two 2.4 Gig TX in the same plane. How bad?

[Medve]

Just wondering if anyone has tried using two separate 2.4 TX's in the same plane, and if there is a lot of interfearence. I'm thinking of using a blackwidow video TX as well as a Maxstream Radio Modem for telemetry info.

[Medve]

Or maybe making the Maxstream be on 900 Mhz would be sufficient.

[clolson]

We have two blackwidow 2.4Ghz video transmitters on one of our airplanes. We haven't really wrung out the system, and we only have one receiver, but the camera we select *seems* to work ok. I didn't setup the video system on the airplane so there may be more going on with that than I'm aware of.

We also have a 900Mhz radio modem (aerocomm) on board, so we have 3 transmitters flying. We found that if we put the ground based radio modem transceiver too close to the blackwidow video receiver (on the ground) the aerocomm radio modem transceiver would step all over the video receiver and we got tons of interference. But by spacing the two ground antennas far enough apart (say 10 feet) we cured that particular problem.

I'm a software guy and R/C pilot so all this radio and electronics stuff is pretty much way over my head. :-)

Curt.

[danstrider]

I've done it with the Black Widow 900MHz system with two transmitters on different channels with no problems. I've also run an aerocomm 900Mhz model, one black widow 900MHz vid tx, and one black widow 2.4GHz tx with no problems. Granted, this setup isn't identical to yours, but just to let you know it's possible with those BW transmitters :-)

Dan

[typicalaimster]

Yes you can use the two. Just assign the BWAV to say channel 1. You can then assign the Maxstreams to another channel for example channel 7. The Maxstreams operate between 2.400 and 2.4835 ghz. There are also 7 channels you can choose from.

The X-CTU software that came with the Maxstreams has a part for range checking. After assigning channels flip on the Maxstream card first and do a quick range check. Once you're done with that flip on the BWAV system and see how much signal you lose. It may be easier to change the signal on the Maxstream cards since you can do it via the X-CTU software.

I've asked the same question in the Spread Spektrum Radio thread. Those new TX's are going to be using the 2.4 range. I have had problems at home with my wireless network and 2.4 ghz phones when I flip on my BWAV system. I eventually had to find a channel on my BWAV system that was not used by my devices at home.

[typicalaimster]

Or maybe making the Maxstream be on 900 Mhz would be sufficient.

Blah I should have answered both questions in this one.. Muh bad!


You will get better range with the 900mhz system. This is based off of the specs they provide about the X-Stream modudles.

http://www.maxstream.net/products/xstream/module/datasheet_XStream_OEM-RF-Module.pdf

I've had both a 2.4ghz BWAV and a 900mhz XStream setup 1500' away from me. They both worked like a champ.

--Scott

[space_case]

900mhz XStream setup

What is the price on this system? I'm having trouble finding this info on their site - usually not a good sign for a shoe string budget.

[mckaneorg]

This industry as a whole is not good for a shoestring budget! :) Goto http://www.gpsflight.com and talk to Walt. He is a really good guy, very knowledgeable about this space.

I spent almost $650 for my gps telemetry setup. But I have the ability to add on more stuff. I am now working with it to now tie into the Linksys NSLU2 system. This seems to be a great platform. But like I said, this hobby/business is not really meant for a shoestring budget. everything does add up as my wife would say! :)

-j

[space_case]

Thanks mckaneorg. I will put that sight in my UAV favorites file for future use. Are you doing any video telemetry? Does the unit you have transmit video also?

I plan on contacting the Maxstream people for the price.

[mckaneorg]

I have a seperate Video and Audio system. My plan for the Maxstream is strictly IFR. You cannot get 7mi Video telemetry.. not that I know of anyways.

If someone knows how, please inform.. but the Maxstream is always a great backup. You can program it and tie it into other things.

[air]

What are you doing with the NSLU2?

[mckaneorg]

What are you doing with the NSLU2?

I am currently exploring options as to what I would like to use it for. You can control servos with it you can write everything in c and even run gcc onboard to compile your app. Its a nice little platform. I have allot of plans for this little box.

[Medve]

My intent with this is to use the radio modem, X-stream or maybe something else that someone can recomend, to be my telemetry device. It will send the GPS data down to the laptop, where simple GPS software available anywhere for driving will give me real time, moving map display along with speed and altitude. The BW TX's go up to 6 watts I believe, so they could cover quite some distance for video if you needed it.
The radio modem would allow me to always know where the plane is and what it was doing. In case it ever went down, it would still be fairly easy to locate. And if it is on an autonomous photo mission, it would be easy to tell when it is coming back into radio range to take over. Are there other radio modems that are as good as the X-stream, and a good value? Maxstream was the only one I'm aware of.