DX7 for Thermal duration

[Hoot]

Horizon says the DX7 has been thoroughly tested in open class gliders. Where did they mount the dual antenna's for the DX7 receiver? Does the DX7 have a four servo wing capabilities and can you change flight modes by flipping a switch?

[Curare]

I don't know whether I'd trust spectrum gear Juuust yet...

[will_newton]

If you would use a JR 7202 on your open class glider, I don't see why not. That's what the DX7 tx is modelled on. It seemed limited on glider features IMHO.

[zackesch]

do you have all the same mixing features needed for sailplanes with the dx 7?

[Curare]

Apparently not.

having said that the range is apparently " further than out of sight"

Give it time and I'm sure it'll become sailplane friendly

[cooper998]

Hoot,
check out the manual its online at;
http://www.horizonhobby.com/ProdInfo/Files/SPM2710_DX7_Manual.pdf
should clear up any programming issues. Me personally I am sticking with my current futaba 9C since I have plenty invested in it, but if I were to buy now I would seriously consider the DX7

cooper998

[wrinkled]

Are you flying a 9303 or another module based TX??? This is an interesting thread if you do. The DX7 may be obsolete already.

http://www.rcgroups.com/forums/showthread.php?t=566018

Dave

[mlee8249]

After careful study of the DX-7 system, I don't think this radio has what it takes for a competition type F3J/TD aircraft. I say this for the following reasons:

1. The receiver is actually two modules with each containing a reciever and separate antenna. Those antennas, although short, are to be mounted perpendicular to each other inside the plane. Not too many modern F3J types have an abundance of space in there.

2. The system itself has some pre-mixed programs and 5 programmable mixes. Of the pre-mix programs, aileron to rudder is useful to us and that's all. In using the 5-programmable mixes, you will get the flap servos to mix with the throttle stick, (using two programs), then you can get the flaps to mix with the elevator (using the third program), and then you wil have to mix the two ailerons together which will use up the other two programs. This now means you cannot get CROW, launch mode, camber or reflex from the model.

You could cheat a bit and connect the flaps to each other by Y harness, but then you would lose the ability to mix flaps to ailerons. You could also use a Y harness to connect the two aileron servos, and that would probably be okay, but you could not get CROW mix, nor launch mode with both ailerons down, nor camber and reflex.

I feel this is a great system, but not truly suitable for full-house sailplane use. Something that doesn't use all the mixing like an F3J bird could have a great time with the DX-7, especially a fast slope bird or slope scale. Any RES type would have a blast, provided you can fit the two receiver modules in the plane with the perpendicular antennas.

Mike Lee

[davidjensen]

I bet the 9303 (or what ever they call it) will have the spectrum modules within the next 2 years. I do wonder what the carbon/kevlar fuse will do to the range of the dual receivers even when their antennas are perpendicular to each other.

[mlee8249]

Hi David,

That's a pretty good question. Normally, we find that with the higher frequencies, the penetration of the signal through walls, trees and other 'soft' objects is better. However, we are speaking of carbon fiber, which may as well be lead. The kevlar will be transparent, but the C/F is what worries me. To be sure, I am not volunteering to the be the guinea pig on this one. (I would normally use my Slo-Stik for such folly, but being mine is a stock Slo-Stik and not a C/F enclosed canopy version, I will have to pass on using it.)

Anybody care to comment on 2.4 Ghz signal penetration through C/F?

Mike Lee

[h.eberbach]

Mike,

your concern regarding C/F fuselages is absolutely correct and unfortunately, this concern holds true as well for "softer" objects as you go to higher frequencies - yet to a lower extent compared to C/F.

Thorough testing would be advisable!

Herbert

[Johnnie Paul]

Here is what I did for a 2M vista, seemed to work ok for the DX6.

Johnnie

[davidjensen]

I doubt anyone would want do this to a Pike, Muller, Mibo, HKM or any of the other expensive moulded fuses.

[Johnnie Paul]

Good point...but it is a fix :o

So tell me, (out of pure curiousity) where does the 40" long FM antenna go in a Pike or Mueller etc? I saw one fly last Sunday, and I don't remember seeing one tagging out the rear...

...my thoughts on the DX7...currently to pricey at nearly double the DX6...I shudder to think what the DX9 will run :rolleyes:

Johnnie

[davidjensen]

Most of the pilots here in the NW double the length of the antenna and run it down the fuse and have about 20" hanging out under the rudder. The Samba web site has a good article on antenna placement in carbon/kevlar fuses.

[Hoot]

The DX 7 has a dual antenna, the second antenna conects to the receiver via an electrical wire. Why couldn't the detachable antenna be mounted in the center section of the wing and the other antenna be mounted in the fuse. You could get the 90 degree separation that way

[mlachow]

I put togther a 6 servo program on the 7202 for sailplanes. This gives you the following mixes/presets

Aileron to Rudder
Aileron to Flap Coupling
Elevator to Camber, full span
Two Camber Presets (Launch and Reflex if you have a TD ship)


With a 7 channel RX, you can do the following.

Channels on a 7 channel JR RX
Thro - Left Flap
Aile - Right Aileron
Elev - Elevator
Rudd - Rudder
Aux1 - Left Aileron
Aux2 - Right Flap

Setup

Wing Type - Flaperons, V-tail as required

Switches, Aux2 [Inhibit], Aux2 Trim [Inhibit]
Flap [System], Flap Trim [Inhibit]

Left 3-position switch will be down for launch, up for reflex


Programmable Mixers

Aile - Rudder +10, +10 (Only one aileron to rudder mix is available, but you could turn it off)

Elev-Flap Mix +20, +20 (This is elevator to camber for the ailerons)

Mix1 Elev - Throttle, +20 +20 (This is for elevator to camber for the flaps)

Mix2 Aileron - Aux2 +50, +50 (Part of Aileron to Flap mix)

Mix3 Aileron - Thro +25, +25 (Part of Aileron to Flap mix)

Note that the numbers are different for aileron to aux2 and aileron to throttle because the Aileron to throttle changes both flaps so Mix2 must negate that. That is why the value of Mix2 is double Mix3

Mix4 Thro - Elevator 0, -30, 100 Offset (This is your elevator compensation for landing)

Mix5 Flap - Throttle +70, +70 (This is lap system preset mix into the flaps, Use Flap System meny for preset settings for the ailerons)

Mix 6 Thro - Aux2 -100, -100 (This is to get second flap mixed in. Note -100 values)


Flap System, Use Up Flap value for Reflex and Down Flap value for Launch. You can also use elevator presets in there if you need a little elevator offset for launch or reflex. (Or you can use reflex and camber if you don't need launch like on the slope)



What is missing is from the program that you normally have in a sailplane program:

Multiple aileron to rudder mix settings.
Change differential in launch or other flight modes
Changing aileron position when landing for crow/butterfly

You could probably trade off crow mixing of ailerons with aileron to flap mixing if you wanted.

[onemetre]

Folks, given the procession of DX6 to DX7 there's got to be a 9303 version (DX9) on the way. My major question - will it remain module based or will we HAVE to purchase a new radio?

There are ways that people have converted 6102's to 2.4. Horizon went and copied the 7202 to be the DX7. Maybe one takes a DX7 and makes a piggy back module for a JR / Futaba radio. It seems expensive to go that route. Assuming it works as advertised, it's nice to have the peace of mind that spektrum offers. In my other flying channels are becoming less contentious as people convert. For TD we're still stuck as the offering doesn't yet allow some of us to make the conversion to 2.4Ghz.

Rob