Pingers and Hydrophones to save your sub

Putting an underwater sound generating Pinger on your sub when combined with the use of an onshore hydrophone means that you are almost certain to be able to recover your submarine (if or when?) you get a sinking.

The Pinger chips are easily available for AMS members (for £5) but the hydrophone can be an expensive item to purchase.

A number of people have made their own hydrophones based on the Loughborough University model.

I include a reference to this to give you an idea but we have a lot more expertise within the AMS and I will post more in future. Generally when the AMS meets e.g Alfold, Barrow etc someone has a hydrophone so you only need the Pinger on your submarine but the more hydrophones out there the better!

The instructions for the very useful Loughborough unit can be found at:

The hydrophone itself:
http://sonar-fs.lboro.ac.uk/uag/downloads/bender2.pdf

The preamplifier:
http://sonar-fs.lboro.ac.uk/uag/downloads/preamp2.pdf


(Note to Webmaster, I will also put this in the electronics section.

I've put this thread over in the electronics section.

Could I recommend also getting a set of lightweight nylon waders (About £30 on eBay).
They are all you will need to recover your sub in many boat ponds. You get close to the sub using the hydrophone then feel for it with your feet. I speak from personal experience the photo is on Facebook somewhere!
Waders are much better than swimming in winter too.

Some competition for the Pinger coming from the use of openLRS technology.

https://www.theassociationofmodelsubmariners.com/t83p120-2-4-ghz-and-submarines-also-458-9-mhz#9939

Have a look at my posting about using a Yagi directional aerial.

My trials with this suggested that in relatively shallow water (about 4 feet) you could narrow down the search area for a lost sub to about a 20 foot diameter circle.

About the same as a Pinger and hydrophone. However the Pinger has self contained batteries lasting several weeks. The openLRS receiver will only transmit as long a your main battery lasts.

What would be really good is if the sunken sub could transmit a GPS location back via Telemetry. As far as I know, the GPS signal does not get through any depth of water?

But there is still life left in the Pinger concept!