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Old Aug 06, 2011, 03:08 PM
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Quote:
Originally Posted by JLC_BOULOT View Post
....Man who works in the only electronic shop I go, is not able to recognize antenna connector... and I'm starting to not believe at all in his radio skill ...
If this guy did not recognize an F connnector, I think he probably has very little "radio skill"

OMM
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Old Aug 07, 2011, 05:14 AM
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Thank you for your replies,
I think have enough informations to order all I need to make a real antenna.

JL
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Old Aug 07, 2011, 03:43 PM
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Sorry I still have a problem : I don't undersand about antenna and plug impedances.
BIQuad antenna is 50 ohms.
F connector are 75 ohms.
Is there a special connector (50 ohms) or is it ok (I would be surprised...) ?

Thanks
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Old Aug 08, 2011, 07:06 AM
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SMA and N connectors are 50 ohms and are fairly common. In FPV we almost universally use SMA. N connectors are used very often for HAM radio. I would suggest getting an F male to SMA female adapter and using prefabricated cable with an SMA end on it to build your antenna.

-Alex
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Old Aug 08, 2011, 10:35 AM
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Thank you Alex,

I'm going to proceed as you've told me.
Searching for F connectors was starting to be a bit difficult (Till today all persons I asked for knew only F connectors for TV - ie 75ohms).

JL
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Old Aug 08, 2011, 10:31 PM
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Quote:
Originally Posted by JLC_BOULOT View Post
Thank you Alex,

I'm going to proceed as you've told me.
Searching for F connectors was starting to be a bit difficult (Till today all persons I asked for knew only F connectors for TV - ie 75ohms).

JL
This is one of the biggest problems in this hobby: There are many people who think they know what they're doing/talking about that really have no clue. That other BiQuad tutorial you read is someone's poor interpretation of a BiQuad antenna. Looking at it, It looks like they combined mine with MartyBug's website without understanding how the antenna worked.

-Alex
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Old Aug 09, 2011, 08:14 PM
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Hello Alex, sorry if this has been asked before, i just got .035" mig wire to do a CL and SPW, can i use this wire to build this BiQuad or it is too thin ?

Also, what would be the performance of this patch with a CL on the VTX ?

Thanks Alex for your great work !!
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Old Aug 10, 2011, 09:46 PM
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Newbie question

Hey all, can anyone out there tell me(dont laugh too hard) If I can use different Vtxs with one set of Vrxs as long as they are the same ghz? I have a hobywireless 2.4ghz system with 2 Vrxs and a 1000mw Vtx. The 1000mw Vtx works great on my camera plane but I am getting into A.P. with a gaui 330xs and I have been told that the 1000mw Vtx will "swamp" all the other electronics. I need to know if I can use a 10mw or 100 mw Vtx with the Vrxs that I have. I have a few successful fpv flights but it is a little on the heavy side.

My setup:

Stock Gaui 330xs
Batteries 2200mah 3s lipo
800mah 3s lipo for Vtx
1000mw Vtx
Gopro helmet hero
1 futaba servo for camera tilt
Futaba t9cap super w/ stock 72mhz rx
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Old Aug 11, 2011, 03:07 AM
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Quote:
Originally Posted by isaacintheclouds View Post
Hey all, can anyone out there tell me(dont laugh too hard) If I can use different Vtxs with one set of Vrxs as long as they are the same ghz?
Yes, you can, if they are using the same frequencies - check it before buy and find corresponding channels.
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Old Aug 11, 2011, 07:17 AM
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Quote:
Originally Posted by bakchos View Post
Hello Alex, sorry if this has been asked before, i just got .035" mig wire to do a CL and SPW, can i use this wire to build this BiQuad or it is too thin ?

Also, what would be the performance of this patch with a CL on the VTX ?

Thanks Alex for your great work !!
You could, but I'd use 12 or 14 AWG copper wire simply for ease of assembly. The wire thickness matters very little in the BiQuad design, which is very different from almost any other antenna.

-Alex
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Old Aug 11, 2011, 07:38 AM
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Good reference for connector types

Reference for connectors; should be a sticky.
http://usacoax.com/coax-connector-pi...es_photographs
Cadzilla <easily confused>


Quote:
Originally Posted by JLC_BOULOT View Post
Thanks for your answers.

I saw IBC antenna a few months ago, and when I had time to make one, I used first link I found... but was not IBC !!! But antenna looked like his...

here the link, it is said it works perfectly :
http://www.modelisme.com/forum/aero-...ion-video.html

Man who works in the only electronic shop I go, is not able to recognize antenna connector... and I'm starting to not believe at all in his radio skill !

I looked on internet, and found so many different SMA plugs...

I'm going to order radio components (plugs and cable RG58U), so could you please tell me where I can get information to know exactly what is this SMA plug ?
I'd like to get connector to solder antenna wire as you guessed.
I suppose radio impedance is 50ohms, I couldnt get this data on my receiver datsheet.

Thank you for your help.
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Old Aug 14, 2011, 03:05 PM
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Can two (or even four) BiQuad antennas share the same reflector when using multiple receivers? I would expect the reflector to be twice (or four) times the size. But be a single sheet of metal instead of two antenna mounted side by side.

Could you put two 1.3 ghz and two 900 mhz ByQuad antenna's in a quad formation on a single reflector?
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Old Aug 15, 2011, 07:00 AM
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Quote:
Originally Posted by chuck99z28 View Post
Can two (or even four) BiQuad antennas share the same reflector when using multiple receivers? I would expect the reflector to be twice (or four) times the size. But be a single sheet of metal instead of two antenna mounted side by side.

Could you put two 1.3 ghz and two 900 mhz ByQuad antenna's in a quad formation on a single reflector?
Yes you can. If you can keep the centers 1/2 wavelength apart, they should not interfere with eachother. For non active antennas (ie 1.3 GHz while flying 900MHz) the spacing is irrelevant.

-Alex
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Old Aug 16, 2011, 03:53 AM
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Thanks Alex,

What about with 1.3 GHZ antenna receiving video downlink and the 900 mhz transceivers receiving and transmitting MAVLINK using XBee RF Modems?

Will they interfere? Should I use some sort of band pass filter on the 1.3 ghz feed?

Maybe put a perpendicular ground plane to separate the 900 and 1.3 antennas?
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Old Aug 16, 2011, 12:35 PM
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So long as you separate the elements you should be fine. The only issue you would have is if you wanted to transmit on one and receive on the other. If you are using the array to transmit, it will make it difficult to receive on another band.

-Alex
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