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…
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!
In this episode, we will have a nice chat about decibels. Why we use decibels, what is the difference between dB, dBm, dBd and other similar things.
FrSky R9 radio system is storming the RC hobby. It's super cheap after all. But there are problems: EU version is facing a lot of problems and people like to replace original antennas with something else.
Last week I was asked to check what is going on with antennas shipped with FrSky R9 Mini. After all, the same hardware can be used both for FCC 915MHz and EU 868MHz version. Is the antenna tuned somewhere in between? Or not so much?
When FrSky R9M long range transmitter and FrSky R9 receiver series started to pop up some time ago, there was a lot of speculations "it is any good?" "is it a Team Black Sheep Crossfire killer" "cheap Crossfire alternative?". In time, new firmware started to appear, new receivers and so on. And oh yes, EU LBT version finally also appeared. And what… FrSky even was giving R9M for free with X10S Horus.
- FrSky makes radios. Good and very good. Dominates the market. Taranis, Horus and all of them
- TBS makes bloody good long range 868/915MHz long-range radio system called Crossfire that is commonly used by FrSky radio users
- FrSky tries to make its own 868/915MHz long-range system called R9
- FrSky releases new R9 firmware called Flex, new receiver, and new antenna. The new antennas look the same as TBS Immortal-T antennas for Crossfire receivers
- Hell breaks loose and Team Black Sheep steps in and makes a policy that any dealer that restocks and tries to sell both TBS products and FrSky R9/R9M system, is removed from official TBS dealer list
After weekend tests of Betaflight 3.5 and some discussions with Betaflight developers, here are two things you have to (yes, have to) change in Betaflight 3.4 and 3.5 if you did not did that yet. Worth to do it!
Details for halfwave dipole for an 868MHz band are quite simple:
- two 0.8mm copper wires (used for welding) cut to 77mm and solder to the end of coax cable. Here I've used RG174
- put that thing into a 3D printed casing
- put antenna tubes around wires. I got mine from here: https://goo.gl/HrWNcY
- glue everything together
- you are done!
FPV, right? Long range maybe? With a 5.8GHz system, it’s really hard to call it a long-range but what if you put a ridiculous amount of power on transmitter module? 500mW? 800mW? Nope, not enough. Let’s go big and have a practical look at AKK X2-Ultimate which says it does 1200mW of RF output power! 1.2W put into the aether. Wow…