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Old Sep 13, 2011, 02:28 AM
QiW
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south east asia
Joined Mar 2009
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Originally Posted by markus123456 View Post
If memory serves, the AIOs have the same sky-rf reciver module inside like the RC305 reciver. Me thinks that the main difference in range etc. is a potential different placement of the RC305 versus the fixed mounted rx on your head. I use a tripod, and my RC305 is about 3 m (~9 feet) above ground. Having the rx antenna so close to your head (and note, makeing a longer coax would be a bad idea) is definately sub optimal. However, flying out 1km with such an uncomplicated setup also sounds like fun at times but again, for serious flying, the reciver and antenna should be placed high above ground.

Put a wooden stick on a tripod and mount your RC305 on top, then try what range you get this way. Regarding the blocked signal upon return, you found your answer, the motor and battery is blocking the signal. There are two thinkable solutions. a) don't fly back to you in a direct line or b) place the antenna BELOW your plane. Maybe out on a wing.

HTH

Markus
i do not have a RC 305 ...
tested with SPW on the AIO and stock antenna on the AIO .. both tested with me wearing the goggles flying in the same flight path

the AIO claims to have the same rf module as rc305 ... that does not explain why i have much more range with SPW compared with stock antennas as SPW cures multipath not range .. very strange

just chiming in to see if there are any other AIO users with CL/SPW combo with this problem ...

currently using 1.2ghz as main video and a 10mW 5.8 to relay the video to my AIO so that i can be "cable free"
this 5.8 will prolly just go into my current tricopter build since i do not plan to fly the copter far (mostly within 500m) so it should be good
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Old Sep 13, 2011, 02:28 AM
Kiwi in Germany
whakahere's Avatar
Germany
Joined Jun 2010
2,284 Posts
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Originally Posted by QiW View Post
i am using my AIO built in 5.8 vrx to receiver video from my plane foxtech 200mW 5.8
using stock antennas i got to about 400m before totally losing video (total snow)
made the CL/SPW combo to replace the antennas on both ends ... that gave me just over 1km of usable video ..

since i have more than double the range since replacing the antennas ... but still nowhere near the range u guys getting ... can i come to the conclusion that my AIO built in vrx is the main culprit ? i do not have rc305 to test with though ...
i cannot find any info on anybody else using the AIO built in vrx and range ..

edit ... after turning the plane around and heading back towards me after 1km .. the battery/motor/ESC/OSD all get in the way and i get very very bad video until i get close to about 500-600m then it starts to clear up
vtx with CL is mounted on skysurfer tail boom ...
Strapping it to your head effects range a lot. With my gear I have two different setups on CP omni's. For a start my head bound gear for short range flying. I get about 1km -1.5km through this system. This is all I need. On my other setup where I am like Markus I have my rx on a wooden pole about 3 meters in the air I am getting about 3km.

Another thing I have noticed is where I stand and what other high powered gear I have around. More high powered gear does seem to shorten my overall range. To help with everything I make sure that my video tx is far away from everything, doesn't get blocked on return trips. All my wires are twisted. torrid cores on anything that transmits power (GPS). I try to give my tx the cleanest environment I can.

With regrades to aSa2, I too have found that having my chainlink near the receiver does effect it. This is the reason I have the tx so high. I am still getting 3km on a day that has high humidity. I also saw you said you have your gear ontop of your car. I have found that near the car it does give me a few problems so I move well away from anything metal.
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Old Sep 13, 2011, 02:31 AM
Kiwi in Germany
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Germany
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Quote:
Originally Posted by QiW View Post
i do not have a RC 305 ...
tested with SPW on the AIO and stock antenna on the AIO .. both tested with me wearing the goggles flying in the same flight path

the AIO claims to have the same rf module as rc305 ... that does not explain why i have much more range with SPW compared with stock antennas as SPW cures multipath not range .. very strange

just chiming in to see if there are any other AIO users with CL/SPW combo with this problem ...

currently using 1.2ghz as main video and a 10mW 5.8 to relay the video to my AIO so that i can be "cable free"
this 5.8 will prolly just go into my current tricopter build since i do not plan to fly the copter far (mostly within 500m) so it should be good
stock antennas give crap range because the signal can't transmit a clear signal. I noticed flying on stock antennas that I didn't have great range as well, but also the placement of the gear is very important on 5.8ghz. If it is near anything it does reduce range.
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Old Sep 13, 2011, 02:42 AM
Jets Suck (and blow)
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Australia, QLD, Deception Bay
Joined Jan 2008
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WOW, that's some fast posting, everybody home from work at the same time

I made this, hopefully it's built well enough, anyone in Sth Sydney area have a 5.8G capable SWR meter?? Made from 0.8mm Brass with RG316, is stiff and should hold up to punishment well. Working so on small antennas is a bit tricky, but one good side effect is that they won't be causing much drag on the plane

I seem to remember that we used to get better results on 27mhz gear if we made the coax a wave length multiplier. So for kicks I made the coax on this 5.8G CL ~one wave length long (105mm) this was about the length I needed and can't hurt.

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Old Sep 13, 2011, 02:56 AM
Kiwi in Germany
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Germany
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Originally Posted by Peril View Post
WOW, that's some fast posting, everybody home from work at the same time

I made this, hopefully it's built well enough, anyone in Sth Sydney area have a 5.8G capable SWR meter?? Made from 0.8mm Brass with RG316, is stiff and should hold up to punishment well. Working so on small antennas is a bit tricky, but one good side effect is that they won't be causing much drag on the plane

I seem to remember that we used to get better results on 27mhz gear if we made the coax a wave length multiplier. So for kicks I made the coax on this 5.8G CL ~one wave length long (105mm) this was about the length I needed and can't hurt.

Damn Australians ..... some of us are on the other side of the world P.s. I am in the full right to make as much fun of you as I can ... I am a little cuz from NZ .... living in Germany.

make sure you have a SPW on your RX. clover by it's self isn't that great. Oh it looks fine by me. Just check all your angles and you should be fine.
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Old Sep 13, 2011, 03:11 AM
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Switzerland, LU, Buchrain
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Quote:
Originally Posted by Peril View Post
WOW, that's some fast posting, everybody home from work at the same time

I made this, hopefully it's built well enough, anyone in Sth Sydney area have a 5.8G capable SWR meter?? Made from 0.8mm Brass with RG316, is stiff and should hold up to punishment well. Working so on small antennas is a bit tricky, but one good side effect is that they won't be causing much drag on the plane

I seem to remember that we used to get better results on 27mhz gear if we made the coax a wave length multiplier. So for kicks I made the coax on this 5.8G CL ~one wave length long (105mm) this was about the length I needed and can't hurt.
No need for a special lenght of the coax cable.

Visually the antenna looks ok, but remember, without measureing equipement you can't know if you are 200Mhz (or more) off from your targeted frequency on 5.8Ghz and on top of that you also don't know if the antenna is resonant anywhere at all. The latter you will find out with a ground range test, the former is harder as it limits your range and also will have influence on the image quality. Signal to noise ratio depends a lot on how sharp/deep resonant the antenna is etc. So give it a try!

Markus
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Old Sep 13, 2011, 03:21 AM
Jets Suck (and blow)
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Australia, QLD, Deception Bay
Joined Jan 2008
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Yep, trial and error, less error is always preferred, hehehe.

It's not perfect, I could do better I think second time round, but ya never know, antennas are strange buggas. As whakahere suggests, the SPW will be next, if I had access to an SWR Meter I'd be a little more confident that I had this correct enough.
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Old Sep 13, 2011, 03:27 AM
Kiwi in Germany
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Germany
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Originally Posted by Peril View Post
Yep, trial and error, less error is always preferred, hehehe.

It's not perfect, I could do better I think second time round, but ya never know, antennas are strange buggas. As whakahere suggests, the SPW will be next, if I had access to an SWR Meter I'd be a little more confident that I had this correct enough.
don't stress about it. my close in stunt planes are all homemade and not tested. then again my long range relies on the tuned antennas from markus.
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Old Sep 13, 2011, 03:29 AM
Jets Suck (and blow)
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Australia, QLD, Deception Bay
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PS I married a Kiwi, familiar with the country and the people
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Old Sep 13, 2011, 03:42 AM
Kiwi in Germany
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Germany
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PS I married a Kiwi, familiar with the country and the people
my family live in Australia like all kiwis. Muy brother works in the mines as a shot blaster .... in other words .. a kiwi blowing up australia ... he couldn't be happier.

I am a true black sheep .. I married a German!
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Old Sep 13, 2011, 03:47 AM
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Switzerland, LU, Buchrain
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Originally Posted by Peril View Post
Yep, trial and error, less error is always preferred, hehehe.

It's not perfect, I could do better I think second time round, but ya never know, antennas are strange buggas. As whakahere suggests, the SPW will be next, if I had access to an SWR Meter I'd be a little more confident that I had this correct enough.
The swr only would tell you how good or bad the antenna is on the frequency where you transmit. It does however not tell at what frequency the antenna is resonant and as such what to correct and how to get to the frequency you want. But still better than nothing. Unfortunately SWR meters at 5.8Ghz are hard to get / expensive. I bought myself a Rohde & Schwarz vector network analyzer cause I wanted to know what I was ending up with. It tells you everything you need to know momentarily and you can tweak the antenna up until it's ok or up until you realize that something must be wrong with the geometry or construction. It also tells you a lot about the overall quality (HF wise of course) of a given antenna. I.e. how wide or narrow band it is, how deeply resonant and so on. It was a major investment though but that's another story....

Markus
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Old Sep 13, 2011, 06:00 AM
Jets Suck (and blow)
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One more question if I may.

vRX antennas.

I read that getting the antenna up high on a pole is recommended, how is this best done? Do you mount the vRX and the antenna on the top of a pole, or can you simply run 4m of coax to the top of a pole to the antenna, with the vRX at the bottom?
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Old Sep 13, 2011, 06:19 AM
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NRW, Germany
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Originally Posted by Peril View Post
One more question if I may.

vRX antennas.

I read that getting the antenna up high on a pole is recommended, how is this best done? Do you mount the vRX and the antenna on the top of a pole, or can you simply run 4m of coax to the top of a pole to the antenna, with the vRX at the bottom?
Hi, i use a tripod (~1.87m high) with a piece of EPP on Top. I hooked the FPV Rx with velcro on the EPP and the LiPo for the Rx is mouted on one leg of the tripod. My Fatshark cable is 3m long, so i can still sit down and relax while flying.
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Old Sep 13, 2011, 06:26 AM
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Originally Posted by Peril View Post
One more question if I may.

vRX antennas.

I read that getting the antenna up high on a pole is recommended, how is this best done? Do you mount the vRX and the antenna on the top of a pole, or can you simply run 4m of coax to the top of a pole to the antenna, with the vRX at the bottom?
You definately mount the rx on top of your high pole with an antenna using a relatively short coax on it. I personally don't like the "blue beam" aproach with the lobes soldered onto the connector as with 5.8Ghz, this already interfres with the fresnel zone. My antennas all come with a ~6cm cable which then places the antenna above the RX.

While we are at it, and assuming you use an RC-305 rx, make sure to power it off a 2s lipo or use an external DC/DC converter to bring your (most likely) 3s power source down to about 7volts. Feed that into the RC-305. At the same time also make sure the RC-305 is covered with some cardboard or similar (still allowing air flow) to protect it from direct sun light. Unfortunately the RX-305 uses a linear voltage converter to power the internal HF-module which requires 5V. Linear regulators kind of have to convert the voltage difference into heat and if this rx heats up, there is a point where all of a sudden the picture turns black. You don't want this to happen during flight.

Markus
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Old Sep 13, 2011, 10:41 AM
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Extending Range for Lower Level Flight

I fly a quadcopter with the Foxtech 5.8 ghz 200mw transmitter/rx combo with SPW antenna on Rx and Cloverleaf on tx facing down under the quad between the legs. I have my rx SPW mounted at the very top of a 72 inch tripod cranked up as high as it can go. I have a solid crisp picture with little interference at <500 meters line of sight. Truth is I prefer to fly down low right on the deck, but find I can't get very far without getting video problems. I attached a photo with my antenna placement. So my question is...

Is this just what I have to live with with 5.8, that I have to stay higher when I am more than 300m away or can I add a second rx antenna like a biquad or helical along with an Eagle Eyes diversity unit and second rx that would give me better range in the general direction I am trying to fly low in? What if I moved up to 600mw on the tx?

Edit: As you can see, gear separation is a real challenge on a quad. That is a DragonLink rx up front. Just switched over to that last week from Spektrum gear.
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