Page 1 of 12

Janus Project style Stumble rig

PostPosted: Tue Feb 13, 2007 5:48 am
by Mark57
I've been making a parts list and creating a design over the last few days for a Janus Project style stumbling setup. It's very doable. What I can't decide on is how to arrange the antennas and their connections to the cards. I want all the antennas to be amped with a mix of directional and omni types but my quandary is how to do that and still take advantage of the separate channel scanning of the 8 cards. I could do 8 omni's on the roof and look like an FCC unit driving down the road. :D

I suppose I could use two or four way power splitters and run one amped antenna for every two or four cards. :confused: Insertion loss runs 0.4 - 0.6 dB for the two types of splitters. Any thoughts on this are welcome.

PostPosted: Tue Feb 13, 2007 7:06 am
by shamrock365
May I just say well done for getting this far. Fair play and best of luck with the rig. Where are the official specs on the Janus Project by the way? And what Linux Distro does it run? Building one was sort of on my wish list.

Best Of Luck,

Shamrock365

PostPosted: Tue Feb 13, 2007 7:19 am
by itsnotme
shamrock365 wrote:May I just say well done for getting this far. Fair play and best of luck with the rig. Where are the official specs on the Janus Project by the way? And what Linux Distro does it run? Building one was sort of on my wish list.

Best Of Luck,

Shamrock365


I read this: article on it which was posted by Madhatter here earlier. If you had actually searched and read around, you would have discovered that they ran Ubuntu Linux with 8 a/b/g mini-pci cards.

PostPosted: Tue Feb 13, 2007 7:31 am
by Mark57
shamrock365 wrote:May I just say well done for getting this far. Fair play and best of luck with the rig. Where are the official specs on the Janus Project by the way? And what Linux Distro does it run? Building one was sort of on my wish list.

Best Of Luck,

Shamrock365


The link I gave above gives you a taste of the hardware used. There are other articles that give slightly different details on other hardware parts if you look around.

I'm not trying to duplicate exactly what they've done rather leverage their mini-pci idea to make an optimal stumbling rig. Ideally, the maximum networks can be found by having a dedicated card for each channel. I'm using the mini-pci method that the Janus Project used to accomplish this.

PostPosted: Tue Feb 13, 2007 7:32 am
by whitedice
Nearly all of my antennas are N-male or N-female connectors, and from the searching I've done a lot of the miniPCI cards I have seen have u.FL connectors. FAB-Corp sells u.FL pigtails to various connectors for $10.99.

PostPosted: Tue Feb 13, 2007 7:38 am
by Mark57
whitedice wrote:Nearly all of my antennas are N-male or N-female connectors, and from the searching I've done a lot of the miniPCI cards I have seen have u.FL connectors. FAB-Corp sells u.FL pigtails to various connectors for $10.99.


Very true. My question comes beyond that point. I'd use the u.Fl to N type pigtails on each card but I still have to come up with a good way to bridge those to the various antennas. If each card is scanning one channel only you want it to have the opportunity to see the maximum area, and so on for each card. Connecting them all to omni's is one way but I'd like to use high gain panels as well. I'm sure it's doable. The config just hasn't revealed itself to me yet.

PostPosted: Tue Feb 13, 2007 7:50 am
by Mark57
What I'd "like" to do is use one or two omni's on top, and four 19 dBi Patch Antenna's, 2 per side. Each side would have one aimed around 45 degrees (or less) forward and one aimed 45 degrees (or less) to the rear on each side. I've done the measurements and have the room for placement and coverage angles. Unless there's something I'm missing, I just don't see the Janus style box lending itself to that type of antenna setup.

So I'm trying to merge what I see as the ideal antenna setup with the ideal computer setup and that's where I'm having the problem.

To me, Omni's make more sense with the Janus setup and a 2 or 3 card setup fits the antenna arrangement I described above.

PostPosted: Tue Feb 13, 2007 7:55 am
by streaker69
Mark57 wrote:What I'd "like" to do is use one or two omni's on top, and four 19 dBi Patch Antenna's, 2 per side. Each side would have one aimed around 45 degrees (or less) forward and one aimed 45 degrees (or less) to the rear on each side. I've done the measurements and have the room for placement and coverage angles. Unless there's something I'm missing, I just don't see the Janus style box lending itself to that type of antenna setup.

So I'm trying to merge what I see as the ideal antenna setup with the ideal computer setup and that's where I'm having the problem.

To me, Omni's make more sense with the Janus setup and a 2 or 3 card setup fits the antenna arrangement I described above.


Why not just build something that will sweep your patch antenna's 45° each direction, then you'd get the maximum coverage.

PostPosted: Tue Feb 13, 2007 8:03 am
by Barry
I've been looking into the same thing. http://www.mini-itx.com has the same computer used in the project. They also carry the dual pci riser card.

PostPosted: Tue Feb 13, 2007 8:04 am
by Mark57
streaker69 wrote:Why not just build something that will sweep your patch antenna's 45° each direction, then you'd get the maximum coverage.


That's an excellent idea and fixes the coverage issue. Now I still have to connect those in a way the each card can use them.

The farther I go with this, I'm thinking it makes more sense to use 4 or 6 mini-pci cards rather than 8 and modify the source channels settings for each based on the antenna connections. This takes me away from one card for each channel but it'll still have better performance than one or two cards.

PostPosted: Tue Feb 13, 2007 8:07 am
by streaker69
Mark57 wrote:That's an excellent idea and fixes the coverage issue. Now I still have to connect those in a way the each card can use them.

The farther I go with this, I'm thinking it makes more sense to use 4 or 6 mini-pci cards rather than 8 and modify the source channels settings for each based on the antenna connections. This takes me away from one card for each channel but it'll still have better performance than one or two cards.


http://www.geeks.com/details.asp?invtid=CAM-SCANNER-NC&cat=VID

I have one of these, except it's the remote controlled one. Depending upon the weight of your patch antenna's they could possible work for you.

Only problem is, they run off of 9VAC.

PostPosted: Tue Feb 13, 2007 8:13 am
by Mark57
Barry wrote:I've been looking into the same thing. http://www.mini-itx.com has the same computer used in the project. They also carry the dual pci riser card.


The whole idea just makes sense to me. I haven't decided how I'm going to monitor the system from the driver's seat just yet. It might be as simple as a crossover cable to my navigation laptop or a 7" LCD on the dash.

streaker69 wrote:http://www.geeks.com/details.asp?invtid=CAM-SCANNER-NC&cat=VID

I have one of these, except it's the remote controlled one. Depending upon the weight of your patch antenna's they could possible work for you.

Only problem is, they run off of 9VAC.


Sweet! Power conversion can be done without too much pain. Very interesting.

PostPosted: Tue Feb 13, 2007 8:27 am
by beakmyn

PostPosted: Tue Feb 13, 2007 8:30 am
by Mark57
beakmyn wrote:http://home.utah.edu/~mcm5849/wince/vnc.html

or other variant


I could use my HTC 8125 in a pinch with a long USB cable.;)

PostPosted: Tue Feb 13, 2007 8:53 am
by beakmyn
I just tried the VNC client on my Ipaq, not bad might be pretty good since my Axim is 640x480 and kismet looks nice at that resolution, hmmm.