Greetings Stefan and congrats on your remarkable work on ELF.
I am still thinking about the guard rail for VLF. It is 10km+ from the
shack so any operation will have to be mobile and of courss must
have the prior approval of Elmer the Safety Elephant. (hi hi)
EbNaut LF TX:
The signal is taken from the time pulse output of the NEO7 board
which has a LED and dropping resistor across it. Paul has written
code to control the frequency, duty cycle etc with a Raspi. Very handy.
This goes directly to a TTL XOR and then a TC4426 driver thence a
class E 100w TX or the Decca. If you have any questions, I'll be happy
to help. This system is very simple.
73
Joe VO1NA
On Wed, 13 Feb 2019, DK7FC wrote:
Hello Joe,
Your NEO7M emits 137 kHz directly? How do you tell it to do that?
Ehm, did i ask you the same question some weeks ago or did i just thought
that i should ask you.
Ebkey, so your'e using a Raspi for the job? I think so but maybe i remember
wrong.
Would be interesting to know your rig in detail, the exciter stage.
73, Stefan
PS: Do you know, there are such forums, when you ask a question then someone
answers "This question has been asked before. Did you run a search
before?...". Terrible!
Am 13.02.2019 21:15, schrieb [email protected]:
Hi Riccardo, Group.
Thanks for the details of your experiments and the signal reports.
The set up here is an NEO7M to a Decca (one PA module) to a 100x20m
RL aerial. Paul's Ebkey.c clocks the XOR. The RL has several dB over
the monopole. Perhaps running a counterpoise under the top loading wire may
yield another dB or 2. Stefan's and Markus's grabbers are
very helpful too.
73
Joe VO1NA
On Wed, 13 Feb 2019, Riccardo Zoli wrote:
Joe, Stefan, LF
Another night with a strong signal from you, Joe. Thanks again for your
transmissions which provides good opportunities for RX equipment testing.
Last night, in particular, I tried to listen your signal with my *SLMS
HP-3746A*, equipped with its high stability oscillator (OPT.014). I have
got good decodes with *NO GPS* *reference* connected to audio card or
instrument; I noticed only a slight phase rotation in a couple of cases.
I used my TX inv. "L" antenna (that was tuned this time) and a 6 dB
attenuator.
You can see here the results:
UTC Eb/N0[dB] Carr.S/N[dB] Mess.
0030 7.1 32.14 *******
0100 8.0 32.20 VO1NA_R
0130 5.2 29.08 *******
0200 4.0 27.95 VO1NA_R
0230 5.7 29.01 *******
0300 3.3 27.79 VO1NA_R
0330 NIL - -
0400 9.0 32.46 VO1NA_R
0430 7.3 31.49 *******
0500 6.2 30.55 VO1NA_R
0530 6.1 29.86 *******
0600 -0.3 24.48 VO1NA_R
All the best
73 de Riccardo IW4DXW
Il giorno lun 11 feb 2019 alle ore 21:05 <[email protected]> ha scritto:
Hi Riccardo, Stefan, LF,
Pleased to get your report of improved signal strength Riccardo.
The R means "Rotated L" so it is in the sky again since yesterday.
Today a cermaic feedthrough was installed on the PVC bucket
that houses the coil. It was cold (-10 C) today but the work had
to be done; there was too much charring and arcing. All seems OK
now and the TX is on (one Decca module) 2.2A RF
73
Joe VO1NA
On Mon, 11 Feb 2019, DK7FC wrote:
Hello Riccardo,
I like the precision of your RX frequency. I should add a few nulls to
my
file too :-)
Good work regarding Joe's reception!
73, Stefan
Am 11.02.2019 12:56, schrieb Riccardo Zoli:
Joe, LF
Very strong signal last night continuously from 2330z to 0530z.
Best decode at 0300z, info attached.
RX setup: inverted "L" TX antenna (slightly detuned, 6 dB attenuator
inserted) and SDR.
All the best,
73 de Riccardo IW4DXW
Il giorno gio 7 feb 2019 alle ore 17:44 <[email protected]
<mailto:[email protected]>> ha scritto:
Apologies: I misspelt Domenico and did not acknowledge Riccardo's
autodetector.
73
Joe
On Thu, 7 Feb 2019, [email protected] <mailto:[email protected]> wrote:
> Dominico,
>
> Thanks to you and Markus and Domenico for the autodecoder service.
> I will check the modulator and try again tonight. Some antenna
work
> is planned as well when the wx improves so there should be some
more
> dB available soon.
>
> 73
> Joe
>
> On Thu, 7 Feb 2019, Domenico IZ7SLZ wrote:
>
>> Joe, LF
>> in my EbNaut log
>> *https://qsl.net/iz7slz/EBNAUT/DECODED.TXT
>> <https://qsl.net/iz7slz/EBNAUT/DECODED.TXT>*
>> there are some decodes of your EbNaut of last nights (QRB=5426
km). Seems
>> that since yesterday, only carrier is sent on usual qrg 137477
Hz.
>> Autodecoder here is now running, every XX:00 and XX:30 on Joe's
parameters:
>>
>> 137477.000Hz N=7 T=3s 8K19A CRC=16 list=2000 sym=608
Duration=1824s
>> T_OFFSET=0.0s F_OFFSET=0.000Hz
>>
>> 73, Domenico IZ7SLZ / JN80nu
>>
>
>
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