I have a 142 with weak receive and weak transmit.I see that the 1306 transistor was replaced by someone with a 2166 transistor -could this be the problem?The 2166 is rated at 6watts while the 1306 is 16 watts. I also know that IC5 is a common problem with these radios-should I try replacing IC5 first?The radio does receive and transmit with good modulation but I can only hear close stations and transmit is only about 1.5 watts.I would appreciate any help. :roll:
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Cobra 142 GTL
- Thread starter sportygreg
- Start date
Well,I bought a new IC5 [mb3756] and will see what happens.The radio is in nice condition and I am determined to fix it.I already replaced an audio IC in a Cobra 29LTD that I bought for $5.00 and now it works great-I even installed a roger beep in the 29 and now it sounds like an export radio.The schematic for the 142 shows a 1306 as the driver transistor so I am guessing the 2166 is a replacement-does anyone know if the 2166 is suitable?
The 2166 is a good driver, and the 1969 makes a good final for that radio. Make sure you do a FULL PLL alignment on it to get best performance.
Thanks for the reply-I am one of those"screwdriver"experts just trying to get my radio working.The radio does have a 1969 final but I have no idea if it's good or not.I'm hoping the new IC solves the problem.
Cobra 142Gtl
I was just wondering whats the best Final and driver you can put in a 142 Cobra mine went bad and needs to be replaced and just wanted to put in the highest one I can to boost up my radio. If any one nows I would appreciate it alot Thanks.
I was just wondering whats the best Final and driver you can put in a 142 Cobra mine went bad and needs to be replaced and just wanted to put in the highest one I can to boost up my radio. If any one nows I would appreciate it alot Thanks.
the best driver is the 2SC2166 and the best final is the 2SC1969.
you can also use a 2SC1306 for a driver if you can find one, and you can use a 2SC1307 or a 2SC2312 for a final if you can find one of those. (all are out of production)
with regards to replacing the final to "boost up" your radio; remember that to increase your signal by 1 S-unit in someones receive; you have to increase your output power by 4x.
that means if you are deadkeying 4 watts and hitting someone with an S-5; you will have to increase your deadkey to 16 watts to get to S-6.
this should provide some perspective on how effective changing the final to get a few more watts would be.
LC
you can also use a 2SC1306 for a driver if you can find one, and you can use a 2SC1307 or a 2SC2312 for a final if you can find one of those. (all are out of production)
with regards to replacing the final to "boost up" your radio; remember that to increase your signal by 1 S-unit in someones receive; you have to increase your output power by 4x.
that means if you are deadkeying 4 watts and hitting someone with an S-5; you will have to increase your deadkey to 16 watts to get to S-6.
this should provide some perspective on how effective changing the final to get a few more watts would be.
LC
The 2sc2312 is a 25watt unit,if your just looking for HP under the hood, but loosecannon is right about the S-unit part.