Problem with ST MC34063C DC to DC converter

[DeepOne]

Possible do else such converter, it not so moody as based on 34063.

 

[xaccto]

...
Are you suggesting that I am trying to run the chip at a frequency that is too high to be reliable? If so what is the most often used frequency range for this chip?
The inductor is from the power supply section of a tv circuit board and has quite coarse guage wire. I would have thought that it could handle a few amps.

...

I think I know your problem. I too sometimes use recycled inductors from tv boards, BUT you need to be careful, some are only useful as filters and
are saturated inductors. Hold some iron metal near them, does it attract strongly - you won't be able to use this as a high frequency inductor as in
the 34063 converter. If you have an oscilloscope you would see the problem.