On Sat, 31 Mar 2007 16:14:38 -0700, RHF wrote:
Which is the Better "HD" FM Radio ?
-and- Is and External FM Antenna 'critical'
for "HD" FM Radio Reception ?

More importantly which is the Better "HD" AM/MW Radio ?
-and- Is and External AM/MW Antenna 'critical'
for "HD" AM/MW Radio Reception ?

I have only the Boston Acoustics.

FM: at my location, 25 miles from the nearest HD station, an external
antenna is critical for HD reception. Right now, I have a set of TV
rabbit ears connected, and can reliably receive three HD stations. Five
more local stations are known to be HD but don't come in on the "bunny
ears" - I need the rooftop TV antenna for those. I'm near Nashville -
which is Class C territory, so if you're in the Northeast where stations
are limited to 50,000 watts a better antenna will be even more important.

AM: An external antenna is even more critical for AM. We have two local
HD AM stations, WPLN-1430 (15,000 watts) and WLAC-1510 (50,000 watts).
Neither can be received for more than a few seconds with the antenna
provided with the radio. Both can be received reliably with my 160-meter
ham antenna. I don't have anything between the two - I suspect you don't
need anything nearly as big as the ham antenna but have no way of knowing.

The BA is to a considerable degree subject to self-interference. (the
radio emits spurious signals that interfere with its own reception...) It
may not be as much that the external antennas are necessary to increase
the signal strength of the HD signals, as that the external antennas are
necessary to reduce the amount of the radio's own spurious RF interfering
with the stations...