HAB Tracker Station

Project HAB Tracker Station
Status	In progress
Contact	User:Costyn_van_Dongen, Maxell, Bertrik
Last Update	2013-01-10

Project page for the high altitude balloon tracking/listening station we are setting up in the space.

Done

Acquired Hardware

• "ezcap USB 2.0 DVB-T/DAB/FM" dongle, RTL2838U, Fitipower FC0013 tuner, Supported gain values (23): -9.9 -7.3 -6.5 -6.3 -6.0 -5.8 -5.4 5.8 6.1 6.3 6.5 6.7 6.8 7.0 7.1 17.9 18.1 18.2 18.4 18.6 18.8 19.1 19.7
• VK5QI HABamp
• Raspberry Pi
• Test payload, RFM22b sending RTTY strings on 434.250MHz. Code here: https://github.com/costyn/rfmtest/blob/master/rfmtest.pde

Software

• Sending test payload --> works!
• Sending data from rtl_tcp on RasPi over the network --> works! (1024000 samples/second seems to go fine when both are on a wired connection)
• gqrx to listen to audio --> works!
• dl-fldigi RTTY decoding --> works!
• Testing VNC performance with gqrx and dl-fldigi --> usable with JPEG compression and 8 bits of color

Todo

• Setting up a virtual machine with gqrx and dl-fldigi

revspace@habraspi:~$ rtl_tcp -a 10.42.43.20

Found 1 device(s). Found Fitipower FC0013 tuner

Using ezcap USB 2.0 DVB-T/DAB/FM dongle

The roof

• Currently there is no lightning protection installed. We need to figure out how we are going to ground the antenna.
• POE seems doable, also makes it easy to restart the setup.
• Penetrating the roof would increase the risk of any leakage
  • Our best option is to guide the UTP-cable down the drainpipe, in a separate PVC-pipe.

Todo

• Currently we have no antenna. Well need some heavy duty (directional?) antenna.
  • Do we make one or do we buy one?
  • What kind of antenna? (keep in mind we only have line of sight towards south/southwest) http://www.handelsondernemingveenstra.nl/webwinkel/diamond-50-p-309.html
  • How do we mount it? Something like this:

http://i.imgur.com/X3xsd.jpg with tiles in the corners to weigh it down

• Find and buy IP56 enclosure: http://www.conrad.nl/ce/nl/product/531547/Hammond-Electronics-Kunststof-behuizing-IP66-1554KGY-ABS-kunststof-l-x-b-x-h-160-x-90-x-90-mm-Lichtgrijs-RAL-7035/SHOP_AREA_14740&promotionareaSearchDetail=005
  • How do we deal with heat in the box in the summer?
• Obtain 48v PoE injector, make 48v-5v power regulator for inside enclosure:
  • http://tweakers.net/pricewatch/288179/tp-link-tl-poe150s.html (injector)
  • http://tweakers.net/pricewatch/280388/tp-link-poe-splitter-tl-poe10r.html (splitter)
• Your ideas, we love them!

Lightning protection

09:53 < costyn> so guys, how do you ground your antenna's? what the consensus on lightning arrestors?
09:56 < fsphil> there's so little lightning here I don't bother
09:57 < costyn> hmm
09:58 < costyn> we're going to place an antenna on the roof of our hackerspace, but it's not our building and we'll have to convince the 
                owners that it's safe
10:18 < SpeedEvil> you need to ground to a separate rod, with a straight cable to it
10:20 < SpeedEvil> thick insulated cable
10:20 < costyn> define thick?
10:29 < gonzo_> you are only going to be able to disipate static with earthing. very little you can do against a direct strike
10:29 < griffonbot> Received email: NickB "[UKHAS] Re: DL-FLDIGI question"
10:31 < gonzo_> most lightening arrestors are really just spark gap's, that allow some high voltage coming down the centre of the coax, to 
                jump to the outer.
10:32 < gonzo_> your typical short colinear is possibly going to be DC short between the centre and braid anyway. (You can test with a DVM)
10:34 < gonzo_> long colinears are not much of an advantage for HAB use, so I assume it will be a short one. So will not extend much above 
                the existing roof profile? So will not be any greater risk of lightening than anything else
10:34 < costyn> gonzo_: it'll be a short one yea, Diamond X-50 likely
10:35 < costyn> gonzo_: and it'll raise some above the roof line, but it's not a high building (2 stories) and there's higher buildings and 
                trees around
10:35 < gonzo_> not siure of your mounting options, but if mounted to existing metalwork up there, like handrains etc, it will be earthed to 
                the building anyway (or at least the owners metalwork)
10:35 < costyn> it's basically a flat roof with some outlets for hvac 
10:36 < costyn> so no existing metal work. we're thinking of using/making a stand with metal weighted down with tiles
10:39 < gonzo_> then an extra ground wire would prob be worth adding. If the building or roof is metal, then that could be an option to 
                earth to, or as SpeedEvil said, an earthing rod
10:44 < costyn> ok. thanks for the advice. will see what we can do. not even sure if we're going to get permission to route the coax on the 
                outside of the building, so we'll see