neschultz wrote:
There are electronics and 3 coax input\outputs (1 in from antenna, one in from cable jack and one out to TV) on the back of the wall plate.
The OP has told us he has a Sensar III antenna so his Winegard wall plate contains
no "electronics" as it has
no ability to amplify the signal. When the switch is depressed and the light is on the wall plate routes 12 vdc power to the antenna head which
does contain an amplifier that
does boost signal strength. That switch also routes the output from the antenna head to the wall plate's output connectors, one on the front of the wall plate, a second located on the PC board which can be connected to a second television set. When the switch is retracted, the light goes out, 12 vdc is disconnected from the antenna head, and the cable feed located the side of the RV instead of the antenna head is routed to those two output coax connectors. NO "electronics" involved.
Yes, one can still buy an amplified Winegard wall plate for older non-amplified Sensar I and Sensar II heads but there's little reason to these days when the better solution is to replace the older non-amplified Sensar with the latest amplified Sensar IV which includes the Wingman UHF array.
If the OP wants to improve reception I'd recommend he add a Winegard Wingman to his Sensar III, in effect making it a Sensar IV. The next improvement would be to replace that non-amplified wall plate with a Winegard SensarPro which does offer +/- 10 db of signal amplification / attenuation. I've done both.