R/C buddy box plugs/ pin assignment

For running a R/C transmitter with the R/C Interface the transmitter has to be equipped with a buddy box, that makes the PPM-Signal accessible from outside. Unfortunately, each manufacturer uses its own type of buddy box connector:

 

Multiplex	Futaba	Robbe	Graupner/ JR
all   DIN female plug 5-pin 45° (180°), mating face GND: 3 Signal: 4 short-circuit 3 with 5 (1: Bat+, 2: Bat+, 5: NC)   (DIN female plug 7-pin: additional pins 6, 7 for copying, 5-pin male plug also fits the 7-pin female plug)   appropriate male plug for female plug           Hitec   Fokus 4, Eclipse 7, Flash 5, ..     DIN female plug 6-pin 60°, mating face GND: 0 = shielding Signal: 4 short-circuit 3 with 5 ( 1: Bat+, 2: Signal in, 5: Bat+, 6 : GND)             Jamara   Compa x4+1 Trainer   DIN female plug 6-pin 60°, mating face GND: 0 = shielding Signal: 4 short-circuit 3 with 5 ( 1: Bat+, 2: Signal in, 5: Bat+, 6 : GND)     transmitter of model "Calisto" 4 pin female mini DIN plug (without blue contacts)   GND: 9 Signal: 3 1+2 trough for plastic pin   4 pin male mini DIN connector       Awesome R/C Product by Model Engines Transmitter E8 of model "Twister CP" 4 pin female mini DIN plug, default colors of the cord   GND: 5 PPM Signal: 1     E-Flite Transmitter 6-channel CCPM E8 of model "Blade CP", Belt CP 4 pin female mini DIN plug, default colors of the cord   GND: 5 PPM Signal: 1	9ZAP/9ZHP, FF8/8UAP, FF7/7UAP, FC16, FC18, FC28, .. DIN female plug 6-pin 60°, mating face GND: 0 = shielding Signal: 4 short-circuit 3 with 5 ( 1: Bat+, 2: Signal in, 5: Bat+, 6 : +5V )     3PJ, T3PJ, .. female plug for 3.5 mm mono jack GND: 1 Signal: 2   3.5 mm mono jack connector         FX15, FX18, .. female plug for 2.5 mm mono jack GND: 1 Signal: 2   2.5 mm mono jack connector     4C, 7C, 9C, FF 4, FF 7, FF 9, T6EXA, Skysport T4YF female plug, square 6-pin, mating face GND: 2 Signal: 1 short-circuit 5 with 6 (3: NC, 4: Signal in, 5: Bat in, 6: Bat+)           Walkera WK-0701 4 pin female mini DIN plug, default colors of the cord   GND: 3 WK-701 PCM Signal: 2   Walkera 4-channel 4 pin female mini DIN plug, default colors of the cord   GND: 3 short-circuit 3 with 4 UART PCM Signal: 2 connect 2 with 1 temporarily to activate the signal output or PPM-Signal: connector for crystal oscillator with crystal unplugged GND: 3 or charging connector   Walkera 22 E (35, 36, 39) 4 pin female mini DIN plug, default colors of the cord GND: 3 PPM Signal: 2     Walkera transmitter of model "Dragonfly R7C"   PPM-Signal: connector for crystal oscillator with crystal unplugged GND: other crystal pin or charging connector	CM-Rex, Terra Top FMSS/PCMS, ..   DIN female plug 5-pin 45° (180°), mating face GND: 2 Signal: 1 (3: Bat+, 4: Signal in, 5: Bat+)     Sanwa RD8000, RD6000, VG400, VG600, Radiant, Vanguard PPM, ..  DIN female plug 5-pin 45° (180°), mating face GND: 2 Signal: 3 (4: Bat+, 5: Signal in)     Stylus, M 11, .. 4 pin female mini DIN plug (without blue contacts)   GND: shielding Signal: 7 1+2 trough for plastic pin   4 pin male mini DIN connector     M Zechs, ..   female plug for 3.5 mm stereo jack connector Signal: 1 GND: 2 NC: 3   3.5 mm st. jack connector     Kyosho   Caliber M24 transmitter female plug, square 6-pin, mating face GND: 2 Signal: 1 short-circuit 5 with 6 (3: NC, 4: Signal in, 5: Bat in, 6: Bat+)	FM 314, mc-10, mc-12, mc-14, mc-15, mc-16, mc-16/20, mc-18, mc-20, mc-22, mc-24, FM4014, ..   European RF part and buddy box: JR Quattro, JR 9x, X-347, X-387, X-388, X-756, X-3810, ..   female plug for 3.5 mm stereo jack connector Signal: 1 GND: 2 NC: 3   3.5 mm st. jack connector     all MX transmitters with DSC connector: MX-12, MX-16, MX-22, mc-19 (with DSC-connector only)   American RF part and buddy box: X-347, X-387, X-388, X-756, X-3810, .. female plug for 3.5 mm mono jack GND: 1 Signal: 2   3.5 mm mono jack connector     Micro 47G 4 pin female mini DIN plug (without blue contacts)   GND: shielding Signal: 7 1+2 trough for plastic pin   4 pin male mini DIN connector       Spektrum 2.4 GHz   DX 7   female plug for 3.5 mm mono jack GND: 1 Signal: 2   3.5 mm mono jack connector         Lexors     Nova 4, Nova 6   female plug for 3.5 mm stereo jack connector Signal: 2 GND: 1 NC: 3   3.5 mm st. jack connector       T2M   transmitter E-Fly female plug for 3.5 mm mono jack GND: 1 Signal: 2   3.5 mm mono jack connector

All female plugs viewed from mating face/ outside = view on solder side of the corresponding male plugs; blue bridges are used for deactivation of the RF-part. The RF-part should be switched off in pupil/master mode because no disturbing antenna is plugged into the transmitter and, therefore, the generated energy is not emitted, that can lead to heating and destruction of the RF-part.

Your transmitter is not equipped with a buddy box..

.. is not intented to be used in pupil/master mode, but it should be connected to the PC. That is possible anyway, if the transmitter uses PPM. With following steps, one can find out this and can upgrade the transmitter:

• Choose microphone as input for your sound card. Test the setting with a real microphone.

• Solder 2 wires at a 3.5 mm stereo jack connector (to contact 1 and 3, see figure of Graupner connector).

• Plug the cord into the soundcard, open the case of your transmitter and switch it on. Touch the ends of the cord with contacts inside the transmitter. If you hear a buzzing noise that changes while moving the sticks, you have found the signal. Commonly, GND is the negative pole of the battery and PPM signal one of the wires leading from the main board to the RF part.

• Drill a small hole in the R/C transmitter casing and attach e.g. a 3,5 mm female stereo jack plug at the casing and connect it with GND and PPM signal.

Further information:

traced PPM-Signal of Graupner/JR mc22 visualized with Oscilloscope program

hints:

• Upgrade your transmitter at your own risk.

• Be careful while seeking the PPM-Signal in the activated R/C transmitter, cause no short-circuits.

• The self-made buddy box may work well with the RC-Interface, but not in the pupil/ master operation with another transmitter as master. Without further knowledge both transmitters can be damaged.

upgrade example 1 - Graupner mc 15

Since a buddy box is offered for mc15, upgrading should be no problem. The PPM-Siganal is detected fast:

A matching self-made buddy box looks like this, the prefabricated parts are easily to get from the direct mail selling or a local electronics store:

The protection resistances are important if a short-circuit happens through a faulty plug.

upgrade exampe 2 - Graupner FM 314

A low priced, used FM314 is optimally suitable for flight simulators and for buddy box operation. Unfortunately, the manufacturer doesn't offer any body boxes, however, it can be upgraded easily with the same parts as with the mc15.
There is the FM314 in 2 different versions, that don't differ externally however.

The signals are connected though the same two resistors with the female stereo jack plug: If the male jack connector is plugged in, its top is connected with PPM-Signal and the middle with GND.

This is FM314 v2.

On the circuit board right beside the connectors for the axis resistors is the 5-pin row. GND is the most upper pen, PPM-Signal of the 4th. GND is connected through a 100 ohm resistor with the middle contact and the PPM-Signal through 120 ohms with the rear contact of the 3.5 mm stereo jack plug.