[BC] FM Stereo Question

[Dana Puopolo]

Most radios made in the last 35 years use phase lock loops (PLLs) for their
stereo decoder. 
A PLL regenerates the 19 kHz by locking onto the transmitted pilot. A PLL can
find the 19 kHz pilot buried in the noise. I experimented back in the '80s and
we were able to lower the pilot injection to as low as .5% before the
'average' radio went to mono. Now, it is true that some radios blend to
mono-and may monitor the noise on the pilot to help do the blending-but I
don't believe that changing the pilot level by 1% is really going to make any
real difference. We took a rimshot oldies station in Tucson mono and the
ratings went up a bit-because more people could hear it.

-D

From: ChuxGarage at aol.com

I'm considering taking the station mono to see if that helps, but before I do
that, I'm wondering if experimenting with the 19 kHz pilot level would make
much difference? Right now it is at 9%.  I'm pretty sure lowering it would
make things nosier, but how about increasing it to 10% (which I think it the
edge of "legal")?

Has anybody experimented with this?  I realize that I'd sacrifice a little
loudness for the increased pilot level.  I'm not interested in being the
loudest signal on the air, but I'd like it to be one of the best sounding
signals.  I know that isn't fashionable, but it's my station, and I think
there is a place for decent quality.

That said, I think going mono would help more than messing with pilot level,
but I'm not sure.  I think good mono is better than bad stereo.  I doubt that
many people would notice the difference. I do run RDS on the station, so I'd
have to fool my RDS encoder into thinking there is a 19 kHz pilot to lock on
to. Has anyone done that?  It might be easier (and cheaper) to just buy one of
the Pira-CZ RDS encoders, which does not require an external pilot. 

Any suggestions are appreciated.

TIA