2.4ghz 2watt booster transplant

My Irange multiprotocol module have a very weak transmittion power and can’t be able to control my quad to the next room. I have tested different antennas but i’m still not happy with the results, so I have decided to transfer my 2.4ghz booster pcb inside the diy multi module case. Here’s my questions.

  1. What’s the purpose of the heavy metal booster case?
  2. Is it possible to use a 29mm wire as an antenna for the booster with no ground antenna connection without frying the booster?
  3. Is it safe to use the booster without the metal case?

Just to kick things off: if you’re in the USA that booster is quite illegal, likely for multiple reasons. There’s a cap on transmit power on 2.4ghz at around 150mW. And anything that transmits needs s licence.

Beyond that, the metal case is to prevent the RF noise the booster makes from escaping Anna’s playing merry hell with devices of all sorts within a few hundred to thousand meters.
Exactly what devices will be effected in what way is hard to say. The fact that it has such a gnarly case implies that it’s RF noise radiation is a mess.
This is with the case that it’s a FCC violation or three btw. (Unless, to my surprise, it has a legit FCC section 15 sticker/stamp on it)

Without the case:

Your can expect worse WiFi for everybody within X meters for starters(where X is 10-500), and I don’t think I’d use it around anybody who has an older pacemaker or other sensitive device.

Your sticks may have random inputs from the RF noise, your TX may randomly crash/reboot, etc.

Or it may work perfectly with and without the case.
Just don’t disrupt an amateur radio person’s WiFi as they have the means to track you down and turn you over to the FCC, and the fines are huge.


Take all of what has been said above on board, don’t use a booster.
The solution to your range problem is very likely to be the antenna on your quad. Many tiny whoop styles have a single strand wire antenna that is often lying across the fc or tucked away somewhere. If you can improve the position of the antenna you’ll probably notice improvement. Where you fly can affect things too, close to powerful wifi routers for example, they share the 2.4G band with us as well as the 5.8G fpv bands.

1 Like

I’m living in the Philippines and I asked my parents if there are rules and regulations about transmitting power, but they said that there are no rules about these things in the Philippines. You can even fly drones anywhere exept an airport. My neighbors are more than a hundred meters away.
I’ll do some testings first without the booster case of how it would affect my tx, fpv reception, wifi, phones, and my neighbors at my own risk before using it with my micro quad.

I’m tired of experimenting with antennas because the power of my multi module is 1:3 ratio of the power of the stock e011 tx. I’m not the only one who’s getting these kind of issues with the irange for flysky, it seems like everyone have the same issue. One of them used a 2w booster from banggood and got awesome results. I was planning to do the same. The h8 mini video to the clouds with booster(with plastic case) connected in his multimodule on youtube also inspired me as well.

Awesome, that gets rid of most of the issues of using a booster.
I would keep it external and in the case if you can.

You should be getting more range than you are right now though, there is an issue with your current setup that is causing short range.
(Assuming you’re not in a house with concrete/brick/cinder block/metal walls)
Alternatively, copper foil does a lovely job of containing RF also. A layer of kapton tape for insulation and then copper tape that is tied to ground should do quite well, and is far smaller than the current case.

@Bobnova I think my transmitter also did something about the poor range of the multi module.

What is the function of the ground connection of antennas? Are they necessarry?
Will a diy coax antenna soldered on the booster can fry up my booster?

The ground is crucial, without it the antenna will not function correctly.

The very simplified version of antennas is that the center bit of the coax is the signal that the transmitter is pushing out. The ground gives it something to push against in order to push that signal out.
Without the ground efficiency goes way down.

As long as you don’t bridge the center pin to the ground/shield, soldering your own should be fine. You don’t want any gaps in the shielding as it will leak RF and cause inefficiency.
Running the booster without a proper antenna runs a very real risk of killing it, as there’s nowhere for the 2w of energy to go if there isn’t an antenna to get rid of it, so it reflects back into the driver chip and cooks it.

1 Like

about the case, it most likely doubles as a heatsink. There are 2 voltage regulators visible and they will probably heat up depending on the voltage you power the module with

the second issue is the input power. For amplifiers to work they need a minimum input power, and you may or may not have that from the tiny module

the antenna “might” work with a 28mm wire ( using the pcb as ground ), this kind of amps usually have protections ( because people remove wireless antennas all the time )

Anyway, great project, I hope it works out for you

1 Like

@FPV_Lover Do your parents know anything about radio regulation? This type of regulation is standard all across the world, even in places like Africa. So I am skeptical of their answer. Unless your parents are HAM radio operators or something of the kind, I’m not sure I would trust their answer.

Instead, I would contact your national HAM radio association. They will be able to provide more reliable advice on what is legal and what not.


@Bobnova This is the diy coax antenna I have made for my booster. Is it correct? will it fry up my booster?

As long as the center conductor isn’t shorted to the shielding, you should be fine. Both ends need to be hooked up of course.

@Bobnova It worked! I powered the booster from a 5v regulator instead of 6v adapter connecting to the wall socket. The good thing is the output power is decreased and I’m getting exactly the same range as my modified e011 tx. I confirmed that the signal conductor and ground was not bridged by using a multimeter.

The center signal wire needs to stick out from the coax shielding as close to 31mm as possible, I can’t really tell how long it is in the pictures, but if it’s longer or shorter than 31mm it won’t work nearly as well.