5FP7 project starting with the focusing coil.

[AdrianPH]

Mark i will get there eventually, I have not needed to make my own transformers before getting into valve tech. I have built a small valve audio amp with a push pull output transformers for a small less than 1 watt amp, but was basically told the formula to use put the numbers in and off I went. I changed a secondary winding on a mains transformer simply by counting the turns as I took them off, I knew what the secondary voltage was before hand so I could wind a different secondary knowing what the TPV was. Other than that I just bought them in for any typical application.

The Scroggie Foundations of Wireless book I read talks of ampere turns to generate a back EMF, so it may be the generation of this back emf I am not understanding. Much of this project is falling apart, I calculated that I need 13.6 Volts peak to peak to swing the line trace from top to bottom, I am actually needing double that and I do not know why. The transformer I made up for that at 400Hz working is an air cored one as it is basically a Single ended driver amp, and looking at my turns per volt I could have gone way over the top. Much of this is try it and see how it works try to understand why it does or why is does not. I will stick with it and get there eventually. I need sleep, I was up into the early hours yesterday so I better not push it to long this morning.

Cheers

Adrian