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Old 06-30-2020, 08:52 AM   #10 (permalink)
Thomas.Heiss
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Join Date: Mar 2015
Location: Germany / Nuremberg
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Hello,

Quote:
Originally Posted by flightengr View Post
The radio signal radiates "sideways" from the length of the antenna. There's hardly any signal coming from the tip, so if you spend most of the time flying with the tip of the antenna pointed at your aircraft, the signal is not going to be very good for the receiver in the aircraft.
My DX8G1 and Devo10 let me move the antenna 90 degree sideways.

I don't hold the transmitter in front of me in any weird angle (with a neckstrap or pult) that I would clearly point the antenna tip to the ground....like it was suggested by users for the DX10T.

Instead the TX is pointing levelled "forward" (even on the strap) in a normal way in front of the stomache.


Quote:
Originally Posted by flightengr View Post
Fast forward to 2020 (this is a pretty old thread)

and now most of the newer Spektrum transmitters have antenna diversity, which means there's a second antenna in the handle of the transmitter that sends a signal in a direction that's perpendicular to the main antenna.
Yeah, most.
The Dx6e and DX8e do not have diversity.

https://www.spektrumrc.com/Content/M...Comparison.pdf

Looking back:
I did not really understand why HorizonHobby came up only with a fixed perpendicular antenna design on the black DX6G2 (Super V2) and DX7(G2).

That fixed design won't allow us pilots to move the antenna 90 degree sideways like we usually do on our transmitters which do not have 1-2 internal patch antennas.
But the benefit of this of course is that you do not damage the plastic antenna on the inside (articulated joint) that quickly; I broke 2+ antennas on the DX8G1.

Now both these "older" (well not really) Spektrum transmitters are discontinued and are replaced by the DX6G3 and DX8G2.....which both have diversity.

I had opened a thread -- in October 2014 -- about that fixed "new" antenna design about the "DX6 Super V2" (with missing diversity) in a German RC forum but nobody from HorizonHobby bothered to answer:

HF Abstrahlung bei nur einer fix montiert senkrechten Sendeantenne

Instead they responded with the new diversity successors in the lower/mid entry range
What a coincidence!

Not that I would really think that a US company bothers to read through threads in a German RC forum :-)

--------------------------------------------

I am still curious.

Q: Does anybody know for sure with a profound electrical engineering background how the HF exactly works with a "fixed antenna design" (Dx6G2/Super V2, Dx6e, black DX7, DX8e) -- without diversity -- when you do not point the transmitter with the tip to the ground (not only holding it in your hand with that angle but having a strap) but instead you follow the aircraft/heli?

I am happy for any interesting link.

Did the engineers change the HF module somehow? Is it using a different modulation? Adjusted firmware?

How can this be accomplished when there usually is no/not much radiation on the tip (apple principle)? What could be adjusted to make it work?

Best regards from Germany
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Last edited by Thomas.Heiss; 07-02-2020 at 09:02 PM..
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