[BC] IBOC AM Quality

[Mark Humphrey]

On 3/26/07, Mike Erickson <wirelessmedia at gmail.com> wrote:
> I have seen the BA and Accurian drop in severe multipath situations, similar
> to what you describe.  I don't know how much better your listening
> experience would have been.

Does anyone happen to know offhand the "guard interval" specification
for OFDM carriers in the iBiquity FM system?  This is directly related
to the amount of multipath delay it can handle without inter-symbol
interference.

My personal experience has been that FM HD Radio works well in urban
multipath situations (because the delays are relatively short) but I
haven't observed good results while driving in mountainous terrain.
Recently, I spoke with a station engineer in the Bay Area who has been
using the FM system for a few years; he tends to agree this is a
shortcoming.

Mark