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Attention: RC-CAM.com will be closing down August 2021.

The RC-Cam.com forum was the very first online community dedicated to the advancement of wireless video cameras on radio controlled (R/C) models. This is now called "FPV" (First Person View). We are proud of the contributions that our members have made to the FPV hobby.

We've seen significant changes over the last twenty years. Initially there were a lot of eager R/C hobbyist that built their own video systems. Allowing these creative individuals to share their work was the purpose of this site. Now the FPV market is flooded with low cost systems; Sadly DiY FPV video projects are now rarely discussed.

RC-CAM.com (main site and forum) will be closing down August 2021. This is being announced now (March 2021) so that everyone has time to download any information that is important to them. After the site is shutdown the information will no longer be available here.

We appreciate every member's involvement with advancing the FPV hobby. It is indeed sad to say goodbye to all our online friends. Be safe and stay healthy.

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Hello everybody from a new member

I am about to start the building of the GP patch but many measurements are given in US system and though it's probably not so important, what is the thickness in mm of the metal from which I'll cut out the radiator and reflector? (24to 30 gauge sheet)? What is the diameter of the added short piece soldered to the centre post(24-26 AWG)?

Before soldering this extra bit to the small metal plate would it be possible to maintain it with a short piece of shrinkable tube which will stay there of course?

If I have understood properly the wooden spacers should be 0.20*0.20*0.25 in mm 5*5*6 . It does make a slight difference.

To finish with my questions should the patch stay naked or is it possible to wrap it in Oracover or paint it? Does it change anything in its performance if the patch touches the box where the receiver is, which might be a metal box? Thankings to any one who will take the trouble of answering my questions and good flights to all. Gemobis1

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Hello Mr RC-CAM Thank you for answering my post. Looking through the 3 pages about the GP Patch I found a few answers to my questions, particularly the wrapping with Oracover or similar, although I can't see why wrapping the outside without changing anything between the two plates should affect the signal. I 'll abstain from holding the piece of wire to the the centre pin of the SMA plug with a piece of heatshrink while soldering, I'll hold it with something I can remove afterwards. I've had to order this SMA Plug to Conrad in Germany, the male inverted type for PCB is not to be found round Toulouse where I live. My only problem is that their data mention an impedance of 80 ohms instead of 50, which I find hard to believe. The plates could be from 0.4 to O.7 mm thick, the small holes 1.5 mm and the big ones 2.5mm and for the soldered centre bit 0.4 to 0.5 mm should be suitable. Thank you for your work, I'won't forget to report about the results obtained with my antenna.

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I can't see why wrapping the outside without changing anything between the two plates should affect the signal.

The signal travels over the surface of the whole aerial and the effect of covering any of it can not be forseen.

My only problem is that their data mention an impedance of 80 ohms instead of 50, which I find hard to believe

80 ohms is close enough to make no noticable difference.

The exact thickness dose not matter so much, the design seems to work well even when built with different thickness plates or connectors but the closer to the design the better.

If you stick to the exact design the performance is know but if you change things it will still work but the performance will not be known.


Edited by Terry
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