Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, HTML_MESSAGE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: : mailn 1480; Body=2 Fuz1=2 Fuz2=2 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id v78HuoOh025262 for ; Tue, 8 Aug 2017 19:56:52 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1df8eZ-0001Np-Qt for rs_out_1@blacksheep.org; Tue, 08 Aug 2017 18:50:51 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1df8e1-0001Ng-Gi for rsgb_lf_group@blacksheep.org; Tue, 08 Aug 2017 18:50:17 +0100 Received: from mout02.posteo.de ([185.67.36.66]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1df8dw-00041u-S7 for rsgb_lf_group@blacksheep.org; Tue, 08 Aug 2017 18:50:14 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id DC78B20C9B for ; Tue, 8 Aug 2017 19:50:09 +0200 (CEST) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3xRhkT1Thbz10HW for ; Tue, 8 Aug 2017 19:50:08 +0200 (CEST) Message-ID: <5989F9D0.7050308@posteo.de> Date: Tue, 08 Aug 2017 19:50:08 +0200 From: DK7FC 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: <15db2643c6f-5f13-23c2@webprd-m101.mail.aol.com> <5986259C.8020409@posteo.de> <59864218.1030605@posteo.de> <75b1b001-f17e-35b0-bcb4-6535fe67fc38@sky.com> <59886FDE.20509@posteo.de> <983eafc2-82df-d307-07d8-0070762b99bb@sky.com> In-Reply-To: <983eafc2-82df-d307-07d8-0070762b99bb@sky.com> X-Scan-Signature: 8ac9f0a1bced50a7ada6578ede3fb6ae Subject: Re: LF: vlfrx tools question (a bit OT) Content-Type: multipart/alternative; boundary="------------070505090903090305030703" 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 2.75 Status: RO X-Status: X-Keywords: X-UID: 12347 This is a multi-part message in MIME format. --------------070505090903090305030703 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Terry, Am 08.08.2017 09:08, schrieb Terry G0EZY: > > I see from ntpq - p that you left the on-line ntp servers > operational, in addition to your gps > Yes. Sometimes i want the GPS module to set the time because i have no internet access (portable) and sometimes vice versa. > > (I understood Paul's email to disable external ntp by removing these > lines as part of the ntp.conf modification) > I don't think it is problematic to leave a few servers in the file. The GPS server entry has a 'prefer' added, so i think this server will be preferred when many are available. It is not critical... > In your photo of the complete assembly, it is interesting to see your > modifications. I can see clearly the gps interface connected to the > RaPi gpio pins extended through the Octo board. Yes, the simplest and compactest and energy savingst way to go i bet. > It looks as though you have made your own interface plug for the input > of the Octo and using only Ch1, Ch2 with Ch3 as PPS?. Correct. I wanted to get rid of the ribbon cable and use RG174 instead, as well as BNC connectors, for RF, not for AF! The ribbon cable can't be a good choice when thinking about EMC and/or cross talk... > > What are the two vertical boards on the left? the smaller one looks > like (but not exactly) the DC/DC inverter. > Sounds like your inverter order has not been delivered yet :-) These two boards are the DC/DC converter, vertically mounted. > > Also a direct power connection to the RaPi, as you are not using the > microUSB power connector. > Yes, i just soldered two cables on the bottom of the board. No mechanical instabilities. It is one unit. BTW my 64 GB stick arrived, now i can record 2 channels for 4 days or 3 channels for a week or so :-) > > Have you added the modifications to give the RaPi a "soft" on/off > switch (to protect the SDCard) and a reset button? > In the upper vertical plate on the photo you can see a red key button. This is for shutting down the Raspi (running a dedicated shutdown script started by crontab). Then there is a red LED which quickly starts to blink when the boot process is completed. Also it starts to shine permanently when the shutdown process is in progress, until it stops when it is completed. 10 seconds later i can disconnect the power. A restart is done by shutting down, removing the supply and connecting the supply again. Another LED is the clear one (blue). It is for giving feedbacks from the record process: When switching the green key in the upper plate, the record script start to leave its while loop, configures the GPS module for a 2 ms pulse width, starts gpsd, waits until GPS-system-time is less than 2 seconds, starts all the vt processes including vtwait inbetween. During that time the blue LED shines permanently, so i know that the preparation is in progress. After that, when the recording has been started successfully, it blinks, 10 ms each 3 seconds. So then i know that everything is fine and the recording is running. Yesterday i made a first recording in the forest. It was good to have that kind of feedback there. All went well. > > Finally, I see you have a USB plug connected - is this for the wifi? I > think you are using a RaPi2 without an onboard wifi.. > Correct. This is not used in the field of course. Usually i connect to the Raspi only by PUTTY, command line only... > > and I remember from your earlier posts that you are using 2.4 GHz WiFi > to link from your remote forest listening post back to your main site > in the University. > Correct. This project is running nearly 2 years now and meanwhile the system availability is > 95% > > This must be a LoS path? > I don't know what that means. > > Even so, quite impressive to work with the interference from the mass > of other Wifi in the city... > I'm unsing high gain yagis on both sides. The one in the forst is 1.1m long! The other one is on the top of the building in 33m above the ground. This already helps a lot to cause interferences (to my link and to others). > > It gives me the thought to run a RaPi system at my local radio club > which is in a relatively radio-quiet site outside the City of > Doncaster. But this is about 12km away and not LoS. It would be a good > LF/VLF education for the members as their main interest is microwave > and nanowaves (light transmissions)..... > Yes, do it! It makes a lot of fun (even without beeing fully solar powered, the next thing!) and we need more monitors :-) 73, Stefan > > 73 Terry > > --------------070505090903090305030703 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Terry,

Am 08.08.2017 09:08, schrieb Terry G0EZY:

I see from ntpq - p that  you left the on-line ntp servers operational, in addition to your gps

Yes. Sometimes i want the GPS module to set the time because i have no internet access (portable) and sometimes vice versa.

(I understood Paul's email to disable external ntp by removing these lines as part of the ntp.conf modification)

I don't think it is problematic to leave a few servers in the file. The GPS server entry has a 'prefer' added, so i think this server will be preferred when many are available. It is not critical...
In your photo of the complete assembly, it is interesting to see your modifications. I can see clearly the gps interface connected to the RaPi gpio pins extended through the Octo board.
Yes, the simplest and compactest and energy savingst way to go i bet.
It looks as though you have made your own interface plug for the input of the Octo and using only Ch1, Ch2 with Ch3 as PPS?.
Correct. I wanted to get rid of the ribbon cable and use RG174 instead, as well as BNC connectors, for RF, not for AF!
The ribbon cable can't be a good choice when thinking about EMC and/or cross talk...

What are the two vertical boards on the left? the smaller one looks like (but not exactly) the DC/DC inverter.

Sounds like your inverter order has not been delivered yet :-) These two boards are the DC/DC converter, vertically mounted.

Also a direct power connection to the RaPi, as you are not using the microUSB power connector.

Yes, i just soldered two cables on the bottom of the board. No mechanical instabilities. It is one unit.
BTW my 64 GB stick arrived, now i can record 2 channels for 4 days or 3 channels for a week or so :-)

Have you added the modifications to give the RaPi a "soft" on/off switch (to protect the SDCard) and a reset button?

In the upper vertical plate on the photo you can see a red key button. This is for shutting down the Raspi (running a dedicated shutdown script started by crontab). Then there is a red LED which quickly starts to blink when the boot process is completed. Also it starts to shine permanently when the shutdown process is in progress, until it stops when it is completed. 10 seconds later i can disconnect the power. A restart is done by shutting down, removing the supply and connecting the supply again.
Another LED is the clear one (blue). It is for giving feedbacks from the record process: When switching the green key in the upper plate, the record script start to leave its while loop, configures the GPS module for a 2 ms pulse width, starts gpsd, waits until GPS-system-time is less than 2 seconds, starts all the vt processes including vtwait inbetween. During that time the blue LED shines permanently, so i know that the preparation is in progress. After that, when the recording has been started successfully, it blinks, 10 ms each 3 seconds. So then i know that everything is fine and the recording is running.
Yesterday i made a first recording in the forest. It was good to have that kind of feedback there. All went well.

Finally, I see you have a USB plug connected - is this for the wifi? I think you are using a RaPi2 without an onboard wifi..

Correct. This is not used in the field of course. Usually i connect to the Raspi only by PUTTY, command line only...

and I remember from your earlier posts that you are using 2.4 GHz WiFi to link from your remote forest listening post back to your main site in the University.

Correct. This project is running nearly 2 years now and meanwhile the system availability is > 95%

This must be a LoS path?

I don't know what that means.

Even so, quite impressive to work with the interference from the mass of other Wifi in the city...

I'm unsing high gain yagis on both sides. The one in the forst is 1.1m long! The other one is on the top of the building in 33m above the ground. This already helps a lot to cause interferences (to my link and to others).

  It gives me the thought to run a RaPi system at my local radio club which is in a relatively radio-quiet site outside the City of Doncaster. But this is about 12km away and not LoS. It would be a good LF/VLF education for the members as their main interest is microwave and nanowaves (light transmissions).....

Yes, do it! It makes a lot of fun (even without beeing fully solar powered, the next thing!) and we need more monitors :-)

73, Stefan

73 Terry


--------------070505090903090305030703--