Re: WXKS-AM & WJIB

[dan.strassberg@att.net]

You miss the point. I did not propose a move; I proposed the ADDITION of one or 
more low-power, nighttime-only synchronous transmitters. The FCC is 
granting "experimental" licenses for such operations and indeed just granted 
one last week to a Class D AM in Virginia that will add a synchronous 
transmitter to serve Portsmouth and parts of Norfolk--well outside of its 
nighttime service area, which is about 50 miles to the north. In WXKS's case, a 
low-power nighttime-only synchronous transmitter, with a power of, say, 10W 
could be nondirectional. It could not radiate too much to the east without 
interfering with the main signal from Revere Beach Parkway nor could it radiate 
too much to the west without interfering with the stations that WXKS protects--
mainly Newark, Endicott, and Toronto.

The reason that the kind of problems that plague WLLH's synchronous 
transmitters need not be an issue in this case is the very high level of co-
channel nighttime interference on 1430. The so-called "hash zones" would appear 
in areas outside the NIF (nighttime-interference-free) contour, which I imagine 
must be at least 30 mV/m. Technically, the station does not provide nighttime 
service outside of its NIF contour--although the signal is audible in some 
areas outside that contour. Because WXKS's night pattern protects several 
stations to the west, the NIF contour probably lies less than 1 km to the west 
of 99 Revere Beach Parkway, which is why the station cannot be licensed to 
Medford. The 30 mV/m contour of a 10W ND signal from the WJIB stick would, to a 
first order, form a circle with a radius of somewhat less than 1 km centered at 
443 Concord Ave.

--
dan.strassberg@att.net
617-558-4205
eFax 707-215-6367
 
> For that matter - I don't think it will work.  WXKS-AM requires a two-tower 
> array to null to the southwest at night, WJIB is a one-tower solution and 
> for those of you who haven't seen the surrounding area, there's not a 
> chance in hell of a second tower ever being erected near WJIB's (there's 
> just literally no room).