range of futaba or spektrum 2.4ghz radios

[jimbo24]

Sorry if this is a redundant post, but i've searched all the threads and all the "range" issues seem to address only the video transmission.

How do i ensure that my radio range is ok? what kind of antennae, booster do i need if any. Looking to go no more than 1 mile or so with a trex 450 or 500.

thanks.

[JimLerch]

I've been out to a half mile now with my plank and the 900mhz video link.

On the list of things to get is one of the recent OSD GPS display units. Some of these now have "Oh Shit" auto-pilots built in. When the receiver looses signal from the transmitter, it will auto pilot the bird and point it back at home.

So far this only works on fixed wing airframes, but I'm guessing with a little finessse it could be made to work with rotory wing as well.

[srhammett]

Jim's point about OSD is important. The IMU technology on the horizon (pun intended ) seems poised to revolutionize - and bring about a merger of - hobby-priced navigation, OSD and flight stabilization product lines. It looks to me as if, in another year or less, FPV and solo AP with helis will be much safer and more practical propositions than they are now.

However, I'd also like to see some input on Jimbo's original question. There's all kinds of technology out there for boosting video downlinks - if you need another mile or two of range, you just need to open your wallet. There are powerful tx's, better antennas (along with servo-powered tripod gimbals to keep directional antennas aimed at the aircraft), diversity boxes and more rx's to plug into them, etc etc. But you don't see much discussion as to the range limitations of the good old rc uplink, and how to boost it, and I'm not sure why. The few threads I've seen on the subject over in the rcgroups forum tend to be of the more abstruse diy variety.

Of course we do have some options to up the capabilities of on-board rx's (old club field pro to nooby: "You should up your gain." Nooby: "Up yours!" ). These include diversity as well - the higher-end rx's give you the option of stringing satellite min-rx's all over your ship. But there's nothing I'm aware of - off-the-shelf, anyway - to boost transmitter signals.

So, while we're busy squinting at the video feed we're pulling in through a ground station that looks like a SETI research facility, how far out can we expect a heli to continue responding to our thumbs? And what can be done - by clueless liberal arts majors like myself - to improve things?

Stu

[jrlederer]

wow, that's quite a response post! Very thought-provoking. i am looking forward to see how this thread progresses.

thanks,

jonathan

[JimLerch]

I'm just throwing this out there. My best guess now is the end of the rope is about 0.8 miles on my AR7100R with a single satellite ant all stuffed inside the plank with little to no regard for "doing it right"......

My guess on 0.8 miles being the end of the rope happens in this video at the 3:40 second mark....

FPV out past the end of the "Rope" (6 min 32 sec)

[jimbo24]

equivalent range if you're out by yourself and interference from other fliers is not an issue?

[JimLerch]

I was out by my self with most likely no other interference. I'll need to re-test at another field to see if I get similar results. (After getting a proper GPS autopilot installed to nav the bird back when the link fails! )

[Gary Evans]

I am using a DX7/AR7000 and the range is just under 1 mile. If you fly near the max range without a back up you will sooner or later lose your ship. I used to fly with the antenna pointed sideways and if communications were lost I would raise the antenna vertically. This worked a couple times but not the third. On the third i was able to save the plane only by holding the Tx over my head to re-establish communications. I now use a parabolic reflector that can be rotated behind or below the antenna. It is pointed down until commincations are lost and then rotated behind the antenna. On the ground it increased range about 25%. If you try this satisfy yourself on the range check with your equipment don't just assume it will work. The parabolic can increase the signal directly in front but obviously will result in less signal to the sides and behind so it is only useful when pointed directly at the ship.

[jimbo24]

nice tip. thanks.

I assume that for the most part, futaba vs spektrum vs JR 2.4ghz all have similar radio mW and range.

am I wrong? I currently use a Futaba 6EX faast.

[R-4-L]

to reply on the original post, I'm using 2.4ghz FASST futaba module on a Futaba 12Z radio, with 14ch 2.4ghz Rx.. I remember flying an MJ2 with MarkIV retrated mount, The heli was BIG , I fly up high , infact so high i almost lost sight of the heli, as far as radio, I had total control, with a 900mhz downlink , and 3800mah duralite Rx batt for the radio and servos.etc

to me that was the ultimate test of range. though almost pissed my self trying to figure out the orientation of the heli to safely land it

This was the flight:

Q8HeliCam Take One (1 min 11 sec)

mind the quality, it was my very first with certainly wrong choice of mount for the airframe

[Mr Boombastic]

Sorry but I can't help with the initial question but this might get you where you want to be.

Check this product catalogue linked below, specifically page 11. It has a booster that may be of help. It works on TX and RX.

(2 Meg Download) http://rfi.com.au/downloads/wireless...-catalogue.pdf

This company does top quality products to the level of custom work by request. They design & manufacture. All specs are realistic minimum ratings.

Also check http://www.immersionrc.com/products.htm for an Antenna Tracker that can be used with Zlog. This combined with an RFI Antenna or other should give the range you need on any frequencies with R/C TX or Video. Advertised release date is soon.

[jacky65]

Hi,
Below a lockout I had with my DX7 / AR7000.
Now I have a Futaba 7C 2.4GHz and never had any lockout @ 500 meters around.