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GP patch questions

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I am sorry if these have already been asked / answered, I did quite a bit of searching / reading and could not find the answers.

In building the GP patch I used JB weld to join the galvanized plates to the hardwood separators. After only slight handling the glue joints broke. I then ground the surface of the galvanized and re-glued with the same results. I am thinking the separation distance is important and trying to think of a way to hold them together. One thought was drill both plates at the corners through the blocks with a.080 and use 2mm nylon screws through both plates. Does anyone see why this would be a problem?

I have been using the stock dipole antenna on my RX and am familiar with its range. I have made, but not tested a GP patch and have this question if anyone knows. What it the beam width of the GP patch, and what point beyond that beam width does it become equivalent to the stock dipole?

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That is odd, JB Weld should work. If your metal is thin and too flexy then maybe some contact cement would be better for you. Small diameter Nylon screws are ok, but Teflon is better. The -3dB beamwidth is about 85 degrees.

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Thank you for the quick response.

I built the antenna to your exact specs using the same material from the same source. I only have the nylon so I will try that.. I was more concerned with the holes I would need to drill in the metal causing a problem.

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ive bought a metal sheet...it is from material that doesnt rust(dunno the word)..like usual metal sheet material..not copper nor brass..

anyways it is 0.7mm thin...is that ok?

im also using F connectors cuz i have F connector on my reciver..

i will drill a hole in bigger metal plate and put thru coax then weld sourounding coax wire to bigger plate and mid wire to upper plate and glue some mechanical reinforcements

i guess ill use 10cm of coax

do u guys think that i could have some improvement comparing to standard rx antenna(ebay hongkong cheapo cam)

oh yeah i guess ill cut tx antenna to 65mm...

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so ive made my gp patch...used a sort of electric saw to cut metal plate..very unprecise method..not accurate..i have few milimeters mistakes in every dimension and edges are not straight+i acidently bend metal plate so i just make i flat again w my hands so thats not 100%flat

so when i made a pretty lousy cutting job and assumed that my frequency was 1.16Ghz(probably not) i then cut some depron to use it as spacers between two plates

i used about 1 meter of coax cuz my reciver has F connector...i just mounted another F connector on 1 side of cable(that goes to reciver)..like male F..

i drilled holes in plates...small one in smaller plate and big one is bigger plate

i welded coax(sourounding wires)to big plate and middle isolated wire to small plate using weak welding tool(sorry for my bad tech english)...50 watts..so i hardly managed to weld that coax to my gp patch..very crappy and bumpy welds...

today ive managed to test it..we were on airfield..it was almost 0 celzius and ive bring my pc there so i recorded my flight directly to pc...my 3200+ amd processor was very cool..hehe...

anyways my friend flew his plane w cam and i was recording it...

1st problem was that my 800mw ebay sh*t cam had black and white pic...i tuned it without antenna and then connected gp patch

so i flew like 10mins b&w and suddenly color apeared...my friend is using 3 lipo cells...2 much voltage...when voltage dropped to like 10v or so i got color..wahooo..

so we had a styro airplane about 1.2m span...we flew it as far as we could see it clear..we assume it was 400meters...

no dropouts,no interferance..nothing..all 100% perfect...beside maybe crud colors cuz it is a cmos cam and some small interferance that is always there..

so what im trying to say here is.."JUST MAKE THAT GP PATCH.."..it doesnt cost almost anything and it rulez

oh yeah i guess cams performance might be better in better weather conditions(maybe,not sure) cuz the temp was loowww...i almost froze..and wind was blowing+airplane speed=even lower sub0 temp..

i have some metal sheet left for 1 more gp patch...this time ill use freq counter and i will give my plate to a pro worker to cut it for me so its going to be 100%perfect dimensioned,100 flat...so we will is will it perform better and if so how much better..

i guess in a few weeks ill put it on my f3j sailplane(heinrich stork) and try to do 700 or 800m or even more using my monitor for flying..

thats all folks( for now)...

i hope this post will encourage few of u guys to make ur patches

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another sub zero temp flight made...

1st i want to apologize..it seems that i gave wrong info about voltage..

we were flying today on temps about 0 deg and i wasnt able to get color..again only black and white pic..no color .. even when voltage droped..

cam works perfectly on 12.5V(3 lipos) in my friends room(normal temp)...it seems that low temperature is affecting cams color but im not sure..if anyone has some knowledge about this temp stuff please write it down

as far as the range goes today we flew our styro 1.2m electric plane as far as we could see it and then much more using my pc monitor...

we assumed that it was at least 650 or 700meters...i guess we lost sight of plane on 400 or 500m and after that we flew using monitor...

on 700m there was aposolutley no dropouts...just slight imperfections w picture wich is always there..on 1 m 100meters or 500 meters...

too bad we had no color...

i think were done flying for at least 2 months..when temps get higher we will try again ..and well go even further..

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Hi Mr. Rc-Cam,

My printer did something goofy on the GP patch template

where the 7.00" horizontal is correct but the 9.00" vertical

is still a 1/32" weak.

So I was wondering if you could verify a couple of dimensions

for me? For the bottom plate I scaled that to be 4.24"x4.24"and

the top plate at 2.23" horizontal x 2.27" vertical.

Thanks for your help!


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Reflector is XY 4.20 x 4.20.

Driven element XY is 2.20 x 2.25.

Feedpoint XY is 1.100 x 0.750.

All in inches.

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