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For those that like figures and data to speculate,
invent or guess erp emitted by others on LF, I measured the signal today from
DL2NDO/P and other associated callsigns used at various times.
on 136.5 khz.
Level meter
SPM-12 (calibrated)
Time 1020 utc
Signal level -50 db
Noise floor -90db
Signal above noise -40 db
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Speclab (plotter)
Signal -18 db max amplitude
Signal -61 min amplitude
Signal excursion (key up/key down) -43
db
Noise floor indicated -90 db
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Antenna type.Vertical Loop, max signal
N/S
Loop 124 feet horiz x 40 feet vertical symetrical
rectangular = 4960 sq feet
Resonant natural freq 3065 khz
wire 2.5 mm insulated
Loop feed 75 ohm coax, connected to loop at
right bottom corner,coax about 150 ft long to shack, parallel tuned
for resonance.
Rx shows an increase of 14 db noise gain with
antenna connected, no preamp, ant fed direct to rx. Local environment
quiet no hostile local qrm.
Rx bandwidth 25 hz
My locator IO94SH
No attempt here to interpret or calculate voltage
at rx input.
Signal steady all day until I went qrt at 1356
utc
73 de Mal/G3KEV
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