RE: Spektrum DX-7 Problem ??
G'day Jack,
I would suspect either a servo, or more likely a servo extension lead problem, either where it plugs into the RX or where the extension plugs into the servo lead.
I have hed problems with extension leads, of varying quality, on a variety of receivers, makes no difference what type it is, 2.4Ghz, PCM or PPM, the servo will do all sorts of nasty things if it don't get a good signal or power supply. I had one, where the brown wire pin (negitive) would push out of the connector, as the two ends were pushed together, I didn't notice, so I heat shrinked, & installed, only showed up as a problem when the engine was running, & that was on PCM, with an OS 160FX, the servo jumped around something weird, so I knew it wasn't a radio signal problem, I replaced the servo & ext lead, & the problem went away, I found why when I got home & dsmantled the lead.
Also if the TX is too close to the RX, it is normal to have problems, due to the TX swamping the RX.