTW: Pin 9 is where you would pick up your B+ voltage for the B+ side of the 10 KHz. plus or minus mod.
Pins 10 thru 16 are the only programming pins that you can work with.
Hope this is of some help. Had to get out the factory shop service manual for the MB-8719 pin out.
Carl CEF-357 |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 615
Registered: 9-2004
| | Posted on Thursday, September 15, 2005 - 9:40 pm: |
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fusebreaker, i found the mods you are referring to, and yes, the info is just wrong.
dont do that mod.
the first one is ok but #2 is wrong.
here is a link to a mod that i know works if done correctly. this is the one i did to my 2000gtl.
if you dont have a freq. counter, find one before you attempt this mod. if you dont, you will be very frustrated trying to retune the VCO. yes, you will have to tune it a bit, and doing it without a freq. counter, well, good luck, im sure it's possible but i wouldnt do it.
hope the link is good.
matt
Moderators Note!
Your Link had to be deleted as it contains links to Competitors of Copper Electronics Web Sites. |
Yankee
Advanced Member
Username: Yankee
Post Number: 905
Registered: 7-2003
| | Posted on Friday, September 16, 2005 - 3:01 am: |
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Allen, I only believe about half of what I read for mods. on the Internet. I will first check here on the Copper Talk Forum, to see if anyone has done a mod. on the Internet and if it worked for them. Many of the members here on the forum know more about mods. than any posted on other forums and even CB Tricks website.
Need to remember that most of the posts on CB Tricks are much the same as any other forum, and a great share of the mods. on CB Tricks are not all tried and tested mods. some of the people posting them will even say,"I'VE HEARD ABOUT THIS. BUT HAVEN'T TRIED THIS MOD. ON MY OWN EQUIPMENT". So in most cases, ask the Copper Forum Members First. All you need to ask is, (has anyone done this?)
I for one am in agreement with Matt about the second poorman's MB-8719 PLL mod. Posted on the CB Tricks site being incorrect, although the first one works great, along with the pin 13 mod. for chnls 41-44, and the pin 16 mod. for the plus or minus 10 KHz. jump. And have been done and proven to work.
Hopes this is of some help.
Carl CEF-357 |
Yankee
Advanced Member
Username: Yankee
Post Number: 906
Registered: 7-2003
| | Posted on Friday, September 16, 2005 - 10:57 am: |
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Some time ago there were many sites on the Internet pretaining to modifing CB radios that are no longer on the Internet, I have many of them that have something to do with the older uPD-858 sideband chassis and the newer MB-8719 sideband chassis.
One of the best was "Welcome to my Cobra 148 GTL page", of which I have a print out.
In the Sams Photofacts shop manuals for each radio there is a 40 channel truth chart and once you have figured out how to read a truth chart you can figure from there what any PLL circuit can or can't be made to do. A few of the newer PLL chips are made so they can't be modified such as the one in the Cobra 2000 GTL from the factory, that has to be changed to the MB-8719 before you can do any PLL modifications. |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 622
Registered: 9-2004
| | Posted on Friday, September 16, 2005 - 10:07 pm: |
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can you believe that yankee, they make a radio like the 2000, that all the hardcore modders are going to drool over, and then they put the MB8734 in it!!!
sorry about the link, i wasnt sure what the rules were. i know now!
matt |
Fusebreaker
Intermediate Member
Username: Fusebreaker
Post Number: 178
Registered: 3-2004
| | Posted on Saturday, September 17, 2005 - 11:30 am: |
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kid good point on the mb8734 in the 2000`s kinda ignorant to me |
Yankee
Advanced Member
Username: Yankee
Post Number: 909
Registered: 7-2003
| | Posted on Saturday, September 17, 2005 - 12:43 pm: |
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At this day and age I can believe almost anything. As yet I haven't been able to figure why Uniden engineered the MB-8734 into the Cobra 2000-GTL and it's the only radio they did this on. Another thing Uniden did was to use a crystal in the Cobra 142 GTL series of radios that had to be changed before the PLL mods. would work.
Carl CEF-357 |
Fusebreaker
Intermediate Member
Username: Fusebreaker
Post Number: 182
Registered: 3-2004
| | Posted on Saturday, September 17, 2005 - 3:44 pm: |
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LOL that is kinda ignorant |
Yankee
Advanced Member
Username: Yankee
Post Number: 910
Registered: 7-2003
| | Posted on Saturday, September 17, 2005 - 5:11 pm: |
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Allen, Have you been getting my E-mails in the past few days, just wondering? Haven't had any answers.
Carl CEF-357 |
Fusebreaker
Intermediate Member
Username: Fusebreaker
Post Number: 184
Registered: 3-2004
| | Posted on Saturday, September 17, 2005 - 5:57 pm: |
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i have 3 email accounts i have not checked inbox i will though. sorry |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1495
Registered: 7-2004
| | Posted on Saturday, September 17, 2005 - 8:32 pm: |
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that was cobra's attempt at satisfying fcc threats of retribution for designing so easily modified of a radio. others were just as easy, if not easier to mod, why'd they pick on cobra? grab a quick settlement from a company with lots of cash, that 'settled without admitting guilt'. that the 8719 was a direct drop in for the 8734 was merely coincidental .
uniden went through the same thing with the 2510/2600. |
Yankee
Advanced Member
Username: Yankee
Post Number: 912
Registered: 7-2003
| | Posted on Saturday, September 17, 2005 - 9:42 pm: |
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Thanks Pat, I was thinking it might have been done to please the FCC. Because if memory serves me correctly I remember hearing about the FCC crack down on easily modified PLL circuits about the time the Cobra 2000GTL first came on the market.
Carl CEF-357 |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 641
Registered: 9-2004
| | Posted on Sunday, September 18, 2005 - 12:11 am: |
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did you guys know that uniden got smart and made sure the contract they had to build those radios with that design had no expiration date.
previous radios had the problem of their contract expiring and they would have to "reappease" the FCC with a new design.
my point is, uniden could be producing those same radios today if they so chose.
what's wrong with these people.
matt |
Fusebreaker
Intermediate Member
Username: Fusebreaker
Post Number: 189
Registered: 3-2004
| | Posted on Sunday, September 18, 2005 - 2:55 am: |
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the email with six position switch did not come threw right |
