Author Topic: futaba skysport 4 tx (Read 886 times)

vanmantony · « **on:** June 19, 2013, 02:37:52 PM »

hello just been given the above tx no battery, so i plan to use a small lipo, thing is a JST plug wil fit the battery pins either way round so I need to know which one is positive, anyone know? cheers tony

p.s pic enclosed

bigMouse · « **Reply #1 on:** June 20, 2013, 01:06:30 AM »

Are you asking about the three pin (servo type) socket on the futaba tx? if so it's ground-positive-ground on the FF8 and FF9 so expect it will be the same on that one. you could check while the case is off. pin 1 & 3 is likely to be soldered to the same copper on the power PCB.

vanmantony · « **Reply #2 on:** June 20, 2013, 07:39:27 AM »

big mouse ,thanks for the reply so what your saying is that the left pin in the pic is ground the right pos there is no third pin so I need a furaba type servo lead plug for battery connection I shall give it a try later cheers Tony

bigMouse · « **Reply #3 on:** June 20, 2013, 09:36:37 AM »

You must test, can't assume anything! I might have some pics here of the FF9 power board will have a search

bigMouse · « **Reply #4 on:** June 20, 2013, 12:43:34 PM »

Here is the ff8~ff9 power board, it contains the servo lead style 3 pin connector. The close up shows three pins pointing down (they are accessible in the battery compartment) left = -ground, center = +supply, right = -ground. the idea of that connection is that if you plug in a battery with a servo style 3 pin connector, you can't make a mistake.
BUT if you only have a 2 pin connector then it absolutely must only be connected the correct way! There is no protection diodes on those boards!

Check the tracks from your pins on the board, there is probably an electrolytic capacitor nearby connected across the supply pins (little round black things with silver end) If they are there, they will show you the right polarity the sign "-" on the side of the cap means negative pin

vanmantony · « **Reply #5 on:** June 20, 2013, 07:47:02 PM »

big mouse, all sorted thanks for your help, in the end it was pos+ on the left neg- on the right pin, gonna (stick to me sanwa Rd8000 in future), managed to get the rx that came with it so its all going on a tricopter thats up for sale once i have it all dialed in cheers Tony