Graupner x=8n
 

Got my x-8n in and have been playing with it. I have had the m11(great but too heavy), flysky gt3b(first radio, still have), gt3c(in trash bin after 2 weeks) and have been using the mx-v.

First impression

the grip is a little thicker than the airtronics(more like the futaba 4pl I have used). The wheel does not look as cheap in person as it does on pics.

As far as assignable buttons we have the 3 rocker switches around the wheel. Along with two more rockers on the grip. Then above we wheel we also have a push button and a dial button and one more push button on the grip.


Comes with 4000mah 1s lipo that you can charge with supplied charger though jack or take the lipo and use servo plug. 4000mah should last a while in a radio.

Had headphone jack, usb connection, Sd card. You can update firmware though sdcard or usb. The unit has voice output but I can only get the voice to work though headphones so I prob wont use it. Also connector to update the rx firmware.

I bound another receiver to it and what I like about it is you only control the model your on. I have on occasion forgotten to turn off one car when switching to another between classes and this will stop the runaways.

I tested the telemetry and it worked fine as well as the remote beeping when applying heat to sensor with heat gun. My first telemetry radio.

The screen is nice and big and the balance feels good to me. I adjusted the trigger and wheel tension to where I like them. Also rotated the drop down a bit to my liking. Feels even better for me. Since the head is wide the antenna does not stick out too much if you put it to one side. And the antenna feels pretty solid. You also get readouts on rx volts and temp as well as range and connection data. Also can be changed over for left handers.

I assigned buttons so I can do laps and it works good. Giving best lap, average lap etc.

I think im going to like it more than the m11 for sure. Rx are pretty cheap too. All the normal stuff is there, trims, epa, exo, servo speed, idle up, ABS, 4 wheel steering. Servo mixing, esc mixing, etc. prob has way more stuff than ill ever use. The menu is pretty easy to navigate and the model selection is first thing on menu(which it should be)

Overall I think if the long term shows it is as good at it looks and feels initially. It will be a good radio alternative. Hopefully I can get a raceday in with it soon.

http://i1288.photobucket.com/albums/...psc12a2a35.jpg

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Cool I've been looking at this radio. Thanks for the info and pics.

Subscribed! Thanks for the write up!

Trick, may I ask you to check if the 1,5 ms and 3ms RF speed settings are compatible with your other stuff. As I have written in my previous reply in the x-8e thread - my equipment is not working at these speeds.

Thanks

I'm pretty sure that you have to have digital servos. Modern esc's should be fine. That might be your problem.

your right. when i cranked it down to 1.5 or 3ms. they no longer work. with 6ms. they do. radio may be faster than my esc and servos.

big al -yes sure. my servo is a digital 0,06 sec one and the esc is skyrc Toro esc - so modern enough.
I have the feeling that the 3.0ms and 1,5ms signals are of different range. I have connected the rx to VRC usb dongle with speed of 6ms and calibrated as joystick in windows. When I changed the speed to 1,5 ms I had to recalibrated again as the signals from receiver are obviously different. Once calibrated It works fine. Seem the 3 ms and 1,5ms signals are wider than 400us-1500us band. It is interesting just for comparison to have the speeds of Sanwa MT-4S for normal mode - high speed mode and max pseed which requires Sanwa servos.

I can confirm my feeling regarding the different signals coming out of the receiver for 3ms (fast) and 1,5 ms (utrafast) speeds. I used a skyrc programming card to mesure the reciever ppm with the following results:

for normal signal down to 6ms
Signal frequency: 165 Hz
Left:1105 uSec
Midpoint: 1507 uSec
Right: 1909 uSec

for Fast and Utrafast:
Signal friquency: 331 Hz
Left: 130 uSec
Midpoint: 300 uSec
Right: 472 uSec


So obviously Fast and Utrafast will not work for equipment expecting standard (1500 uSec) signal modulation.

It is a question how one finds equipment for Fast and Ultrafast signal as most of the time there is no specifications available for the accepted ppm.

wonder if the swana servo would work with the faster speeds.

I have done some more research and measurements including Sanwa mx-V and Radiolink RC3S outputs from receiver. To your question - I guess the Sanwa servos in superfast mode are with centerpoint at 760 mSec which is far from 300 mSec. Anyway here is what I have measured:


https://docs.google.com/drawings/d/1...ub?w=480&h=360

It is interesting the 24 ms setting appears as 10 times faster than expected -gives 441 Hz Frame rate corresponding to 2.3 mSec which is quiet fast. This all is assuming the latency is given by the frame refresh rate.

Futhermore The Graupner x-8N seems to be of higher internal quality then mx-v as the x-8n shows no midpoint signal drift compared to the 7 uS of mx-v and the 17 of Radiolink.

so according to that it is facter in 24 than 6ms? wonder why.

also intertesting to not that the 2channel receiver does not give the option to adjust latency.

Well it looks like that but I do not know how to verify.
And yes the 2 chanel reciever is HoTT only ans as per the manual it does not allow to change frame rate/latency. The GR-8 is apparently HoTT V2.

i put the 2 channel in the ST. I figure its acutally a good thing to be slower in 2wd.

thanks for posting up test results.

@ sbd... thanks for posting your test results between the RC3S vs MX-V vs X-8N

I'm curious for you to explain how you measured those test values? I'd like to conduct the same experiments myself to include testing on several other brands of radios too. It would be really nice to have an apples to apples comparison for ALL brands of radios.

Sbd, thank you for the info! I wonder if re-binding the receiver after you change the response time is necessary?