GE
dears,
I'm also following your TX, Stefan, with a 424 uHz grabber with no
result at the moment. I'll try also the 42 uHz one.
As antenna I'm using the MF TX marconi because whip and loop are ready
for the qsy in the "silent-qth". Noise with this antenna is very high
but I'm in RX anyway.
Thanks for transmission.
73, Max IK0VVE
______________________________
...here some of my HAM Radio projects...
Cc:
Data:
Thu, 30 Nov 2017 13:50:54 +0100
Oggetto:
Re: VLF: DK7FC close to SAQ
Hello VLF freinds,
I spent some day in Berlin, thus the late reply, sorry.
The carrier is actually running since 25.Nov 23 UTC witout any
interruption! I have/had control over the TX via the samrtphone.
I can
follow the antenna current and can access the PC to stop the
transmission if something would be wrong. Also there is the
safety
function that stops the transmission as soon as the antenna
current
drops by more than 30 mA under the target level of 700 mA.
Thanks to all stations who gave a feedback and RX report of the
first
amateur transmission on 17.47 kHz.
Special congrats to IW4DXW who made his first amateur VLF
reception at
all (i think)!
Riccardo, is that spectrogram really set to 3.8 mHz FFT bin
width, as
stated in the text field?
Your simple antenna matching schmatic is apprechiated. It may be
helpful
for further stations. I note that no special preamp is needed.
Luis, your few bright pixels look most promising. But maybe it
is better
to wait until tomorrow before claiming that new distance record
on the
17 km band. It would be a first amateur detection on VLF between
DL and
EA! This evening i will finally rise the ERP by 3 dB, going from
700 mA
to 1 A antenna current... With 3 dB more, the few pixels should
become a
solid line.
BTW all this helps to see how 'far' you are away from getting a
detection on 8270 and below..
Sq5BPF has set up a grabber but didn't see a trace so far. I
started a
grabber window at RC4HAA running at 212 uHz. There is no trace
at all! I
did expect much better results over that distance.
Also KL7L has set up a grabber window, without results so far.
My first impression is that the band offers less better
propagation than
expected! So let's hope that QRO will help :-)
Before loosing these informations i set up a small list
containing
informations about RX stations and SNR reports, see attachment.
Tell me
if there is something wrong or if i forgot something.
I will inform when the signal level has changed or when
interruptions
happened. So far the transmission is still running. Ah yes the
antenna
current ca be followed at
unspectacular but some kind of feedback...
73, Stefan
Am 29.11.2017 22:46, schrieb Riccardo Zoli:
> Hi Stefan, VLF
>
> I got your signal in JN64bw, dear Stefan. Depending on the
QSB and/or
> QRN, you're peaking 15dB over noise. Fantastic! :-))
> I'm using my LF antenna tuned on your QRG with a (approx.)
200mH coil.
> The 17470.5 signal (locally generated by a GPS disciplined
DDS) is
> used for Spectrum Lab SR correction.
> Schematic and capture attached.
>
>
> Congrats, Stefan, and keep up the good work!
>
> All the best,
>
> 73 de Riccardo IW4DXW
>
>
>
>
>> Hi VLF,
>>
>> Since 23 UTC a 700 mA carrier is running on 17.4701 kHz!
>>
>> It is a little surprise to the VLF community i think ;-)
>>
>> Legal? Yes:
>> Actually the document has 3 pages but the other ones
are no so relevant.
>> My ERP is limited to 5 mW. I did not request more
because more isn't
>> possible anyway with this antenna.
>>
>> I wound a big single layer coil with 0.5 mm enameled
wire on a PVC tube with
>> 315 mm outher diameter.
>>
>> 0.7 A is just a first careful step. The coil is
designed to hold 1.5 A 'key
>> down'.
>>
>> The carrier will run the whole night and even tomorrow
at daytime.
>>
>> Worldwide reports are welcome ;-)
>>
>> It is not sub-9-kHz but still VLF, the 17 km band!! So
give it chance :-)
>>
>> The tree has still some solar power to stream the
signal from the EW loop
>> down to the city, so there is a feedback spectrogram at
>>
>>
>> 73, Stefan
>>
>> PS: I still can hear that tone of the coil. It is
terrible! Be happy when
>> you are older than me!
>>
