Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

LF: FS measurements, EMRP calculations

To: [email protected]
Subject: LF: FS measurements, EMRP calculations
From: [email protected]
Date: Mon, 1 Oct 2001 20:00:36 EDT
Reply-to: [email protected]
Sender: <[email protected]>
Dear group,

here comes a log of stations received last weekend:

UT   kHz    call dBµV/m dist

Friday, 28.9.01:
2204 136.7   OK1FIG +13  376km? beginning of our QSO
2018         OK1FIG +23   end of QSO (nighttime QSB)
2027 136.5   EI0CF  +11
2330  71.924 M0BMU ?     841km
2330 71.9215 G3AQC 0.1 Hz DFCW
Saturday, 29.9.01:
0925 136.9   OK1FIG +19   stable daytime level
    136.66  DL3FDO +23  197km
    136.9   PA0BWL  +7  474km
    136.9   DF0WD  +14  357km
    137.3   DJ5DI   +4
1315 136.83  OM2TW  +10  496km?
    136.83  DF0WD  +15
    136.83  SM6PXJ  +3  1035km
    136.5   G3KEV   +9  963km
    136.8   DK6NI  +28  20km
1435 136.8   OM5CW
2330 135.923 M0BMU  +0...+6 QSB

Sunday, 30.9.01:
0857 136.59 DL5WF +4 135km? 136.69 G3KEV +6
    136.76  OM2TW   +7
    136.61  OK1FIG +18
0903 136.54  DK6NI  +28  20km
136.76 OM2CW +7 136.76 DL3FDO +22
0922 136.76  DJ7RD  +26  129km
    137.16  carrier  0   FSK bursts 1.8s, bear. 285°
    136.68  carrier -1   FSK bursts 40s, bear. 285°
    136.549 DCF IM -11  165km (reduced since 22.09.01)
    135.36  DCF IM +28  165km
0938 136.6   SM6PXJ  -2
0940 136.7   G3KEV   +9
    136.7   DK3GH  +24  23km
    136.56  M0BMU   +2
1040 137.59  OM2TW   +6  QRSS/DFCW QSO
1209 136.7   DK7SU  +10
    136.9   OZ8NJ   +6 436km
1910 138.83  DBF39  +68 310km

The fieldstrength measurements were taken from calibrated spectrogram readings and should be accurate to a couple of dB's. Given the distance d from my QTH (JN59NK), you can estimate your radiated power by the formula
EMRP /dBW = FS /dBµV/m - 79.55 + 20 lg (d /km) + GL /dB.

The additional ground-wave loss GL is generally neglegible for distances up to 100 km. Assuming no ionospheric propagation (which is not valid for long-distance paths, especially in darkness), GL can be estimated from the CCIR ground-wave charts, and for average soil conductivity (land, 3 mS/m) one gets a table like this
d/km GL/dB
  1   0
100   1
200   3
300   5
400   8
500   9
600  12
800  17
1000  22
1500  31

73 de Markus, DF6NM



<Prev in Thread] Current Thread [Next in Thread>
  • LF: FS measurements, EMRP calculations, MarkusVester <=