View Full Version : antenna advise
tobiokanobi
06-30-2009, 09:09 PM
Hi!
Looking for a suggestion regarding antennas for a Pico2 - since it is for a mobile application, it needs to be "small" and "leightweight"
Omnidirectional rubber 10-14dBi
and or
or directional circular polarized (size not bigger as 15x15cm)
Thanks a lot!
Tobias
Do you mean mobile or portable?
Mobile is usually associated with vehicular applications. Portable is either hand held or easily moved about applications.
The included 6 dBi omni antenna would be a good choice if you don't know where to point your antenna, as with a directional antenna. Circular polarized requires a matching CPOL antenna at the other end? Is the other end CPOL? If it is, then its directional and you would have to be within the area its pointed at.
Can you be more specific what you want to do.
tobiokanobi
07-06-2009, 01:24 AM
Thanks for your answer.
According your description - mobile -
We are going to connect the picostation to a net-webcam (from Elphel) and attach them and some other (metering-)devices to a radioprobeballon (ceiling height 30km).
On ground (connected with the NS2) we have a 21dBi antenna (dish + patch) ( http://www.jrmiller.demon.co.uk/products/s_ant.html)
Now we are looking for a nice antenna for the ballon (Picostation).
Any advise?
Tobi
Now we are looking for a nice antenna for the ballon (Picostation). There are some threads covering remote control airplane antennas.
tobiokanobi
08-05-2009, 07:33 AM
@WHT: thanks, I had a look around, but could't find anything covering distances above 30km for remote control AC. Just short distance control.
I've now got a Pico2HP - my question is now: is the antenna for the european version wtih 6dBi gain or 0dBi gain?
-thanks
tobi
skyhook
08-05-2009, 07:50 AM
Do you mean mobile or portable?
Mobile is usually associated with vehicular applications. Portable is either hand held or easily moved about applications.
The included 6 dBi omni antenna would be a good choice if you don't know where to point your antenna, as with a directional antenna. Circular polarized requires a matching CPOL antenna at the other end? Is the other end CPOL? If it is, then its directional and you would have to be within the area its pointed at.
Can you be more specific what you want to do.
6 dBi is for US market, for UE market the PICO2 is provided with 0 dBi antenna... ;)
tobiokanobi
08-05-2009, 08:07 AM
Is there a way to get the 6dBi antenna?
BTW: I obtained the Pico2HP and not the Pico2
-tobi
I had a look around, but could't find anything covering distances above 30km for remote control AC. Owwwww...that's gonna be tough.
You could use an inverted 0 dBi ground plane antenna. Anything with more gain would have a more flat pattern and shoot over you on the ground.
That means you'll need a very high gain antenna on the ground.
Bullet -HP 5 at 6 Mbps data speed TPO is dBm.
0 dBi antenna gain
130 dBm free space diversion loss at 30 KM
28 dBm antenna on ground
94 dBm RX sensitivity
30 + 0 -130 + 28 + 94 = 22 dBm
At twice the distance, 60 KM, you would have a 22 - 6 = 16 dBm level
But a 28 dBi antenna is VERY hard to aim, you would have to calibrate a telescope along the feed horn tube to aim the grid.
tobiokanobi
08-05-2009, 09:45 AM
Owwwww...that's gonna be tough.
...For ground we have a 21-24dBi dish with a patch antenna connected to a Nanostation2.
21dBi - 2dBm (connector) + 26dBm (TXpower) = 45dBm
5 Mbits seams reasonable, I expected something around 90dBi sensitivity and a fade margin from about 7dBm. But we could life with less Data, and go for 1Mbits - most important is to recieve GPS data ;-) .
For the ballon we have the Pico2HP with 29dBm TX and according to my reseller the 6dBi omni antenna - but I don't know if the gain for the antenna is now correct (european version yes or no??).
... Anything with more gain would have a more flat pattern and shoot over you on the ground.
...unfortunately my knowledge is here a bit low level! Time is running we heading for the first or second weekend in September. That's why I asked for advise ;-)
Best regards from Austria,
-tobi
Can you test your set up with the balloon payload sitting on or hanging from something? I want to know if you have a basic connection problem. use about a fifty foot distance.
Unless there is a rare oddball camera out there, an IP or network ready webacm have am embedded web server for viewing. I stuck a Bullet 5 with an omni antenna on a doggie harness late last summer. 90% of the time is showed the same scene...dogs sleep a lot.
tobiokanobi
08-10-2009, 07:02 AM
On the webcam runs Linux, it works as web/php and ftp server - the cam USB, i2C, RS232, eSATA connections and supports internal CF Memory Cards
You only need to set a static IP and set the Picostation as bridge, allowing multicast - here it goes!
-tobias
P.S We don't have the money and the time to buy much equipment, we plan the start on the first weekend in Sept. But we welcome sponsored equipment ;-)
The Elphel webcam is pretty high priced, but has lots of features. For 90% of my customers, they use a $69 IP cam.
Not that I'm advertising pricing for cameras, but take a look at the diagrams.
http://whtonline.com/video/index.html
tobiokanobi
08-10-2009, 06:28 PM
A good offer you posted WHT. And for sure the elphel cam is much more expensive.
One of the reasons why we have chosen the elphel cam is that linux runs on it and we can use the camera also as interface to a motorcontroller and some other devices we need. (Also, all hard and software on the cam are opensource :-) )
-tobias
I have the SDK for the Aviosys cameras. Its like pulling teeth to get it from them.
