FrSky R9M vs R9M2019 teardown

I do not why, but FrSky does not want to keep things simple. Not only it's migrating from ACCST to ACCESS, it also makes a mess with FrSky R9M system by releasing new hardware that looks like old hardware, has a very similar name and can run ACCESS but only on some radios, not on the other. The nightmare…. Today let's compare the FrSky R9M transmitter module I own for last (almost) 2 years with a brand new FrSky R9M2019

Matek VTX 1G3 Long Range Video Transmitter Power Test

New long-range 1.2GHz video transmitter and receiver from Matek are hot topics of the last few weeks. They seem to be a very interesting proposition for all long-range flyers that are not happy with more popular 5.8GHz FPV systems.

Matek 1G3 VTX and VRX with antennas

Last week I've connected Matek VTX-1G3 to an RF power meter and this is what came out of this.

Bottom line: this looks like a very decent 1.2GHz FPV system and Matek VTX-1G3 and VRX-1G3 might be what long-range community really needed!

Radio modules FS1000A and XY-MK-5V – pros and cons

When looking for radio modules for your next Arduino project, you might have come across the couple named: FS1000A and XY-MK-5V. At first glance, they might look like the next best thing, but it's not that simple.

FS1000A and XY-MK-5V

Before you start hacking anything with FS1000A and XY-MK-5V, read the following pros and cons:

Pros:

  • simple – to send a signal you do not need much. Only to power them up and set LOW or HIGH on the data pin
  • cheap – true, they are not expensive

Cons:

  • pretty much everything else, including the same things that are their pros…
  • too simple – they are just too simple and offer no other functions than transmitting a wave through the void. No CRC, no packets, so SPI or serial, no bidirectional communication
    everything has to be done in the software, including encoding and CRC.
  • transmitting and receiving devices have to use the same libraries and support on some platforms like Raspberry Pi might be problematic at best
  • the frequency can not be changed!
  • no frequency hopping or spread spectrum
  • you have to get your own antennas
  • range is poor at best and depends on things like voltage of the transmitter
  • build quality varies a lot and you can not be sure that TX and RX are really tuned to the same frequency

Verdict? At leat be very careful when choosing hardware for your next Arduino RF project…

Manage your OpenTX trims like a PRO!

Almost all RC radio transmitters (Jumper, FrSky, Nirvana and all other OpenTX radios) have trims. When flying classical airplanes, their usage is obvious: you trim your airplane with trims. When using any flight controller or stabilization, they immediately become useless. Trimming has to happen on flight controller (INAV, Betaflight, Pixhawk, Ardupilot), not on the radio itself. Luckily OpenTX allows you do some tricks with trims:

  • disable trims so they will not accidentally break anything
  • use trims as 2 position switches and assign them to any radio channel
  • use trim to reset flight and timers in OpenTX

FrSky X9 Lite radio and what they don’t tell you about it

On a first glace, FrSky X9 Lite looks like a thing you might want to have. As your first radio even when you are entering a hobby, or as a secondary transmitter just in case when the first one dies on you. Theory often does not match reality tho. I doubt there are samples around independent reviewers yet so it will have to wait to know if it’s any good. But until then we can take a look a specification and think if it really looks like a good radio at all…

Radio Magic – the one with the antenna gain

Hands up, who gets antenna gain? Like why 2dBd is better than 3dBi and why 8dBi might not be a good choice after all? This whole antenna gain topic might be quite confusing. Not only there are 2 units dBi and dBd (since blame marketing for that!) but also one must realize that antenna does not really have a gain like an amplifier or transistor. If 100mW will be put into antenna it will never radiate more than a 100mW. Truth to be told, it will always radiate less than that!