[MrBungle]

Managed to get the sweep generator working with linearity control finally. The thing uses 8x diode clamps driven from a resistive divider each (each one a trimmer). This is followed by an emitter follower. I now have reasonable linearity. I haven't drawn up a schematic for it yet.

I have however got my hands on a 145MHz helical filter finally. Some progress at least.

At the current rate I will complete this some time in 2025...