WDER-AM 1320 DA Out Of Tolerance; Running NDA Temporarily

[Dan.Strassberg]

WDER's 10-kW day pattern is severely nulled to the south to protect WRCA.
Normally, the daytime signal to the south should be equivalent to ~250W ND.
Not so the 1-kW night pattern, whose major lobe, equivalent to close to 5-kW
ND, lies to the south. Since you live to the south of WDER and the station
is temporarily running 2-kW ND days, the stronger daytime signal that you
report seems completely logical. If you lived east or west of WDER, where
the licensed 10-kW D power combines with the daytime DA to produce a signal
equivalent to almost 50-kW ND, the effect of the temporary reduced-power ND
operation would be just about the opposite (assuming that your radio's AGC
didn't mask the effect of the weaker daytime signal).

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

----- Original Message ----- 
From: "Laurence Glavin" <lglavin@mail.com>
To: <boston-radio-interest@lists.BostonRadio.org>
Sent: Thursday, January 10, 2013 4:46 PM
Subject: WDER-AM 1320 DA Out Of Tolerance; Running NDA Temporarily


> WDER-AM 1320 in Derry, NH is authorized for 10,000 watts directional days.
> It must be pretty directional since I
> receive only a moderately strong signal not far from the MA/NH border and
> the towers are a little more than
> halfway between Methuen, MA and Manchester, NH. But for a couple of days
> thru Thursday afternoon, while
> I was scanning the AM dial, it was considerably stronger. The WDER website
> offers a comments block, so
> I emailed the station to see what was happening. (The FCC records show no
> CPs or other authorized
> changes). In the reply, their engineer stated that the antenna array had
> gone out of compliance and they
> are currently running 2,000 watts NDA. WDER has a fairly impressive set of
> towers, and the 2K into just
> one of them is providing a pretty good signal at home and on the road. The
> subject of short vs more-or-less
> tall towers for AM has been discussed lately. I don't know about the
> qualities of the terrain in the center
> of Derry, NH that might help an AM signal, but while work is being done on
> the array, that one tower is
> emitting better coverage to the south that their authorized pattern
> offers.