500mw output tests for RC submarine at 915mhz for under water control

[Thorbrandr]

Just so. So far I've had mine out 25 meters in so with some poor lighting, and running submerged on dead reckoning. A bit hair raising, especially when the water is cold.

If the telemetry works at that range (doubtful) it may open possibilities. There is still a question of surface reflection off the water, so the range may be shorter.

[Sinksalot]

I was reading up on this receiver and it says it has a Receiver sensitivity:Up to -130dBm. Receiver also has an onboard LiPo battery to operate
in beacon-mode. That is one thing I will test to see if it works underwater. Basically a signal is sent out and using the transmitter it can point you to where the receiver is.

[Sinksalot]

Ok first one of my subs to be tested with a 915mhz TBS crossfire receiver will be my Neptune.

[trout]

Tim Senecal uses 900MHz frequency range for many years now. He posted on different sites. He noticed certain waters had more issues than others. The 433MHz he uses works well. I am really glad to see that you are doing a more thorough investigation on this and documenting your trials. Thank you!

[Sinksalot]

Tim Senecal uses 900MHz frequency range for many years now. He posted on different sites. He noticed certain waters had more issues than others. The 433MHz he uses works well. I am really glad to see that you are doing a more thorough investigation on this and documenting your trials. Thank you!

It was one of Tim Senecal videos a bit ago that started me thinking about it. I tried to contract him to ask, what radio, 915mhz module and receiver he uses. Some people said he use some type of crossfire 915mhz stuff and some people said he uses 915mhz Express LRS stuff. I went with the best 915mhz receiver I could find and the best 915mhz module, also the most powerful, TBS crossfire stuff made for long range aircraft. Basically a drone receiver with servo inputs with 8 channels. I also bought the same TBS crossfire 8 channel receiver in a smaller form, with smaller antennas.

[PerryShark]

Even though this thread is from a year ago, your tests for the RC submarine at 915mhz are still quite fascinating. The fact that the transmitter is outputting 500mw of power and has the potential to go up to 2 watts is impressive. It's clear that you've put some serious thought and effort into this project.

Having the receiver and servos in a water-tight clear box for visibility is a clever idea, and it's great to hear that the tests have passed. If you have that video of the second test, sharing it could provide valuable insights for the community.

For those interested in RC submarines and underwater control, exploring https://www.sub-merge.com/ might still be an excellent resource.