rfk1381

My Feedback: (7)

I mount my R617 7-channel receivers like this. I glue a small block of shock absorbing foam to the inside fuselage, 1/4 inch thick and the size of the receiver. I glue or screw two strips of Velcro on either side next to the foam pad, and use the strips to hold the receiver to the foam block. For the antennas, I use small diameter clear plastic tubing taped or glued in place to securely hold and route the dual antennas. Each antenna is inserted into its plastic tube. Using the plastic tubes to route and hold the antennas makes it easy to remove and replace the receiver since the antennas will slip out and into the tubes but when the receiver is removed and remounted for maintenance.

Cougar-RCU

My Feedback: (2)

That doesn't sound to hard to do thanks. now how are your duel antenna's running? one straight and one at 90 Deg?
could I use fuel line for the tubes maybe?

rfk1381

My Feedback: (7)

The antennas need to be oriented someway so that they are 90 degrees offset in orientation that is convenient within the fuselage. The antennas are the last 1/2 inch or so - the bare wires. The rest of the antenna about 4 inches is just a coaxial cable. You can bend and route them whatever makes sense for your particular installation. The two important items are 1) make sure there are no sharp bends or kinks in the coax/ antenna, and 2) make sure the antennas are secure and not flopping around. Oh yes, and that the two antennas, the last half inch of the actual antenna wires, are oriented 90 degrees (or so) from each other however you mounted them. The orientation directions are not critical, just make sure they are at about right angles to each other.

Cougar-RCU

My Feedback: (2)

So like this then... thanks so much for all your help today Sir.

and I could just put all this at the bottom of my fuselage body then this way?
nothing has to hang out of the body correct?

THANKS !

Cougar-RCU

My Feedback: (2)

I guess more like this with no SHARP bend sorry

BuschBarber

My Feedback: (2)

It should be more like a Y, where no part of one antenna is parallel to the other antenna.

rfk1381

My Feedback: (7)

Yes more like the second drawing, but also the wires could be spread out in a "Y" like the heli folks do. Actually it does not matter if the coaxial (insulated) part of the antennas are installed parallel to each other, because the active reception of the signal happens only with the exposed wire portion of each antenna. Included some pics of how I mounted the R617 and its two antenna in several aircraft.

ALSO, DO NOT MOUNT THE ANTENNA ENDS INSIDE CARBON FIBER OR METAL FUSELAGE OR COVER OVER THE ANTENNA ENDS WITH METAL FOIL OR CARBON FIBER! Carbon fiber shields/absorbs the radio signal, resulting in NO SIGNAL RECEPTION!

Cougar-RCU

My Feedback: (2)

Great pics there ,, thanks much... However I do have on plane the GeeBee that
I changed over to Carbon Fiber push rods.. Will this be a problem? Love the photos THANKS!

rfk1381

My Feedback: (7)

Yes, you could use fuel tubing instead of plastic, but I wouldn't recommend it. I found that the rubbery coaxial insulation on the antenna wire snags onto the silicone fuel line, making insertion difficult, and the silicone tubing inside diameter can allow the antenna wire to move inside the tubing. Plastic tubes are rigid and keep the antenna wires stable and not vibrating. I also push a sliver of balsa scrap into the entry of the tube to gently secure the coaxial insulated wire in the tube.

I used scrap pieces of flexible push-rods left over from various projects. There isn't any electrical requirement for the plastic tubing to be clear, I prefer to see inside to ensure the antenna wire isn't being jammed into a chunk of junk or dirt when inserting the wire - don't want kinks. You could use some kinds of tubular coffee stir sticks, small diameter paper or plastic drinking straws, etc.

rfk1381

My Feedback: (7)

Keep the active part of the antenna wires - the bare/uninsulated wire portions - away from metal or carbon fiber push rods or right against a battery. I like at least a couple inches distance (at least one inch) between the metal/carbon fiber and the end of the antenna. The idea is while the aircraft is in flight, we don't want the metal/carbon fiber BETWEEN the transmitter antenna and the receiver antenna, shielding the signal. That's why there are two antennas mounted 90 degrees apart because the receiver will pick the antenna with stronger signal. Of course there will be times when the engine is between one of the antenna ends and the transmitter, and again, mounting the antenna with some distance between them, and 90 degrees offset in orientation, will allow the receiver to pick the best signal.

I have been flying RC since 1967, and I have to say, this FASST is a great system for stability and reliability of reception. Futaba mainline of business are industrial controls and displays, so they sell this spread-spectrum radio stuff for their industrial line of factory controllers - now a large industrial factory is about as noisy electrically as you can find anywhere, and boo-boos in dropping radio linkage can cause havoc or death. They understand bullet-proof radio links. It's about as bullet proof a linkage as it can be and yet still be affordable to the average RC hobbyist. (...just my opinion as an old electrical engineer)

Cougar-RCU

My Feedback: (2)

Thanks very much for all your help today This sure is fun getting all these planes
down off there hangers and putting the new stuff into them once again. Batts, Rec. extra.
Been way to long. ready to go again one day.. hoping I can be able to fly a few days in
this Iowa Winter once it comes. I miss Ca. for this reason as I could fly almost everyday
there.

Now to figure out what I will be doing with my awesome 9C as well over the next couple months
so many modules and rec for that too.

Jeff

rmh

It really doesn't matter which 2.4 radio is used - the rules for antenna are same for all-

Carbon fiber with antenna taped against outside is a no no -and tho having the whiskers sticking out away from the carbon fiber may not look kool - it is the only workable setup

Cougar-RCU

My Feedback: (2)

RMH I am not sure I understand what your saying , taped against the outside of what?
And should I remove my Carbon Fiber Rods?
Thanks,
Jeff

rfk1381

My Feedback: (7)

You can keep your carbon fiber push rods. No biggie. I beleive our friend means "antenna" when he says "whiskers".

Cougar-RCU

My Feedback: (2)

AND (( antenna taped against outside is a no no )) means?

sorry about all these qustions but trying to learn 2.4 Fasst after
about 35 years of 72 Mhz

Silent-AV8R

It means if you have an airplane with a fuselage made entirely (or mostly) of carbon fiber it is better to have the antennas away from the side of the fuse. Having said that, I have the antennas on my Futaba R6008HS RC taped to the outside of my all carbon and kevlar electric glider. It is 3.2 meters in span and I can fly it as far away as I can see it.

On my planes I run the antennas inside a small pice of plastic tubing to protect the fragile ends. Just do not use a carbon fiber tuber. CF pushrods are not an issue as long as the antenna is not rubbing them etc. The FASST receivers are not terribly picky about how they are installed. At least that has been my experience in everything from several high end competition gliders, IMAC planes, pattern planes and helicopters. I just get the two as close to 90 degrees from each other and away from wires and CF as best I can and go fly.

rfk1381

My Feedback: (7)

I believe I know what RMH means by not taping the antenna to outside of carbon fiber... if the fuselage is made of carbon fiber, like many high performance gliders, the ends of the antennas - the bare wire portion - "the whiskers" - must extend OUTSIDE the carbon fiber fuselage structure. They need actually to "extend" outside and away from the fuselage surface to be able to receive the transmitter's signal. The antenna ends must not be taped down flat against the outside body of the carbon fiber fuselage - they need to stick out in the wind, so to speak.

The Futaba Radio manufacturer direct support forum is a great place to ask specifics about installations within a carbon fiber fuselage.

For example, here is one of many threads the Futaba team answered about installing a Futaba FASST receiver's antennas in a fuselage made of carbon fiber...

http://www.rcuniverse.com/forum/m_81...tm.htm#8130681

Now you go have fun with your new system!

Cougar-RCU

My Feedback: (2)

Gattcha..... I understand now

OK one last Question If I may... how is this 2.4 around power lines. not that I fly around them all the time
or anything. but I have a few that are behind me from time to time. is there any problems with 2.4 for that condition?

Found my Velcro and still trying to figure out what I will use for tubes tp attach , thinking the yellow casing of
my smaller left over flex push rods maybe.

Jeff

rfk1381

My Feedback: (7)

Well, personally I prefer not to fly near power lines, and doing so probably could be a safety issue, but there is no interference - unless you smack into the line. [X(]

Yellow is a lovely color...

rmh

Yes - the antenna is NOT the coax it'sself -the antenna is the small length of wire at the end of the coax
No brand 2.4 is immune from lousy antenna setups
Having supplied plastic tubes to help fix problem setups -I am getting pretty familiar with what is really a good setup and what is not.

rfk1381

My Feedback: (7)

RMH,

Amen about lousy antenna setups - plus cheap switches, cheap cables/connectors and weak batteries... [:@]

Today's class of 2.4 radios are incomparably better and a bargain far beyond anything we used to have for RC!

pkoury

My Feedback: (7)

Did not see the show but why do you say there was no way they could have an external antenna? The short antenna that comes with the receivers is easy to change to a longer one.

OliverJacob

My Feedback: (12)

The FASST system is supposedly the safer one. You can google it, or look on Futaba's website, how the frequency hopping works on each one. The range should be the same for both.
In real life, you probably never see any difference between FASST and FHSS.
The FASST system seems to be more popular, I have a 8FG and a 7C as a backup and they are both great radios.
The 8FG can be programmed very fast, once you figure out how the menus work, the 7C is not as user friendly, the small display does not contain as much information as the 8FG does.

Also the 8FG used a SD card, it will hold hundreds of models while radios in the lower price range mostly have limited memories.

I fly planes and helicopters, this radio is perfect for both and I'd buy it again

Silent-AV8R

I do not recall ever seeing or hearing that. I know that Futaba does not feel that way.


I put a S-FHSS RX in one of my high end gliders and flew it like normal Did not notice any difference in performance. So go figure. I could still fly it until it was a dot in the sky.


BTW, here is wht Futaba says about FHSS:

OliverJacob

My Feedback: (12)

Read and understand the whole post and you will get the idea. The FASSTsystem is superior to FHSS and like I stated - you will probably not find a difference in the range.
Just on a very busy 2.4 Ghz band FASST will have a safer link between rx and tx while the FHSS system could cut out. But practically, it's unlikely ever a problem.


fyi - ALL 2.4 Ghz systems are changing their frequency (hopping or whatever the different manufacturers call it). What you quote here is written by the marketing department, nothing "FUTABAfeels'.
Get a more technical information and see what the difference is.

You can google it or go to the Futaba forum and get educated. I won't do it for you.