Smart-Fly (Quest Engineering) Support Forum Support forum for all Smart-Fly products. Equalizers, Batshare, Ignition Cutoff, Regulators.

Dual 2.4 Ghz Futaba Receivers

Reply
Old 03-08-2008, 08:37 PM
  #1
Capt Midnight
Thread Starter
 
Capt Midnight's Avatar
 
Join Date: Jun 2006
Location: Oak Brook, IL
Posts: 78
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Dual 2.4 Ghz Futaba Receivers

Hi Bob,

Sometime this summer, I plan to start construction of a 30% something-or-other aircraft (probably a W/H 540TV2 Edge) in which I plan to use dual 2.4 Ghz Futaba receivers (probably the 8 channel R-608FS units which consume about 7.4 Ma to 8.0 Ma @ 4.8V). Futaba's website states that 2 (or more) receivers may be used with their FASST system simply by binding the new receiver to the transmitter, to get into using a dual receiver setup. It is left to the consumer to decide whether to run the receivers concurrently (with each receiver controlling the same set of servo channels), or in series with each receiver controlling 1/2 of the available servo channels.

Futaba's methodology of frequency hopping and their "Look\Ahead" channel selection technology evidently will permit this type of setup and operation without operational conflicts between the receivers, whereas Spektrum's / Jr's will not. The Power Box Royal has a dual receiver (RRS) function which selects the receiver with the best signal, and uses that receiver for operation as it appears to be designed and optimize for 72 MHz eguipment.

Do you have any thoughts or recommendations on this approach and / or how to set it up?

I was thinking initially of using the 8 channel Power Expander Sport with one of the R-608FS's mounted directly on it amidships. The 2nd R-608FS would be mounted 6" to 12" aft of the Power Expander (with the antennas 90 degrees to the 1st receiver), and the two receivers linked to the input leads of the Power Expander by way of custom Y-cables.

Questions:

1. Will the internal regulated power bus support 2 receivers?

2. Would you suggest the use of RF filters (Toroid Coils) on the long leads from the 2nd receiver in order to reduce any possible RF input noise?

3. Would it be possible to offer the Power Expanders with an option for dual input leads "built-in" so that the Y adapters can be eliminated?

I would appreciate your comments or suggestions.

Thanks

Bob


Capt Midnight is offline  
Reply With Quote
Old 03-09-2008, 01:01 PM
  #2
rrritchey
 
Join Date: Sep 2004
Location: Tempe, AZ
Posts: 949
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Dual 2.4 Ghz Futaba Receivers

Hi Bob,
You could run two receivers off one PowerExpander, I have seen it done but we do not encourage it. The reason is this, the two receivers get electrically connected through the power and ground wires. If one recevier were to have problems that caused noise to go out the power or ground wires it would go directly into the other receiver, possible causing it to have problems. Now, the issue of "Y" leads. Are you saying you want to connect channel 1 to both receivers? This is a really bad idea. If one receiver were to fail its output on the channel may be the last position seen. The other receiver, it good, would try to put the right position on the output. Electrically connecting these together would cause the servo to go nuts. I really, really hope this is not what you are proposing. If it is, I highly recommend you abandon this approach.

1) The power for the receiver can support 1 amp, this should be plenty for 2 receivers.
2) I would not worry about Toroids on the long leads to the second receiver. I would worry about the power leads.
3) Absolutely not, see above.
rrritchey is offline  
Reply With Quote
Old 03-09-2008, 08:18 PM
  #3
Capt Midnight
Thread Starter
 
Capt Midnight's Avatar
 
Join Date: Jun 2006
Location: Oak Brook, IL
Posts: 78
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Dual 2.4 Ghz Futaba Receivers

Hmmmmmm...

Back to the drawing board then Bob. I'll have to query Futaba on how they propose a dual receiver setup with their system, and will let you know.

Thanks,

Bob
Capt Midnight is offline  
Reply With Quote
Old 03-10-2008, 09:15 AM
  #4
rrritchey
 
Join Date: Sep 2004
Location: Tempe, AZ
Posts: 949
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Dual 2.4 Ghz Futaba Receivers

Hi Bob,
I bet they will tell you they recommend splitting the plane down the middle, one receiver for each side. This is the way its always been done. For maximum redundancy you want to keep the halves completely separate, no electrical interaction between them.
rrritchey is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 08:58 AM.