ORIGINAL: rmh

HORIZON introduced the SPEKTRUM aircraft 2.4 systems in fall of 2006
First radio was DX6- which was NOT a DSM2 system
in 2007 -Spektrum inroduced the DX7 radio with DSM2 technology
Then in rapid order - they introduced other tx and many rx -all DSM2 technology
Also -they made adaptions for other brand radios (modules and rx ) which used DSM2 technology
Also they originated Bind N Fly -which uses DSM2
Other manufactures introduced their own versions of 2.4 spread spektrum radios NOT DSM2
Small wonder - with the huge lead and sales of the DSM2 technology- the Chinese - make no mistake here - simply made their own products which were to operate with DSM2 and sold them in complete disregard for existing patents and laws in the USA.
Tho some of these seem to work with the DSM2 radios - they are not licensed and not approved or supported by Horizon /SPEKTRUM. Use at your own discretion- The situation will only get worse as the toy guys continue to flood themarket with knock offs of DSM2 and likely other systems such as Futaba FAAST
These guys will knock off anything
I have a Chinese knock off of the ROLEX Submariner that fools some ROLEX owners- and it cost well under 100 bucks- appearance is VERY good -the ''ticking'' of the slug wind movement is a bit slower -which is the giveaway -if you know what the real ones sound like .
Caveat Emptor

ORIGINAL: BuschBarber

Initially, when 2.4 was introduced, there was not Third Party Rx's. Companies like Hitec, that had Rx's compatible with Futaba, JR, and Hitec, etc. did not or could not produce 2.4 compatible Rx's. I assumed that it was a patent thing. I do know that JR/Spektrum and Futaba use different implementations of Spread Spectrum technology.

Park Zone sutff uses Spektrum compatible Rx's. Anything that says Bind n Fly is usually Spektrum compatible. Plug n Play means you supply the Rx that is compatible with your Tx,

I have recently seen advertizements for Orange 2.4 Rx's, from China, that can be purchased and used with either Futaba or JR/Spektrum. They are only 4ch Park Flyer Rx's

Hitec, Airtronics, XPS, JR/Spektrum, Futaba, etc., all make 2.4 Tx's and Rx's, but none are compatible with each other.

If you have a 2.4 Rx from a manufacturer other than the one who makes your Tx, and it Binds with your Tx, then it was probably designed to be compatible and the manufacturer somehow got around the patents or licenses that prevents others from selling products with someone Else's technology.