Spam: WCBS Newsradio 880 in HD, FM that is!

[Eli Polonsky]

-----Original Message-----
>From: Roger Kirk <rogerkirk@ttlc.net>
>Sent: Oct 2, 2008 8:30 PM
>To: Eli Polonsky <elipolo@earthlink.net>
>Cc: boston-radio-interest@tsornin.bostonradio.org, 
>"Dan.Strassberg" <dan.strassberg@att.net>
>Subject: Re: Spam: WCBS Newsradio 880 in HD, FM that is!
>
>Eli Polonsky wrote:
>> ... if my home HD tuner loses a subchannel, it falls back to 
>> the stations main analog channel, just like when it loses the 
>> HD-1. 
>
>Odd decision on the part of the architects. I'd prefer silence.  
>Imagine if an AM radio lost a signal and just automatically 
>scanned to the next higher signal on the band?

Well, that's not really what the HD radio is doing when it loses
a subcarrier and falls back to the main analog channel. It's not
scanning to another frequency, it's simply switching to the main 
analog carrier program on the same frequency. 

I doubt it was a conscious decision by the manufacturers. It's 
just designed to fall back to the analog station if it loses 
the HD, whether it's the HD-1 or an additional subcarrier. To
make it differentiate between the HD-1 and any additional
subcarrier to make the HD-2 or HD-3 default to silence would 
probably need an extra circuit, or extra system programming.

The radio doesn't default to silence at any time. It's falls to
analog whenever it doesn't get an adequate digital signal. It
gets typical analog FM static on unused frequencies. It's not
like a HDTV on which you can switch it to receive only digital 
signals.

EP