[BC] Noise Floor...

[Jerry Mathis]

On 2/18/06, Phil Alexander <dynotherm at earthlink.net> wrote:
>
>
> > 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
>
>
>
>
>
> I don't think the reality of today's AM broadcasting has set in with most
people. The majority of new buildings going up today are made with STEEL
beams, where they used to use 2X4's. These buildings TOTALLY block broadcast
band (~1MHz) signals. IBOC, full digital, or no, AM band reception is only
going to get worse.

I once worked for a 1KW AM on 1450. We did election coverage one year at
their new Election Central, a brand new building with the afore-mentioned
construction. This building was less than 2 miles from our tower. We could
not receive the station's signal inside this building AT ALL.  In order to
hear the station and get cues, I had to set up a radio outside, and run a
wire into the building (big mess, lots of people, had to tape down the wire,
etc. etc.) This was 6 years ago. It's only gotten worse since then.


--
JM