Are there any HD radios that actually have a good AM front end. We have the
Boston Acoustic non-HD clock radio. While the AM band has very good
sensitivity, the adjacent channel selectvity is a bit wide. Also, the LO
isn't very clean....early evenings, I can hear 49 Meter stations coming in
around 950kHz. This is because of mixer products occuring from the 5th
harmonic of the LO. This is even while using an external tuned loop antenna.
Inexcusably poor design, from an RF standpoint.
I wanted to clean up the design a bit.........when I called Boston Acoustic
and asked for a schematic, I was told "we don't release that kind of
information". Translation? We want to continue selling junk to the public,
and we don't want anybody improving our poor electrical design. Needless to
say, I never bought another Boston Acoustic product. Come to think of it,
their speakers were never anything to write home about either.

Pete

"Chuck Forsberg" wrote in message
...
On Tue, 22 Jan 2008 09:49:31 -0800, Rfburns wrote:

Anyone know the current status of the HD radio implementation that has
been forced upon us? How many receivers were sold during the Xmas
season? How many new stations have started or terminated transmitting?
How long will it take fior the noise to stop, etc?

jw

I have a Yamaha 4600 receiver and JVC car radio with HD radio.

On AM, only 1190 KEX broadcasts in HD. KEX is a talk radio station
with little stereo content. A few commercials are in stereo and
they really jump out. HD audio sound quality is similar to analog
on a 680NAB tuner.

Quite a few FM stations have HD. I listen to all classical KBPS.
Sound quality is indistinguishable between FM and HD except for
the noise floor. KBPS compresses the HD signal just as much as
the analog signal.

The non HD AM reception on the JVC car radio sucks. Reception is
weak and the audio is poor. HD sound is fine, but the least bit
or powerline interferece knocks the radio back to muffled analog.

HD FM on the JVC car radio is weak, dropping back to analog at the
slightest provocation.

I would like to see a Ramsey kit am transmitter with HD.

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