HAB Tracker Station

Project HAB Tracker Station


Status	In progress
Contact	User:Costyn_van_Dongen, Maxell, Bertrik_Sikken
Last Update	2013-03-05

Project page for the high altitude balloon tracking/listening station have set up in the space.

Overview

File:RevSpaceHABtracker.png

Done

Hardware

"ezcap USB 2.0 DVB-T/DAB/FM" dongle (RTL2838U, Fitipower FC0013 tuner)
VK5QI HABamp
Raspberry Pi (+ power supply)
Antenna: Diamond X-50N
Test payload, RFM22b sending RTTY strings on 434.250MHz. Code here: https://github.com/costyn/rfmtest/blob/master/rfmtest.pde

Software

The raspi running rtl_tcp can do around 2MS/s, and you can connect with it on habraspi.space.revspace.nl:1234. Make sure you use a wired connection, or else the latency and overall experience will be horrible.

Todo

Hardware

Earth the antenna, to prevent static buildup
Install the HABamp
Test other DVB-T sticks, the mini-R820T could be interesting
Moar ferrite
Metal box for some shielding
If P2000 remains a problem: coaxial stub filter would be a good solution

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 for a while too

Problems we ran into

As soon as the P2000 tower transmits, it looks like the Fitipower FC0013 overloads, even on lowest gain.
- If the HABamp doesn't fix this we need to test other tuners.

OMG! HUGE SUCCESS!

First radio signals have been heard at 16 Feb. 2013.
The next day we tested Costyn's next payload: the Habanero!
- $$HABANERO,41,15:09:39,52.0647,+4.3642,45,7,6,16,23,4.15*AE4C (GPS location on Google Maps)

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