What's a good Radio?

[NavyShooter]

Ahoy Gents,

What is a good radio for controlling an RC sub nowadays?

I've got a Radiomaster TX16S for my other models (one TX + many RX and different model configs)

Is that a suitable model for subs as well, or should I get a dedicated Sub Radio? I'm thinking I should get a dedicated sub one...and I understand that lower freqs are better for signal propagation?

How many channels do I *need*?

Throttle, Rudder, dive planes, ballast fill/empty, Torpedo launch? (maybe?)

I found this one that's a Dual Band 2.4 GHz and 900 MHz:

FrSky Tandem X18 Radio Transmitter Dual-Band 2.4GHz & 900MHz TD System 4ms Low Latency Color Touchscreen ETHOS OS Metal Hall Gimbals for Airplane Sailplane Multi-Rotor and Helicopter(Blue) : Amazon.ca: Electronics

[Surcouf]

I have the FrSky X18, and really like the setup. Programming model settings and mixes is relatively simple- especially if you look at the videos put out there. When I was doing trimming and initial sea trials on my HMCS Victoria, I was able to maintain communication with the receiver on 900 MHz down to about 2.5' in a saltwater pool. In a freshwater location it should do even better. I have not increased the power output yet to see how much that would affect the range at depth. The transmitter screen showed that I had 2.4 GHz for a short bit below the surface as well.

Note also that I had the transmitter on the side of the pool facing away, as I was in the water with the model. If I was standing at the edge facing the model, I would expect better reception. I was also able to verify the sub fail safes responded as programmed when it lost signal.

How many channels is up to you, but the system is capable of more than you will ever need in a submarine. There are 6, 10, and 18 channel tandem receivers available for the dual frequency.

[Subculture]

The TX16s is capable of dual band 900mhz/2.4ghz isn’t it?

Use the one you have.

[NavyShooter]

The TX16s is capable of dual band 900mhz/2.4ghz isn’t it?

Use the one you have.

I think it's only 2.4.

[Surcouf]

I believe the newer versions (Mk III) of the Radiomaster TX16S are capable of both 2.4 GHz and 900 MHz already. If I understand correctly, older variants can be upgraded with an external module like the Nomad Dual Gemini Xrossband ELRS module that does both.

Definitely worth verifying based on your current transmitter and look at cost difference and capabilities versus a new radio. The X18 is a good price, but there is also something to be said for using a familiar radio and menu system.

[Fishb0y]

I have both a FrSky X18 and an X20R. Personally, I think the X18 fits my hand a little better, and it’s also a bit less expensive.

With LUA scripts—and some help from ChatGPT—I’ve been able to customize my displays exactly how I want them. I can also take advantage of the built-in stabilization in FrSky’s receivers, so there’s no need for a separate Angle Keeper.

I’ve also got some ideas for experimenting with their pressure telemetry module, but I think that project is still a ways down the road.

[Marylandradiosailor]

External radio module plugin for the TX16 gives you 900 mhz elrs which is best for subs. In addition BR3 receiver provides 500mw for telemetry, I think the highest frsky telemetry power is 100mw.

[timsenecal]

If you want to keep your TX16s, I would recommend the following items: BetaFPV SuperP 915mhz PWM receiver, and BetaFPV ExpressLRS 915MHz Micro TX Module... Then upgrade the transmitter to EdgeTX 2.12.4, and all the ELRS components to 4.1.0. Those are the latest firmware for both systems, and offer the most functionality.