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Old Aug 23, 2011, 12:24 AM
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United States, CA, Elk Grove
Joined May 2010
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Quote:
Originally Posted by ScooterInVegas View Post
Take the filter out and check your range. 900mhz shouldn't need a filter. Which filter? Some of them are junk.
I got it from Range video. Please don't tell me it's junk, lol. I've read that the 900mhz system wreaks havoc on the harmonics of 2.4G signals, or is it the other way around.
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Old Aug 23, 2011, 12:25 AM
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United States, NV, Las Vegas
Joined Apr 2011
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Quote:
Originally Posted by gent96 View Post
maybe because of my 900mhz video TX? My RC receiver was inside the fuse while my Vid tx was on the flat portion of the Skywalker's tail. It's about 6-8 inches away from the RC Rx.
Try getting your vTx and Rx away from each other. More than 6-8". Try putting the vTx in the very back and move the Rx as far forward as possible.
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Old Aug 23, 2011, 12:28 AM
KJ6RCJ
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Quote:
Originally Posted by ScooterInVegas View Post
Try getting your vTx and Rx away from each other. More than 6-8". Try putting the vTx in the very back and move the Rx as far forward as possible.
I will try that. Or I will put the vTx and ant on the wing as what IBCrazy suggested.
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Old Aug 23, 2011, 12:29 AM
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Any ideas for my recent post?
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Old Aug 23, 2011, 12:29 AM
Village Idiot!
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United States, NV, Las Vegas
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Quote:
Originally Posted by gent96 View Post
I got it from Range video. Please don't tell me it's junk, lol. I've read that the 900mhz system wreaks havoc on the harmonics of 2.4G signals, or is it the other way around.
Haven't read anything bad about the RV filter.

900 bad on 2.4? Maybe Im wrong. 1/4 1/2 3/4 wave all miss 2.4Ghz, or at less I thought so...
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Old Aug 23, 2011, 12:35 AM
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Quote:
Originally Posted by ScooterInVegas View Post
Haven't read anything bad about the RV filter.

900 bad on 2.4? Maybe Im wrong. 1/4 1/2 3/4 wave all miss 2.4Ghz, or at less I thought so...
Now I'm confused too, lol. I'll try to work on your suggestions, Scoot. Thanks for helping noobs!

Good night everyone!

Gent
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Old Aug 23, 2011, 12:39 AM
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Originally Posted by gent96 View Post
Now I'm confused too, lol. I'll try to work on your suggestions, Scoot. Thanks for helping noobs!

Good night everyone!

Gent
I think the 900mhz might mess with some gps. Move the vTx to the back of the plane and range check on the ground.
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Old Aug 23, 2011, 01:21 AM
OSUFPV - KF7VFT
Corvallis, OR
Joined Apr 2010
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Quote:
Originally Posted by gent96 View Post
I got it from Range video. Please don't tell me it's junk, lol. I've read that the 900mhz system wreaks havoc on the harmonics of 2.4G signals, or is it the other way around.
Too much power next to any receiver can cause problems regardless of the
harmonics. Not to mention that spectrum is terrible for FPV. Their receivers and
transmission protocol are absolute garbage.
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Old Aug 23, 2011, 01:27 AM
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I think he is going with a DL.
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Old Aug 23, 2011, 06:12 AM
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Quote:
Originally Posted by ScooterInVegas View Post
Haven't read anything bad about the RV filter.

900 bad on 2.4? Maybe Im wrong. 1/4 1/2 3/4 wave all miss 2.4Ghz, or at less I thought so...
The RV filter is actually rated for 1550MHz as the determining band before cutoff. While this is a bit far away from 900MHz, the 2.4GHz cut band is something like -34 db or something. I doubt the problem is the filter. It could be the RX all together. Sometimes you just get a bad one.

-Alex
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Old Aug 23, 2011, 06:18 AM
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Originally Posted by electricflyman View Post
I have a quick question for y'all. Why is it that i recently purchased a 1.3ghz 300mw tx&rx combo and hooked it up and tested it in a field and at about 500 feet away i was getting static! Why is this happening. And i know that range only increases in the air but what i dopn't really understand is why would it bee so different if i still have line of site in a field? And what exactly is RF noise?
Thanks
Static is usually a result of weak signal. However, what most people call static is often multipathing as it can be hard to tell the difference. Look at the video below which shows what multipathing looks like. If your video looks like that, you need a directional antenna or circularly polarized system.

The other issue could be noise floor. This is a very misunderstood concept, but think of it as if someone is trying to talk to you. If you are in an open field, it would be much easier to hear them than if you were at a rock concert. That's noise floor in a nutshell.

IBCrazy's FPV "New system" - Cloverleaf demo (4 min 42 sec)


-Alex
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Old Aug 23, 2011, 09:33 AM
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United States, TX, College Station
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Quote:
Originally Posted by electricflyman View Post
I have a quick question for y'all. Why is it that i recently purchased a 1.3ghz 300mw tx&rx combo and hooked it up and tested it in a field and at about 500 feet away i was getting static! Why is this happening. And i know that range only increases in the air but what i dopn't really understand is why would it bee so different if i still have line of site in a field? And what exactly is RF noise?
Thanks
The exact same thing happened with my 1.3 ghz 400 mW, except I don't think I got 500 feet. We may just have to buy some new antennas and try again.
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Old Aug 23, 2011, 10:25 AM
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United States, AZ, Mesa
Joined Jul 2007
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Originally Posted by gent96 View Post
Strange really. I hope it's just a atmospheric glitch or something 'coz that is the only field (farm actually) where we fly unobstructed. And the local police don't bother us. Since it is a farm, walking out to the field to do range testing is out of the question, out of respect to the owners of the land who let us fly. Anyway, I'm going to try out to fly again minus the FPV system. I will just test the Spektrum signal on the field. BTW, did you ever recover the range after failing it during that fateful day at your club?
Yes I moved the receiver slightly - basically just rotated it 90 degrees, and I never went back to that place again. Didn't have any more problems with that plane until the motor quit after flying the crap out of it for 4 years.
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Old Aug 23, 2011, 12:29 PM
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United States, CT, Norwalk
Joined Jan 2009
102 Posts
Just as a quick question, what is the polarization of the inverted vee antenna? I read that it is both vertical and horizontal, is that true?

Also this antenna in the picture here, if the antenna is pointing up, then its vertically polarized?
http://www.readymaderc.com/store/bmz...ge.574x550.jpg
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Old Aug 23, 2011, 01:37 PM
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You need to watch the video on antenna polarization. Someone will have to post the link for me. The link is at home on my computer and I'm at work, on my iPhone, sitting on the toilet.

I wonder if I really needed to tell you all that I'm on my iPhone....
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