HAB Tracker Station

Project HAB Tracker Station
Status	In progress
Contact	User:Costyn_van_Dongen, Maxell, Bertrik_Sikken
Last Update	2013-02-11

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)
• VK5QI HABamp
• Raspberry Pi (+ power supply)
• Test payload, RFM22b sending RTTY strings on 434.250MHz. Code here: https://github.com/costyn/rfmtest/blob/master/rfmtest.pde
• Antenna: Diamond X-50N
• Enclosure to keep everything together and make it draw less attention

Assembled hardware

• Put the Raspi, ezcap and HABamp inside the enclosure
  • Drilling holes for all the cables
  • Reaming the Raspi's mounting holes to mount it

Software

• rtl_tcp on RasPi over the network --> works! (1024000 samples/second seems to work (make sure to be on a wired connection))
• VNC performance with gqrx and dl-fldigi --> usable with JPEG compression and 8 bits of color (why not SPICE? http://www.spice-space.org/)

Todo

Hardware

• Piece of aluminum pipe with a inside diameter of 29mm
• 2x inbusbout cilinderkop rvs (A2) M6x50
• 2x borgmoer rvs (A2) M6
• 4x sluitring rvs (A2) M6

Software

• Setting up a virtual machine with gqrx and dl-fldigi.
  • Blokje told us we could use his machine for permanent setup
    • This requires us to move the SpaceSoundSystem] towards something like a Cubieboard
      • Preferred to setup a complete NAS at the same time, this idea has been floating around also

Shit just got real

<foobar> Maxell: had xander gevraagd over die plaatsing van een antenne, is geen probleem, mits netjes aangelegd/afgewerkt
<foobar> je kan eventueel bij de zonne-collector naar binnen, daar is al een kabelgoot o.i.d.
<foobar> komt uit in de wc's boven, kan dan door naar de meterkast, en vanaf daar zijn al ducts naar beneden/kelder

OMG! HUGE SUCCESS!

The old geyser's ventilation pipe is still penetrating the roof. Cat5e UTP and 230v at your fingertips. It looks like we don't need to put our setup on the roof anymore, just the antenna! The enclosure we are going to use doesn't need to battle mother nature anymore, easy replacement if something breaks, etc, etc.

Grounding

<costyn> so guys, how do you ground your antenna's? what the consensus on lightning arrestors?
<fsphil> there's so little lightning here I don't bother
<costyn> hmm
<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
<SpeedEvil> you need to ground to a separate rod, with a straight cable to it
<SpeedEvil> thick insulated cable
<costyn> define thick?
<gonzo_> you are only going to be able to disipate static with earthing. very little you can do against a direct strike
<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.
<gonzo_> your typical short colinear is possibly going to be DC short between the centre and braid anyway. (You can test with a DVM)
<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
<costyn> gonzo_: it'll be a short one yea, Diamond X-50 likely
<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
<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)
<costyn> it's basically a flat roof with some outlets for hvac 
<costyn> so no existing metal work. we're thinking of using/making a stand with metal weighted down with tiles
<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
<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

Pics

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  One of the first payload tests

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  The antenna: 'Diamond X-50N'

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  Coax will leave/enter the building trough the little chimney

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  The ideal antenna mounting spot; the old zonnecollector

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  Enclosure almost ready to rock