trainer /buddyboxing?

[glenngb]

Hi!
New to the forum so I start out with this. My brother in law would like to try out my tricopter but he can`t fly.. so.
I want a trainercabel to use my 9x as master and a old Hitech flash6 as slave. Can I make a cabel from signal out (pin 4 on hitech) to the senter pin on the back of my 9x?
ref this site (http://www.mftech.de/buchsen_en.htm)

I use the orignal turnigy v2 firmware..

Hope someone have an idea?

Thanks for all help..

[ShowMaster]

If everything is stock as you say the direct answer is no because .....

One major reason is the 9x wants to see 5 volt data ppm from your trainer tx. Most output a ppm signal of 3v or less. The next issue is rearranging channels in your 9x or trainer tx so that ch1 is channel 1 and so on for all channels. Usually they don't match between differant brand TXs.
Work arounds that will make it happen.

Er9x firmware can rearrange the channels. Free + cost of programmer options.
A one transistor addition inside your 9x will level convert most any non 9x ppm inputs to the correct 5v level. Cost $ 1 transistor 3 resistors and a small perf board to mount it on and 3 small wires. This mod does require good soldering skills and you will be cutting circuit board trace to install it
If you solder well upgrading to er9x is a whole new world.

A drop in ersky9x or Gruvin TX motherboard is another option $100
A new 9x TX is the $44-58 fix.
So far there is no external level converter you can just add to the trainer cable. It's been discussed apt but I don't think a working circuit has been posted.
I'm sure others will comment and hopefully have a better answer you're looking for.
SM

[MikeB]

If the Hitech flash6 is anything like my Hitech Eclipse, the trainer signal out is the full battery voltage (10V or so). On the Eclipse, it appears to be driven by a transistor pulling it to 0V, and a resistor pulling it to 10V. If you put a diode in the signal line, band towards the Hitech, you should block the 10V, and just drive the signal low. The 9x should have an internal pullup to 5V, although with the stock firmware we can't be sure if it is turned on.

Mike.

[MikeB]

As always, too many things to do, so I haven't tried this, but it might work.

Trainer.png (8.31 KiB) Viewed 5908 times

It's AC coupled, so the input voltage shouldn't be a problem. It has a transistor, so low level signals will be boosted to the required 5V. It doesn't need power, so it should just go in the trainer cable.
Possibly, the 200nF capacitor may need to be a larger value. If I get time, I'll test it out, but if someone else can build and test it it would help.

Mike.

[ShowMaster]

Good circuit ideas. I'll give them a try since its been a problem with the. 9x from the start. I've done ghe 1 transistor mod but souls rather not have to in any future 9x TXs.
Ther's still the channel order issue if your tx firmware doesn't have that feature as er9x and other FW upgrades offer. The best stick 9x trainer tx may still be another 9x since the two will match comparability wise?
In my case I want the external level converter because many weekends at our field (over 100 visitors and or flyers on weekends) boxes of surplus rc gear are just put out on tables for free. Many times there are older 72mhz TXs in the boxes. Great source of free trainer TXs so I grab a few newer modelones for trainer R&D. Many still have working nicad tx batteries.
SM

[Kilrah]

One major reason is the 9x wants to see 5 volt data ppm from your trainer tx. Most output a ppm signal of 3v or less.

Actually it's the opposite. Only recent JR radios and their derivatives (some Graupner and Spektrum) give out those low voltages. The others (Hitec, Futaba, Multiplex,..) output either 5V or the battery voltage.

[ShowMaster]

Good to know. Ive only owned JR since the 80' and Spektrum dx6 and dx7 when they came out.
Many other brands before that. I modified my 9x so I can use it with Spektrums because that's the most popular tx at our field and seems to also be the case with new flyers. Many Chinese brands are showing up now because of the combo plane tx prices. I'll have to see what their ppm level in out is. Most do have a trainer/sim port. Maybe a topic on brands and ppm levels will be of help? I just don't have a portable scope to take with me. Maybe a iPod touch scope app is available that will be good enough? I'll have to search for one.

What about channel assignments? I think without agile firmware that will be the biggest comparability issue with mixing brands even if the ppm levels will work?
SM

[Kilrah]

Yep, channel assignments is usually the biggest pain. Only high end radios let you rearrange the trainer input channels. Or 9x alternative firmwares of course

For the incompatible combinations the easiest is this, of course at the price of more mess in the aircraft:
http://www.hobbyking.com/hobbyking/stor ... duct=18703

[ShowMaster]

Yes ever since this type of device was posted its been calling to me to order one next time I order from HK just to try it. I teach more on the fly so a buddy box setup is more common to run into. Still I like the idea.
It would let any 27, 35, 72, 50, or 53 system be used with a club trainer let's say as long as the tx chsnnels were the same or one could be remapped. Same for anyone's setup I guess. Easiest is getting the external circuit working with a er9x tx to keep on topic.
Maybe tonight I'll have time to try it?
SM

[glenngb]

Let me know if anyone have tried the external fix?
Can I measure signal output with a el cheapo scop? Have one small digital Laing around.(looks like a modified mp3 player..) But haven't used a scop since school 12 years ago.. :/

Correction: The hitech radio is a laser 6 not flash.