HobbyKing.com New Products Flash Sale
Reply
Thread Tools
This thread is privately moderated by IBCrazy, who may elect to delete unwanted replies.
Old Aug 19, 2011, 04:13 PM
Team Basement-RC
Tracks's Avatar
Canada, ON, Toronto
Joined Jan 2011
1,987 Posts
Some widescreen cameras will letterbox the image on a standard display, like the GoPro does. Unfortunately, the GoPro needs a LOT of light for FPV.
Tracks is offline Find More Posts by Tracks
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 19, 2011, 06:31 PM
OSUFPV - KF7VFT
Corvallis, OR
Joined Apr 2010
1,778 Posts
Quote:
Originally Posted by jasmine2501 View Post
But that is just the fact of 2.4GHz systems, having nothing to do with FPV really. And Spek isn't any worse off than anyone else. Some systems hop around, some systems spam the whole band, and some use wide-band channels. As long as your video system isn't on 2.4GHz, all of these methods should suffer equally in the presence of your video transmitter. IBCrazy just pointed out a few posts back that the harmonics DON'T interfere, and I'm not sure why people keep saying that.

There's a video on my channel which shows a Spek system competing with a "deliberate" wide-band jammer. What's interesting is this - with the jammer turned on, you can still see the Spek signal, but the Futaba signal fades into the background (it is equally jammed everywhere it tries to go). I've seen this on a spectrum analysis - so don't tell me Spek is worse in the presence of a jammer - it's not.
Yes, Spectrum DSM2 IS worse off than other systems that use FHSS or
other methods. I was just pointing out that DSM2 is of the worst frequency
hopping methods to use around FPV, and really any interference in general.
This is why, after long denying that DSM2 and their others sucks, Spectrum
decided to join the rest of the modern world with DSMX.

And, yes, all stock 2.4ghz pretty much do suffer equally in the presence of a
video transmitter. It doesn't matter what stock 2.4ghz you use there's just
too much power from our VTx's making a large noise floor next to 2.4ghz
receivers. This is why you can either switch to a different frequency (one
that is lower and with an efficient and robust frequency hopping system), or
you can ramp up the 2.4ghz signal to compete with the larger noise floor the
receivers are subject to (add a 1W-2W booster to your stock 2.4ghz
controller).

The problem with that test with the jammer which makes it very misleading is
that its not a problem of jamming but a problem of noise floor. These 2.4ghz
systems were never designed nor intended for the ranges we aspire to go
FPV.
Blueshy is offline Find More Posts by Blueshy
Reply With Quote
Old Aug 19, 2011, 06:36 PM
QiW
Registered User
south east asia
Joined Mar 2009
956 Posts
i am curious to see the post where IBCrazy says harmonics do not interefere
i have read time and time again .. 1.2vtx gives bad harmonics to 2.4rc (i am still flying 2.4 fasst to range of about 2km+) and i am trying to avoid that 1.2vtx but i may be adventurous this weekend and try it out .. LOL
QiW is offline Find More Posts by QiW
Reply With Quote
Old Aug 19, 2011, 09:02 PM
^(_MăĻēŜĐ_)^ ЯuĽe U
Greece, Attica, Elefsina
Joined Sep 2010
221 Posts
Quote:
Originally Posted by jasmine2501 View Post
if you hook up a widescreen camera to your normal screen goggles, it will simply squish the image horizontally - and while you are viewing a wider angle, it isn't physically any larger to your eyes - so you've stuffed more information into the same space, and that may not actually be better.

HeadPlay 800 x 600 FPV goggles
http://www.rangevideo.com/index.php?...roducts_id=218

Are these normal? Aren't better than the 640x480? I think these can take a better and wider camera!!!

# Native Resolution: 800 x 600 pixels
# Supports Resolution up to: 1280 x 720 HD
MoRaLeSD is offline Find More Posts by MoRaLeSD
Reply With Quote
Old Aug 19, 2011, 10:29 PM
Village Idiot!
ScooterInVegas's Avatar
United States, NV, Las Vegas
Joined Apr 2011
1,932 Posts
Quote:
Originally Posted by QiW View Post
i am curious to see the post where IBCrazy says harmonics do not interfere
......

Quote:
Originally Posted by IBCrazy View Post
A low pass filter removes the harmonics of a system. At 1.3GHz, the second order harmonic is 2560MHz, which is well outside the 2.4GHz band. Also, this harmonic is typically very small. The third order harmonic is the killer. Luckily, we have no control systems on that band. Now if you are flying 1200 or 1240 MHz, the filter will help you.

This also assumes that you use adequate separation. All the filtering in the world will not help you if you place your components right on top of each other.

-Alex
ScooterInVegas is offline Find More Posts by ScooterInVegas
Last edited by ScooterInVegas; Aug 20, 2011 at 02:38 AM.
Reply With Quote
Old Aug 20, 2011, 02:51 AM
QiW
Registered User
south east asia
Joined Mar 2009
956 Posts
aaaahhhh ... its outside the band that is used
i was thinking a general statement saying harmonics do not interfere .. LOL
QiW is offline Find More Posts by QiW
Reply With Quote
Old Aug 20, 2011, 12:01 PM
Rocket Programmer
jasmine2501's Avatar
United States, AZ, Mesa
Joined Jul 2007
25,460 Posts
Quote:
Originally Posted by QiW View Post
aaaahhhh ... its outside the band that is used
i was thinking a general statement saying harmonics do not interfere .. LOL
Yeah I was just meaning the 1280MHz vs 2.4GHz setup - which is what I use. The video transmitter I used reduced the range with the AR6100 receiver, but I don't see any difference with the R921. So, it is doing something to it, but it's not the harmonic interference, it's more likely just plain old swamping because the higher quality receiver eliminated the problem.
jasmine2501 is offline Find More Posts by jasmine2501
Reply With Quote
Old Aug 21, 2011, 03:59 AM
Registered User
QIK_RX's Avatar
Australia, QLD, Raceview
Joined Jan 2011
140 Posts
Could some please give me some sort of advise towards mounting my tx antenna on my plane.
Is it better to have it say pointing upwards or pointing towards the ground?

I have clover leaf antenna. I was thinking of mounting the video tx to the side of my plane (multiplex funcub) and have the antenna just pointing downwards.

Or should I mount the tx ontop of the wing and point it skywards.

All i use atm is my AIO goggles without a patch antenna, just the goggles fitted with a skew-planar antenna.

I am yet to fly the plane with the antennas as my micro tx died and I am waiting for the new one on the mail.

Cheers,

Rob.
QIK_RX is offline Find More Posts by QIK_RX
Reply With Quote
Old Aug 21, 2011, 09:20 PM
Registered User
Australia, SA, Adelaide
Joined May 2011
95 Posts
AIO system

Quote:
Originally Posted by QIK_RX View Post
All i use atm is my AIO goggles without a patch antenna, just the goggles fitted with a skew-planar antenna.
Just out of curiosity how would you rate your All In One system? I am looking to get into FPV shortly and am muddling my head round what gear to get.

Thanks.
S.Bartfast is offline Find More Posts by S.Bartfast
Reply With Quote
Old Aug 22, 2011, 12:57 AM
Village Idiot!
ScooterInVegas's Avatar
United States, NV, Las Vegas
Joined Apr 2011
1,932 Posts
Here is a good "starter" kit for $289. Just add a inverted V for the vTx and tune the patch when you get it.

http://www.readymaderc.com/store/ind...roducts_id=279

If you have a 1000w generator, just use a 19"-25" LCD with some shade and you good to go. I bought goggles first, now I use a 23" TV. I like it better, MUCH clearer picture. Oh, the camera that comes in that "starter" kit is really good. You can put it right behind the prop and not even (barely) see it when your flying.
ScooterInVegas is offline Find More Posts by ScooterInVegas
Reply With Quote
Old Aug 22, 2011, 04:17 AM
QiW
Registered User
south east asia
Joined Mar 2009
956 Posts
Quote:
Originally Posted by S.Bartfast View Post
Just out of curiosity how would you rate your All In One system? I am looking to get into FPV shortly and am muddling my head round what gear to get.

Thanks.
here is a thread on the AIOs .. http://www.rcgroups.com/forums/showthread.php?t=1343478

i have not used fatsharks before so i dunno how they compare but if u read that thread there are others who have fatsharks and others for comparison

i have tried a 200mW 5.8 vtx (cloverleaf) transmitting directly to the AIOs (SPW) but i lost video at around 700m (the AIO vrx quality/capability may or may not be the same as the other tested RC305 models that claims 5-6km on a 200mW 5.8) .. i posted pics but it looks like my self made antennas may not be up to specs so i remade new ones but have not gotten around to testing then yet
i now use a 10mW 5.8 vtx to relay video from my main 1.2 video system to my goggles .. i am almost cable-less (just the cable from AIO to my radio and nothing else) and free to wander around .. headtracking on the AIO is spot on for me.

my take on the AIO .. this is good enough for me and has everything i will need in the foreseeable near future unless technology and price wars take 10 steps forward .. LOL
QiW is offline Find More Posts by QiW
Reply With Quote
Old Aug 22, 2011, 07:57 AM
Nakelp
nakelp86's Avatar
United States, NJ, Union
Joined Sep 2004
6,794 Posts
Someone mentioned tuning the patch antenna.
How do you tune the antenna without million $$ equipment ??
nakelp86 is offline Find More Posts by nakelp86
Reply With Quote
Old Aug 22, 2011, 09:12 AM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,567 Posts
Quote:
Originally Posted by nakelp86 View Post
Someone mentioned tuning the patch antenna.
How do you tune the antenna without million $$ equipment ??
Like this: http://fpvlab.com/forums/showthread....ght=tune+patch
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote
Old Aug 22, 2011, 09:14 AM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,567 Posts
Quote:
Originally Posted by S.Bartfast View Post
Just out of curiosity how would you rate your All In One system? I am looking to get into FPV shortly and am muddling my head round what gear to get.

Thanks.
All in one is the way to go IMHO. This coming from the guy who has just about every RX, antenna, and diversity scheme in his toolbox. I find my favorite set up is my head mounted station. Grab and go. That's all there is to it. Definitely the most fun.

-Alex
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote
Old Aug 22, 2011, 09:16 AM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,567 Posts
Quote:
Originally Posted by QIK_RX View Post
Could some please give me some sort of advise towards mounting my tx antenna on my plane.
Is it better to have it say pointing upwards or pointing towards the ground?

I have clover leaf antenna. I was thinking of mounting the video tx to the side of my plane (multiplex funcub) and have the antenna just pointing downwards.

Or should I mount the tx ontop of the wing and point it skywards.

All i use atm is my AIO goggles without a patch antenna, just the goggles fitted with a skew-planar antenna.

I am yet to fly the plane with the antennas as my micro tx died and I am waiting for the new one on the mail.

Cheers,

Rob.
Up or down does not matter. Place the antenna as far away from the electronics as you can. if you can mount it under the wing without risk of damage, then that would be best. That is how I mount mine usually.

-Alex
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion How to calculate flight time - guide ikorman Multirotor Talk 11 Dec 30, 2011 08:22 PM
Discussion How many FPV pilots in the world? rbmaze FPV Talk 10 Aug 03, 2011 07:16 AM
Poll Would you be interested in buying Ready to Fly FPV airplanes from a new FPV store? FPVNOW FPV Aircraft 36 Oct 06, 2010 09:56 PM
Discussion Can this cam be used for FPV ? SpookiePower FPV Talk 8 Sep 12, 2010 08:12 AM
Cool How cool would this be for FPV Kai_Shiden FPV Talk 2 May 11, 2009 08:41 PM