References: <44960D15E9F74D8DBBE05E8A24298450@AGB> <1422413C99FE494EA95C4A94103353A8@AGB> <5670AA40.7020206@posteo.de>
From: Mal Hamilton <g3kevmal@talktalk.net>
In-Reply-To: <5670AA40.7020206@posteo.de>
Message-Id: <E5AA2C6C-502D-4000-85FF-75C3B0433157@talktalk.net>
Date: Wed, 16 Dec 2015 00:48:28 +0000
To: "rsgb_lf_group@blacksheep.org" <rsgb_lf_group@blacksheep.org>
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Subject: Re: LF: DK7FC remote forest grabber now running
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Good effort Stefan.
Merry Xmas
73
Mal/g3kev


Sent from my iPhone

On 16 Dec 2015, at 00:03, DK7FC <selberdenken@posteo.de> wrote:

> Hi all,
> 
> Finally my new remote forest grabber, version 2.0, is now active in JN49ik36! There, in a radius of 1000m, there is no electricity. The new version uses the new Raspberry Pi 2 which performs much better. The overall power consumption of the system is below 3W. The stereo RF stream is stable and the CPU load is just about 22%. There are 3 lead acid gel accus, 18 Ah each.
> 
> In the last weeks i finished the last important steps.
> 
> -Installed the (first) 50W solar module in an angle of 60 deg (winter optimised)
> -Installed the accu charger circuit which has a variable voltage limiting depending on the accu temperature (PTC sensores installed)
> -Put the stereo MF DC converter into the box
> -Painted the WLAN yagi in military green, camouflage-antenne :-)
> -Installed scripts to track the battery voltage, WLAN link level and CPU temperature
> - Updated the grabbers website, http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_remote_Grabber.html
> 
> So far, there is only one antenna on the tree. A loop for 630m, beaming NW/SE. Seems to work well from what i saw so far. However there is still QRM coming from the far field. Some QRM traces are visible on the DL3ZID grabber in > 500 km distance. Maybe there is some noise from the DC/DC converter, not sure. Will check that later.
> 
> You can't imagine the feeling beeing up on the tree there. Its just peace and freedom! Worth all the "effort".
> Some images at https://www.dropbox.com/sh/iogg0azyaezrg0y/AADJGvxaq4OEJuNYZ2YyfP_Ca?dl=0  (beeing not happy with seafile as an alternative for dropbox. Will try owncloud soon)
> 
> Next steps are:
> 
> -Building a second loop, orthogonal, for MF.
> -Building an active antenna for LF/MF. A power saving model, running at 5V/1mA!
> -Starting with first steps for 2200m!
> -Installing a web-cam.
> -Further crazy ideas...
> 
> 73, Stefan
>