Stefan DK7FC transmitted at 6 aptil 2019 20:25 UTC at 2970.1Hz. The TX power was 487W into a 1130m ground dipole antenna. The ebnaut transmission parameters were:
f = 2970.1 Hz
Start time: 06.APR.2019 20:25:00.3 UTC
Symbol period: 6 s
CRC bits: 16
Antenna current: 2.4 A
Duration: 02:04:48 [hh:mm:ss]
The signal was received by Jacek / SQ5BPF in Warsaw/ Poland KO02md, at a distance of 976km!
After the filtering and noise blanking was optimised, the signal could be decoded:
[email protected]:/stuff2/sq5bpf/vlf_stefan2$ vtcat -p < stefan_2970_1 | vtfilter -a th=4 -h bp,f=2970,w=2200 > ../vlf_stefan2/pliktmp6
[email protected]:/stuff2/sq5bpf/vlf_stefan2$ vtblank -v -d0.0007 -a20 -t 50 < pliktmp6 | vtmult -f 2970.1 | vtresample -r 240 | vtresample -r 10 |vtraw -oa | ebnaut -dp16K21A -r10 -c2 -v -k16 -S6 -N7 -PS -L 50000
vtblank: selected channel: 1 = -:1
vtblank: channels: 1, sample_rate: 48000
vtblank: hfactor: 0.000e+00
vtblank: afactor: 20.000
initial reference phase -89.4 amplitude 7.496e-04
phase 0 0 0 0 0
vtblank: end of input
vtblank: dropsum 0 64750004, nfp 359999999
vtblank: dropfactor 0 1.799e-01
found rank 14143 ber 4.2548e-01 Eb/N0 -2.5 M -2.143712342e-02 ph 0 0,0,0,0 [ DK7FC/P]
carrier phase: -10.6 deg
carrier Eb/N0: -0.4 dB
carrier Es/N0: -15.33 dB
carrier S/N: 15.63 dB in 133.5 uHz, -23.11 dB in 1Hz, -57.09 dB in 2.5kHz
The message was: DK7FC/P
Link to Stefan’s email:
Stefan DK7FC did a succesful transmit experiment utilising a ground diole on VLF. This resulted in a really strong signal on our Warsaw grabber (over 900km distance):
Continue reading “DK7FC ground dipole experiments on VLF”
We are starting to have pileups in the 8270Hz band, you can see this on our grabber:
Joe VO1NA on 8270.0075Hz , Stefan DK7FC on 8270.0Hz, Uwe DJ8WX on 8269.996Hz. And maybe Riccardo IW4DXW on 8270.003Hz
Continue reading “8270Hz pileup”
I made a 17470.1Hz grabber with a GPS reference. QTH at SQ5BPF Warsaw/Poland KO02md.
This is for Stefan DK7FC tests on this frequency.
92.6uHz bins, 1 hour steps.
In 22 and 23 april 2017 Stefan DK7FC did additional test ebnaut transmissions on 6470Hz. Similar to the previous tests, the transmission was decoded as usual by Paul Nicholson (850km) and also by Jacek SQ5BPF (900km).
Continue reading “Next tests in the 6470Hz band”
Stefan DK7FC has been recently transmitting on 6470Hz (46km wavelength) from a stationary antenna between two buildings.
The Ebnaut transmissions were received by Paul Nicholson (England) and Jacek SQ5BPF (Poland) at a distance of 900km (IN49IK to KO02MD).
Continue reading “6470Hz transmission by DK7FC succesfuly received at SQ5BPF (900km distance)”
On 10 march 2017 Stefan DK7FC experimented with transmitting on 2970Hz. The signal was received in Todmorden, England by Paul Nicholson at a distance of about 850km!
Continue reading “Succesful transmission on 2970Hz”