Evan Salant wrote:

I was flying the ILS 06 approach on my plane equipt with an Aspen and
Garmin 430. I had the Garmin set up for vectors to final, tuned
properly, set on VLOC, station identified and was flying near the OM
towards the FAF. Then I noticed the Aspen said "BC1", was reverse
sensing, and showing no vertical navigation guidance. My other VOR
(standard VOR) was tracking correctly. There is no runway 1 at MJX,
just 6/24. I have no idea why this happened. Any ideas ? Possibly I
did not have the course set correctly on the Aspen. Would that cause
this to happen ? Auto-course select may have been turned off.

Thanks.

Don't know the Aspen. Some systems use the (HSI) course setting to
select ILS versus B/C with glideslope suppressed for a given nav
frequency. The FAA makes efforts to afford locating adjacent ILS navaids
on a common frequency. Last time I talked to that department, I seem to
remember they said they aim for a 100 mile separation.
My best guess is your course setting gave the B/C indication on rwy06.

What leads you to think a runway 1 was involved? "B/C1" means back
course is indicated on nav radio ONE.

Regards

Brian W