Return-Path: X-Spam-DCC: paranoid 1233; Body=1 Fuz1=1 Fuz2=1 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.4 required=5.0 tests=BAYES_00,HTML_40_50, HTML_MESSAGE,RATWARE_GECKO_BUILD autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id s9RLNeha030480 for ; Mon, 27 Oct 2014 22:23:40 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1XirhG-0007mG-IW for rs_out_1@blacksheep.org; Mon, 27 Oct 2014 21:19:26 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1XirhG-0007m7-5O for rsgb_lf_group@blacksheep.org; Mon, 27 Oct 2014 21:19:26 +0000 Received: from mail-la0-f65.google.com ([209.85.215.65]) by relay1.thorcom.net with esmtps (TLSv1:RC4-SHA:128) (Exim 4.82) (envelope-from <73dk7fc@googlemail.com>) id 1XirhD-0005ID-F9 for rsgb_lf_group@blacksheep.org; Mon, 27 Oct 2014 21:19:25 +0000 Received: by mail-la0-f65.google.com with SMTP id gm9so1522468lab.4 for ; Mon, 27 Oct 2014 14:19:22 -0700 (PDT) X-DKIM-Result: Domain=googlemail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20120113; h=from:message-id:date:user-agent:mime-version:to:subject:references :in-reply-to:content-type; bh=YGgr0KyWVQhouvV5PpaID4YbYKVXnbN8w4V91camhFI=; b=y8+UExtqrlPjRXMAsCIH2cGTWoinZ1qPhsHAlLNlUucnST8NSygMBJ3j9fZ5De8OSZ j1JmODsbqTKtmajtIpzWBTbsbXbXAl/HUp2GWs4DPZJsdWR9ml22tferJsOZaWp5jQux Z3+fC0T5i8fggkvj+6R2Gfr5jkFmRvGCXNG9AKQ5o41FRU85w1I67mQ64VJu8wmWvIdY V3AoujuGetQ2Fy4IqTl8MQ6NXzS7Hf1xRbkyM7RIfAiHii7vKF0n2x4DwrLTbPTnDMem WcKgMaMCzryOloP3N3yg+yT1itm08yb1Of9YOHfbYnyK3OGgvz+zg9uJVoEU6w0jr/k6 mOcw== X-Received: by 10.152.27.67 with SMTP id r3mr26451039lag.19.1414444762261; Mon, 27 Oct 2014 14:19:22 -0700 (PDT) Received: from [129.206.22.206] (pc206.iup.uni-heidelberg.de. [129.206.22.206]) by mx.google.com with ESMTPSA id e3sm5387195lam.26.2014.10.27.14.19.20 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 27 Oct 2014 14:19:21 -0700 (PDT) From: DK7FC <73dk7fc@googlemail.com> X-Google-Original-From: DK7FC <73dk7fc@gmail.com> Message-ID: <544EB6D7.108@gmail.com> Date: Mon, 27 Oct 2014 22:19:19 +0100 User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <544C1724.6020605@gmail.com> <8D1BEC25CB8E32C-D9C-11EBD@webmail-va032.sysops.aol.com> In-Reply-To: <8D1BEC25CB8E32C-D9C-11EBD@webmail-va032.sysops.aol.com> X-Scan-Signature: 222431427b0fb799ed82c2c5d7851cd5 Subject: Re: LF: Re: Schumann in my garden, final circuit design Content-Type: multipart/alternative; boundary="------------050509000209080100040802" X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 912 This is a multi-part message in MIME format. --------------050509000209080100040802 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Markus, Another thought: Could it be the frequency of an old monitor running 60Hz frequency for the screen? Wolf already sentioned something... It was a matter of frequency stability that gives the proof, if i remember... I like to watch that propagation on 5000 km wave length. You said +-2...3 dB between daytime and nighttime. I find 3 dB is quite much and will show clearly on the screen! Time for my remote grabber... 73, Stefan Am 26.10.2014 01:32, schrieb Markus Vester: > Hi Stefan, > very nice result! Your spectrogram also contains 60 Hz from America, > not too conspicuous but easily visible with a little visual averaging. > 73, Markus (DF6NM) > > > -----Ursprüngliche Mitteilung----- > Von: DK7FC <73dk7fc@googlemail.com> > An: rsgb_lf_group > Verschickt: Sa, 25 Okt 2014 9:34 pm > Betreff: Re: LF: Re: Schumann in my garden, final circuit design > > Hi ELF friends, > > Just for those who are interested... > I have now finished my modifications to the ELF RX / preamp design for > a long wire (E field) antenna. This is the final schematic > https://dl.dropboxusercontent.com/u/19882028/VLF/DK7FC%20ELF%20RX%20schematic.jpg. > Despite the low frequency, it is improtant to use goos shielding in a > metallic box. This is how it looks here: > https://dl.dropboxusercontent.com/u/19882028/VLF/DK7FC%20ELF%20RX.jpg > > I've been in the garden today again and recorded the ELF spectrum > (file: > https://dl.dropboxusercontent.com/u/19882028/VLF/VLF%20Garten%20in%20T%20Antenne25102014_1st.WAV > (584 MB)). Unfortunately ZEVS was off the air during that time but i > got SNR of Schumann resonances again and very low man made noise and > design noise. Spectrogram: > https://dl.dropboxusercontent.com/u/19882028/VLF/Schumann%20resonances%20on%20final%20design.png > > Soon i will do another attempt to trynsmit in the ELF range to detect > my signal in 2.4 km distance... > > 73, Stefan/DK7FC > > > > > > > > Am 07.10.2014 00:37, schrieb DK7FC: >> Hi ELF friends, >> >> Now the circuit is in a box: >> https://dl.dropboxusercontent.com/u/19882028/VLF/Living%20in%20a%20box.jpg >> >> I measured the resistance against ground (which should be infinity!) >> with an old Rohde & Schwarz tube multimeter, maybe from the 1960s. It >> can measure R up to 3 G Ohm. Positive results, no change of the >> displayed R if i connect the D.U.T. >> I think Ha-Jo DJ1ZB may know the multimeter from his early days :-) >> Image: >> https://dl.dropboxusercontent.com/u/19882028/VLF/cooperating%20generations%20of%20technique.jpg >> >> New measurements tomorrow... >> >> 73, Stefan/DK7FC >> >> >> Am 06.10.2014 22:29, schrieb DK7FC: >>> Hi Edgar, >>> >>> Of course you were right. >>> I thought i don't need a completely shielded box because i am in the >>> garden and there is no electricity. >>> But, the gate of the FET is quasi-floating and there is always some >>> stray-C between the antenna wire and that gate. >>> Even 0.1 pF coupling C and 100 MOhm means a HPF cut off near 16 kHz >>> !! I run a test, disconnecting the antenna from the preamp and >>> placed the end of the wire in 0.2m distance. The SNR of DHO38 on >>> 23.4 kHz was 30 dB, despite connected circuitry (diodes, filter, >>> stray-C to ground). >>> Now i will again move the circuit, into a shielded box :-) >>> More results tomorrow. >>> Nice stuff to play with! Still some warm autumn days here... >>> >>> 73, Stefan/DK7FC >>> >>> Am 06.10.2014 00:51, schrieb edgar: >>>> Hi Stefan, >>>> >>>> I suggest that you cover the LPF and FET with a piece of tin to >>>> stop any external signals entering the circuit after the LPF. >>>> >>>> A thin piece of metal from coffee tin or similar food container can >>>> be bent in a U shape to cover the components and then soldered at a >>>> few points to the copper ground plane. >>>> >>>> Just leave a small clearance holes at the ends for the wires to >>>> pass through. >>>> >>>> Regards, Edgar >>>> Moonah, Tasmania. >>>> >>>> --------------050509000209080100040802 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 8bit Markus,

Another thought: Could it be the frequency of an old monitor running 60Hz frequency for the screen? Wolf already sentioned something... It was a matter of frequency stability that gives the proof, if i remember...
I like to watch that propagation on 5000 km wave length. You said +-2...3 dB between daytime and nighttime. I find 3 dB is quite much and will show clearly on the screen!
Time for my remote grabber...

73, Stefan

Am 26.10.2014 01:32, schrieb Markus Vester:
Hi Stefan,
 
very nice result! Your spectrogram also contains 60 Hz from America, not too conspicuous but easily visible with a little visual averaging.
 
 73, Markus (DF6NM)


-----Ursprüngliche Mitteilung-----
Von: DK7FC <73dk7fc@googlemail.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Sa, 25 Okt 2014 9:34 pm
Betreff: Re: LF: Re: Schumann in my garden, final circuit design

Hi ELF friends,

Just for those who are interested...
I have now finished my modifications to the ELF RX / preamp design for a long wire (E field) antenna. This is the final schematic https://dl.dropboxusercontent.com/u/19882028/VLF/DK7FC%20ELF%20RX%20schematic.jpg. Despite the low frequency, it is improtant to use goos shielding in a metallic box. This is how it looks here: https://dl.dropboxusercontent.com/u/19882028/VLF/DK7FC%20ELF%20RX.jpg

I've been in the garden today again and recorded the ELF spectrum (file: https://dl.dropboxusercontent.com/u/19882028/VLF/VLF%20Garten%20in%20T%20Antenne25102014_1st.WAV (584 MB)). Unfortunately ZEVS was off the air during that time but i got SNR of  Schumann resonances again and very low man made noise and design noise. Spectrogram: https://dl.dropboxusercontent.com/u/19882028/VLF/Schumann%20resonances%20on%20final%20design.png

Soon i will do another attempt to trynsmit in the ELF range to detect my signal in 2.4 km distance...

73, Stefan/DK7FC







Am 07.10.2014 00:37, schrieb DK7FC:
Hi ELF friends,

Now the circuit is in a box: https://dl.dropboxusercontent.com/u/19882028/VLF/Living%20in%20a%20box.jpg

I measured the resistance against ground (which should be infinity!) with an old Rohde & Schwarz tube multimeter, maybe from the 1960s. It can measure R up to 3 G Ohm.  Positive results, no change of the displayed R if i connect the D.U.T.
I think Ha-Jo DJ1ZB may know the multimeter from his early days :-) Image: https://dl.dropboxusercontent.com/u/19882028/VLF/cooperating%20generations%20of%20technique.jpg

New measurements tomorrow...

73, Stefan/DK7FC


Am 06.10.2014 22:29, schrieb DK7FC:
Hi Edgar,

Of course you were right.
I thought i don't need a completely shielded box because i am in the garden and there is no electricity.
But, the gate of the FET is quasi-floating and there is always some stray-C between the antenna wire and that gate.
Even 0.1 pF coupling C and 100 MOhm means a HPF cut off near 16 kHz !! I run a test, disconnecting the antenna from the preamp and placed the end of the wire in 0.2m distance. The SNR of DHO38 on 23.4 kHz was 30 dB, despite connected circuitry (diodes, filter, stray-C to ground).
Now i will again move the circuit, into a shielded box :-)
More results tomorrow.
Nice stuff to play with! Still some warm autumn days here...

73, Stefan/DK7FC

Am 06.10.2014 00:51, schrieb edgar:
Hi Stefan,

I suggest that you cover the LPF and FET with a piece of tin to stop any external signals entering the circuit after the LPF.

A thin piece of metal from coffee tin or similar food container can be bent in a U shape to cover the components and then soldered at a few points to the copper ground plane.

Just leave a small clearance holes at the ends for the wires to pass through.

Regards, Edgar
Moonah, Tasmania.


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