Electronics

Can You Hear Me Now?

Alexander Graham Bell patented the telephone only 22 years before Simon Lake installed one in the Argonaut I. It would be another 58 years (1956) before the first telephone line connected Europe to the United States.

Today Simon would be elated  with the options available for communicating over distances because he would still recognize its

importance. The communication link for Argonaut Jr. 2010 is no less important for both safety and enjoyment. We plan to install a CB (Citizens Band) radio, an

 underwater voice communication system and multiple cameras connected to the Internet. 

VHS Radio

Radio waves do not penetrate water, not easily or far enough anyhow, but VHS Radio is an easy to use and can carry for miles above the water so when on the surface Argonaut Jr. 2010 will be able to stay in touch with other boats and the shore.  And because she only dives to 20ft, she can easily float a buoy on the surface and extend a cable from inside the submarine to an antenna mounted on the buoy. 

DIY VHS Antenna

We purchases a used VHS radio for $25 and built a VHS marine radio antenna for Argonaut Jr. for less than $10 with instructions off the Internet.  Then we incased the circuit board in plastic so the parts would not be destroyed by the pressure change inside the submarine as it descends.

It turns out that other people have now built this antenna and it has been tested against store bought units.  While it does not perform as well as the store bought unit, it does match carry for three fifths of the distance, which is not bad for a piece of wire inside a PCV pipe.
 

Underwater Voice Communication

Have you ever tried talking to someone while underwater in a swimming pool or while scuba diving?  If so, probably no one understood what you said and you likely swallowed a lot of water.  But talking through the water is quite easy with the right equipment.  The strange thing is that water conducts sound waves better that air.  The problem is that our vocal cords are built for making waves in air and not water.  Commercial divers use microphones inside a full mask that let them talk through air into the microphone and then their voice is electronically converted and placed on a high frequency wave through the water.  Our ears can't detect the high frequency waves, but a receiver placed on another diver or a boat 3,000 feet away can hear the signal. The receiver then converts the waves back into audible sound. The way an underwater transmitter and receiver uses high frequency waves is similar to how a radio above the water. However, radio waves can't travel through water like the high frequency one do.

An easier way of talking through water is to use a microphone to convert sound waves that usually travel through into sound waves that can travel through the water.  This part of the wave spectrum is called broadband sound. Not static or tones, but the full range of sounds our ears hear.  Converting  our voices into broadband sound waves in the water is done by using an underwater speaker or a transducer that is built to move water instead of air. The advantage is that anybody in the water can hear what is being said without any equipment.  Your ears actually do not work very well underwater because, like your vocal cords, they are made for sound traveling through air. But sounds in the water will hit your skull and vibrate the bones in your ear just like your ear drums do above the water.  With an underwater transducer you can hear what is being said over 100 feet away. 

We can also improve on your human ears if we give you a hydrophone.  A hydrophone is a microphone made for listening underwater.  It uses a piezo disc like most regular microphones but the discs are larger and better for picking up the waves that travel in water.  The signal from the hydrophone is then amplified and played out over a regular speaker or headset.  With a sensitive hydrophone you can hear an underwater speaker up to 600 feet away.  Hydrophones also let you better hear all the sounds in the water even when you are sitting on a dock on in a boat.  The hydrophone will let you hear boat motors, waves on the shore, splashes, and even fish like carp feeding on the bottom.

Read more: Hydrophone and Underwater Voice Communications

Video

There will also be a 12v DC Linksys wireless-g router on the buoy also powered off the battery.  That will support 2 or 3 IP web cameras inside and outside the submarine. We are open to suggestions for the cameras.  Pan/Tilt Web Server cameras, wired (not wireless) with Power Over Ethernet would be best, I think.  Sound is not needed.  Infrared LED lights are not preferred on the cameras as they cause too much backscatter. Better to just use ambient light so something with a low lux would be best. I nothing else we can cut the power to the Infrared LEDs to move them to a separate housing away from the camera lens.  Lower resolution will be fine. The boat is only 14ft long and that's about as much visibility as we can hope to get here in Oklahoma.

GPS

Fish Finder

The poor man's active sonar.  Great for telling how far it is to the bottom.

The Buoy

A buoy connected to the submarine is inherently dangerous because the tether can become snagged on something and prevent the submarine from surfacing.  The local lake does get trees in it from floods. And I mean the whole tree!  I nearly hit a 30ft oak tree in the middle of the lake while sailing one day.  However. there is no current in the lake so these are just static obstacles.  There are also brush piles sunk by fishermen as well as jugs and trot lines.  Most of these are in coves or easy to spot.  There is one other benefit - a buoy the size of a car tire inner tube can add an additional 320 pounds of positive buoyancy and help prevent the submarine from accidentally descending below the safe limit.

Things a buoy could do for us:
1) Platform for antennas. Radio, Video, and GPS.
2) If the buoy is an inner tube with a strong tether then it could also provide additional buoyancy at the maximum dive depth.
3) Fly a dive flag and provide the lake patrol with an easy way to identify AJ on the water.
4) House a camera so AJ can see the surface. Lots of those home security units come with a mic and speaker so you'd be able to hear and talk back to the surface as well.
5) A 1/4" air line could be in the tether for a means of providing emergency air supply to AJ from a scuba tanks 1st stage regulator.
6) We would want to be able to disconnect the tether when needed or not wanted.