Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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Its actually at a nice angle, you shouldnt ever point a rubber ducky at the object as you will hit a dead spot, 90/45 degrees is perfect, although i can angle it to whatever really as its adjustable
[Edited on 29-03-2013 by Steve]
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DaveyLC
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Registered: 8th Oct 08
Location: Berkshire
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Its a linear antenna Steve, it should be polarized the same as the main RX on the copter.. The loses are PHENOMINAL for being out of phase.
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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Its an omni directional antenna
watch this vid, its quite informative
http://vimeo.com/8826952
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DaveyLC
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Registered: 8th Oct 08
Location: Berkshire
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Its a linear antenna.. The fact it has no reflector and is Omni has NOTHING to do with it..
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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watch the vid dude, an omni directional pattern has everything to do with it
[Edited on 29-03-2013 by Steve]
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DaveyLC
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Registered: 8th Oct 08
Location: Berkshire
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..Don't mix up Omni-direction and circular-polarization they are two VERY different things.
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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http://en.wikipedia.org/wiki/Omnidirectional_antenna
quote: In radio communication, an omnidirectional antenna is an antenna which radiates radio wave power uniformly in all directions in one plane, with the radiated power decreasing with elevation angle above or below the plane, dropping to zero on the antenna's axis.
[Edited on 29-03-2013 by Steve]
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Ian
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Registered: 28th Aug 99
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The pattern is very all the way around it. Sound.
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DaveyLC
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Registered: 8th Oct 08
Location: Berkshire
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The waves are polarized though so the rx antenna needs to be of the same polarization.. Yes the waves being emitted have a generally equal gain around the centre of the antenna (with dead spots top and bottom) how ever the antenna IS NOT circular polarized.
Clover leaf, skew-planar and time-phased bi-quad groups / patch groups are circular polarized.
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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I know what daveys saying, and is right to that degree.
Im going to play around with it like it is, i only really need to worry if it drops out before my FPV does, if it does I can simply relocate the antenna to the stock location on the radio
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DaveyLC
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Location: Berkshire
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quote: Originally posted by Steve
I know what daveys saying, and is right to that degree.
Im going to play around with it like it is, i only really need to worry if it drops out before my FPV does, if it does I can simply relocate the antenna to the stock location on the radio
I'm 100% right..
General rule of thumb being out of polarization by 90 degrees gives you 1/10th of the power at the RX end. The efficiency goes right up the shitter.
So your super-doper Chinese wifi-booster which is probably massively over quoted on power (the Chinese always lie to sell stuff) is completely pointless because your antenna is so poorly positioned and polarized you might as well have not bothered.
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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Dont worry I know not to expect massive quality from the asians
Its already matched the stock setup in terms of range at 1.2kms so its not made anything worse
I think il take a drive with the drone and leave the tx at home switched on
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DaveyLC
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Registered: 8th Oct 08
Location: Berkshire
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Pointless range testing on the flat, you'll get no where.
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DaveyLC
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Location: Berkshire
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This s what you want, nice circular polarized waves
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DaveyLC
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If I've learned anything from this hobby steve, it is to listen to the people who have been there, tried it, done it and picked up the piece of smashed plane/heli
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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where can i pick up a 2.4ghz circular polarised antenna? cant find any of ebay, I could bung my spironet one on but thats 5.8 wouldnt work right?
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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what about these cunts?
http://www.ebay.co.uk/itm/FPV-5-8-2-4Ghz-1-3-RP-SMA-Antenna-Kit-Skew-Planar-Cloverleaf-mad-mushroom-/140943053988?pt=UK_ToysGames_RadioControlled_JN&hash=item20d0dc54a4
[Edited on 29-03-2013 by Steve]
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DaveyLC
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Location: Berkshire
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Theres a SHIT HOT bloke on RGGroups called markus123456 who owns a network anaylzer.. He can make you a matched pair of 2.4ghz C/P antennas (1x C/L, 1x SPW).. I paid 50 odd quid for a matched pair and they were spectacular.
You will need
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DaveyLC
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Registered: 8th Oct 08
Location: Berkshire
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quote: Originally posted by Steve
what about these cunts?
http://www.ebay.co.uk/itm/FPV-5-8-2-4Ghz-1-3-RP-SMA-Antenna-Kit-Skew-Planar-Cloverleaf-mad-mushroom-/140943053988?pt=UK_ToysGames_RadioControlled_JN&hash=item20d0dc54a4
[Edited on 29-03-2013 by Steve]
They look like home made shit.
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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interesting, do you think he could do a set for the 5.8 fpv stuff?
also if i stuck a 2.4ghz skew planar on the radio, would that help even though the spektrum RX on the drone wouldnt be using a skew planar? just the boggo antenna wires
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DaveyLC
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Registered: 8th Oct 08
Location: Berkshire
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His 5.8 stuff will be marginally better than the fatshark stuff.. They do actually test stuff on a network analyser but markus is SUPER ANAL so his will be a touch better.
When it comes to microwave frequencies its a dark art building good antennas.
You need a C/P both ends.. So either make sure your TX is vertically polarized and one of your antennas on the quad is also vertical and you'll be fine having both of them in just any old position will equal shit results.
[Edited on 29-03-2013 by DaveyLC]
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John
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Registered: 30th Jun 03
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I don't know anything about drones but I do know that although there is a lot of maths behind designing perfect antenna (antennas antennae?), a lot can also be done with bending bits of wire, doesn't need lots of money and equipment to make it perform well.
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DaveyLC
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Location: Berkshire
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Steve I make sure my spectrum stuff is V and H polarized and I always have the antenna vertical on the TX.
quote: Originally posted by John
I don't know anything about drones but I do know that although there is a lot of maths behind designing perfect antenna (antennas antennae?), a lot can also be done with bending bits of wire, doesn't need lots of money and equipment to make it perform well.
A microwave network analyser costs TENS of thousands.. Down in HF/VHF/UHF above is true but when you're up in the GHZ ranges you can't get it exact with a pair of cutters because even a fraction of solder can fuck it all up.
[Edited on 29-03-2013 by DaveyLC]
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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Driving me mad trying to find anywhere that sells a u.fl to male sma cable
this is the sma end i need
and ufl the other, can only get them from usa or china sellers, driving me mad
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neoquip
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Registered: 12th Aug 02
Location: Nottm
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if you can get them off Ebay.. buy it.
maplin's don't do them then or RS components
http://uk.rs-online.com/web/?cm_mmc=UK-PPC-0212-_-00_Brand-_-RS_Brand_Exact-_-rs_components&gclid=CKvt6s3lpLYCFUbKtAodd1UAcg
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