Message-ID: <3.0.6.32.20000209133433.0084ce70@laatikko.saunalahti.fi>
Date: Wed, 09 Feb 2000 13:34:33 +0200
To: rsgb_lf_group@blacksheep.org
From: =?iso-8859-1?Q?V=E4in=F6_Lehtoranta?= <vaiski@dlc.fi>
Subject: LF: LF Fs vs effective ground conductivity vs EMRP
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Hi all,

I found from my archives an old report about
flight measurements of Swedish Decca's dated
in May 1970. A DC-3 was used for measurements.

*MARKENS KONDUKTIVITET BESTÄMD MED HJÄLP AV
FÄLTSTYRKEMÄTNINGAR INOM LÅNVÅGSOMRÅDET*
 (translated as):
Ground conductivity determined from Field
strength measurements of Long wave stations

*FOA 3 rapport, A 3743-60, Maj 1970*

There is a map showing calculated effective
conductivity for more than 25 radials, with
Sigma values varying between 0.24 to 0.60 mS/m.

Decca frequencies cover roughly 84...128 kHz.

Swedish report also gives estimated EMRP values
derived from flight measurements and they vary
from 400±100 W for Kallax Green (127.4) to as
low as 24±5 W for Årjäng Purple (71.5).

Note: Swedish Decca's went qrt on 31 Dec 1999.

73 de Vaino, OH2LX

PS  Our measurements correlate well with these

----------------------------------------------------------
V.K.Lehtoranta, OH2LX, POBox 50, FIN-05401 Jokela, Finland
------ Tel: +358-9-4173965 ---- Fax: +358-9-4173961 ------
E-mail: vaiski@dlc.fi - alias: oh2lx@dlc.fi & oh2lx@sral.fi