[BC] Noise Floor...

[Phil Alexander]

On 18 Feb 2006 at 9:36, Mark W Earle wrote:

> The digital signal is indeed subject to noises in the analog realm.

Most tests I've seen report either an average power reduction or
a signal improvement of 7 - 10 dB with digital. Thus, while IBOC
will actually be weaker, once (if ever) we get rid of it and
transition to full digital broadcasting, there will be improvement
to the extent that power can be increased. 

> Also, the laws of physics apply. On AM broadcast, signal penetration in
> to buildings will not magically improve. 

At IBOC signal levels that is true, but the main reason for using low
digital levels with IBOC is reducing interference to analog. Without
analog, power can be increased very significantly. If the building
is shielded, there will be no better penetration, but where shielding
is not total, there will be better penetration.

> Hate to say, ain't so. It may make an already- receivable weak signal,
> able to be listened to. 

Not with IBOC it won't.

> But digital is not going to cause a signal to "appear" where no 
> signal now appears. 

Full digital does appear to have the possibility of making 
marginal analog signals become useful signals.


Phil Alexander, CSRE, AMD
Broadcast Engineering Services and Technology 
(a Div. of Advanced Parts Corporation) 
Ph. (317) 335-2065   FAX (317) 335-9037





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