WWZN and Kinstar antennas

Garrett Wollman wollman@csail.mit.edu
Wed May 10 00:55:00 EDT 2006


<<On Tue, 09 May 2006 23:40:47 -0400, Scott Fybush <scott@fybush.com> said:

> I'm much more curious about how a WWZN move would be affected by 
> ratcheting. Even if then-WITS *was* ratcheted in 1981 (and I don't 
> believe it would have been), my casual reading of the rules seems to say 
> that a subsequent move would again require ratcheting. Reducing WWZN's 
> night signal toward WLAC by 10% would hurt. So would reducing WWZN's 
> night signal toward WRNJ in New Jersey.

Interestingly, WWZN's pattern min is not in a direct line towards
WLAC, but about 15 degrees north of it.  WLAC's pattern min is in the
direction of Spokane, but there's also a secondary null in the
direction of Boston (although the deepest point is again slightly
north of there).  WWZN has a very mild null (6.8 dB below pattern max)
in the direction of Sherbrooke; Sherbrooke is close enough to Boston
that it fits within WLAC's null towards Boston.  WRNJ does not appear
to protect CJRS in the pattern at all; presumably any protection that
the Canadians demand is provided by the limited (230 W) night power.

> It's a mixed blessing for WWZN, though, because it means that all the 
> signal coming its way at night - and at a pretty substantial level - 
> comes from the single source of WLAC.

A quick listen test.... Here in Framingham, the biggest interferer
tonight on 1510 appears to be WRNJ -- no sign of WLAC.  Framingham is
just south of the line from Nashville to Boston, and thus deeply
nulled by both WLAC and WWZN.  WRNJ is supposed to have a deep null
this way as well (although not as deep as its nulls towards Nashville
and Spokane).  In any event, I found WWZN to be copyable, but the
average listener would not tolerate it for long.  It's a good signal
here daytime.

-GAWollman



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