Michael Graham to be on WCRN, 3 other stations

Bob Nelson raccoonradio@gmail.com
Wed Feb 6 10:38:43 EST 2013

I have heard WCCO bubbling under WCRN at night. btw WGBH 89.7 has hired Eagan and Braude for noon with Rooney,Crossley and Deval Patrick's monthly gig alo g for the ride

Sent from my Virgin Mobile phone

"Dan.Strassberg" <dan.strassberg@att.net> wrote:

>As a VERY rough rule of thumb, an AM station's signal strength appears to
>drop off VERY roughly as the square of the distance between the transmitter
>and the listening point. (In fact, more than a few things influence this
>square-law relationship: soil conductivity and the station's operating
>frequency are the two most important--and most often cited--influences. With
>a salt-water path between transmitter and listening point, instead of a
>square-law relationship, you have a nearly linear relationship between
>distance and signal strength.) However, if you accept the square-law
>relationship and use it judiciously, you will find that the 10 mV/m contour
>lies (VERY roughly) half as far from the transmitter as the 2.5 mV/m
>Applying this to WCRN, its calculated NIF (nighttime interference-free)
>contour is, IIRC, 10.55 mV/m. IOW, what R-L shows for WCRN's nighttime
>coverage (inner contour) is roughly twice as far from the transmitter in
>Leicester as is the actual NIF contour. WCRN's real NIF may be a skosh lower
>than 10.55 mV/m, however, because at least one of the major contributors is
>a now-dark Canadian AM. And then there is the argument over whether an NIF
>contour should be weaker than 20 times the RSS (square root of the sum of
>the squares) of the interfering co-channel 10% skywaves. (I think the FCC
>has added to the NIF calculation some first-adjacent-skywave value, but I am
>unclear on how that term enters into the calculation. For example, does WHAS
>really interfere with WCRN at night?)
>Dan Strassberg (dan.strassberg@att.net)
>eFax 1-707-215-6367
>----- Original Message ----- 
>From: "Scott Fybush" <scott@fybush.com>
>To: <boston-radio-interest@lists.BostonRadio.org>
>Sent: Tuesday, February 05, 2013 11:37 PM
>Subject: Re: Michael Graham to be on WCRN, 3 other stations
>> On 2/5/2013 1:54 PM, Dan.Strassberg wrote:
>>> 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.
>> Experts whose opinions I trust tell me that in major markets where it's
>> possible to do some fairly granular breakdowns of ratings data, the
>> evidence is now clear that mass-market AM stations get essentially no
>> listeners in areas where their signals are less than 10 mV/m - and that's
>> rapidly edging up to 15 mV/m as "all that stuff" continues to raise the AM
>> noise floor. (Stations with specialty formats still draw audiences at
>> lower signal levels; if the music you want can be found only on WJIB,
>> you'll make a much bigger effort to tune in 740 even if you're in an area
>> where its signal is weaker.)
>> If R-L showed the 15 or 10 mV/m contours, they'd be significantly smaller
>> than the 2.5 mV/m "inner" contour now shown.
>> s

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