148Gtl alignment question

[kaos513]

I was following the alignment procedure and frozed on tp14,cannot find anywhere on older cobra 148gtls.Any help would be appreicated.

 

[sonoma]

here is a service manual that shows you the locations for adjustments.

http://downloads.cobra.com/CB/Models/148-SERIES/148alignment.pdf

 

[unit_399]

If you have an early model 148GTL, these are the test point locations from Sams #249 circa 1979. TP14 is under the bundle of wires running up/down the center of the board. Good luck & 73s.

- 399

 

[Robb]

Yeah, I don't use that method to tune the last - or 'offset' - oscillator chain. I use a RF sampler with a dummy load hooked up to a freq counter to the radio's output; then keying the mic adjusting the AM oscillator coil first. Then I put a 1khz audio signal into the mic and then tune the LSB oscillator coil; then the USB oscillator variable cap last. Works for me; use this method on all of my alignments. Same results; different method. Sure I'm not the only one that does it that way . . .

 

[kaos513]

If you have an early model 148GTL, these are the test point locations from Sams #249 circa 1979. TP14 is under the bundle of wires running up/down the center of the board. Good luck & 73s.

- 399View attachment 18624

Thanks will look into it tonight.

 

[sonoma]

did you even look at the service manual I left for you. if you look at the last page it has a clean layout showing the hookup locations.

 

[kaos513]

did you even look at the service manual I left for you. if you look at the last page it has a clean layout showing the hookup locations.

Yes

did you even look at the service manual I left for you. if you look at the last page it has a clean layout showing the hookup locations.

yes its an older model,but i do not see tp 14 on my radio board.

 

[sonoma]

it may be a resister that does not have the coating on the leg that is used for tp14 test point. some of the older radios would do that for a test point. if you look at the resisters one right in the location marked will be bare and shinny and not have a coating on it.

 

[Radio Tech]

TP-14 is pin 7 of IC3. It is a AN612 single inline package chip.

 

[kaos513]

TP-14 is pin 7 of IC3. It is a AN612 single inline package chip.

That is for the newer models from looking at schematics

 

[kaos513]

That is for the newer models from looking at schematics

My radio has a white power jack

 

[sonoma]

the sams and cbtricks has the old radios in it. they are the same. the test point is in the same location .

 

[Radio Tech]

That is for the newer models from looking at schematics

Nope, I have 2 148's from the late 70's. The picture I posted is right out of the 197X manual.

 

[Radio Tech]

My radio has a white power jack

Why not post a picture of your board

 

[sonoma]

use this service manual to adjust the portion you do not seem to find TP14, this is the same board as a cobra 148. I have done cobra 148's both ways.

http://www.cbtricks.com/radios/rci/tr_296gk_dx/graphics/tr_296gk_dx_sm.pdf