Herald: Where have you gone Air America

[Dan Strassberg]

Depends on what the FCC's ratchet rule would have to say. I think there IS
prohibited overlap between WEZE's 0.25 MV/m contour and WTAG's 0.5. There
may also be probhibited overlap between WTAG's 0.25 and WEZE's 0.5. (WEZE's
signal toward Worcester is just a bit stonger than WTAG's signal toward
Boston.) Any such overlap would have to be reduced or the application would
be summarily rejected. One way to address this problem would be a 590/850
diplex from Needham. (If you move 590 westward and reduce the signal behind
the array, you can wind up with impoved coverage to the west.
Counterintuitive, but true! The idea is NOT new; it was thought of and
applied for maybe 40 years ago--long before overlap with first-adjacent 0.25
mV/m contours was even mentioned in the FCC regs.) At that time, I believe
the FCC rejected the idea because Class IIIA AMs (590) were limited to 5 kW
and from that distance, 590 could not deliver the then-requisite 25 mV/m to
Boston's South Postal Annex. Now, with the possibility of 50-kW and only 5
mV/m required over the CoL, the idea just might be workable--during the day
anyhow. At night, 590 must protect a bunch of Canadians to the north--even
though all of them may now be dark. That would probably limit 590's night
power to something less than 5 kW because there's only so much you can do
with three towers and because the 850 towers are taller than the 590 towers,
resulting in higher efficiency that would have to be offset by lower power.

Another interesting possibility is a 590/680 diplex. The filtering problem
would be difficult but not impossible The 90-kHz frequency difference is
more than 13% of the higher frequency. Burlington IS west (as well as north)
of Medford. Not as far west as Needham is, so the payoff might be smaller,
but the idea might still be worth some study.

--
Dan Strassberg, dan.strassberg@att.net
eFax 707-215-6367

----- Original Message -----
From: "Garrett Wollman" <wollman@csail.mit.edu>
To: "Sid Schweiger" <sid@wrko.com>
Cc: <boston-radio-interest@rolinin.BostonRadio.org>
Sent: Tuesday, September 19, 2006 4:39 PM
Subject: Re: Herald: Where have you gone Air America


> <<On Tue, 19 Sep 2006 14:28:26 -0600, "Sid Schweiger" <sid@wrko.com> said:
>
> > limited signal is one reason WEEI migrated to 850 in the early 90s...)<<
>
> > WEEI is limited in its westward radiation as well, since it must protect
co-channel KOA in Denver.
>
> But as I'm sure you're aware, WEEI's signal problems on 850 are
> nothing compared to 590.  WEEI has *only* to protect Denver.  WEZE has
> to protect a co-channel in Albany and even worse, a first-adjacent in
> Worcester.  (I don't think it could ever be usefully upgraded without
> significant modification of at least WTAG, if not WROW and WICC.)
>
> -GAWollman
>