RE: Jitter/glitching on HS-7940TH 2S lipo direct
This morning I tried a smaller (22uf) tantalum cap between power (+) and ground (-) leads at the servo end of the extension and this also eliminates the glitching.
What gave me this idea in the first place is that we use caps on the battery to ESC power lines, at the ESC end, with our electric powered planes to control back EMF and I thought possibly the same thing might be happening here and causing the glitching.
My other identical elevator servo glitches only very rarely when plugged into the exact same extension, but I _have_ seen it glitch also so I'm considering putting caps on both of these extensions at the servo ends. There definitely is variability from servo to servo in terms of the degree to which they are susceptible or perhaps even cause the glitching.