Frsky DIY in Polk Hobbies Tracker III

If you've been building electronic bits or modifying stuff you've bought then tell us all about it here. A good place to discuss the installation of 2.4GHz DIY modules too.

Frsky DIY in Polk Hobbies Tracker III

Postby TailDragger » Wed Nov 03, 2010 5:35 am

Greetings from Kansas, USA

I'm hacking a Tracker III transmitter from Polk Hobbies with a Frsky V8HT (XYFV8FTR), to the trainer port, so it will switch between 72mhz and 2.4.

According to: (post 2)
http://www.rcgroups.com/forums/showthread.php?t=1235628

"Simulator Mode must be "ON". (This will disable the FM transmitter signal)

Trainer Mode must be "ON".

And you must enter "Student Mode" when you switch-on the TX by pressing down on "B" Mode key while turning on the TX.

Now once you have the TX set-up and on, you turn on the 2.4GHz power switch on the back of the radio and you should be up and running."

I understand that, and it works fine


The PROBLEM originally was:

Only servos plugged into only even numbered channels in the receiver work, channels 2,4,6,8. And, with the Tx set to "Standard receiver", (the Tracker 3 will transmit to "standard" = Futaba, JR, and Airtronics) the order is: aileron, elevator, throttle, rudder. The others don't work. Tried it with the battery in number 8 and number one. And, the servos "chattered"

So:
I measured the voltage between PPM In and ground
PPM OUT and ground
and Power and ground

in both 72mhz mode and 2.4ghz mode

Those voltages, in that order, were:
72mhz -- 0, 2.5, and 9.4 (using the 8 pack battery that came with the Tx)
2.4ghz -- 3.8, 3.2 and 6.2

The really weird (and great) thing is, when I put the probes on to test the voltage from PPM OUT to Ground, all the servo chattering stops, AND, the receiver works PERFECTLY, on the channels it is supposed to work on.

I learned about "overpowering" the module from:

http://www.rcgroups.com/forums/showthre ... 28&page=91
and found diagrams on post 1360

By the way, my DIY module came with the diode


With the help of a knowledgeable person on RCGroups, I:

soldered a resistor between PPM OUT and Ground, 3.3k, all servos worked properly, no chattering, but very poor range

soldered a 27nF capacitor WITH the resistor, range became somewhat better, still too short

soldered just the 27nF capacitor, range is almost up to snuff (sometimes up to 28 meters with the green light on)

tried a 150 ohm resistor, and a 100pF capacitor, separately and together with poor results

posted tracings of my PPM on:
http://www.rcgroups.com/forums/showthre ... 8&page=138
post 2063, done on a laptop with xoscope, so no DC voltage available

Trying to fine tune this thing. Don't understand electronics, but can solder and can follow directions.

Any suggestions?

Love your Youtube videos
TailDragger
 
Posts: 4
Joined: Wed Nov 03, 2010 4:04 am

Re: Frsky DIY in Polk Hobbies Tracker III

Postby RCModelReviews » Wed Nov 03, 2010 9:23 pm

I'm not familiar with the Polk radios but changes to the PPM signal shouldn't affect the range of the radio.

I'll have a think and see what I can come up with.

I wonder if I can find a schematic for the Polk radio somewhere.
RCModelReviews.com, just the facts.
User avatar
RCModelReviews
 
Posts: 2120
Joined: Tue May 04, 2010 3:40 am

Re: Frsky DIY in Polk Hobbies Tracker III

Postby TailDragger » Wed Nov 03, 2010 10:57 pm

Thanks for your reply. No schematic available at the FCC, but I'll try to call Polk tomorrow to see if they will part with one. ht
TailDragger
 
Posts: 4
Joined: Wed Nov 03, 2010 4:04 am

Re: Frsky DIY in Polk Hobbies Tracker III

Postby TailDragger » Sun Nov 07, 2010 3:35 am

I'm going to keep trying for a while with this Tracker III, but would like suggestions on a radio to convert to 2.4. We have a large club and someone will probably have a Jr, or Futaba that would work, or I will look on Ebay. (guys in my club lean toward JR) I would like to get a programmable radio that I can convert to 2.4 with Frsky, either a module or the DIY. I like Frsky, and would like to have a reliable "tried and true" radio that people can advise me on if necessary. I lost a plane with the Tracker/Frsky DIY which programmed well, bound every time, flew great, but I couldn't get the range needed, 300-400 yards and poof, gone. I like the Polk Hobbies Tracker III programming, but can't find a schematic and very few people have this radio.

I fly planes only, probably not over 60 inch wingspan, electrics, no heli's, no 3D, just sport and pattern.
I will probably never use more than 6 channels, and probably never (again) have more than 3-5 planes, and don't mind programming. I do like aileron differential.

Just started looking on Ebay, saw a JR XP6102, but know little about them, and would prefer to ask those more knowledgeable.

Whatcha think? Thanks in advance. ht

P.S. FM, PCM, PPM ???
P.P.S I have driven Toyota pickups since 198
TailDragger
 
Posts: 4
Joined: Wed Nov 03, 2010 4:04 am

Re: Frsky DIY in Polk Hobbies Tracker III

Postby TailDragger » Sun Nov 07, 2010 3:36 am

that is, 1985
TailDragger
 
Posts: 4
Joined: Wed Nov 03, 2010 4:04 am


Return to DIY Projects and Hacks

Who is online

Users browsing this forum: No registered users and 1 guest

cron