"Bob Haberkost" wrote in message
...

"Frank Dresser" wrote in message
...

"Doug Smith W9WI" wrote in message
...

It's commonly not understood by non-engineers that a radio station
(broadcasting or otherwise) causes interference over a much wider area
than it provides service. This is especially true on AM where multiple
signals on the same frequency mix together.

The open frequencies I mentioned aren't silent, but are a mish-mash of
low
power signals. They aren't useful in this area.

Then they're not "open". And adding another signal, even a low power one,
in this
space would then interfere with the otherwise serviceable coverage closer
in to these
stations.

There's no evidence the Chicago street gang FM pirate ever took one listener
away from any licensed station. Their signal was lost in the noiise a few
miles from their transmitter. The nearest licensed station was over 60
miles away. The FM pirate was playing rap, much of it was offensive, and
there were no complaints


The new Chicago X-band station moved from downstate - Johnson City
IIRC.
A station on that frequency in Chicago would not have been allowed if
WRLL had been operating downstate.

I live within 15 miles of WRLL, and it's almost unlistenable at night
after
they drop power to 1 kW. Skywave comes in from all over. A much larger
number of daytimers could be worked out, however.

That doesn't make the area unserved by WRLL's nighttime pattern "open". A
facility
allowed to fill in this "unserved" area would interfere with the stations
whose
skywaves come in from all over.

Of course not. But it does indicate that the FCC's interference standard is
weak. If the FCC had a strong stand on interference, WRLL wouldn't exist as
it is in either Chicago or Johnson City. Given the interference and power
situation, it's practically a daytimer for most of it's listeners anyway.


And the FCC no longer licenses daytimers, and all
attempts to apply for one will be rejected on this criteria. As it is,
the FCC is
looking for daytimers below 1600 (and encourages, through policies in
place) to move
to the X-band, in order to clear out the congestion and permit more
regional service
by the full-time stations on those frequencies.

The irony is the Xband is best suited to daytimers. Or true clear channel
24 hour operations. As it is, it's a mess at night.


That's the point. The allowable amount of interference isn't really a
technical consideration. At one extreme, we could have a very small
number
of true clear channel stations. Or we could have super saturated radio
markets in which the only clear reception would be within the shadow of
the
station's antenna. Allowable interference is a political consideration,
not
a technical one.

Actually, no. The interference standards provide for usable coverages to
the limits
of receivers (very few radios will provide a listenable output at 500uV,
the current
protection limit for nighttime service, which affords a 26dB signal to
noise ratio,
give-or-take).

What is the noise in the signal to noise factor? Do they take into account
the cochannel interference, or they just assuming natural plus manmade
backround noise? On nearly all AM nighttime frequencies, the cochannel
interference is much stronger than the backround noise.

And there are very few FM frequencies which go down to the backround noise
anymore.


But protecting out to that limit means that for every 20dB increase
in signal strength for the desired station (by moving closer to the
transmitter) also
means at least a 20dB boost in the signal to noise ratio...thus, the
rural-grade
5mV/m contour would be a listenable signal. Allowing increased
interference (by
raising the protected contour to, say, 2mV/m) means that a listenable
signal would be
obtained at the 20mVm contour....which is a metro-grade signal-strength.
So, in the
interest of expanding coverage, you'd actually be reducing it. For both
the new, as
well as the existing, stations.

I think we're saying the same thing here. I said:

"Or we could have super saturated radio markets in which the only clear
reception would be within the shadow of the station's antenna."

Which sounds much like:

"Allowing increased interference (by raising the protected contour to, say,
2mV/m) means that a listenable signal would be obtained at the 20mVm
contour....which is a metro-grade signal-strength."

If the FCC really wanted to take a stronger stand on interference, it could
bring back it's older interference standards with wider frequency spacing
between stations in the same market, fewer AM nighttimers and fewer
stations overall.

If the FCC wanted to take a near absolutist stand on interference, they
could get rid of about 75% of the stations. The remaining stations would
have a much wider coverage area.

The FCC has neither a wide open stand on interference nor a absolutist stand
on interference. The current standard is a comprimise with elements of both
technology and politics. I belive politics is the bigger factor. The NAB
didn't like the old interference standards, so we have new standards. The
NAB and NPR didn't like the low power FM proposal, so they screamed
"interference!". I think there's plenty of room for low power 10 to 1000
watt FMers which would serve a community.
...

All the details about how this is done can be found at
http://kauko.hallikainen.org/FCC/FccRules/2003/73/182/ and
http://kauko.hallikainen.org/FCC/FccRules/2003/73/37/

IMHO the FCC has grounds to regulate both services on content if they
chose to do so. IMHO they need to either do so, or lift content
regulations on OTA.

Maybe so....but, for the former proposal, would you want a situation where
the FCC
can delve into the private affairs of these operations? You know, the
next step
would be censoring telephone conversations, as the analogy holds.
Subscription
services, and other non-broadcasting licensees, are not public entities.

What about OTA subscription services? The used to be pay TV stations in
areas which weren't wired up with cable.

Suppose IBOC AM flops, and Clear Channel converts their digital sidebands
into a subscription service. Should those stations be allowed the same
speech rights as satellite stations?

Better that
if the FCC feels obliged to limit what can be said on OTA, they feel that
it's the
only area where such pervue exists. While I'm not so keen to remove those
restrictions on OTA, the Canadians and other democracies have no such
limits
(although there's some discretion in how often the ability to say anything
is
exploited) and they haven't come to the end of the world.
--
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If there's nothing that offends you in your community, then you know
you're not
living in a free society.
Kim Campbell - ex-Prime Minister of Canada - 2004
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