[BC] Power side...

[Burt I. Weiner]

The typical receiver has an envelope detector and sums the two 
sidebands.  It's really only necessary to have one sideband in order 
to properly recover the audio.  Any difference between the two 
sidebands due to propagation or any other sideband distortion causes 
the two sidebands to add together and sometimes in a not so nice 
way.  This is part of the reason for the severe distortion that 
results from selective sideband fading.  Reducing or eliminating one 
of the sidebands could be a good thing.

The station is not moved from its assigned frequency and 20 Hz 
tolerance.  It's strictly to do with the amplitude of one of the 
sidebands.  Pick one.

Burt

>Barry Mishkind wrote:
> >         Aren't there two reasons for power-side?
> >         1. To "move" a station slightly up/down the dial.
> >                 this is less useful on digital receivers.
> >         2. To better match the sidebands into a DA.
> >                 this may still be useful in some cases.
>
>There is also supposed to be a another reason, that is to cut down power
>line interference. What I have been told is that by unbalancing the
>sidebands it causes a cancellation of power line noise in the receiver.
>I don't know why exactly that is nor can I explain it.
>I was called in to assist Lenard with a Power Side installation last
>year. He explained quite a bit about how it works and why it works,
>unfortunately my grasp of what he was saying wasn't keeping up with him.
>
>I'm not either pro or con on PowerSide, but listening to some stations
>that have it, doing A-B tests it does make a positive difference. The
>question is is the difference enough to warrant the investment?
>
>It was also interesting to note that with some new AM TX designs coming
>out that the same effect as PowerSide could be now done simply by
>software. Of course that opens a whole new can of worms.
>
>--
>Alan Alsobrook CSRE AMD CBNT