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KeithLuneau

Built my GPP, now a couple of questions...

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I built a GPP for a 1.2GHz receiver. I scaled the reflector and element to 200%, and the spacing between the two to 0.4". I have a couple of questions.

1. In the picture on the page about building the antenna, there is a black one. Is it painted? Can I paint mine without hurting it's performance? I'd like to paint it black to match the receiver.

2. My receiver has an F-connector. The only connector I had on hand was a standard connector that the cable screws onto, so I used that and made up a short (5-6 inch) coax cable to connect it up. I know it's not the preferred way to go, but will that short cable impact the antenna's perfomance significally?

I haven't got a chance to try it out yet, it was dark outside after I finished it today, so I'll have to wait until tomorrow afternoon if the weather permits a test flight.

Thanks in advance!

Keith

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1) The antennas shown on project page are unpainted. All are galvanized tin. But, you can paint yours with microwave safe paint. A very thin coat of Krylon enamel would be fine.

2) I'm not a fan of using coax. One of the reasons for the success of the GP Patch is that part of its design criteria is to not use it. In the FAQ section of the project there is a note to avoid it.

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OK, I see now, it just looked dark. I'll probably just leave it unpainted. If I don't get the results I'm looking for, I'll have to get a case mounted f-connector to put on the antenna.

I'll be sure to let you know how it works once I try it out.

Thanks again,

Keith

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Another question...

about how wide is the "beam" of the antenna? Is there a drawing or something that would give me an idea?

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Well, I got a flight in with the new GPP. I must say that I am VERY pleased with it. I just set it next to my runway looking up at about 45 degrees, and that seemed to be fine. I got a great signal throughout the entire flight, and flew pretty far away and high, just to see how far I could go. I was actually flying most of the flight watching the TV, and looked up a few times only to realize that I couldn't spot the plane in the air! I just circled around until I saw my house, and got an idea of where the plane was and found it int he sky, it was higher than I though, just a speck. I still had a perfect signal though. :) This was on a Slowstick. The only complaint I can come up with is that I forgot the hit record on teh VCR before taking off. Arggg! :lol: Oh well, I'll go fly again now, just to get a video.

Thomas, thanks so much for sharing the antennas design! I would definately recommend it to anyone and everyone trying out wireless video.

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I have velcro under my receiver and I can either mount it on top of a small motorcycle helmet or on a five foot tall pole with a swivel platform.

With the helmet mounted receiver I'm always assured that the antenna is facing the plane. It's rather odd looking but it works very well. This head ain't just a helmet rack, it's a tracking device.....

Mr RC CAM...when you refer to 80 degrees, does that mean 40 degrees each way from center or 80degrees on each side?

post-2-1098935643_thumb.jpg

Edited by randall1959

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does that mean 40 degrees each way from center or 80degrees on each side?

The -3dB point is approx 40 degrees from center.

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Hey keith, any chance you would build me a patch antenna for my 1.2 system? I'm going to use it on my GWS Slow Stick, but I want to use a patch antenna for the better range. My system is supposedly 400mw. I bought it from TinyWireless.com with a CCD camera. LMK what you think.

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