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Old Nov 22, 2011, 12:52 AM
Team White Llama!
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they usually mean 1280, as that's the only legal channel.

you've been around FPv long enough, there really is no "better" channels for FPV. Out in the country, my 900mhz system is balls to the walls awesome. Down in the city (chicago) it's terrible. That's why i use 2.4ghz video on my quad (much cleaner in the city), but i cannot fly with other people on 2.4ghz radios. 5.8 works great and has high bandwidth, but multipathing is bad and penetration suffers, plus there aren't many high powered 5.8 transmitters. 1.3ghz is usually really clean, so you don't need alot of power to go far. The downside here is it shares a harmonic with 2.4ghz radio control, and it seems to be getting crowded as of late(picking up other FPV'rs signals).


So personally, i think 1280 will work well for you. you seem to have alot of noise on or near 900mhz where you are flying. I can easily get crystal clear video for over a mile on 900mhz 500mw with just a patch and the stock crappy whip. my friend gets 2 miles on 200mw with a helical and a CL.

Just double check that your RX does 1280, and that whatever 1280TX yuo buy uses the same pin layout, like this one:

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Old Nov 22, 2011, 12:59 AM
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yeah I can't find what frequencies the channels on my RX correspond to. 1040MHz = channel 3. Starts at 0 and goes to 8 I think. Then there's A B C and goes back to 0.
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Old Nov 22, 2011, 02:44 AM
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Switzerland, LU, Buchrain
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Quote:
Originally Posted by chatch15117 View Post
http://www.hobbyking.com/hobbyking/s...Receiver_.html

http://www.hobbyking.com/hobbyking/s...er_600mw_.html

^^ is that your setup? I am looking to switch from 200mW 900MHz to 5.8GHz. Would you recommend getting it from hobbyking or is there a better quality tx for the same price or less?
For 5.8G, I would go this route:

http://www.hobbyking.com/hobbyking/s...Tx_Rx_Set.html

Stay clear from the RC-805 reciver whoes link you gave, oh, and the rx and tx you linked to do not match eachother.

I agree with the other poster that there is no "better" frequency. With propper equipement, 5.8G can be quite powerfull too. My current cloverleaf and helical combo bridge 15km with ease. I could not test further as its freaking foggy here all times... Time to move to florida it seems. You don't have a job for me down there do you?

BR,

Markus
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Old Nov 22, 2011, 03:06 AM
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If you do anything defense related both lockheed and northrop are hiring. Siemens has a large division here too so if you're a metallurgical engineer they'll snatch you right up. Other than that, it's pretty tough around here .

I just bought http://www.readymaderc.com/store/ind...roducts_id=324

I realize it's 600mW output. It works with channel 9 of my Rx so it'll be easy to make a vee+patch for it.

BTW I'm selling most of my stuff to switch to 72MHz RC + 1.3Ghz video. Nothing is inherently wrong with it... I just have a huge noise floor and didn't realize it. It'll be great for someone that doesn't want to fly in the middle of a city with 2 million people(literally).
http://www.rcgroups.com/forums/showthread.php?t=1543601
http://www.rcgroups.com/forums/showthread.php?t=1543565

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Old Nov 22, 2011, 03:23 AM
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Originally Posted by chatch15117 View Post
If you do anything defense related both lockheed and northrop are hiring. Siemens has a large division here too so if you're a metallurgical engineer they'll snatch you right up. Other than that, it's pretty tough around here .
Defense related and being from a foreign country seems to be mutually exclusive.

I used to work for a company in FairFax (Northern VA) from 06 to 09. Was BIG fun actually, but they ran into financial problems for various reasons. It's not easy these days.

BR,

Markus
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Old Nov 22, 2011, 08:06 AM
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http://www.youtube.com/watch?v=E-gT92w-y9U


noise floor shmoise floor. it was because I was positioned close to that VACANT building and it was creating multipath interference
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Old Nov 22, 2011, 08:12 AM
Team White Llama!
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Quote:
Originally Posted by chatch15117 View Post
http://www.youtube.com/watch?v=E-gT92w-y9U


noise floor shmoise floor. it was because I was positioned close to that VACANT building and it was creating multipath interference
or the RF caused by the legal aviation broadcasts are now off, thus not swapping you're illegal transmissions.
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Old Nov 22, 2011, 04:57 PM
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Signal reflections with circular polarisation?

Hi guys, especially IBcrazy!
I'm seeking any advice or tip for my problem.
I made FPV RX-TX chain from cheap 1.2G chinese modules from ebay and DIY cloverleaf antennas. Initially it worked GREAT (please see 1st part of the attached video) but then after a crash where I broke TX cloverleaf I'm getting always stripe in the image. Now is the stripe very strong (please see 2nd part of the attached video) but when I carefully inspected videos recorded during the time I noticed it was appearing even before but not so badly.
I tried to cure it with building new cloverleaf for TX and new skew planar wheel for RX but no improvement. Please note in the video at about 4:00 and again at the end, that for the stripe appearing is important the tilt (pitch) of the plane. (Camera looks under fixed angle down (cca 5 in the 1st part and 15 in the 2nd part). Please consider that OSD data are in meters.
In meantime I also replaced SAW filter in the receiver from 30MHz for 17MHz wide version but it seems not to be connected to this problem. Also nice weather in early autumn changed to almost winter but still I don't know what is the cause. Can anyone thing about possible cause and give me any tip?
Thanks!
Roman



http://www.youtube.com/watch?v=1tYQJRRduBo
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Old Nov 22, 2011, 05:58 PM
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Originally Posted by daronj View Post
Must be something wrong with the build. I verified the tx and rx channels.
By the way, here is a quick 60 second sample of what I have. This is all well within 1/4 mile.

5.8GHz test (1 min 3 sec)
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Old Nov 22, 2011, 06:04 PM
Engineer for Christ
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Amherst, VA
Joined Jun 2006
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Quote:
Originally Posted by RBirdie001 View Post
Hi guys, especially IBcrazy!
I'm seeking any advice or tip for my problem.
I made FPV RX-TX chain from cheap 1.2G chinese modules from ebay and DIY cloverleaf antennas. Initially it worked GREAT (please see 1st part of the attached video) but then after a crash where I broke TX cloverleaf I'm getting always stripe in the image. Now is the stripe very strong (please see 2nd part of the attached video) but when I carefully inspected videos recorded during the time I noticed it was appearing even before but not so badly.
I tried to cure it with building new cloverleaf for TX and new skew planar wheel for RX but no improvement. Please note in the video at about 4:00 and again at the end, that for the stripe appearing is important the tilt (pitch) of the plane. (Camera looks under fixed angle down (cca 5 in the 1st part and 15 in the 2nd part). Please consider that OSD data are in meters.
In meantime I also replaced SAW filter in the receiver from 30MHz for 17MHz wide version but it seems not to be connected to this problem. Also nice weather in early autumn changed to almost winter but still I don't know what is the cause. Can anyone thing about possible cause and give me any tip?
Thanks!
Roman



http://www.youtube.com/watch?v=1tYQJRRduBo
That looks like a camera or RX problem. Nothing to do with the antenna. It looks like a section of the video feed loses synchronization or the levels shift. It could be a setting in the camera. In any case, I think your camera is at fault. Do you have another camera to try?

-Alex
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Old Nov 22, 2011, 06:07 PM
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Quote:
Originally Posted by daronj View Post
By the way, here is a quick 60 second sample of what I have. This is all well within 1/4 mile.

http://youtu.be/_759r20zQvM
The problem is noise floor (or lack of TX power/RX sensitivity). You might have some 802.11n (5.8GHz Wifi channel) interference around you. This is rare. Try changing your channel and see if the results are repeatable.

-Alex
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Old Nov 22, 2011, 08:26 PM
'FPV'er...not a "LOS'er
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Quote:
Originally Posted by markus123456 View Post
For 5.8G, I would go this route:

http://www.hobbyking.com/hobbyking/s...Tx_Rx_Set.html

Stay clear from the RC-805 reciver whoes link you gave, oh, and the rx and tx you linked to do not match each other.
I just received this same set. The HK write up says the Rx is 5v, mine's labeled for 12v. Do you have one of these systems? Does the Rx say 5v or 12v???
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Old Nov 22, 2011, 08:55 PM
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Australia, SA, Adelaide
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I have two rc 305 receivers and they run on 8-12 volts i use a 3 cell lipo for mine -
HK have it wrong yet again LOL.
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Old Nov 22, 2011, 09:03 PM
'FPV'er...not a "LOS'er
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Originally Posted by helichoper View Post
I have two rc 305 receivers and they run on 8-12 volts i use a 3 cell lipo for mine -
HK have it wrong yet again LOL.
Thanks. I was going to try it off 5v first vs frying it with 12v and finding it was mislabeled...I might still try that though...good to know they're 12v though...won't need a voltage regulator now...
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Old Nov 23, 2011, 03:35 AM
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Quote:
Originally Posted by Vantasstic View Post
Thanks. I was going to try it off 5v first vs frying it with 12v and finding it was mislabeled...I might still try that though...good to know they're 12v though...won't need a voltage regulator now...
There is a simple 7805 linear voltage regulator inside. You best drive it off a 2s battery as with 3s it may get's too hot in summer days. The bad thing is that if this happens, it all of a sudden will turn to a black picture. So if you want to stay on the save side, either use an external DC/DC converter that goes down to around 7 volts, or use a 2S battery for it. I personally run it also off a 3s battery, so far without DC/DC regulator, but I'm aware of the problem and make sure it gets some cooling if it's really hot. Not really a problem here at this time of the year though. brrrr... winter is coming.

Markus
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