RC Model Reviews

Hello Bruce,

I hope weather clears up over there for you so we can see the results of the 9X V2 in action. I am waiting patiently for this. I'm assuming other people are as well.

Come on down and move to sunny california...

I might just buy this radio system and go with your route of switching the module with Frsky. How much are Frsky module and receivers?

I, as well, am waiting to see the results of flight/range testing as I already have this unit but it's not installed in anything, yet...

Sidewinder wrote:I, as well, am waiting to see the results of flight/range testing as I already have this unit but it's not installed in anything, yet...

hey Sidewinder, how is the transmiter and reciever working out? I mean did you atleast plug in the servos and test it ? Are they jerky or anything and are you getting full movements on the servos when you move the sticks?

Hi Bruce,

FHSS is not always superior to DSSS.
http://www.rcgroups.com/forums/showpost ... ostcount=6

What is your opinion to this comment?

John

johnkim100530 wrote:Hi Bruce,

FHSS is not always superior to DSSS.
http://www.rcgroups.com/forums/showpost ... ostcount=6

What is your opinion to this comment?

John

True FHSS isn't -- but our RC systems (despite the claims) aren't "true" FHSS.

With a true FHSS system, the signal is transmitted on a very narrow frequency that is constantly changing (hopping). This means that any individual frequency is as easily blocked as our old 72MHz gear used to be.

DSSS systems work by combining the data with what's called a "spreading code" which means that instead of taking up just a very narrow space (like our old 72MHz systems), it is spread across a wider range of frequencies. It is therefore harder for interference to knock out a DSSS signal because much of the "good" signal will lay outside the area of interference.

Now, what we've done with our "FHSS" RC systems is combine DSSS and FHSS to get a hybrid that should really be called "constantly agile DSSS".

These RC systems use a spreading code to "spread" the signal so wide (usually 1-5MHz) that it becomes very resistant to interference. Then, to increase the interference resistance even more, the DSSS signal is constantly moved up and down the band (by hopping).

So, while a "true" FHSS system may in some cases be worse than DSSS at handling interference, our hybrid systems represent the best of both worlds.

The original poster clearly didn't understand exactly how our so-called FHSS RC systems actually work.

RCModelReviews wrote:

johnkim100530 wrote:Hi Bruce,

FHSS is not always superior to DSSS.
http://www.rcgroups.com/forums/showpost ... ostcount=6

What is your opinion to this comment?

John

True FHSS isn't -- but our RC systems (despite the claims) aren't "true" FHSS.

With a true FHSS system, the signal is transmitted on a very narrow frequency that is constantly changing (hopping). This means that any individual frequency is as easily blocked as our old 72MHz gear used to be.

DSSS systems work by combining the data with what's called a "spreading code" which means that instead of taking up just a very narrow space (like our old 72MHz systems), it is spread across a wider range of frequencies. It is therefore harder for interference to knock out a DSSS signal because much of the "good" signal will lay outside the area of interference.

Now, what we've done with our "FHSS" RC systems is combine DSSS and FHSS to get a hybrid that should really be called "constantly agile DSSS".

These RC systems use a spreading code to "spread" the signal so wide (usually 1-5MHz) that it becomes very resistant to interference. Then, to increase the interference resistance even more, the DSSS signal is constantly moved up and down the band (by hopping).

So, while a "true" FHSS system may in some cases be worse than DSSS at handling interference, our hybrid systems represent the best of both worlds.

The original poster clearly didn't understand exactly how our so-called FHSS RC systems actually work.

A good eye opener. Good lecture. Thanks.

One question. What is the criteria to determine which brand is better than the other? by the number of frequencies it hops?

Thank you Bruce for a very good review
this is my first digital RC controller and have found it very good
one thing i found was when i was Binding my second Receiver i had to put the bind-plug into the BAT slot for it to bind

have found the range so far with my park flier do be quiet good and survived 3 crashes still working ok. so far

only thing i have found is that my dads Topfire 6 Channel 2.4GHz is locked out when i have my Trunigy 9X on

link to Topfire http://www.trademe.co.nz/Toys-models/Ra ... 341055.htm
is there any way to have them both working ?

kind regards
Andrew

Butterfly program

Factory programmed Butterfly was not working. So, I am using programmable mixer as follows.

Mixer 1 Throttle to flap
Mixer 2 Throttle to aileron left
Mixer 3 Throttle to aileron right
Mixer 4 Throttle to elevator

wavejet wrote:
only thing i have found is that my dads Topfire 6 Channel 2.4GHz is locked out when i have my Trunigy 9X on

link to Topfire http://www.trademe.co.nz/Toys-models/Ra ... 341055.htm
is there any way to have them both working ?

kind regards
Andrew

Topfire 2.4 is probably flawed. Auction it off and buy Turnigy 9X.

The TopFire is probably a "parkflier" radio and as such it will have much less tolerance for co-existing with other "Full-range" radios.

However, this is the first time I've heard of any interference between 2.4GHz radios to this extent.

As an interesting aside -- I did notice that the FlySKy V2 FHSS system does produce a certain amount of noise in my lapel-microphone when I'm making videos and the transmitter is nearby. None of the other 2.4GHz systems I've tested do this.