On Aug 26, 2:26*pm, K7ITM wrote:
On Aug 26, 10:46 am, Tim Shoppa wrote:
...

The brass-screw-in-a-solenoid is something I just tried in my
reproduction of the MMR-40 and I am very impressed with its stability
and mechanical simplicity as a PTO. A similar but not identical
mechanical design is used in the WA6OTP PTO, I haven't tried it yet.

Tim.

Though not actually PTO if it's a brass screw, right?

Permeability of brass is slightly less than air, which is why the PTO
goes up in frequency as I screw the brass screw in.

It's not an iron-powder slug (which would go down in frequency as it
enters the solenoid) but it's still a PTO.

If you haven't tried them, I highly encourage you look at the PTO in
the MMR-40 and the WA6OTP PTO. Completely 100% homebrewable and I'm
very happy with the results.

Tim.