Cobra 148 gtl china model

[kaos513]

yes meter lights up and channel selector

 

[Robb]

Does the TX/RX light change when you key the mic?

 

[kaos513]

you mean tr30?

 

[kaos513]

Does the TX/RX light change when you key the mic?

doesnt do anthing when i key up

 

[Robb]

Then; test the loop osc circuit.

 

[kaos513]

so its tr30, or tp 10?

 

[Robb]

Hook up your freq counter red lead to TP1 and the black ground lead of the counter to the radio chassis ground.

Test in each mode and see if there is a steady reading - very important!

If these freq readings are not steady - but random; then the PLL is out of lock and therefore no RX or TX . . .

 

[kaos513]

i checked osc section i getnothing on my frequency counter .

 

[Robb]

Check VCO voltage next.
Then, the PLL voltage.

 

[kaos513]

I get nothing

 

[Robb]

Then I suggest that you re-check R130 again (that it is getting voltage fed to it) and also check the points between the voltage reg and the PLL. Use the schematic.

 

[kaos513]

k thanks

 

[kaos513]

I will test all pll pins and post my readings later thanks , everyone here is really helpful to me i appreciate everyones help

 

[kaos513]

r130 i get around 8 vots

 

[Robb]

Transistor voltage chart for your radio: http://www.cbtricks.com/radios/cobra/148gtl/graphics/cobra_148_gtl_sm_pg31_pg47.pdf