PAL Communications VFO


Amateur Station
I recently found the old PAL VFO (11 Meter Slider / Scanner) below. You know how CB'ers were with their misinterpretation of the terms and definitions along with the ones they simply made up. However, the thing about a lot of these old CB accessories from the early and mid 1970's is that many of them worked better when modified for the ham bands than the higher priced amateur junk being made at the time and even now.



Amateur Station
Decided to open up the VFO and as I stated they were designed and built really well. They have very slow and weighted gear reduction too and this one still has a solid output and in the correct place, but that filter cap and maybe the 3 diodes should be replaced.


Then the main oscillator board below. All you had to do was change that one xtal down in the bottom left hand corner of the board to shift the whole thing up. Then sometimes you had to change 2 of the coils too which you could order from them along with the xtals, but that was more than 40 years ago. I played around with a few of them back then and they worked better and were more stable than most ham VFO's were. People today say you need a DDS VFO, but in this case, I fully disagree. These things use to make the old tube CB's like the Courier 23 for example rock solid on frequency.


Then here is the back showing that it's the A-1 model. These things were the easiest way back then to make the old xtal 23 channel radios slide up to 10-meters. You just needed a frequency counter, xtal and a few component changes.



Amateur Station
Here is the VFO's schematic below. A very nice and stable design with a mixer, driver and a buffer output stage with an adjustable level .

And then the actual VFO engineering notes below for the component values in each of the models they made.



Amateur Station
Picked up another one of the PAL VFO’s dirt cheap for $30. It’s one of the higher letter models with the higher frequency coils.