jrflyboyVP2

Hi all, I am just returning to the hobby after many years and after much research on various forums I just ordered the Corona DIY 2.4 GHZ conversion kit from Hobby King. I have 2 Airtronics 72 mhz transmitters an old Vanguard VG6DR and a Radiant. I opened up both transmitters and am not sure where the signal wire is. On both transmitters the RF module has two connectors, a Black, Brown wire on one connector, and a RED, White, White on the other. Iexpect one of the white wires is the signal wire, but which one. Also once I disconnect the Black, Red, and "correct" White and connect them to the 2.4GHZ corona RF unit, will the battery meter not work (brown goes to the battery meter). Is there a way to connect the corona unit up and still retain the battery meter function. Any help from electronics gurus would be very appreciated.

Best Regards,
John Reinschmidt
Austin, Texas

coriolan

The 5 pins to the RF module are for voltage (+/ground)signal from the encoder and RF to the antenna, the 5 is probably a connection to the meter since Aitronic show the RF out instead of voltage. To use the DIY module you need to remove the RF board. You can identify what is V+ with a voltmeter or an oscilloscope as well as the ppm pin. Or simply follow the trace on the PC board to see where they lead. You can also connect to the trainer socket (from the inside). This site show what is what:
http://users.belgacom.net/TX2TX/tx2t...h/tx2txgb3.htm
Contact pin configuration of Sanwa viewed on female plug mating face :
1 = ??
2 = Ground
3 = OUT
4 = +V switched
5 = IN
It seems that the Sanwa/Airtronics Infinity, Quasar and Stylus are fitted with other connectors and that for buddy box purpose these transmitters are only compatible with an identical transmitter (thus Infinity to Infinity, Stylus to Stylus or Quasar, Quasar to Quasar). No problem between the RD8000, RD6000, VG400, VG600, Radiant and Vanguard PPM.

jrflyboyVP2

Thanks for the help, I really appreciate the reply, but Iam still confused. If I connect to the trainer plug, do I connect the signal wire to the "in" (#5) or the "out" (#3) pin? Also do Ithen have to have the trainer switch toggled to activate the 2.4GHZ module? Do I have to disconnect the 72 mhz board from the system somehow? I don't have an oscilloscope, but I do have a voltmeter. Ihave no problem finding the + and Ground, but I need to know where to connect the signal wire.

Thanks, JR

coriolan

You connect the ppm wire (from the Corona) to the pin #3 to send the ppm to the 2,4Ghz module and the ground to pin #2,the V+ to pin #4. You don't have to toggle the trainer switch to operate since the ppm is transfered when the trainer switch is not activated and cut off only when actuated. You can remove the RF module completely or just remove the crystal to prevent modulation. Pin #5 (ppm in)is used only on the student side of a trainer set-up to recieve signal from the teacher Tx. A voltmeter is enough to determine what is what. Some DIY modules are sensitive on the kind of pulse they work with (negative or positive)there is a circuit for an inverter in that link if necessary. I use an old Airtronic Tx for FMS and its very simple to hook-up, here is a review for your system:
http://www.rcmodelreviews.com/corona_dsssv2.shtml
It is for the module type, but the DIY is the same in a different case (no case!) and also here is a Pdf from another manufacturer on how to install their module inside a Tx case:
http://www.fd-rc.com/en/manual/manual_1288169465.pdf
With the Aitronic radio the meter wont read anything since there will be no RF from the regular module but you can re-wire the meter with a small resistor to read your battery condition. 2.4Ghz RF modules consume less than a regular 72Mhz RF board but you still need to know when you Tx battery get low. Welcome back in the flying group, things have changed a lot in the last few years but for the better specially price wise

jrflyboyVP2

Wow, Thanks Coriolan. That is just the info I needed. I can't wait to get my 2.4GHZ DSSS module. I flew (electric piper cub) my 72 mhz at a nearby school yard last week and got shot down twice. First time I got an uncommanded full left rudder, and a couple of days later I got an uncommanded full down elevator on the second flight. Needless to say I have been doing a lot of balsa glueing and spliceing the past couple of days. There are no model flying fields within 20 miles of where I live, so I thought I would be safe on 72mhz, but I guess not. I hope the 2.4ghz DSSS fixes the glitches.

Regards,
JR

coriolan

Thats the best thing about 2.4 Ghz, not having to worry about being shot down by somebody nearby turning on a Tx on the same frequency. Because of the very high frequency its also virtually immune to electrical noises from electric motors or esc. This is for the ASSAN DIY module, a rather long thread on RCG but there might be infos about doing an Airtronic conversion in it:
http://www.rcgroups.com/forums/showthread.php?t=994433