Permeability Tuning

[pwdrive]

Andrew,

The slugs I've used in my limited efforts with rf have been quoted by the Manufaturer for a maximum frequency. I don't remember a minimum being quoted.
These were Neosid ferrite 6mm and 4mm screw in ones. One variety was used at rf - 140 to 170MHz - and the other at IF - 10.7MHz.
If I remember rightly they had a different coloured strip on them.

Alan

Thanks Alan, the ones in the R1155 are colour coded (dot) I seem to remember, I have considered using standard tuning slugs as found in old RF coils but I suspect I wouldn't get the tuning ratio, Ideally the ratio needs to be the usuall 3 to 1 or there abouts, wonder if I could glue 2 o 3 of them length wise to get the required inductance change? Next time I'm at the bench I could try that and check the inductance swing on the bridge.

Lawrence.