Cobra 2000 GTL service manual error...

[Cable Guy]

I was blindly following the sams for this rig through the alignment of the synthesizer and noticed, after finishing, everything was spot on using AM and USB, but LSB was 500 Hz high. I double checked everything and it was spot on, from the vco to the 7.8Mhz. Then, while contemplating my life choices, it hit me. The manual was wrong, and I am documenting it here for anyone else.

Manual states to adjust for 7.798Mhz, however that is wrong, it should say 7.7985Mhz.
That is all, carry on...

 

[Klondike Mike]

40 years on and not mentioned anywhere online. Good catch and good-on you for posting. Never had the problem since I always used the Dynascan manual.

 

[999]

40 years on and not mentioned anywhere online. Good catch and good-on you for posting. Never had the problem since I always used the Dynascan manual.

View attachment 73425

I was gonna say that I just checked the Dynascan manual and it's spot on.

Here is the PDF of the service manual if anyone needs it.

 

[Cable Guy]

I was gonna say that I just checked the Dynascan manual and it's spot on.

Here is the PDF of the service manual if anyone needs it.

Thanks, for the Sams I expected better. I noticed this dynascan manual looks practically identical to the Sams. I wonder if the Howard Sams company wrote this version also, sans errors.

 

[999]

Thanks, for the Sams I expected better. I noticed this dynascan manual looks practically identical to the Sams. I wonder if the Howard Sams company wrote this version also, sans errors.

I find it more likely that Sams just copied the factory manual and just missed a digit.

 

[nomadradio]

The Howard Sams' books were traced down. This was Sams' claim to fame in the 1950s. Rather than rely on errors in a factory manual, their copyrighted name for it was "Circuitrace". They would tear down, photograph, label the insides and show what was actually being sent out the factory door. Factory data was famous for being older than the production-line revisions made after the info was printed. Seeing what was actually in the production. TV/stereo/CB was their selling point.

Somebody corrected that carrier-frequency error between the Sams CB251 being printed, and the B&K reprint of it being sent out. B&K had the money to pay Sams a license fee, copy and distribute it legally.

73