ImmersionRC VTX antenna posision

saidquad

Member
I use ImmersionRC 600mW 5.8 VTX with stock antenna for my fpv. I have placed the TX on top of the quad with antenna pointing 90 degrees upwards. The video is not clear and gray while flying. I guess it may be because CF plates under the VTX which block signal. Would it be better to place the VTX under the Quad and point the antenna 90 degree downwards? Does it work with downwards antenna?
 
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kloner

Aerial DP
leave it where you have it for the time being. Try changing the channel on your receiver. it sounds a channel off

it will work hanging up, down or to the side, the trick is making the receivers antenna the same plane so it the quads is up or down, put the rx ant up or down. if the quads is on the side, follow suit with the rx.
 

saidquad

Member
Thank you Kloner. Since my vrx is integrated to fatshark RCV22 AE I cannot point the rx antenna upside down, So it is not possible to hang the vtx antenna upside down either, Right? I tried different channels, no lock for better picture. I suspect the quad frame CF plates under the vtx are shading the signal. What do you think?
 

kloner

Aerial DP
that shouldn't be an issue like testing it on the bench. can you change the channel the vtx is on then change the receivers? it might just be something aorund you on the same channel screwing with you.....

what powers the vtx? can you power the vtx and cam without turning on your quad?
 

saidquad

Member
Hi Kloner. I played with channels and tested in flight. The best result I get now is 700 meters before the picture gets gray and distorted. I guess 700 m using stock coaxial antenna on both immersionRC 600mW 5.8 VTX and fatshark rx is in acceptable range. Should I expect more range out of this setup? I power the vyx using the same lipo which powers the Quad. I use no filters. I have heared that there is no need to use filter for immersionrc vtx.
 

kloner

Aerial DP
that sounds exceptional for rubber duck antennas and 5.8. the step up would be a directional antenna or a set of CP antennas with one being a high gain directional type.....

Were you pushing through alot of static to get that far or was it pretty clear up to a certain distance?
 

saidquad

Member
My poor English tells me you mean 700m range is very good by using the word “exceptional”. Also I don’t know what you mean by “pushing through a lot of static”. Anyways, as mentioned both tx and rx used stock rubber duck antenna and no custom hardware and software modifications were doneto tx or rx. But if this range is good the key for luck was the desert! No trees,no buildings and no electrical or telecommunication signals around. I’ll go for directional antenna when I get used to controlling the quad by FPV. I forgot to mention that the altitude was100m. Maybe if I fly higher the range would decrease.
 
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kloner

Aerial DP
sorry about that, yes rubber duck to rubber duck antennas on a 5.8 signal and quad is very very good.

pushing through static= was it static then clear, static then clear or just clear till all a sudden at 700m it goes to junk

Floy higher and the range should improve. Especially at distance,,,, you know how when you use a radio or anything with an antenna you extend it to get it up higher for a clearer signal, this does that with elevation

I'm unfamilliar with those goggles or how the antenna is... if the quads is down and the goggles is pointed up, thats perfect..... Were looking at the ground plane, it is either horizontal or vertical, as long as they share the same plane, your fine and doing all it can
 

saidquad

Member
Thank you Kloner. I am glad to hear that I get a good range and even better if I fly higher. I’ll test that. Until 700 m away the picture was colored and clear. From that point it started to get distorted and gray. I guess I could still fly 50m or so further until I totally lose the picture, but I did not risk it. I turned while the picture was clear. So it was clear from the take off until the turning point at 700m. Antennas of both tx and rx were pointing up.
 
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kloner

Aerial DP
that was why i asked,,,,,,, most likely it'll be screwed up and come back, but it is a weird feeling at first. it's usually something shaddowing so the leg theory could be or a tree, mountaint, tv antenna on some guys house, anything inthe way and dense is gonna make a shaddow..... try flying a different direction and see if it's the same. Careful with the 2.4 radio, it is possible your close to the edge of that signal. but it might not with as well as the video is working.....

show us a picture of your rig, we'll use it for an example of what is working
 

saidquad

Member
I’ll take a picture of my setup tomorrow. Since I am using WKM flight control, I am not very much worried about losing 2.4 radio signal. The bird will come back to take off point if the radio signal is lost. I have tested it and it works.
 

kloner

Aerial DP
just so i said it, that's not the best way to ensure she comes back


with that said, that's my backup plan, but i'm on lrs gear and even that gets them little shaddows from stuff between ya...

Good luck, i'll be looking forward to hearing and seeing some fun with it
 

saidquad

Member
Here are pictures of my rig.
Frame: X650 V
Motors: Tiger Motor MT3506 650 kv
ESCs: AKE 30 amp ESC
Props: 12x6 CF
Flight control: WKM
Battery: 4s 6500mah Maxamps

Fpv:
Camera: Exview HAD II CCD Camera 650 Line Sony Effio-E
vtx: ImmersionRC 600mW 5.8 rubber duck antenna pointing up
vrx: fatshark RCV22 AE rubber duck antenna pointing up
osd: EZOSD
fpv power: sharing with the quad


Total weight with fpv gear 2250g.
Flight time 13 minutes discharging to 3.7 per cell on load (3.8 per cell on rest) or the 80% on load. If I go down to 80% on rest I’ll probably get 15 minutes flight time.
Pretty much satisfied with this setup. Very stable on winds and motors and esc’s quite cool after flight.
I am replacing Sony camera with goprohd2 (including gimbal) now. I guess the total weight would be 2500g or more, hence less flight time but how much less I don’t know yet.

I am still a bit worried about if I fly very high (say 300 meters or higher) the CF plate bellow the VTX (as in the picture) would shade the signal. But I hope it won’t and as Kloner said the signal would be stronger doe to the height.

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saidquad

Member
Sony ccd is replaced by goprohd2 and the gimbal. The rest of rig is the same. Total weight is 2450g now (hoping it is not too heavy). I have removed the cf plate under the VTX and VTX is closer to the GPS and RC TX now. I hope they won’t interfere. Pictures and test results will be added later.
 

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