The channel available for smoke control on my Vanguard transmitter will not operate a variable speed smoke oil pump. The twin cylinder engine is too smooth to use the varsanne oscillating pump.

I can manually regulate the smoke oil flow to the pump with a simple squezzing device such as the TME or similar, but that means you can adjust only on the ground.

Has anyone been able to find and use a servo driven valve which allows for some degree of inflight change in smoke oil flow?