The future of AM radio

[Garrett Wollman]

<<On Fri, 1 Feb 2008 22:00:34 -0500, "Kevin Vahey" <kvahey@comcast.net> said:

> For example when CINW took over the slot that CBM once occupied were
> they given an exemption since the station was the former CIQC (CFCF)
> 600?

It wasn't a new station, so there was no additional competition for
advertising.

> In theory couldn't the pattern be tweaked to allow the signal to
> continue north while not in any way be beamed to the west and
> southwest?  I do know WEEI booms into Quebec City at night.

Um, Quebec City is literally due north of WEEI.

WEEI unaugmented night pattern, electric field at 1 km (mV/m)
RMS = 2623
min =    1.13 (at 277 degrees true, almost precisely toward KOA)
max = 4168 (at 29 degrees true and again at 131 degrees true)

The field at 0 degrees true (towards Quebec City) is 3298 mV/m.
The null, loosely defined, is from 311 degrees true (approx. NW) to
221 degrees (approx. SW).

KOA, as a class-IB station, would have required stronger protection
than any of the class-II stations on 850, and I believe the pattern
itself is clear evidence that the WEEI array was designed only to
protect KOA, and the protection it gives to the other stations on the
channel is an artifact.  (That is to say, at the time it was built,
eliminating all of those stations from consideration would have
resulted in an identical array design.)

-GAWollman