Hello Jim and the group,
Today i did the test with the 1m*1m loop again. It was necessary to go
down to abt 750 mHz and indeed, the DHO38 signal appeared at about -100
dB when turning the loop for optimal reception (just like the earth
antenna). This confirms your calculation of -94 dB in 3 Hz.
So the earth antenna really seems to behave like a loop with an area of
18000 m^2.
Additionally i tried what happens when i connect the earth antenna
directly to my IC706MK2G, without any matching and resonating. The RX
was set to CW mode with the noise blanker and without the preamp and a
250 Hz CW filter.
Some results:
DCFG39: S7
129 kHz: S9+10 dB
137.7 kHz: S0, little noise audible
DCF77: S6
75 kHz: RST 409
60 kHz: RST 309
36 kHz: RST 409
425 kHz: ("HDL") RST 559
153 kHz: (DLF carrier) S9+20 dB AM mode: S9+30 dB (after 18 UTC DLF
transmits with 250 kW in 40 km distance)
Since the 706 is rather not one of the top class RX and there is no
matching of the antenna these results are not to bad i find.
Maybe Horst Stöcker can do some similar RX tests? Would be interesting
to see a difference.
Today i prepared 400m wire and tomorrow i will increase the length of
the earth antenna by some 100m ;-) About 600m should be the maximum
length to form the first half of a dipole for 137 kHz so the rest will
be attached on the other end...
73, Stefan/DK7FC
PS: If David Gibson is right when he says that a earth antenna acts not
like a single turn loop there should be some RX results out of a
direction of the minimum of a loop. The should be more RX stations in a
radius of some Lambda ;-)
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