Give a Second Chance to your Old Radios (Part 1)

Give a second Chance to your Old Radios

Sure you have read articles about upgrading your 72Mhz Radios to 2.4 Ghz this is the way I did it, I just wanted to make it cleaner easier an less invasive, I never liked the idea of drill my Radios or change it's original look adding switches and leds, then I made it trying that they look original inside and outside

So let's do it

Before start be aware that the electronic devices are really fragile in some ways, always check twice before connect, cut, or solder anything

In this article I'll show how I modified 3 JR radios, two of them with the FRSKY DHT and the third with a Hitec Spectra 2.4 module, the radios are JR XF-622, JR SX -600, JR X-378

XF-622

In my experience the radios always have a separate PCB in charge of transmitting the pcm signal in this case at 72 Mhz, as you can see there is a connector in the right upper side of the brown board the 3 cables are Ground, Vcc and PCM. But warning, in this case for example ground isnt brown neither red Vcc or yellow signal(pcm) as in the servos o esc's.

To solve this I checked where they come from and re-solder in a standard way, here you can see it.

Now the new module, its a frsky DHT , this is what you get and what's inside

here you can see the new module placed in site, after I replaced the "in" cable with a 3 pin connector, the reason to reorganize the cable from the radio is that now it matches with the new module

Other thing  we can improve is the way to mount the antenna connector, also you can use hot glue, or take your time and use some heat-shrink and use it as shown. put short pieces until the diameter is near to the hex then longer pieces over, untill you get a diameter slightly larger than the hole in the TX, trim the excess of heat-shrink to guarantee the removable antenna connection,

 then you can push the antenna in the hole.

The next step is the reason of this article,  there is no need to add a switch that barely will be used  if you have a telemetry receiver you can just unplug the switch and install only the led and binding button, in my case I have both kinds, so I have to install the switch.

For the binding button this radio has a nice space where it fit perfectly, in fact is designed to have a button there.

As you can see there is a "bridge" also two cuts in the pcb conductor  to separate the new connection from the original circuit

Here the push button and LED removed, on its places connectors to extend them.

Finally the switch and LED installed. 

And this is how it looks, minor changes and now your radio is in 2.4GHz. 

Thanks for viewing, if you liked this I'm preparing two parts more, for two other transmitters with better and nicer improvements.