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AM Stn Groundwave vs Freq, Power & Conductivity

ddsparxx said:
Thought I would bring this up after reading the Paper 7 of R. Fry's publication. If you look at the US Soil Map at http://www.soils.umn.edu/academics/classes/soil2125/img/4usoils.jpg and http://transition.fcc.gov/mb/audio/m3/ (ground conductivity), there are some similarities on both maps. This may explain why I get low MW daytime sensitivity in a wooded area of northen VA and a little better sensitivity in mostly farmland nearby toward the west.
Click to expand...

The truth is that the Soil Map and the M-3 Map are only grossly accurate. At the local level, there may be tremendous variations. Look at some recent applications on CDBS and you'll find believable conducitvity measurements that are well below M-3. There are some fairly accurate Quaternary Geology maps online of various states including Ohio and Michigan. Look at the 1939 table in R. Fry's paper. Industrial development, and I would say even any urban development, will reduce the effective conducitity. A recent application for WCCW Traverse City, MI extended a radial for WOOD Grand Rapids' Proof of Performance. A radial across the Grand Rapids area was 1 mS/m where the M-3 value is 8 mS/m. Other areas show a low as 0.1 mS/m where M-3 is 8 mS/m, and they are believable on both measurements and observed signal performance.
 
I am not that technical of a person but like gar fla have property in SW FLA the Gulf amplifies signals to the N and NW but the enhances conductivity enhances signals that primarily travel over land such as from Miami-Orlando and Jacksonville and even further during the day. I THINK it's all about the quality/strengthj and sensitivity of one's radio/receiver. Like gar, i enjoy hearing very faint sounds from far away and wait, and wait for an ID even having to wade thru the religious huckser's B.s. it seems like the feds have relaxed their standards on station ID; one has to be listen to a lot of crappe in order to get the ID.
But it seem like there are "hot spots' where a station seems to come in much stronger in a very limited location than at a nearby location. Sort of like a microclimate to the weather geeks. So all this scientific stuff is all cool; all that matters is whether you get the station or not.
But it's time to gey a better radio; be there or be square.
But the discussion is interesting to say the least.
 
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