Hi folks. Here is my first tutorial on how to install a DHT module into a Futaba Attack 4 channel transmitter. Since the introduction of the DHT DIY module I've grown attached to them for their price and ability to give you wide range of receiver options. Without further ado, let's get started. Here we have a factory fresh unused Attack Four that I found at a thrift shop for the bargain price of $25.99 less 30% off. It had all the original equipment and three servos.
First thing we do is remove the battery so we don't have any "magic smoke" experiences. Remove the four screws that retain the case rear, then unplug the battery from the power connection. Once opened up, you can see the main board. Get an aileron extension, cut it in half, strip and tin one half with solder. Solder the black wire to GND, the red to PWR and the white to PPM (shown in yellow)
Here's what it looks like:
Next drill the holes for the bind button and LED board near the top of the rear case. I find using dividers to find hole spacing the best way to mark the holes. I pilot drill then make larger holes to insure the two will center and the button will move freely. I chose to attach my board using .125 plastic strips hot glued to the board, then the case.
The DHT module is hot glued in the center of the rear case. This is the best place to ensure there is no interference with gimbal movement.
The toggle switch can be drilled and placed on either the front or rear base of the antenna mount area, In this case I chose the rear, and it fit there nicely. A step drill will give you control and positive results for the switch hole.
Next we modify the antenna mast for the SMT coax antenna. Using a razor saw, cut off those rings at the top. I call them "Jetsons Rings" because that show was full of them.
After cleaning up the surface, run the SMT through and drive the nut down with a plug wrench. Use a flat tip screw driver on the other side to keep the SMT from turning.
Solder the other half of the extension cable to the DHT module. The white cable will join to the DHT's yellow cable.
You can now connect the two leads and do a check by plugging in the battery and switching on the TX. The LED should be lit. If dull, move the toggle to another position. In telemetry mode you will hear the beep. If that is successful, you can close up the TX. Attach the antenna and you are almost done.
The final and most important step to do is to remove the old crystal. Remove it from its retainer and put the retainer back with hot glue.
First thing we do is remove the battery so we don't have any "magic smoke" experiences. Remove the four screws that retain the case rear, then unplug the battery from the power connection. Once opened up, you can see the main board. Get an aileron extension, cut it in half, strip and tin one half with solder. Solder the black wire to GND, the red to PWR and the white to PPM (shown in yellow)
Here's what it looks like:
Next drill the holes for the bind button and LED board near the top of the rear case. I find using dividers to find hole spacing the best way to mark the holes. I pilot drill then make larger holes to insure the two will center and the button will move freely. I chose to attach my board using .125 plastic strips hot glued to the board, then the case.
The DHT module is hot glued in the center of the rear case. This is the best place to ensure there is no interference with gimbal movement.
The toggle switch can be drilled and placed on either the front or rear base of the antenna mount area, In this case I chose the rear, and it fit there nicely. A step drill will give you control and positive results for the switch hole.
Next we modify the antenna mast for the SMT coax antenna. Using a razor saw, cut off those rings at the top. I call them "Jetsons Rings" because that show was full of them.
After cleaning up the surface, run the SMT through and drive the nut down with a plug wrench. Use a flat tip screw driver on the other side to keep the SMT from turning.
Solder the other half of the extension cable to the DHT module. The white cable will join to the DHT's yellow cable.
You can now connect the two leads and do a check by plugging in the battery and switching on the TX. The LED should be lit. If dull, move the toggle to another position. In telemetry mode you will hear the beep. If that is successful, you can close up the TX. Attach the antenna and you are almost done.
The final and most important step to do is to remove the old crystal. Remove it from its retainer and put the retainer back with hot glue.