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FPV and Real time Video Discussions of receiving video in realtime from the aircraft |
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01-03-2007, 03:35 PM | #1 (permalink) |
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Join Date: Sep 2006
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Video Downlinks and Spektrum 2.4GHz RX
Has anyone successfully used a low power 2.4GHz down link with a Specktrum RX? My assumption is the video down link would overload the front end of the Spektrum and it wouldn't work.
However, if you used a low power down link (say 100mW) and separated the RX and the down link (TX) as much as possible, perhaps with a little shielding, it might work. My plan is to go 900MHz, but thought I'd check what others are doing first. Thanks! |
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01-03-2007, 04:57 PM | #2 (permalink) |
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Join Date: Feb 2006
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Isn't 900 mhz illegal in the U.S.? Perhaps 5.8 ghz is available now?
Maybe remove all of the junk from one of these? http://www.rflinkusa.com/products_AVS5811.html
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01-03-2007, 05:09 PM | #3 (permalink) | |
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Quote:
900MHz cordless phones have been around in the US for many years, so I'm not sure why you think 900MHz is a reserved band. The 900MHz cordless phone band is unlicensed and unprotected as far as I know. In fact, at one time you could "wiretap" a call by listening on the 900MHz band (assuming they were using a 900MHz cordless) without a warrant and not violate any laws. That may have changed by now. |
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01-03-2007, 05:46 PM | #4 (permalink) |
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Join Date: Feb 2006
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As I understand it the 900 Mhz frequencies that these units use are not in the U.S. phone band (902 thru 928 mhz) (maybe in Hong Kong they are) thus making them illegal. Not absolutely sure, but I read it somewhere and they sure are disappearing rather quickly.
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01-03-2007, 06:51 PM | #5 (permalink) |
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Join Date: Feb 2006
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TYpe acceptance is a big part of the issue also. Here is an article geared to the use by police about the topic. Read about half way down the page.
http://www.swssec.com/wire1.html
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Cheers, Rusty |
01-03-2007, 07:57 PM | #6 (permalink) |
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so far I have not heard of anyone that has been able to get any 2.4 or 2.3 ghz system to work in conjunction with the DX6 or Dx7 radios But I may be wrong and some one out there can prove me wrong
Maybe the ticket is to upgrade to the 5.8 ghz Downlink systems to be able to use the DX6 or Dx7 systems with out any problems the 5.8 seems to be still to pricey for this experiment but maybe someone with deeper pockets will step up and prove my theory |
01-03-2007, 08:03 PM | #7 (permalink) |
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Join Date: Feb 2006
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miami16,
Do you have links to something good Who carries 5.8?
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Cheers, Rusty |
01-03-2007, 10:13 PM | #8 (permalink) |
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Join Date: Apr 2004
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I have tried a 200mW DigiLive downlink Tx and a 50mW Tx as well, and both will totally jam the DX6. I haven't tried it with a DX7 yet, but I'm guessing it will be about the same.
I used to use the 900 MHz stuff all the time, but it's hard to find now. I checked with Bill at BWAV and he said he's not carrying 900MHz equipment anymore. The only other source I've found is www.rangevideo.com which I assume is a good company. Ihaven't tried anything from them yet, but I like their website. I don't know anywhere to get small 5.8GHz stuff yet. -- Gary |
01-03-2007, 11:22 PM | #9 (permalink) |
HeliFreak Security Staff
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I just tested mine, spektrumized 6102, RangeVideo 500Mw with standard antennas and the TX made the video dump only if I got too close to the wireless RX, I never lost signal to the bird and video was crystal clear at about a 4 foot distance.
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MSH Protos FBL SK720 Trex 600 14S A123 CCHV110 Actro 24-3 Trex 600 AP 12S A123 CCHV85 NEU 1912 1y Gaui 200 Trex 450 SE V2 Dedicated night Rig |
01-04-2007, 01:22 AM | #10 (permalink) |
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Interesting link Rusty. If for some strange reason I ever get arrested based on wireless video surveillance evidence, I'll have to make sure they used Type accepted equipment.
I was looking at the www.rangevideo.com stuff as well. I called the number on the site and it seems to be a one man shop importing a few items from who knows where (humm....should check Digikey, Mouser, etc). No reason not to deal with them, but I doubt it is type accepted. My main concern is the cellular bands. If it spills into the cell bands it could cause enough problems to attract attention. This would esp be a concern for anyone doing tower inspections like DJ. Cryofix - was this a 2.4GHz system you tested? Was the RX an AR6000? How far apart was the video TX from the AR6000? If I understand your post, the problem was not on the bird, but at the ground - and the 6102/DX6 overloaded the video RX, unless you separated them by 4'. Is this correct? |
01-04-2007, 05:56 AM | #11 (permalink) |
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Join Date: Aug 2005
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I used a 2.4 ghz downlink with a dx6 on my mount for a while last year, before switching to 72mhz. The key is turning the downlink setup on before the dx6, and keeping them as far away as possible. I used a 1 watt setup, and it worked, but I believe the side affect was reducing the range of the radio severly, as it had to sort out all the useless 2.4ghz crap. I've got a dx7 I'm putting in my maxi, and depending on the situation, I might use my 2.4ghz downlink, or the new 900mhz setup I got. for refrence, the 1 watt tx was blackwidow, using ar6000, about 7 inches away.
Rhett |
01-04-2007, 07:00 AM | #12 (permalink) |
HF Support
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Cryofix,
Could you post photos of the installation on your bird ? How far is he video Tx from the R/C Rx ? From your signature I assume this is all on the T450, right ?
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Kenneth * MSH Protos Stock motor/15t/Align75/Align DS510/GL730+DS520/7s A123 2300 * TRex450CF/430L/12t/CC45/HS65mg/L2100T/KP 3s 2200 25C or 4S LiFe Previous rides: HX242, W5-4, TRex450(HDE), TRex450(SE), QJ-EP8v2, BCX2 ,Logo10, Hurricane550 SIM: Phoenix (previously also Reflex/XTR, ClearView, RF, FMS) |
01-04-2007, 10:25 AM | #13 (permalink) |
HeliFreak Security Staff
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My 2.4 is in fact on my rex 450 all equipment was in close proxcimity in my garage, so there was no way to range check, I use an Ar6000 in my 450 SE but this is no longer my primary AP bird I have moved to a Logo 10 and use 72 mHZ, I do plan on using the the XPS wireless setup in my logo when the modules are available.
I turned on my TX and RX for the heli first, did pre-flight like check then I turned on my video equipment which is 2.4 also and it had no interference at all, I continued to do full stick movements with the TX in my hands and the heli on hte ground about 4 foot away from the wireless down link, and there was no problems, I then pu the TX down and picked up the heli, while using one hand to hold the heli and one to run the cyclic I put the heli close the wireless TX and RX and had no problems as the controlls remained accurate. The only problems I did have was when I put the heli TX within 3-4 foot of the wireless base station the closer I got to the base TX with the heli TX I would begin to get more and more static on the screen and then finally the screen shut down due to loss of signal. I also need to update my Signature as many things have changed =)
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MSH Protos FBL SK720 Trex 600 14S A123 CCHV110 Actro 24-3 Trex 600 AP 12S A123 CCHV85 NEU 1912 1y Gaui 200 Trex 450 SE V2 Dedicated night Rig |
01-04-2007, 10:30 AM | #14 (permalink) | |
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Quote:
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01-04-2007, 01:39 PM | #15 (permalink) |
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Join Date: Jan 2006
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This has been covered quite a bit on several forums.
Here is a link to a thread on here about it: https://www.helifreak.com/viewtopic.php?t=25756&start=0 I experimented with using a 2.4g downlink and a DX6. 2 things happened. 1.) When I turned on the DX6 all video signal went away. 2.) When I was more than 20 steps from the heli, I got lockout and still had no video. I even tried leaving the video Rx 20' from myself and the Rx and still had no video. I have read from other people that have actually put their heli's in the dirt using a DX6 and a 2.4g downlink. When I tested I tried turning it on in different order and everything else. It didnt matter. For my TRex 600 camera ship, I am using: DX7 to control heli DX6 to control camera/mount RangeVideo 900mhz 500mw transmitter So far I have tested the setup with both radios on and the Rx's actually sitting on top of each other and my current 900mhz sending unit (not the rangevideo unit yet) all on at the same time with perfect results. I could walk a very long ways away, easily over 150', and everything still worked perfectly. That includes the video at that distance. I am assuming that the RangeVideo unit has a much greater range than the cheapo unit I am playing with now. I hope this helps. I was very confused about all this as well. After emailing a couple of the more popular companies (i'm not naming them because I dont want to throw them under the bus) and not getting an answer from them at all, not even an I don't know. I decided to test it on my own.
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01-04-2007, 03:42 PM | #16 (permalink) |
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Interesting, thanks.
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Kenneth * MSH Protos Stock motor/15t/Align75/Align DS510/GL730+DS520/7s A123 2300 * TRex450CF/430L/12t/CC45/HS65mg/L2100T/KP 3s 2200 25C or 4S LiFe Previous rides: HX242, W5-4, TRex450(HDE), TRex450(SE), QJ-EP8v2, BCX2 ,Logo10, Hurricane550 SIM: Phoenix (previously also Reflex/XTR, ClearView, RF, FMS) |
01-09-2007, 02:55 AM | #17 (permalink) |
Join Date: Jan 2007
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Bump....
Has anyone gotten any further with this? I want to use a DX7 and a 2.4 downlink. Any problems discovered yet? Come on... don't let the newbie waste money. I want to make sure I'm getting the right bang for the buck. |
01-09-2007, 06:59 AM | #18 (permalink) |
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Nick, reading the comments above by outfrontjames and others elsewhere, I would never ever try to run tw 2.4Ghz systems in a heli! I cannot believe that the DX7 is going to have some magic cure for a known problem experienced with the DX6. I think the answer clearly is not to use a 2.4ghz downlink if you run either a DX6 or DX7.
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Tony Stott Trex 450 XL,JGF450TH,GY240 500e fuse, and Hubdave CF frame, JGF450TH,GY401, A109 fuse 1/4 scale hot-air balloon and Rokkaku/Sutton FF16 kites, Brooxes KAP rig, Olympus SP350s 13m Spiderbeam mast, Askman mount, A640, all above with 2.4Ghz downlink |
01-28-2007, 09:09 PM | #19 (permalink) |
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900 Mhz
Outfrontframes. I believe you need a ham license for the 900 stuff over a certain output. I've seen it advertised where 200 mw stuff need the license. What are we to do. Is there a waiver or something?
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01-28-2007, 10:51 PM | #20 (permalink) |
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Join Date: May 2006
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900 MHz (33 cm) is an available amateur (ham) band as well as spectrum used by what is called 'part 15' or unlicensed radiators. It was popular with cell phones and wireless in recent years, probably most of that has moved up in frequency.
You are correct, commercial applications must meet the part 15 regulations and are quite low power. If you get an amateur license the power limit is 1 KW, more than you will be able to haul airborne in your TRex! There are no waivers. However getting the license is not terribly difficult. There is no code requirement for that band (there won't be ANY code requirement after Feb 23) and the test is only 35 questions. The license class you would want is called Technician and gives you full access to all amateur bands from 50 MHz and above. You can learn more by visiting the ARRL website at: http://www.arrl.org. Just a comment about using a 2.4 G down-link with a Spectrum system. I would avoid that if possible. You may be able to get it working but I would never want to place a transmitter and receiver in close proximity on the same band. At the very least there will be degradation in the on-board receivers sensitivity. Hope this helps,
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