The Des Plaines Crater-A Meteorite Hit Near The WYLL Day Site Less Than 280 Million Years Ago

[Schroedingers Cat]

A Meteorite crashed and formed a crater 5 1/2 miles in diameter, the center of impact which was about a half mile Northwest of the WYLL Day site. I wonder if it had any effect on the terrain and conductivity near the numerous AM tower sites near there, though no obvious signs are present at ground level, but buried only about 75 feet deep. Evidence found from drilling around 1962. Much development and many wells were drilled around that time. Maps shown at the following site.

United States Meteorite Impact Craters - Des Plaines CRATER, Illinois

 

[secondchoice]

It was interesting that you can use ground conductivity to check on septic systems failures.* Since this meteorite is about 75 feet deep, and everything else has eroded (around 1000 ft.) I doubt there is much effect except for "the negative gravity anomaly of 8 mgals"**

*https://en.wikipedia.org/wiki/Ground_conductivity
**Des Plaines Disturbance, Northeastern Illinois | GSA Bulletin | GeoScienceWorld

 

[Schroedingers Cat]

If septic tank failure can be detected by conductivity, it would be more likely that ions in the effluent would cause it, not the obvious olfactorily offensive organic material which is pumped out.

 

[secondchoice]

I thought it would be the nasty water along with the regular water in the soil kind of like a lake. The ions in the water makes more sense. To be honest I have never seen a soil conductivity tester.

We use to live in a house on a septic system. When ever the grass over the field lines stayed wet, we called the plumber. He would pump the tank out put a whole box of (special) yeast in bottom of the empty tank and we were good for 3 or 4 years. We now live in town with city sewers. 1000 times better.

Back to soil conductivity, How did the FCC and the US Geological Survey figure out the conductivity charts engineers use to figure coverage? I have a minor in Geology and we studied soil only to figure what and where it was eroded from and its mineral content. Most of the field work was taking samples of out crops, studying well logs and trying to figure out exactly where you were on the 7 and a half minute maps. No GPS back in the day. Some minerals deposits are affected by the earth's magnetism* that can seen in crystals in a microscope.


*BTW there is a lot of evidence that the magnetic poles have "moved" in the past, You have to take into consideration the age of the sample. Also with continental drift a factor too.

 

[Schroedingers Cat]

From what I can gather, the estimates were based on gross soil types in a general area, but it also appears like they did measured signals on Class I-A and Class I-B stations to determine real service areas, and Directional Antenna Proofs of Performance from the early DAs from the 1930s to 1950s, mainly for Class III-A and Class III-A stations authorized from that era. Some other areas appear to have been largely estimated without much data. Vast areas of the country only had 250 watt nondirectional Class IV stations which were only supposed to serve an area within a few miles of the transmitter.

I cannot get many people to agree to its validity, but in my state of Michigan, there is a Quaternary Geological Map which appears to correlate much better to conductivity in much smaller areas. There can be considerable variations within each County. This is why many stations have been squeezed in and have been allowed to increase facilities. Many stations in Michigan have measured conductivites and increased facilities, several to 50000 watts, but though granted CPs, few were built because of construction costs and power bills. One station was originally authorized with 2500 watts, but it gradually increased power and upgraded with extensive measured radials to 50000 watts with the same tower arrangement.

 

[Schroedingers Cat]

The second Class III-A should read Class III-B.

Many Class IVs moved to Regional Channels after World War II and became Class III-As and Class III-Bs. Some moved to Clear Channels and became Class II-Bs. Many new stations were Directional Day, almost all were Directional Night. Only the Pre World War II legacy Class IIIs were still 500, 1000, or 5000 watts Night Nondirectional. Often, when stations went from 1000 to 5000 watts Day or Night, they went Directional. When they didn't quite fit, they often used a series limiting resistor, but used the nominal power. The actual power of many was around 750 watts for 1000 watts nominal power, and 3800 watts for 5000 watts nominal. After they relicense now, they have to use actual power. Their efficiency was equivalent to the nominal power or more though. Later directional antenna proofs were not used for the M-3 Maps.