Michael Graham to be on WCRN, 3 other stations
Tue Feb 5 13:54:27 EST 2013
The signal strengths represented by R-L's (radio-locator.com's) contours are
as follows: Daytime: inner--2.5 mV/m, middle--0.5 mV/m, outer--0.15 mV/m.
Nighttime: inner--2.5 mV/m, outer--0.5 mV/m. IOW, R-L has, in effect, done
away with the outer nighttime contour.
Folks like Mr Nelson, who don't bother to obtain the contour values (they
are listed somewhwere on the R-L site--just don't ask me where; I don't
remember), are likely to be misled about the meanings of the contours--as Mr
Nelson pretty clearly was.
On a good radio, a 2.5 mV/m daytime signal is usually listenable, as long as
interference from all of the stuff (fluorescent lights and light dimmers,
for example) that raises the AM noise floor is not too severe. But 2.5 mV/m
is hardly what most people--even radio geeks--would call a strong signal.
The FCC considers 5 mV/m (twice the field intensity at R-L's inner contour)
to be the minimum for service to a station's CoL. For some purposes, the FCC
still considers 0.5 mV/m to be an AM station's primary daytime-service
contour. But the Commission recognizes that, because of the proliferation of
noise sources in recent decades, there are many situations in which 0.5 mV/m
simply can't cut it. A practical definition of a 0.5 mV/m daytime
(groundwave) signal is one that is listenable on a good receiver under ideal
or nearly ideal conditions. As far as I know, 0.15 mV/m never had any
special meaning at the FCC. The FCC USED TO say that 0.1 mV/m defined Class
I AMs' (now called Class A) secondary (groundwave) daytime-service area.
With a few exceptions, Class A stations are legacy 50-kW full-timers with
highly efficient transmitting antennas and nighttime service that is
protected from interference from co-channel stations of lower classes. Only
a small fraction of US AMs that run 50 kW-U are Class As. In New England,
the only Class As are WBZ and WTIC.
Even though R-L shows three contours for daytime operation and only two for
nighttime operation, the nighttime situation is much more complex and would
require much more space to explain. The most salient point is that, for all
US full-time AMs except Class As, the extent of so-called interference-free
nighttime service is MUCH smaller than is suggested by R-L's INNER nighttime
contours. R-L's outer nighttime contours, though provided for all stations
that operate at night, bear no relationship to reality EXCEPT for Class A
AMs, and for those, the outer contour applies only for groundwave service.
It is still common to receive AM signals from distant stations at night.
This is due to skywave--a phenomenon that results from the reflection of AM
signals from the Ionosphere. Suffice it to say, however that, today, skywave
reception is of interest primarily to AM DX (distant reception) aficionados,
of whom there are quite a few on this mailing list.
Dan Strassberg (firstname.lastname@example.org)
----- Original Message -----
From: "Bob Nelson" <email@example.com>
To: "Larry Weil" <firstname.lastname@example.org>
Cc: "Boston Radio Group" <boston-radio-interest@lists.BostonRadio.org>
Sent: Tuesday, February 05, 2013 10:43 AM
Subject: Re: Michael Graham to be on WCRN, 3 other stations
> You can't totally go by the radio-locator maps but I had checked them
> out (and posted links to them on Graham's site). WCRN's main signal
> (day) only reaches out to the west end of the 128 belt, while the
> distant covers a wide swath from Springfield to the ocean. On the
> North Shore, WCRN does come in but it's not a primo signal,
> at least in my car.The "fringe" signal does include parts of VT, NH, a
> small bit of ME, RI, and CT, but again we're talking fringe. (Part of
> "distant" may reach some of these.)
> WESO reaches parts of MA, RI, and CT. WPLM (day) reaches Plymouth and
> the Cape with its "local" signal and the distant signal reaches a
> swath going from
> Beverly down to Norwood, while WBNW's distant signal will reach
> Fitchburg, Boston, Worcester and Brockton. On radio-locator, the local
> is confined by a red
> mark, distant by purple, and fringe by blue.
> But keep in mind this is very optimistic groundwave coverage and you
> have to factor in interference and workplace-listening situations.
> When the time came for the Big Announcement, I found I could only pick
> up WCRN on my clock radio when I unplugged my cell phone, which was
> Ultimately the signals involved will be "OK, yeah it comes in, kinda"
> more than a real gangbusters signal, but it will depend where you are.
> It won't be as powerful as
> WRKO or the 96.9 signal
> So, they may not reach Boston proper with a LOCAL signal, but the next
> category, DISTANT does qualify. And yes it will reach all 6 New
> England states but only portions of them, and not that strong. It's
> kind of like when I go to Rutland, VT and try to pick up Howie's show
> on WVMT. That starts to fade; I try WRKO, and
> stations in Binghamton and Baltimore are crowding him out. WCRN will come
> faintly.(As will an FM from NH) So yes, they reach New England's 6
> states but only in part and it depends
> on where you are and what type of radio you have. Some at work may find
> better off tuning into the stream via computer or smart phone.
>> I note that none of those stations reach Boston proper, so I wonder among
>> other things if he will bail as soon as he gets an offer from a real
>> Boston station. Also, in calling this the New England Talk Network they
>> are ignoring that New England consists of six states, not just greater
>> Boston or just Massachusetts. Or are there plans for further expansion?
>> Larry Weil
>> Lake Wobegone, NH
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