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Old Feb 28, 2012, 12:11 PM
Always soldering
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Quote:
Originally Posted by costi_n View Post
:d :d :d
Hi costi-n did you have a close up picture of your PCB detector board please???

Nice job, you read the detector DCV on a DMM?

Cheers

Martin
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Old Feb 28, 2012, 12:18 PM
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Martinba I saw that you also made a swr meter for 5.8ghz...Would you make a buildlog? That original swr meter thread is not very newbie friendly, everyone is asking very technical questions...I would you need a list on what part I would have to buy and where...And how to put them together and use them ...In that thread there's a lot of discussion on theory..

Although I'm also talking only in theory since if I were to make a swr meter I would make it in about 1 year from now, since I'm just entering the fpv world slowly..
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Old Feb 28, 2012, 12:26 PM
Always soldering
Joined Dec 2011
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Hi msev is all posted here on the SWR IBcrazy diy meter thread on RCgroups and it is very newbie wellcome I would said. Dont be shy and post your comments too Im just a newbie on all this also but is a lot of helping people right there!

Martin
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Old Feb 29, 2012, 11:21 AM
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Germany
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You don't need to build it if you don't want to. And you can get it cheaper.

http://fpvlab.com/forums/showthread....-DIY-SWR-Meter

tune your own
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Old Feb 29, 2012, 06:52 PM
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I took delivery of the diodes today and awaiting the directional coupler so I can tune my antennas, with 5.8 being such a tight tolerance band to be on as far as antennas are concerned its not a bad idea to buy or make a swr meter
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Old Feb 29, 2012, 07:01 PM
NDw
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Ireland, Limerick, Kilmallock
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Quote:
Originally Posted by whakahere View Post
You don't need to build it if you don't want to. And you can get it cheaper.

http://fpvlab.com/forums/showthread....-DIY-SWR-Meter

tune your own

You have to be logged in to see that thread, and apparently registered for at least 30 days

I checked to see if Mictronics has a shop/buy it section on his website but he doesn't.

Edit: I see now why they did it, but imo mic should put a for sale thing on his website.
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Old Mar 01, 2012, 05:58 AM
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Originally Posted by RENATOA View Post
Your biggest issue is the receiver antenna. It is not omnidirectional at all !
I tested similar, if not identical antenna, and the beam was so narrow that was impossible to make anything than ground tests with permanent manual aiming. I am amazed you are able to fly using this antenna !
Try with the stock antenna, should be much better in 500m radius.
Try keep transmitter antenna vertical.

And prepare to next step... build yourself a pair of CP antennas.
I got mislead then, I have no idea why they sell these under "omni-directional" category. It looked suspitious to me, since it's flat, but I am no expert in antennas, so I thought they surely know better than me...

http://www.foxtechfpv.com/58g-11dbi-...nna-p-369.html


... and why they say 2 km range with stock antennas, when 500 m is probably max in this setup...
http://www.goodluckbuy.com/5-8g-vide...0km-range.html
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Old Mar 01, 2012, 06:35 AM
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Quote:
Originally Posted by alek3d View Post
... and why they say 2 km range with stock antennas, when 500 m is probably max in this setup...
http://www.goodluckbuy.com/5-8g-vide...0km-range.html
In fact here there might be some truth but only if you use it on something else than a moving RC plane , maybe on the roof of your house for example, not moving at all. And of course, after orienting very carefully both antennas. And after checking what those stock antennas have inside. One of mine was shorter with 3 mm
So if you ignore the antennas this marketing statement has a true part.
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Old Mar 01, 2012, 06:35 AM
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Because some did it, in favourable conditions.
I did 1.8km with stock antennas, ground test, receiver on a small hill (10m), no foliage around for many kilometers. I agree in a more normal environment could be less than 1km.
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Old Mar 01, 2012, 02:28 PM
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@futurebreeze : congrats for your record, well done!
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Old Mar 01, 2012, 04:40 PM
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Hi Martin, sorry for delay.
What you see in the picture is a logarithmic amplifier sensor.
A logarithmic amplifier is essentially a converter from an AC amplitude to a DC level. The very nice thing about them, is the fact that the DC voltage is proportional to the logarithm of the input level. In other words, the DC level is proportional to the input level measured in dB. For every dB the input amplitude raises, the DC output raises for some millivolts. Therefore we can measure over a very wide dynamic range (from very small input signals to rather big ones) without the need for a high amplification of the DC voltage. Even with amateur means we can measure over at lease 50-60dB dynamic range.
In this particular case the output of sensor offer 25mv/dB.

Quote:
Originally Posted by Martinba77 View Post
Hi costi-n did you have a close up picture of your PCB detector board please???

Nice job, you read the detector DCV on a DMM?

Cheers

Martin
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Old Mar 01, 2012, 05:04 PM
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Quote:
Originally Posted by costi_n View Post
What you see in the picture is a logarithmic amplifier sensor.
AD8318 ?

Nice job BTW.

Nigel.
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Old Mar 02, 2012, 12:50 AM
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Originally Posted by Devonboy View Post
AD8318 ?

Nice job BTW.

Nigel.
Yes. AD8318
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Old Mar 05, 2012, 01:39 AM
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Romania, Bucuresti, Bucharest
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5,8ghz 200mw 18km flight

Hi folks!

On Saturday morning our attempt to establish a new FPV 5.8 -200 mW distance record succeeded. Futurebreeze was the pilot, me...antenna tracker . But there was a price: we lost the plane. Our target was reaching 12km but eventually (unfortunately) there were over 18km.
Only yesterday we could see the video because after we lost video contact we rushed to our car to chase the signal from the plane and I just unplugged the power connector of the video recorder (thank you Renato for it) without stopping the recording. So our file wasn’t properly closed so we had to recover with some complicated procedures implying headers modifying etc.
Only now we can give an explanation of what caused my disorientation, because yes, at 12km I got disoriented. Why? Because the Remzibi’s OSD arrow got crazy at that time. Every turn I tried to take the god damn it arrow won’t show a trusty way to follow. One moment I tried to ignore the arrow and I was watching the distance but everything I did this was increasing. Underneath there was a river valley… I knew that if I had followed this I could reach home. Combining the landmarks, the sun’s position (or maybe what I thought it was the sun) and the distance showed by the OSD I tried desperately to return home. But unfortunately I failed. Maybe If I had taken the opposite directions following the river I would have reach home safely.
Anyway, the final explanation is simple: when we took off the wind had some direction…in the meantime he changed its direction in a very bad way for our initial flight path. So even if I kept in view some landmarks in fact I was circling around them and at the final point I got disoriented and the way back wasn’t just turning 180 degree. The wind was strong enough that even if I tried to head different ways the resulting movement of the plane was what the arrow was showing. Maybe a magnetic compass would have helped. On the next plane I’ll have a different approach.

5,8ghz 200mw 18km flight record.mp4 (9 min 28 sec)
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Old Mar 05, 2012, 01:43 AM
I can fly this plane
Kingdom of Sweden, Gävleborg County, Sandviken
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Sorry about your plane but at least you got the record ;-)
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