Espritmodel.com Telemetry Radio
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Old Aug 16, 2011, 10:13 PM
T#0
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Steamboat Springs, CO
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hmm what would happen if you put two stacked double quads together, one above the other making a stacked quad quad?

I just realized I know basically nothing about antennas work
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Old Aug 21, 2011, 09:08 PM
DragonLINK UHF only!!!!
Joined Feb 2011
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Hello BiQuad users....

I just put two BiQuads together,
my question is, as long as both BiQuads' are positioned horizontal, does
it matter which way is up or down concerning the copper wires?


If my both my antennas are postion in this position on my Diversity,
is there a "right side up" of the BiQuad? or it doesn't matter?

YOU Can see it on the 1st picture ....the wires coming of that silicon tube in the Center,
the Right Biquad its "up", and on the Left Biquad it its "down" position.

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Old Aug 22, 2011, 08:30 AM
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That construction looks very good The rounded corners are preferential to the sharp 90's. Good support with the wooden blocks too (the same way I support mine). Whether the antenna is upside down or not will not matter at all. So long as the polarization is correct, your antenna will perform very well.

-Alex
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Old Aug 23, 2011, 03:46 AM
Ikaruswannab
Joined Sep 2009
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Quote:
Originally Posted by IBCrazy View Post
How would you like to try a CP BiQuad? That might do even better. I can send you the details if you like

-Alex
I am trying to find a tutorial for a CP patch but with no lack.
I have already build a 2.4GHz CP 5T Helical with success but it is rather big to carry around.
Any help is welcome.
Teo
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Old Aug 23, 2011, 06:20 AM
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Designed as a collective effort betwenn Mictronics and myself: http://fpvlab.com/forums/showthread....P-patch-design

You should visit us over on FPVLAB. This is the kind of stuff you are missing.

-Alex
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Old Aug 23, 2011, 06:22 AM
Ikaruswannab
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On my way already Alex
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Old Sep 15, 2011, 08:17 PM
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United States, MN, Rochester
Joined Oct 2004
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Does not work

I think this antenna is anything but easy to build. Mine no worky. Very, very difficult to solder to a large piece of copper since it is a giant heat sink. Despite throwing 2 propane torches and a 45w iron at it, nothing would work. I took it to the local welder to do it for me for $10. Then, getting the biQuad element lined up also proved very, very difficult.

Anyway, any ideas why mine gets absolutely no reception? Rubber duck in the same room gets signal just fine.
In the pictures, you can see the co-ax shield hanging out. I tried to make it get an electrical connection with the copper tube it is coming out of. Not sure if it did.

The red piece of shrink tubing is there because I think the element is too close to the copper tube. I would think that would isolate them...

My copper tube is not quite on center. But, I have no idea how much tolerance there can be in the alignment.
I used 12AWG wire.

Anyway, an Idea I got from the welder was to split the copper tubing lengthwise and then bend the flanges to a 90 degree angle so that there would be a nice wide surface to weld the copper tube to the reflector. Then, after welding, measure the length and cut it.

Tx antenna is IBCrazy Vee
1280mhz setup
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Old Sep 15, 2011, 10:50 PM
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Can you post a close up showing the top of the center post?
Mike
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Old Sep 16, 2011, 06:57 AM
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Sandmaninator: It looks like the copper is oxidizing under the heat. You need a good flux to allow the solder to bond with that heat. It also could be that your coaxial cable shield is aulminum. I have seen a few Aluminum coxial cable shields that will not solder. Try a different cable and pre-tin the copper tube with solder before you bring the cable through.

-Alex
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Old Sep 17, 2011, 01:56 PM
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Originally Posted by IBCrazy View Post
Sandmaninator: It looks like the copper is oxidizing under the heat. You need a good flux to allow the solder to bond with that heat. It also could be that your coaxial cable shield is aulminum. I have seen a few Aluminum coxial cable shields that will not solder. Try a different cable and pre-tin the copper tube with solder before you bring the cable through.

-Alex
Thanks for the suggestions guys.
I'll take a top-down photo soon. I took my multimeter and measured resistance between the copper tube to the coax jacket where it attaches to the Rx. It measured .5, sometimes dipping down to .4.
When I touch the multimeter leads together, I get .3. This is with the meter set to 200 Ohms. Still think the co-ax jacket has a bad solder to the copper tube? (trying to save myself some work)
I really do not know much about using a multimeter so, I could have screwed something up.
All the other solder joints are strong - they do not come apart when I pull them. I used 60/40 rosin core solder.
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Old Sep 21, 2011, 05:36 PM
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Mongolia, Ulaanbaatar, Khan Uul
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Can someone please post a link to the build information for a double bi-quad?
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Old Sep 23, 2011, 10:53 PM
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Quote:
Originally Posted by IBCrazy View Post
Sandmaninator: It looks like the copper is oxidizing under the heat. You need a good flux to allow the solder to bond with that heat. It also could be that your coaxial cable shield is aulminum. I have seen a few Aluminum coxial cable shields that will not solder. Try a different cable and pre-tin the copper tube with solder before you bring the cable through.

-Alex
Alex, It was the Aluminum shielding! Both my first two cable candidates have alu jackets. I found one with copper and all is good now. Can't wait to test it out in the air! THANK you!
I have extra material... may need to build another...

I have a friend that has built your CP antennas for 5.8ghz. I will use those when I move to 5.8 for Helicopters
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Old Oct 16, 2011, 03:36 PM
SILURIA / UK
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I made up a biquad and it gives same, maybe even better performance than my 14db Lcom patch. Very pleased.

As it is so easy to make I am making a double biquad.

But I have a question.

Is a stacked double biquad viable?
Would both use the same dimensions, with 1/4 wave separation?

As I use a tracker, happy to have a narrow beam width..


http://postimage.org/image/170yz8qdg/
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Old Oct 17, 2011, 02:16 AM
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Hi

I have finished my skywalker with a auto return home module on board and test flight it successfully.

I have been using Cloverleaf and Skew Plana Wheel with go results in under 600M range. (probably could be longer range, but I opted not to challenge it without a return home module on board.

I will soon venture into more range and considering the Biquad.

I would like to check if a Cloverleaf in the VTx and Biquad in the VRx a good combo.

I when through the tread but it has not be stated clear what is the best combo.

Thanks for the answer in advance

Regards

Formosa
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Old Oct 17, 2011, 02:57 AM
SILURIA / UK
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The BiQuad here is for linear antennas - not the best match for your cloverleaf which is CP.


The BiQuad you want is here....
http://fpvlab.com/forums/showthread....e-Quad-antenna

It is directional though unlike the skew plana you have, so you will have to fly in the beam, manually aim or use a tracker

What is best depends upon what you want to do and style of flying !!
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