Use the steps below to add a charging jack to your Futaba T2ER transmitter.
You will need a Coaxial DC power jack and a + and - wires about 6" long to connect the jack to the circuit board.
I use a Coaxial DC power jack from Radio Shack part # 274-1583 priced at $1.99
For the wire I use servo wire or stranded speaker wire.
Below is how it is installed.
PLEASE NOTE: This will VOID your radio warranty so be sure your
radio is in good working order and you follow the directions completely.
Futaba offers a charging jack that fits the radio but the cost is
about 4 times what it is to use one from Radio Shack.
First unscrew the antenna and remove it.
Then remove the 4 screws on the back of the radio.
When the screws are removed. Hold the radio together and
lay the radio down on a flat surface. Split the cover lifting the top
off of the back. The silver switch button will be the only thing holding the
top cover in place. Pull the cover as you hold the bottom of the radio and
it will lift off. The parts inside the radio are drop mounted. (meaning nothing is
screwed down in place)
Once you have the antenna, switch button and the top cover off the radio
set them to the side as there are no modifications done to any of these parts.
You will need to drill a hole in the bottom cover just above the area provided
for a charging jack. Drill the hole for the jack so it is mounted in the bottom cover only.
Doing so will make the installation of the charging jack easy and the top cover
will not come into contact with the jack at all..
Once the jack is mounted. You can connect the jack to the board as shown in the images.
To do this strip and tin 1/8" of both ends of the + and - wires you will be using.
Next locate the 2 holes just above the on/off switch. The + (red wire) needs to be soldered
in the hole closes to the on/off switch as shown in the images. Be sure you use the proper soldering iron for the job.
Getting the board to hot can damage it and as noted above. You now have no warranty to fall back on.
Next locate the 2 holes in the board going across between the servo reversing switches.
The - (black wire) needs to be soldered in the hole on the right as shown in the images.
Next connect the other end of the wires to the Coaxial DC power jack.
Solder the + (red wire) to the center pin on the jack.
Then solder the - (black wire) to the side pin on the charging jack.
Then place the top cover over the gimbals and into place.
Having to do so means something is out of place.
Remove the cover and make sure everything is in its proper place.
When everything is in place the front cover will drop in place.
Next replace the 4 screws and the antenna.
Now remove the battery cover and note the + ends of each battery location.
You need to spring the wire a little by sliding a small knife under the wire and
lifting it up slightly. Doing so will insure proper contact between the battery and connector.
You may notice that the wire at the + locations lays flat and if you look at a rechargeable battery  you
will see the + end of the battery does not stick out as far as the + end does on a alkaline battery.
This is why the contact at the + ends needs to be lifted up slightly.
Next install your rechargeable batteries and use a volt meter to check to be sure the polarity
is correct at the charging jack. If you have done things right.
All that is left is to install the switch button and charge the batteries.
You should note that the batteries will only charge if the radio is in the off position.