John Popelish wrote:
Alex wrote:

I'm trying to make a simple Hartley VFO. I've made one before no
problem, but this one won't start, period. The only difference between
this one and the last one is that I used a T50-2 core instead of an air
core inductor. Is that likely to kill it?

Also, last VFO I made, I tested it by feeding it and a signal generator
into a product detector to listen for a tone, this one I'm trying to use
a frequency counter to make things simpler. It reads crystal oscillators
no problem, and I've even used it to read a VFO in another receiver, no
problems.


Most likely answer is that you have the phase of the feedback reversed
(negative instead of positive feedback). You should be getting better
coupling with the toroid core, so the optimum turns ration may be one
with fewer turns on the feedback winding, but this would show up as a
very distorted output, not lack of oscillation.




?? I attached the feedback wire about 25% up from the ground as the book
said. See my other posting for a schematic.