Ghost vs. Tracer vs. Crossfire (Patreon)

For those who are on my email list and who see this twice, apologies. But many people here are not on my email list and I think you would want to see this.

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When ImmersionRC released Ghost, their new high performance 2.4 GHz control link, TBS hinted that they had something similar in store. Tracer is the answer. Like Ghost, Tracer uses 2.4 GHz for control instead of the 900 MHz frequency used by Crossfire. But there are some key differences between these three technologies that make a comparison between them tricky.

The latency of the control link is a major concern for racers or freestyle pilots who want the most connected feeling. Tracer runs at 250 Hz (about 4 ms latency). Crossfire runs at 150 Hz (about 7 ms latency) when up close, then switches to 50 Hz (about 20 ms latency) when further away. Ghost supports several different modes: 222 Hz "pure race", 160 Hz "race", 55 Hz "normal", and 15 Hz "long range". One important distinction is that Tracer has bidirectional telemetry at 250 Hz, while Ghost's pure-race mode does not.

What about range? To some extent the range question doesn't matter, because the effective range of all of these systems is at least a few km, which is more than a typical video link. As long as your control link outruns your video, who cares? The exception might be Crossfire (150 Hz), which can show its limits if run at 250 mW or lower, but typically still outruns video at 500 mW or higher.

One range test performed by Pawel Spychalsky showed Ghost to have longer range than Tracer. But Tracer is intentionally giving up range to get lower latency, so this result is not unexpected. And Tracer is currently operating at 100 mW to Ghost's 350 mW, so Tracer could increase output power in a future firmware update, which would further close the gap.

Both Tracer and Ghost can get more pilots in the air simultaneously, compared to Crossfire. Especially in the European 868 MHz band, you can start getting micro-failsafes with just 4 or 6 pilots in the air. And some racers are sick of having failsafes during races because some jerk powered up their Crossfire radio in the pits.

One ace up Ghost's sleeve is that Ghost and Tracer are believed to use the exact same RF chip. This means that whatever modulation methods TBS uses, Ghost can follow along via firmware updates if there's demand for it. ImmersionRC is already running private tests of a "Tracer-like" modulation method which runs at high speed with telemetry.

If Tracer and Ghost use the same RF chip, then why did TBS lock Tracer down to one single modulation method, instead of giving Tracer an "ultra long range" mode too? One guess is that TBS doesn't want to compete against its own Crossfire system by giving Tracer too much range. This leaves the door open for Ghost to try to be a do-it-all system: ultra long range and ultra low latency in a single system, rather than having to switch modules depending on your mission.

If you're running Crossfire now, should you switch? Crossfire is great for most people who use it. The main person who might switch to Tracer would be a racing pilot who needs the absolute lowest latency, doesn't care as much about tens of km's of range, and who is tired of micro-failsafes during races (especially in Europe).

As for Ghost vs. Tracer, the biggest advantage of Tracer seems to be TBS's incredibly mature and robust Crossfire framework. Crossfire has been beat on for years in the real world; Ghost is still working out launch-day bugs and feature requests. Tracer will integrate with TBS video transmitters and Fusion module. But in terms of raw performance, it seems like ImmersionRC's willingness to use all modulation methods available means that Ghost can be a jack-of-all-trades to TBS's master-of-one.