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Confirming the size for a 900mhz GP Patch Antenna


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Hi all, I am preparing to make my first GP Patch antenna and just wanted a little confirmation that I am doing things right. Since I am using the 900Mhz freq I have calculated that my scale=2.63 (2400/910). So the 7 inch scale on the example template must be 18.41 inches... this is quite large. Before I start cutting steel is this right?

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Well, my first snag is that my receiver is not the same style as the one in this plan. So the SMA PCB in this plan won't work for me... Mine has a coax type plug (like the type found on the back of TV's, I don't know my terms. Sorry).

So, it looks like IBCrazy's plan for this type of antenna uses that type of connector. So I will go with that, but using the cutout specs for the GP Patch.. since my understanding of the formulas and locations of the cable/connectors in these plans make me look like a pig staring at a wrist watch I was hoping someone could let me know if my plan should work. I'm going to try and locate a ham radio guru in my area to help review my finished antenna to see if it is working as designed.

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Thanks for all the assistance guys. Yes, I've doing as much reading and searching of forums for the answers and other ideas as I can. Like the ever present question of which frequency and power should I use question, this one too has many unknown variables that it boils down to build it or buy it and see if it works for you in your area. I appreciate the help though, I sure need it.

I've test the antenna against the stock (rubber duck?) antenna by riding my sons bike donw the street with the receiver recording the video on my computer (antenna outside). I get about 1.5 blocks before I turned around with the patch and it seemed to drop completely at that point. the rubber duck only gets 1 block. This is in a urban setting, not an open field where I'd be flying so my next test there I hope to get even better results.

I've also contacted a local ham operator who is willing to help test my antenna with his equipment.

I'll update as my test continues.

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