[BC] HDradio & our digital future

[Paul Smith W4KNX]

The first generation of HDTV receivers and converters were both blind and
deaf.  Here in the Tampa area, several stations put their digital on
adjacent channels to their analog.  And to make matters worse, HDTV is not
up to final power yet.  That wont come for a couple years.  So, when you put
a digital TV channel with say 350 watts adjacent to an analog with 5 million
watts, unless you have a great front end, the receiver gets swamped.  I cant
help but believe some of that exists in HD radio.  As with TV, the 5th
generation HDTV chips are much better and I get fabulous HDTV reception off
air.  I believe if allowed to mature, HD radio will be the same way with the
exception that AM HD is a trainwreck and cant be fixed.  When I drive amonst
the buildings in downtown Sarasota, I can get the hiss of the AM HD signal
on WFLA.  It comes and goes but I'm a believer it is caused by reflections
off of the buildings causing phase delays. (digital multipath)?
Pressure on manufacturers to make decent receivers?  If we had decent
receivers all this time, AM HD would never be an issue.

Paul Smith
W4KNX
Sarasota, FL


----- Original Message ----- 
From: <ChuxGarage at aol.com>
To: <broadcast at radiolists.net>
Sent: Friday, December 22, 2006 8:08 PM
Subject: Re: [BC] HDradio & our digital future


>
> In a message dated 12/22/2006 9:55:18 A.M. Central Standard Time,
> broadcast-request at radiolists.net writes:
>
> For  decades to come we'll have very low powered IBUZ stations trying
> to reach  deaf radios. It doesn't seem like a winning plan to me. I
> don't understand  why iBuckuity didn't put more pressure on
> manufacturers to design decent  receivers. At least for a little while
> to get this elephant to  fly.
>
>
>
> I think it is not just the radios, but more importantly the incredibly
low
> power of the HD signal.  It's 20 db down, or 1/100 of the analog  signal.
That
> is not likely to change in the near future as long as analog  broadcasts
> continue.   Otherwise, there really will be an interference  problem.  In
many
> cases that kind of power just isn't going to go very far.  Yeah, I know
that
> digital is very robust, but there is a point of diminishing  returns,
especially
> for smaller stations.
>
> I've really wondered about the future of HD on translators.  Armstrong
sells
> an HD translator, but I don't get the logic unless you are only interested
> in covering a very small area, like a college campus. Assuming your
translator
> is 250 watts, 2 1/2 watts for a digital signal is going to give most
radios
> fits, especially if they are inside a steel and concrete building.  Many
> translators are as low as 10-20 watts.  That puts their HD signal in the
same
> category as the modulators used by XM and Sirius for your car radio. Does
anyone
> have any experience with HD translators?
>
> It is beginning to look like this works OK on FM flame-throwers, but small
> stations are not going to realize much benefit out of it.
>
> Chuck  Conrad
> KZQX Radio
> _www.kzqx.com_ (http://www.kzqx.com/)
>