Barnicle to WBUR?

Sun Mar 16 16:16:46 EDT 2008

There must be more to the rule on aux AM power than you suggest. As
you know, the towers of WSBC 1240 Chicago and WCPT 820 Chicago (I
believe those are today's 820 calls) are on virtually adjacent parcels
of land on Chicago's north side. The WSBC tower is the shorter of the
two and hence is less efficient--particularly on 820, where it is
substantially less than 1/4 wavelength. The main 820 tower (once the
main site for WXRT (FM) and now, I think, the WXRT aux site) is
substantially taller than 1/4 wavelength at 820, though, because of a
substandard ground system (constrained by the size of the property),
the efficiency for  WCPT is well below the ~350 mV/m/kW @ 1 km, that
one might expect with a tower of that height. Anyhow, WCPT, whose
normal operating power is 5 kW from the tall tower, holds a CP to
diplex with WSBC for auxiliary purposes and the power from the shorter
tower is limited to 3.2 kW. Perhaps the limitation derives from some
other criterion. For example, maybe WCPT, for its main operation from
the tall tower, has a waiver covering population within the 1V/m
contour, but the FCC won't grant such a waiver for the aux operation.
Anyhow, WCPT is not unique with regard to having limited aux power.
Note that WCBS, whose relatively short aux tower is on the same little
island off the Bronx as its 207-degree main tower, is limited to
substantially lower aux power than WCBS's normal 50 kW. I've never
heard an explanation of this quirk in FCC regulations.

Dan Strassberg (
eFax 1-707-215-6367

----- Original Message ----- 
From: "Garrett Wollman" <>
To: "Dan.Strassberg" <>
Sent: Sunday, March 16, 2008 2:58 PM
Subject: Re: Barnicle to WBUR?

> <<On Sun, 16 Mar 2008 10:55:31 -0400, "Dan.Strassberg"
> <> said:
>> (KTLK is also likely to move at some point from its diplex with
>> because CCU, which owns KTLK, and SBS, which owns KTNQ, can't agree
>> on the rent.  When that happens, KTLK will have to operate with
>> much
>> lower night power, and probably lower day power as well.)
> Presumably it could move back to Montecito Heights with its old 5
> kW-U
> DA-N configuration.  Clear Channel still maintains the lease there,
> and KFI is operating from there now at 20 kW ND while its main tower
> in La Mirada is being rebuilt.  KTLK actually has a CP for 4 kW-U
> DA-1,
> as an auxiliary, from this facility; the reduction appears to be
> necessary only because of the requirement that the 0.5 of an aux be
> entirely encompassed by the 0.5 of the main; see the exhibit to
> BXP-20070223AGX.  No chance of building new towers there, though.
> -GAWollman

More information about the Boston-Radio-Interest mailing list