[BC] AM Allocation research - Thanks

[Mark Humphrey]

I'm glad this was helpful.  I just remembered that a recent Class C AM
application which relies heavily on measured data can be found in CDBS
for WMJQ 1450 in Milford, PA:

https://licensing.fcc.gov/cgi-bin/ws.exe/prod/cdbs/forms/prod/cdbsmenu.hts?context=25&appn=101191724&formid=301&fac_num=161541

Figure 7 of WMJQ's engineering statement is the allocation study map,
showing protection to 1450 kHz stations WKIP and WCTC.  As you can
see, the new facility never would have fit in Milford under
conventional M3 assumptions.  See Figure 8A for a tabulation of
measured vs. assumed conductivities which were determined by running
radials from a 1620 kHz test station at the proposed site.

By the way, I'm part-owner of an 1140 kHz station in western NY state
which recently filed for a power increase from 2.5 to 8 kW based on
measured data towards CKOC 1150 Hamilton, Ontario.  You can see the
results in Exhibits 15B and 16A -16G of this application.  The M3 map
assumes conductivities of 4 and 8 along these radials, but I measured
only 2 to 3:

http://licensing.fcc.gov/cgi-bin/ws.exe/prod/cdbs/forms/prod/prefill_and_display.pl?Application_id=1352955&Service=AM&Form_id=301&Facility_id=37858

Mark

On Mon, Apr 26, 2010 at 10:08 AM, Jeff Glass <Xmitters at aol.com> wrote:
> In a message dated 4/26/10 8:00:39 AM Central Daylight Time,
> broadcast-request at radiolists.net writes:
>
>> There are many closely spaced Class C AMs in the northeast --  for
>>  instance, WHAT 1340 in Philadelphia, which is only 70.3 km from
>>  co-channel WRAW in Reading, PA and 95.1 km from WMID in Atlantic City.
>>   The M3 map assumes a conductivity of 4 in this region, but in most
>>  cases it's actually much lower, so these old allocations were probably
>>  based on measured conductivities.
>
> Mark:
>
>  Thank you for that very helpful information, and for unraveling a mystery.
> I'm relieved to learn that the discrepancy was not caused by my
> misapplication of the rules.
>
> Jeff Glass
> Northern Illinois University
>
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>
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