Re: WLLZ Monroe-Detroit

[Dan.Strassberg@att.net]

Well, the stuff that's on the tower for WWJ (AM) may no 
longer be necessary. WWJ now runs 50 kW-U from a 6-tower 
array south of Detroit. The old WWJ site has become a TV 
site (I think for DTV). That necessiated removing at 
least one of WWJ (AM)'s towers and the loss of the tower 
was what sent WWJ to a new site. WWJ was licensed to 
operate nights from the new site before it was licensed 
to operate days from the new site (curious, because the 
day setup uses only five of the six towers). In the 
interim, WWJ operated 5-kW ND days from the old site and 
50 -kW DA-N from the new site. The old site may still be 
an auxiliary site for WWJ--at least for daytime 
operation, although with all those towers at the new 
main site, it's not exactly clear who WWJ would need a 
separate auxiliary site.

I think there may be an error in the FCC AM database, 
but WWJ's 50 kW night operation shows an inverse-
distance field at the pattern maximum (just about due 
north) of nearly 8 V/m. That's the equivalent of almost 
640 kW ND into a single minimum-height tower. The array 
uses unequal height towers with the two highest power 
towers being something like 160 degrees and the others 
being shorter. Either the antenna efficiency or the 
peak/RMS ratio appear too high for the facilities.

When you compare the new vs the old coverage maps, it's 
quite surprising to see how little additional coverage 
area was produced by the increase from 5 kW to 50 kW.

--
dan.strassberg@att.net
617-558-4205
eFax 707-215-6367
> Dan:
> No mention is made in the Pop Comm article of what  TV/FM stations use
> the tower.  It  is known locally as the "Motower" (Motown Tower).  It
> does mention that the old WWJ AM site was nearby, and because of that
> the whole tower had a detuning skirt installed on it to eleminate
> interference to that station (WWJ) The article further adds that WLLZ
> installed some ground radials and another skirt parallel to the detuning
> skirt and uses this to load the tower to their frequency.
> 
> You can see the whole item in the June 2002 issue on page 29. But,
> actually, you had much more accurate info about the tower in your
> postings here.
> 
> Rod O'Connor
> Southwest Harbor, Maine
>