RC Tank Warfare community hobby forum

Hi Guys,
I am wondering if someone can help me out.
I have read that some people modify their Futaba 4 channel transmitters (4YWD or 4YF ) for their Tamiya tanks.
In particular, they add a “fire” button to the transmitter so they do not have to use the trim and stick together.
My Pershing requires full positive trim plus full pos stick to fire the main gun, and the opposite to fire the mg.

Is the modification just the addition of a momentary switch on the side of the transmitter with a wire soldered from the trim potentiometer ?
Would switching this be the equivalent of full trim ?
If so, this would mean that i would just press the button(switch) and at the same time press the stick fully forward to fire the main gun ?
Hope this makes sense.
If anyone has a wiring diagram or pics that would be very helpful.

Any advice will be much appreciated.

Thanks
AK

Your spot on with its function and how it works!

Thanks Tomhugill,
I tried it out last weekend but to no avail. I fitted 2 push button momentary switches with a wire from the centre of the trimpot to one side of each buttom. Then from the other side of the trimpot tp the other connection of the button. Likewise, from the other end of the trimpot to the other button switch.
Tested the circuit with a multimeter. But could not get the button switches to activate the mg or cannon.
Have I overlooked something Does anyone have any suggestions

Thanks
AK

I did this to my Futaba SkySport 4 transmitter about 12 years ago following a set of instructions by the Front Range Armoured Group from Colorado. I still have their set if instructions. They are very detailed. If you send me your email address to h5djr@ntlworld.com I will send you a scanned copy.