Ron Natalie wrote:
And I did understand you correctly that the SL30's
internal bar graph CDI does read properly on the
LOC frequency?

Yes. Only the L/R on the VOR indicator is absent. Most of the time
this is a non-issue --- except when on approach, my head needs
to check an additional instrument (the SL30) which is nowhere
near the glideslope indicator.

Another datapoint. Just had a wonderful chat with the Avionics Person
I Trust the Most. She's the
first person (and that includes the Garmin/Apollo people, altho
they may have forgotten to explain it to me) that explained what
could be the problem.

The SL30 has a much narrower horizontal band to receive the localizer.
It's still within FAA requirements, but it's substantially smaller
than what we've been used to for...what...50 years? She says that
Garmin/Apollo knows this, understands this, but since it's legal,
they don't have much motivation to change it. This does not happen
on the 430/530 equipment, BTW.

This is a great explanation, but I still don't understand why I
can see the L/R on the SL30 during approach, but not on the VOR
indicator. Only thing I can think of, in concert with her explantion
is that the SL30 is sending correct info *for the SL30* but the VOR
indicator is "less sensitive" and doesn't display the same level
of granularity. According to the APITTM, going with a different
VOR/GS indicator (e.g. a Garmin) wouldn't resolve the issue.

I dunno. I'm gonna go have more chocolate brownies and chill.