Robert Libby of Brindletown Electronics, offered this solution for RF interference with the DSR922 4DTV.  Thank you Robert for sharing this with all of us.

Problem: Motorola 4D-922 Receivers giving off RF interference.

After installing 3 or 4 of the 4D receivers over the past year, I found one common problem.
They all seem to cause RF interference to a greater or lesser degree across TV channels 2-5,
occasionally channel 7.

Having talked with Motorola technical support, they suggested grounding the receiver and grounding the shield on the pulse wires.  This was a good suggestion except that I always ground all equipment and shields as normal procedure. (however, I tested the grounding solution by removing the shield & equipment grounds and found RF interference became worse. For this reason I always recommend grounding all wiring shields and equipment.)

With further testing I found some of these units transmitted 200+ feet. By removing power to the 4D receivers, RF interference stopped immediately.

Solution:

I found the main source of the RF emissions coming from the Jack motor outputs M1 & M2; the second source coming from the pulse wire outputs. I built a very simple filter using Panasonic ZNR  (V14390) surge suppressors [See diagram]. This simple filter seems to reduce RF interference approx. 85-90%. It also works as a 39-Volt surge suppressor to protect Jack motor (actuator) outputs.

I hope the implementation of the above will provide much needed help with this problem.
 

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