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Aug 25, 2012, 07:50 PM
Engineer for Christ
IBCrazy's Avatar
Quote:
Originally Posted by erkq View Post
The corners in that antenna aren't sharp. Does this matter? I'm thinking it does...
Not at all. Actually the only detriment is that the wire is flat and not rounded.

-Alex
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Aug 25, 2012, 08:11 PM
Registered User
snelan's Avatar
Quote:
Originally Posted by IBCrazy View Post
Not at all. Actually the only detriment is that the wire is flat and not rounded.

-Alex
Hmm, just out of curiosity, how would the signal and performance be affected if instead of two squares, you just used two loops of wire. I assume the polarization would be very erratic?
Aug 25, 2012, 08:40 PM
Registered User
Hi Alex,

I am using your SPW/CL for my 1.2 video link and they are just great. Now I would like get better on the RC link. I know most of you would say: go for UHF, but for the moment I only have 2.4 as an available solution (Spektrum DX8).

With that said I have rather no options on the RX side as it is fix part of my setup (I think it is just non-mod part of my system). However on the TX side the sky is the limit

I have already mod my TX in the way that I can plug in any antenna via SMA connector.

So, after reading many threads on different antennas I came to a conclusion that biquad is possibly my best option. Am I right? Most of you here are using it for video and on the RX. I will be using it on the RC and TX - will this work anyway?

The other concern is that I will have no diversity solution, so will not be able to put two of biquads in order to increase my coverage (horizontally). Is this something to be taken into consideration?
Aug 27, 2012, 09:27 AM
Registered User
Quote:
Originally Posted by julie32 View Post
Alex, I have been reading this thread lately,

https://www.rcgroups.com/forums/show....php?t=1702036

I am thinking I want to build my own biquad for my Frysky tx module. Does the reverse polarity change the construction at all? Do I still connect the coax to the reflector and the cntr conductor to the element?

Thanx in advance for your help.
Update; Tried my homemade biquad yesterday on my frsky module and I got 5381mtrs (3.3 mi) with no faisafes. Was really nice to fly as I didnt have to keep Tx pointed at plane. I turned around because I started losing video. Looks like I will be building a Biquad for that. (using Alex's homemade patch right now)
Aug 27, 2012, 02:22 PM
Happy Days
mudlark's Avatar
Quote:
Originally Posted by IBCrazy View Post
I actually have one of those. Not perfect, but certainly awesome. And for that price, it's a heck of a deal!

-Alex
thanks for the reply.
finally got round to building my own tonight for 1280

will be attempting a 5.8 one soon
Aug 30, 2012, 08:58 AM
Registered User
Can i use 2.4mm Copper Coated Steel wire (TIG welding feeder) for 1280mhz frequency?
Aug 30, 2012, 11:54 AM
Engineer for Christ
IBCrazy's Avatar
Absolutely!
Aug 31, 2012, 02:18 PM
Engineer for Christ
IBCrazy's Avatar
Quote:
Originally Posted by Jack2010 View Post
Hi Alex,

I am using your SPW/CL for my 1.2 video link and they are just great. Now I would like get better on the RC link. I know most of you would say: go for UHF, but for the moment I only have 2.4 as an available solution (Spektrum DX8).

With that said I have rather no options on the RX side as it is fix part of my setup (I think it is just non-mod part of my system). However on the TX side the sky is the limit

I have already mod my TX in the way that I can plug in any antenna via SMA connector.

So, after reading many threads on different antennas I came to a conclusion that biquad is possibly my best option. Am I right? Most of you here are using it for video and on the RX. I will be using it on the RC and TX - will this work anyway?

The other concern is that I will have no diversity solution, so will not be able to put two of biquads in order to increase my coverage (horizontally). Is this something to be taken into consideration?
A biquad would do well. Expect about 4X range or so if you are able to aim it properly.

-Alex
Sep 19, 2012, 06:15 PM
Tree Flyer
WTurbiasz's Avatar
Well its not perfect but it seems to work. I made it for 2.4Ghz and will try it out this coming weekend. For now I just hooked it up to my WIFI and saw networks that I have never seen before so Im thinking its doing a good job.

Tek
Sep 19, 2012, 06:20 PM
Engineer for Christ
IBCrazy's Avatar
^That's what I use my BiQuad for: WiFi sniffing

-Alex
Sep 19, 2012, 06:55 PM
Registered User
Just to make sure I understand this: you're using a FrSky module with a Bi-Quad antenna for RC control at over 5km? That sounds like a great solution, although you need to keep it pointed at the plane with a reasonable degree of accuracy.

So here's the next logical step for that setup....mount a suitable directional antenna for RC control beside your video Rx bi-quad/patch/helical on the same antenna tracker.

For many hobbyists, this could be a genuinely viable alternative to $300+ UHF systems to achieve moderate range.
Last edited by klaw81; Sep 19, 2012 at 07:06 PM.
Sep 20, 2012, 07:13 PM
Registered User
Quote:
Originally Posted by klaw81 View Post
Just to make sure I understand this: you're using a FrSky module with a Bi-Quad antenna for RC control at over 5km? That sounds like a great solution, although you need to keep it pointed at the plane with a reasonable degree of accuracy.

So here's the next logical step for that setup....mount a suitable directional antenna for RC control beside your video Rx bi-quad/patch/helical on the same antenna tracker.

For many hobbyists, this could be a genuinely viable alternative to $300+ UHF systems to achieve moderate range.
Yes that is what I use. I have now been to 5550 mtrs with this setup however I got a failsafe at that distance. I believe I was to low and under the antenna beam.
Next time I go I plan to use an angle finder to carefully set the ant angle. I use a magnetic compass to set my ant direction.
So far this has been a low cost,simple solution for med range flights.
Also check out this thread.

https://www.rcgroups.com/forums/show....php?t=1702036
Sep 25, 2012, 10:59 PM
400' ..... NOT
Martin Y's Avatar
Here are a couple I did. The 5.8 is not an easy one.
Last edited by Martin Y; May 04, 2013 at 11:10 PM.
Sep 27, 2012, 06:05 AM
throw new IOPilotException();
IceWind's Avatar
Would it be really bad to use a 200x300mm copper PCB to use with 910/980Mhz?
I couldn't find bigger PCB's that this and I know it's falling shorter than the expected size. (320x320mm)
Sep 27, 2012, 07:40 AM
400' ..... NOT
Martin Y's Avatar
I found that 1/8 wavelength minimum from the ends of the antenna element is good. So your 200 x 300 mm is spot on.


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