Hitec Focus III (trainer port ?)

[epkoncept]

hi:
does anyone know how to add a trainer port to a Hitec Focus III tx ? I want to attach this tx to my FMS and perhaps make it a slave to my Eclipse .

EP

[olivier2]

Hi,

Look at my website, chapter 1, para. 1.1 on how to search for a PPM-signal in a transmitter without buddy-box-connector; to be used for simulator or to hook on a master transmitter. You will have to download a free scope and do some searching on your radio.
Succes,
Olivier

[Jim Poor]

may be easier and simpler to get an old laser 4 or something, unless you really like to play with tiny electronics :)

[epkoncept]

There is a Samsung micro controller, and the PPM output is on pin 21. The signal needs to be inverted with common emitter stage before being sent out to the master tx.I placed a 1k in series with the base, a 4.7k in the collector to the 9.6V line, and a 1k series resistor between the output of the invertor and the connector.

EP

[Jim Poor]

I guess you really like to play with electronics :)

[epkoncept]

Yes, I do play with electronics.

The reason I wanted to add a trainer port output to my Focus III is that I don't want to have to buy another radio, and the Focus III is very light and easy to hold, which is important as I am trying to get my kids into flying ! Besides, little kids tend to drop things, and my FocusIII is already "well used"

If anyone cares, I can draw the schematic and post it.

EP

[7up]

epkoncept

I'd a[[reciate the schematics for that radio. I have a few DFocus III radios that I could put to use... Thanks

[epkoncept]

Sorry, I tried to post it but the JPEG was too big 344kB.
If you have an email address, I can send it to you directly
I had trouble pdf'ing as the aspect ratio of the page is too wide.
EP

[olivier2]

Hi EPconcept,

I would like you to post me the picture where you found the ppm signal and a ground inside your Focus3. This in order to insert into my website when I ever would have some time again...
Question : was the signal a negative or positive ppm (I guess negative...)?
Thanks in advance,
Olivier

(my adres to be found on my website here :
TX2TX (http://users.belgacom.net/TX2TX) : buddy box compatibility problems between different brands of RC-transmitters)

[epkoncept]

Got the gnd from the power connector
got power from the switch connector
Look at pin 21 of the Samsung IC
It is +ppm, but I have an invertor before I output it so it is negative ppm, which is what the my Eclipse is looking for
EP