How many daytime only stations are left?

[Dan.Strassberg]

FCC rules would never have permitted WILD to operate at night, regardless of
how low the night power and regardless of how complex a directional array
was constructed. A daytime power increase (conceivably, all the way to 50 kW
DA-D) could definitely comply with the rules, however.

The reason that nighttime operation of WILD cannot fall within FCC rules is
that, as a Class A AM, WBAL's nighttime skywave service is protected down to
the Baltimore station's 0.5 mV/m 50%-skywave contour. WILD lies well within
that contour. Plenty of full-time stations (TRUE fulltimers, that is, Class
B AMs, NOT merely Class Ds with nighttime authorization) now exist on former
Class IB channels, such as 1090, and even on former Class IA channels, such
as 1030. All of those stations (both the "new" Class Bs and the Class Ds)
are sited outside of the co-channel Class A's protected skywave service
area. Most of these new Class Bs use nighttime DAs that send much of their
signals in a direction opposite that of the dominant Class A station. Local
examples of new Class Bs include WAMG (protects WLS), WBNW (protects KMOX),
and WCRN (protects WCCO).

Besides WILD, a local Class D that continues to operate daytime only is
WNTN. Unlike WILD, which could not obtain nighttime authorization, WNTN
could operate at night if it chose to. WNTN (along with WJIB, locally) is a
US Class D on a Canadian Class A channel. Effective with the Rio treaty of
30 or so years ago, such stations need to protect the nighttime service of
co-channel Canadian AMs only over Canadian soil. (That is, interference to
Canadian AMs outside of Canada is permitted.) However, to protect the
Windsor ON 1550 over Canadian soil, WNTN, using its existing nondirectional
antenna, would have to operate with such low power that the population it
would reach would probably be limited to a few hundred souls.

The Rio treaty benefited WJIB much more. Its lower frequency allows it to
cover several times the territory with a few watts that WNTN could cover
with similar power (and WNTN would be allowed only about half the night
power that WJIB is allowed). Also, the area of Cambridge where WJIB's
transmitter is located is somewhat more densely populated than the area of
Newton where WNTN is located. Note that there are several US Class Bs with
appreciable nighttime power on 1550. One is north of Hartford CT and one
is in northeastern PA. Both use rather complex nighttime DAs to protect
Windsor.

-----
Dan Strassberg (dan.strassberg@att.net)
eFax 1-707-215-6367

----- Original Message ----- 
From: "Kevin Vahey" <kvahey@gmail.com>
To: "Garrett Wollman" <wollman@bimajority.org>
Cc: <boston-radio-interest@lists.BostonRadio.org>
Sent: Thursday, January 10, 2013 1:16 AM
Subject: Re: How many daytime only stations are left?


>I suspect WILD might have done it 10-15 years ago if transmitter was in
> Boston but low power out of Medford at night was useless.
>
> I believe Boston was the largest city in the country without a fulltime AM
> transmitter inside the city limits.
>
>
>
> On Thu, Jan 10, 2013 at 1:06 AM, Garrett Wollman
> <wollman@bimajority.org>wrote:
>
>> <<On Thu, 10 Jan 2013 00:20:53 -0500, Kevin Vahey <kvahey@gmail.com>
>> said:
>>
>> > I am curious how many daytime only stations are left.
>> > Obviously WILD is one but I suspect in this day and age they could go
>> full
>> > time if they chose to spend the money.
>>
>> Nearly every daytimer could go full-time "if they chose to spend the
>> money".  But why would you bother if nobody could hear the station at
>> night anyway?  It's just an extra expense at that point.  Better to
>> buy a commercial-band translator -- at least that's useful in the
>> daytime as well.
>>
>> -GAWollman
>>
>>