Turnstile UHF RX antenna tutorial

[PnoT]

The TLRS is the best out there. I would certainly benefit from using one turnstile and oune dipole (turstile flat, dipole vertical) and would give you a full 3 dimensional polarization pattern.

I chose a Dragonlink because I know the inventor and like his work. I have no idea how it performs compared to others but I'm certain even the worst LRS would be suitable for my purposes.

I will be doing an LRS shootout at the southeastern fly-in. We will soon know who has the best LRS. I will be putting these to the ultimate tests.

-Alex

Thanks for clearing that up for me and is it 2 late to add the turnstile to my order =P I'll also have to look into what type of connections thomas puts on the LR rXs.

[IBCrazy]

you would be right if all the enclosures were RF shielded. the DL gets incredible ranges with the dummy loads, which leads me to believe it's radiating not only though the SMA.

Hmm.... Perhaps someone will need to loan me a microwave oven for further testing.

[twinturbostang]

I am talking about the build and component quality only when referring to the TLRS. The EZ UHF would also benefit. The RX is the real kicker. I know the Dragonlink has a weak front end and thus noisy environments can affect them greatly. Thus my tests will be dry runs first, then a simulated long range flight where I will find the limits very quickly. Basically what I'm going to do is put a poorly tuned antenna on a 1.3 GHz VTX and place it right next to the UHF RX. The UHF RX antenna will be disconnected and there will be a 50 ohm dummy load on the transmitter. Ths should more or less knock out all variables except sensitivity and out of band rejection. I will then repeat the tests without the VTX.

These test of course assume that each LRS will be available for testing at the fly-in. I only have a DragonLink. The rest of the tests will be loaners.

-Alex

Cool. Thanks. Weak front end... Meaning it is not as good at removing out-of-band noise? What about in-band noise (like a GoPro or other noisy camera)? That seems to be a much more difficult problem to deal with.

[Coyote]

Brilliant build again Alex, im just wondering too, i have a Gopro on board my wing with UHF, im wondering with a better antenna on board does this then mean a higher potential problem from RF influence from the RF noisy Gopro in proximity ?

[IBCrazy]

Brilliant build again Alex, im just wondering too, i have a Gopro on board my wing with UHF, im wondering with a better antenna on board does this then mean a higher potential problem from RF influence from the RF noisy Gopro in proximity ?

I'm not sure. However I am certain that a poor antenna will have significantly worse performance just due to impedance mismatch, so it's better to use the proper antenna.

-Alex

[kev.au]

I made one for my trainer, such a bonus being able to mount this under the wing, awesome.




Thanks again for offering this antenna.


Cheers, Kev.

[Derek_S]

These test of course assume that each LRS will be available for testing at the fly-in. I only have a DragonLink. The rest of the tests will be loaners.

-Alex

I have tlrs pro that I will allow to be subjugated to your tests. I also have a LR and NR rx that can be used.

[Garbach]

This antenna was designed as a substiute for diversity. If you turn your TX antenna to the side rather than upright, this will match the polarization fairly well even when banking. Horizontal polarization of the TX antenna actuall gives longer transmission range. It's also nice to know you have no nulls to worry about either

-Alex

Is this true for the normal LRS dipoles as well? Can you mount those flat on your wing, put your Tx antenna horizontalle and this will give you better range?

And is there a big difference between mounting it on top or at the bottom of your wing (of a foamy)

Kind regards and thanks for the swift delivery of your fast patch kit. It's been put together and works so well I flew out of range of my R/C system...hence a LRS is on its way.. LOL

Maarten

[Mark Hitchman]

Is this true for the normal LRS dipoles as well? Can you mount those flat on your wing, put your Tx antenna horizontalle and this will give you better range?

And is there a big difference between mounting it on top or at the bottom of your wing (of a foamy)

Kind regards and thanks for the swift delivery of your fast patch kit. It's been put together and works so well I flew out of range of my R/C system...hence a LRS is on its way.. LOL

Maarten

Not a good idea to try this at home with a normal dipole on the flat, as you turn around the antenna on your wing will point towards the receiver and you will lose ~26db gain so you will lose control at any long distance. The turnstile so designed to not only have one end

Mark

[Garbach]

Ahhh... I get it....the Dipole has the deep nulls. Thanks for that Mark. Of to solder the turnstile it is then.