PRODUCT CHANGE NOTICE: HELIAXIAL12 & HELIAXIAL24

[sircana]

I hear you will be becomming a birdman soon Sicana

LOL ;-)

I hope you will get rid of your stripes...

[Roel-CP]

I made a setup at home on my big LCD TV
The plane was upstairs cooled by a fan.

Then i tweaked my groundstation.
On the Big TV screen you can see all the stripes very well.

When i turned up my UHF power i got more worse.
Then i removed the UHF lowpass filter the stripes where almost gone on high power (2W).
Then i diconnected the UHF booster and offcouse the stripes are gone with 600mW.

Ok
Now i relayed the video cable directly from the RX to the TV
Nothing happend it was the same as trough the oracle diversity.
Then i turned the helical a little and the image got better.
Also i added my 12dbi yagi antenna (build by Bluefalcon) on the tracker.

On the plane i used the dipole
Then i did a servo test on the tracker and watched the screen.
The antenna's switched very nice on the oracle but the image was a little snowy and the 12dbi yagi was leading.
There was no image loss.

Then i put the CW-SPW on the plane.
Also i did a servo test on the tracker and watched the screen again.
The helical was leading now.
The image was not snowy at all on the helical only on the yagi.
But there where more video drop-outs (not extreme) with the SPW.

Conclusion
Circulair give a better image but has to be aimed very straight to the plane with an antenna tracker.

Also i made a Badge for Roberto he deserves it.
http://static.rcgroups.net/forums/at...57-montiel.jpg

[sircana]

Interesting stuff...

What do you mean by video dropouts? When did they happenned? When moving the helical?

[Roel-CP]

You know when you do a servo test with the EZ antenna tracker its moving all arround and up and down.
Most of the time its on the back side of the antenna.
Don't worrie its not much.
Maybe you can do the test yourself when you have time.


View this video on YouTube

This is the old setup
Now i have the video yagi and the helical next to eachother.
And the UHF yagi on the other side.
Wait ill make a picture

[sircana]

OK, it makes sense. Thank you!

As you are using two antennas of similar gain (12dB) it is logical than depending on the VTx antenna (Linear or Circular) you benefit the helical or the yagi, as one of the two get a 3dB penalty from changing from circular to lineal.

The video dropouts when moving the helical are quite difficult to evaluate indoors and through walls, but most users agree that the helical is less directive than expected. The helical has almost only a single main lobe, while the yagi has multiple side lobes. This makes that for the same gain, the main lobe is wider in the helical.

[Roel-CP]

When i used the dipole on the plane (indoors) both RX antenna,s preformed normal
When i used the SPW (indoors) it changed with a better image on the (TV) but when turning the tracker i had some noise.
Indoors testing is not the best way but i hope the stripes will be gone for now.
Just some funny testing when im bored @ home
I cant wait for my next test flight.

[Roel-CP]

Last weekend i made a flight with the lasdown
The image was much better now because i removed the UHF lowpass filter.
Only nearby i see some fade UHF interference