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Search found 45 matches

by Rich F.
Thu Nov 26, 2020 6:38 am
Forum: Engineering & DX'ing
Topic: Earth Conductivity vs. Groundwave Field Intensity
Replies: 10
Views: 190

Re: Earth Conductivity vs. Groundwave Field Intensity

Turkeytop wrote:
Wed Nov 25, 2020 7:53 pm
WSB has rebranded and now calls itself 95.5 WSB.
Not only that, it looks like they are now using a frequency 94.75 MHz higher in the spectrum than they had been licensed for. :?
by Rich F.
Wed Nov 25, 2020 11:02 am
Forum: Engineering & DX'ing
Topic: Earth Conductivity vs. Groundwave Field Intensity
Replies: 10
Views: 190

Re: Earth Conductivity vs. Groundwave Field Intensity

innate-in-you wrote:
Wed Nov 25, 2020 9:59 am
Pay attention to the fine print distance scales that state that the WJR map should be about twice the size of the WSB! ...
Yes, which difference in scale was stated in the third "bullet" of the list at the top of the graphic.
by Rich F.
Wed Nov 25, 2020 5:18 am
Forum: Engineering & DX'ing
Topic: Earth Conductivity vs. Groundwave Field Intensity
Replies: 10
Views: 190

Earth Conductivity vs. Groundwave Field Intensity

The graphic below is pretty much self-explanatory, and shows maybe some surprising results for the relative coverage areas of those two almost identical AM broadcast station facilities, both day and night. The maps show the 1 mV/m and 0.1 mV/m contours for both stations. https://i.postimg.cc/Mp2GcMt...
by Rich F.
Tue Nov 17, 2020 4:12 am
Forum: Engineering & DX'ing
Topic: The Most Complete Single Conductivity Study Of Northwest And Northern Lower Michigan
Replies: 9
Views: 317

Re: The Most Complete Single Conductivity Study Of Northwest And Northern Lower Michigan

As I recall, WJR was in the vicinity of 50 uV/m near the Straits when I measured it with an FI meter. ... That is in fairly good agreement with the graphic below, which shows the daytime 1 mV/m and 0.1 mV/m calculated field contours of WJR, based on recent understandings of soil conductivities for ...
by Rich F.
Tue Nov 17, 2020 1:43 am
Forum: Broadcasting - General
Topic: Worst-sounding radio stations of all-time.
Replies: 37
Views: 2698

Re: Worst-sounding radio stations of all-time.

...- WJR has been severely overmodulated since last winter. ... Is there accurate, reliable, measured evidence that they are truly overmodulating their AM carrier — as would be true if their negative-going program audio modulation peaks produced carrier-clipping "splatter" radiated well beyond the ...
by Rich F.
Sat Nov 14, 2020 6:38 am
Forum: Engineering & DX'ing
Topic: The Most Complete Single Conductivity Study Of Northwest And Northern Lower Michigan
Replies: 9
Views: 317

Re: The Most Complete Single Conductivity Study Of Northwest And Northern Lower Michigan

... In any event, the signals of Northern Michigan AMs has always been much less than similar facilities in low lying areas of SE Michigan. For example, 5 kw WWJ vs. WHAK ... Do such conclusions consider antenna system "efficiency?" For example, WWJ using a 1/2-wave radiator would radiate about twi...
by Rich F.
Sat Nov 14, 2020 2:54 am
Forum: Engineering & DX'ing
Topic: The Most Complete Single Conductivity Study Of Northwest And Northern Lower Michigan
Replies: 9
Views: 317

Re: The Most Complete Single Conductivity Study Of Northwest And Northern Lower Michigan

Apparently such studies show soil conductivity values in northern lower Michigan to be much less than those shown there on the FCC M3 map. It is puzzling then how WJR, Detroit has produced a measured , daytime groundwave field intensity near the Straits of Michigan that is more consistent with the 8...
by Rich F.
Mon Nov 09, 2020 3:56 am
Forum: Engineering & DX'ing
Topic: Downriver AM transmitters
Replies: 33
Views: 1631

Re: Downriver AM transmitters

... Now I can barely hear WXYT , at night, out here with 50 kW and the deep null to the northwest ! Below is a plot showing about what to expect for the nighttime GW field of WXYT in/near Commerce Twsp, MI — something like 8 mV/m . The slope of their licensed nighttime pattern is getting steep towa...
by Rich F.
Sun Nov 08, 2020 1:58 am
Forum: Engineering & DX'ing
Topic: Downriver AM transmitters
Replies: 33
Views: 1631

Re: Downriver AM transmitters

This is the current Theoretical pattern of WUFL 1030. The maximum is at about 250 degrees true. https://www.fccdata.org/am_pattern.php?antid=99836 Below are plots of the 1.0 and 0.1 mV/m groundwave field intensity contours of WUFL when using that DA: https://i.postimg.cc/xCVHM1qy/WUFM-Daytime-GW-Cv...
by Rich F.
Mon Oct 26, 2020 5:06 am
Forum: Engineering & DX'ing
Topic: Early Development Of AM BC DAs
Replies: 6
Views: 301

Re: Early Development Of AM BC DAs

... This map would seem to indicate that WOW would have rather extreme fading problems. https://www.fccdata.org/?lang=en&facid=50313 So it does (i.e., where their 0.5 mV/m nighttime skywave interferes with their own 2 mV/m day&night ground wave). WKZO running 5 kW directional until 10 pm contribute...
by Rich F.
Sat Oct 24, 2020 3:45 am
Forum: Engineering & DX'ing
Topic: AM Daytime And CH NW Straits Area Of Michigan
Replies: 35
Views: 994

Re: AM Daytime And CH NW Straits Area Of Michigan

Below is a groundwave coverage map of WSCR (ex-WMAQ), using a recent estimate of soil conductivities in that area:

Image
by Rich F.
Fri Oct 23, 2020 5:36 pm
Forum: Engineering & DX'ing
Topic: AM Daytime And CH NW Straits Area Of Michigan
Replies: 35
Views: 994

Re: AM Daytime And CH NW Straits Area Of Michigan

I saw a daytime GW contour map for WGN at that link; is there also a nighttime skywave map there (that I missed)?
by Rich F.
Fri Oct 23, 2020 4:48 am
Forum: Engineering & DX'ing
Topic: AM Daytime And CH NW Straits Area Of Michigan
Replies: 35
Views: 994

Re: AM Daytime And CH NW Straits Area Of Michigan

Below are some observations based on the latest posts in this thread by others ... The 0.5 mV/m contour on the "Neilsen" map I posted appears to be drawn there by a source other than the the Chief Engineer of WJR. But I doubt that the Neilsen data shown there is incorrect for that time period. The ...
by Rich F.
Thu Oct 22, 2020 4:24 am
Forum: Engineering & DX'ing
Topic: AM Daytime And CH NW Straits Area Of Michigan
Replies: 35
Views: 994

Re: AM Daytime And CH NW Straits Area Of Michigan

As a follow-up relating to the coverage of WJR in the Straits area of Michigan, below is a map from the 1960s of the Nielsen ratings showing the county-by-county "penetration" of WJR in its daytime coverage area, Notice that while the antenna of WJR radiates an omnidirectional signal, it becomes def...