Re: 1200 in Meffa

[Dan Strassberg <dan.strassberg@worldnet.att.net>]

At 08:08 AM 11/18/98 -0400, you wrote:
>OK...another dumb question...whatever happened to the "city of license"
>rule...is that the 25kw thing you were talking about?
>
>(I never claimed to the of the engineering sort...)
>
First off, I said nothing about 25 kW, which is a power output. I talked
about 25 mV/m, which is signal strength. A 25 mV/m AM signal is pretty
strong and _used to be_ required over the "principal business district" of
the city of license (COL). Because the term "principal business district"
was so vague, that later was interpreted as the main post office. Don't ask
me what happened in communities that are too small to have a post office or
are not political subdivision that the Postal Service recognizes. I don't
know. The FCC does license stations to such communities, however. Sometime
in the 70s or 80s, the FCC removed the 25 mV/m requirement for service to
the COL, but did not change the third-adjacent-channel overlap rule, which
is still based on 25 mv/m. The only requirements that I know of now for
service to the COL are that 100% of the area of the COL must lie within the
daytime 5 mV/m contour and 80% must lie within the nighttime
interference-free contour, which for most stations is higher than 5 mV/m.
There are execptions to the nighttime signal requirements, however. Class C
AMs (the ones on the "graveyard" channels--1230, 1240, 1340, 1400, 1450, and
1490) have no protected nighttime service and so the rule does not apply to
them. Similarly, former daytime stations that operate at night with powers
lower than 250W equivalent also have no protected nighttime service area and
are also exempted.

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Dan Strassberg (Note: Address is CASE SENSITIVE!)
ALL _LOWER_ CASE!!!--> dan.strassberg@worldnet.att.net
(617) 558-4205; Fax (617) 928-4205

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