Good effort Stefan.
Merry Xmas
73
Mal/g3kev
Sent from my iPhone
On 16 Dec 2015, at 00:03, DK7FC <[email protected]> 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
>
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