Cobra 148 gtl china model

[fourstringburn]

We would have very little to play with

True, I just remembered my TS590 is made in China.

 

[kaos513]

now ihave another issue i lost rx and tx i didnt do the mod yet wonder what it can be? thanks. my channel display works and meter light works looks like i lost tx power and rx power strnge

 

[nomadradio]

Lost?

As in "went quiet while my back was turned" kind of lost?

Or did you make some small change to the radio that should not have shut it down?

73

 

[kaos513]

radio just gave up

 

[kaos513]

Apparently the tx red light didnt work and the rx light was fading in and out and poof seems like something shorted out.

 

[sonoma]

do you have voltage on pin 9 of the PLL. there is a resister to the pll R130 a 10 ohm 1/2 watt they may have shorted. it runs just under the channel control with a wire feed to it. if it gets hot and shorts you can lose all power. I think stock it is a 1/4 watt and goes bad. see if you can find it. may not be it but take a look. here is the bulletin on it.

http://downloads.cobra.com/CB/TSB/TSB10002.pdf

 

[kaos513]

I do get channel display and meter lights up.

 

[sonoma]

have had 3 do this over the years and you will have the light and channel display but normally it will appear to be locked where it is at. you need to at least rule this out to proceed on.

 

[kaos513]

Pin9 3.538 volts

 

[338_MtRushmore]

Not trying to hijack the thread, but what's the point of unlocking the clarifier?

 

[nomadradio]

Not trying to hijack the thread, but what's the point of unlocking the clarifier?

To get every station's transmit frequency the same on the channel. So you don't have to twist the fine-tune every time a different station keys up and talks. The stock setup will cause every radio to have a slightly-different transmit frequency. Having everyone transmit on the same frequency is just easier.

Time to have a look at the 9-Volt regulator. It looks like a final transistor, but should be marked some variation of "7809". Pretty sure it's near the center of one side rail between front and rear, on the same side as the audio-power chip.

Should have the power-supply voltage, 13.8 or whatever your supply is set for on the pin towards the rear of the radio, and 9 Volts on the pin towards the front. Center pin is ground. If the mount screw has come loose, it can overheat and fail.

73

 

[sonoma]

voltage is a little low on pin 9. why not find the R130 resister and change it out and see what happens. if that does not bring it back check what Nomad has told you to try. it should be on a wire with heat shrink on it as the bulletin states I left you.

 

[kaos513]

there is no r130 on this board, reads like r167

 

[kaos513]

I see red wire going from under the channel selector board to under pcb board

 

[sonoma]

if yours has the board I am thinking it is R130 runs under the board and heat shrink over the 10 ohm resister. sounds about like the red wire you are talking about. see if there is a resister in the wire.