20 Most Recent Cobra 148 GTL 120-Channels Base CB Radio - Page 2 Questions & Answers

explain more , and why?

Check to make sure the ext speaker jack is not worn out. Even the internal speaker will not work if it is worn.

In my opinion it is the Turner Road King 56. Made by Telex / Turner

Sounds like a problem with the VCO / PLL Circuit since nothing happens in RX or TX. Check to make sure you have the correct supply voltages to start with and also check to see if you have 10.240Mhz. Use the service manual and go through the PLL/VCO alignment section. If anything is missing then you at least know where to look.

This sounds like a problem with the MB3756 Regulator IC. It controls voltage regulation and TX/RX Switching. It is a common failure in these radios. Check voltages with schematic that can be found at CB Tricks Home Page

Hook up a speaker to the PA jack on the back of the radio. Put the CB into PA mode and see if any audio is coming out of PA jack. This will tell you if the AUDIO AMP IC TA7222 is good.

uhoh someone played around on the inside of the radio. you are going to need a tech

www.cbtricks.com has what you are looking for

did you put it on a frequency counter? they can be set back on freq. if you know how to set it. how old is it? I would send it back to where I got it and have them fix the problem.

you are not matching it correctly. get hold of a friend that knows how to match it and see if he will help you.

new or old version?

same as cobra 29

could be a blown tx diode in am.you would be better off taking it to a tech and let him fix it then to mess with it and have something else go wrong.

I have a a uniden teddy r that won't recieve.

http://www.cbtricks.com/radios/cobra/148gtl/graphics/cobra_148gtl_sch_b_size.pdf There is is another one just stay at cb tricks .com and you'll see the other one .

check the am voltage regulator. you should have 12vlts on pin 1 ,4volts on pin 2 ,13 vlts on pin 3 . go to ( CB tricks .com ) its the same board layout as galaxy 44 . http://www.cbtricks.com/radios/superstar/3900/graphics/ss3900_sch.gif if you are looking at the board on solder side ,knobs faceing you ,it is located on top left hand corner ,about 1 inch down you will see the slot cut into the board .if you have vlt on pin2 less than 4vlts or higher than 8vlts its bad. Galaxy DX Radios DX44V Service Manual its (tr) 51 Galaxy DX Radios DX44V Service Manual

There is no "best smallest" Base antenna. You can get a workman saturn B base antenna, it is small and black, but they do not work so great.

the best bang for your buck is an antron 99 base antenna. Unfortunately it is 18 feet long when put together. But if you spray paint it a dark color, and put it up in a tree you will hardly notice it.

When it comes to base radio's, smaller is not better, and you cannot get a best.

Antron 99 is the smalles antenna that will fall into a near best category.

But the saturn B will still work if you absolutely need small. you can find a bunch on ebay cheap.

try adjusting the L36,L38 to the highest reading on the external meter and then adjust VR10 TO 4 watts. If this doesn't cure the problem, you have a weak final transistor. Good Luck

Main IC or final with driver

why waste your money on an echo board .you should buy an echo chamber . They operate on the outside of the radio so people that don't know how to wire one in can still have one.the echo board should have come with schematics,if it didn't you may have to google it to get the schematic you need.