Ground conductivity should remain reasonably constant with the exception of changes caused by severe or massive grological or weather events, so I wouldn't expect to see much difference.
Russ Edmunds 15 mi NW Phila Grid FN20id <[email protected]> AM: Modified Sony ICF2010's (2) barefoot w/whip FM: Yamaha T-80 & T-85, each w/ Conrad RDS Decoder; Onkyo T-450RDS; Tecsun PL-310 ( 2); modified Sony ICF2010 w/APS9B @ 15'; Grundig G8 w/whip; modified Sony ICF2010 w/whip On Sat, Jan 30, 2016 at 2:27 AM, Nick Hall-Patch <[email protected]> wrote: > That one is quite up to date, Dennis, 1954. Hard to tell what the one on > the FCC site is, but I guess it's something that doesn't change much with > time. > > Note that the Alaska and Hawaii ones are labeled "assumed ground > conductivities" > > At 07:15 30-01-16, you wrote: > >> >> https://en.wikipedia.org/wiki/Ground_conductivity#/media/File:United_States_Effective_Ground_Conductivity_Map.png >> >> Sent from my iPad >> >> > On Jan 29, 2016, at 11:05 PM, Bruce Portzer <[email protected]> >> wrote: >> > >> > Nick >> > >> > I'm not sure where the data came from but it goes back a few years. I >> have a similar FCC map dated 1938. >> > >> > Bruce >> > >> >> On 1/29/2016 9:53 PM, Nick Hall-Patch wrote: >> >> Just in case you have a wall that is bare and just begging for nerdish >> covering, behold, the FCC offers a printable 43x69-inch map (in many >> sheets) of ground conductivity in the US (info from Topband Reflector; see >> below). There is also a text file of ground conductivities for the >> western hemisphere, including such hot beds of DX as Gabriola Island and >> Mayne Island. I haven't quite figured out what all the numbers and >> locations mean however, or where the data originates. Does anyone know? >> >> >> >> best wishes, >> >> >> >> Nick >> >> >> >> >> >> >> >> >> >>> From: >> >>> >> >>> >> >>> >> http://www.radiomagonline.com/fcc/0019/fcc-reveals-m3-map-of-ground-conductivity-in-us/37366 >> >>> [1] >> >>> >> >>> FCC M3 Map of Ground Conductivity in US >> >>> >> >>> Commission offering printable 43x69-inch map >> >>> >> >>> January 28, 2016 >> >>> >> >>> The map shows that ground conductivity across the U.S. ranges >> from >> >>> 0.5 to 30 millimhos (or millisiemens) per meter. The FCC also reports >> >>> that the conductivity of seawater is 5,000 millimhos per meter. >> >>> >> >>> The downloadable map comes in 48 portions that can be printed. >> >>> >> >>> https://www.fcc.gov/media/radio/m3-ground-conductivity-map [2] >> >>> >> >>> The FCC is also offering the conductivity data as text files >> and also >> >>> includes data for the Chesapeake Bay and Puget Sound, which is not >> >>> shown on the printable map. >> > >> > _______________________________________________ >> > IRCA mailing list >> > [email protected] >> > http://montreal.kotalampi.com/mailman/listinfo/irca >> > >> > Opinions expressed in messages on this mailing list are those of the >> original contributors and do not necessarily reflect the opinion of the >> IRCA, its editors, publishing staff, or officers >> > >> > For more information: http://www.ircaonline.org >> > >> > To Post a message: [email protected] >> > >> _______________________________________________ >> IRCA mailing list >> [email protected] >> http://montreal.kotalampi.com/mailman/listinfo/irca >> >> Opinions expressed in messages on this mailing list are those of the >> original contributors and do not necessarily reflect the opinion of the >> IRCA, its editors, publishing staff, or officers >> >> For more information: http://www.ircaonline.org >> >> To Post a message: [email protected] >> > > > _______________________________________________ > IRCA mailing list > [email protected] > http://montreal.kotalampi.com/mailman/listinfo/irca > > Opinions expressed in messages on this mailing list are those of the > original contributors and do not necessarily reflect the opinion of the > IRCA, its editors, publishing staff, or officers > > For more information: http://www.ircaonline.org > > To Post a message: [email protected] > > _______________________________________________ IRCA mailing list [email protected] http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: [email protected]
