ImmersionRC just launched their new Ghost RC system after 4 years of development. IRC Ghost radio control system is designed for long range with best-in-class race performance.
The ImmersionRC Ghost is not just one product, but a whole family of products that will be rolled out over time, including an external JR module, receivers, antennas and PDB. Pretty much like the TBS Crossfire RC system in that sense. But Ghost operates on 2.4GHz, unlike Crossfire’s 900MHz.
Ghost also has the ability to integrate with other parts of the FPV ecosystem. So far we have been told that Orqa FPV.ONE goggles already supports Ghost radio receivers on the FPV.Connect board, but we haven’t been given detail what that actually means yet.
Where to Buy
Available at these vendors:
- BG: https://oscarliang.com/product-nlar
- GetFPV: https://oscarliang.com/product-9ypm
- RDQ: https://oscarliang.com/product-94it
- Amazon (affiliate link): https://amzn.to/3cT1adK
In the package, you get a TX module with two antennas, and 3 receivers with antennas and silicon wires.
Advantages of ImmersionRC Ghost
LoRa – The Key to Long Range
Ghost is an RC control system that operates on 2.4GHz with long range and low latency in mind. Although I feel like the Ghost system is more racing oriented, it’s capable of long range flying too.
This is because Ghost uses LoRa protocol, which is different than traditional technology used in most existing 2.4GHz radio systems. Lora offers much higher sensitivity, meaning it has much better range. Many long range RC systems today use LoRa, such as TBS Crossfire and FrSky R9. That means Ghost can do long range too!
It is 2.4GHz
With 2.4GHz, antennas can be made much smaller compared to 900MHz.
I’ve been using the 900MHz Crossfire for years, mount its antennas on a small drone is always challenging, and often performance is impacted because of less ideal antenna orientation and placement. With Ghost’s smaller antennas, this would be less of a problem.
According to ImmersionRC, the other advantage of 2.4Ghz is the wider bandwidth compared to 433/900MHz, which allows more pilots in the air simultaneously without packet lost. It also doesn’t interfere with GPS as much.
The other arguement is that 900MHz has better signal penetration than 2.4GHz, while it’s true, 2.4GHz is still a lower frequency than 5.8GHz which is used for our FPV video system. Therefore on paper, your RC signal would still out-range your video signal. But of course this is debatable as it involves many other factors.
Super Fast Update Rate
The advertised update rate of the Ghost system is 222.22Hz (or 250Hz? I am getting conflicting data in the manual), which is ultra low latency even compared to Crossfire’s highest 150Hz. This is obviously great for racers where lower latency can help them react faster. However 250Hz is only available in “Pure Race Mode” or “Race250” mode, which either disables telemetry or uses the less range MSK modulation instead of LoRa due to the lack of bandwidth. The next option down is Race Mode which offers 166Hz of fresh rate, but with Telemetry enabled as well as using the robust LoRa protocol.
In Ghost’s normal mode, the update rate is lower at around 55Hz (18ms). Doesn’t sound very impressive, but it’s still quite fast!
But Crossfire can do up to 150Hz right? Well, yea, but when it’s in 150Hz it’s not actually using LoRa. It’s only using LoRa in 50Hz. So really in normal mode, both systems are quite similar. When it comes to racing, I think the Ghost system has an edge over Crossfire thanks to the super fast frame rate. But for extreme long range flying, I think Crossfire can still outperform Ghost given the lower frequency.
A Closer Look at the IRC Ghost System
Ghost JR Module
The Ghost transmitter module supports any radios that has an external JR module bay – including the Frsky Taranis, Jumper T16 and Radiomaster TX16S.
It has a small mono-color LCD screen for menu and signal information, a joystick button and color status LED.
It also has dual RP-SMA antenna connectors and a USB port for firmware updates.
- Retail Price ($USD): $89.95 USD (1x JR Module, 2x Tx Antennas)
- Frequency: 2.4GHz Band
- Uplink RF Power: 16uW – 350mW (+/- 0.5dB)
- Frame Rate: 222.22Hz (pure race), 166Hz (race), 62Hz (normal), 15Hz (long range)
- Format:Standard JR Module, tested with FrSky Taranis™, and RadioMaster™ radios
- Antennas: Twin antenna, with Tx-side diversity. Antennas are 2.1dBi Dipoles
- Compatibility: Any R/C Tx which accepts JR modules (Taranis, etc. )
- Serial Formats: SBus, GHST (Auto-Sense)
- Firmware: USB Upgradable (with OTA updates for receivers)
- Power Supply: 6V-20V, 1.75W @ 400mW, ~250mA at 7.4V
- Modulation: Chirp Spread Spectrum + Adaptive FHSS
- Binding: Bidirectional, with confirmation and protocol negotiation
The Atto receivers for the Ghost system is absolutely tiny, similar size to the Crossfire Nano. Thanks to the 2.4GHz frequency, the antenna can be made much smaller and lighter than 900MHz. 2.6 times smaller to be exact.
Here’s a closer look at the Atto receiver, top and bottom sides of the PCB. The four solder pads are Ground, 5V and two UART serial connections.
- Retail Price ($USD):$29.95 USD (1x Atto Receiver, 1x qTee Antenna, Silicone Cables, Heat Shrink)
- Downlink RF Power: +13dBm
- Sensitivity: -117dBm in Long Range mode
- Serial Formats: SBus, SBus-Fast (200k) , SRXL-2 (400k), GHST, SBus Inverted
- Firmware: Over-the-air (OTA) upgradable
- Power Supply: 5V recommended, as low as 3.3V tolerated
- vTx Control: Tramp control from ‘T’ pin on Rx, regardless of selected serial format
- Dimensions: 14.8mm x 11.5mm, 0.6g (w/o antenna)
- Rx Noise Floor Analysis: Auto on power-up, or on demand from the Tx
Crossfire or Ghost?
Crossfire is a more mature and established system, it’s proven to work reliably and very easy to use and setup. Ghost is so new, it will take a while (months or even years) to catch up.
Crossfire can do pretty much anything I want and I don’t do much racing, so I am not switching to Ghost just yet. But I am quite fond of the smaller antennas, and for those who only fly micro quads this is huge!
I am going to do a detail setup guide for Ghost, but because it’s so new, things can change rapidly, so I will wait.
Right now, you’ll need the latest OpenTX firmware to use Ghost. Older OpenTX builds might not have the “GHST” (Ghost module) added to External RF Mode yet.
With receivers, you can use SBUS protocol, but it doesn’t provide telemetry. To use telemetry, you have to use the new “GHST” protocol which is only supported since the new Betaflight v4.3.
- Aug 2020 – article created
- Feb 2021 – updated image, some info, and added product links