Motorola roundie

[timmy]

Ok still no difference still got a screen of rainbow colors and did the whole afc and A17 if it’s voltage to max it is already it’s at 4.40v won’t adjust any higher it will go lower. Could there be a problem in the demods?

[Yamamaya42]

Originally Posted by timmy

Ok still no difference still got a screen of rainbow colors and did the whole afc and A17 if it’s voltage to max it is already it’s at 4.40v won’t adjust any higher it will go lower. Could there be a problem in the demods?

no, it would not be the demods,95% chance its a problem with the osc circuit, including A18, and the previously broken and replaced core, these are all symptoms of it not being able to be tuned into the correct range.

If you had a frequency counter or oscilloscope you could verify that it is at or near 3.57954 MHz but if its unable to get there due to come fault like in the coil, you will never get the color to lock in.

[timmy]

Originally Posted by Yamamaya42

no, it would not be the demods,95% chance its a problem with the osc circuit, including A18, and the previously broken and replaced core, these are all symptoms of it not being able to be tuned into the correct range.

If you had a frequency counter or oscilloscope you could verify that it is at or near 3.57954 MHz but if its unable to get there due to come fault like in the coil, you will never get the color to lock in.

Ok well the core ferrite was the same size as the old one but I noticed that on the oscillator coil there is a resistor that’s good and a 15pf mica that I can’t check it’s range is to low for me to check and also a 220pf mica at v23 one or both could be bad keeping it from reaching the correct frequency