Underwater Camera - hmm

[ramius-ii]

Hi Guys]http://www.subcommittee.com/forum/icon_smile.gif
Interpol is

Hi Guys]http://www.subcommittee.com/forum/icon_smile.gif[/img]
Interpol is correct about using higher power transmitters and the rules vary per country. I picked 1.2 GHz since cordless phone occupy most of the 900 MHz band. At 1.2 GHz, using RG-142 coax, the antenna lengths I was talking about are about 1.67 inches each.

As for sensors, soon, very, very soon! In the last SubCommittee report, there was an article about the future of subs and the writter, Volker, I think knows about acoustic triangluation and a location methode.

Best, Ed

[interpol]

I am actually trying to

I am actually trying to create a reliable way to control the sub via acoustic transmissions. The range difference between acoutsic, and radio, is quite big.

If anyone else has done research on this, help would be greatly appreciated.

[interpol]

By the way, just so

By the way, just so you guys know, some companies have acoustic stuff that will transmit 19.2Kbps at a range of 2 kilometers.

That's why I want to use acoutsic, and not radio.

[akulaii]

Hi guys,
Thanks ! and especially

Hi guys,
Thanks ! and especially to Ramius-II.

Just one thing. NO electrical connection to the shield of the transmission line, right?
I'll try out the design as soon as I can.

Best
AkulaII

[ramius-ii]

Hi Akula-II]http://www.subcommittee.com/forum/icon_cool.gif
This is

Hi Akula-II]http://www.subcommittee.com/forum/icon_cool.gif[/img]
This is tough to describe without pictures Yes, you do connect to the shield.
transmission line shield to 1st section center wire.
transmission line center to 1st section shield.
Building upward, the now unconnected end of the 1st section goes:
1st section center to 2nd section shield.
1st section shield to 2nd section center.
Building upward some more, the now unconnected end of the 2nd section goes:
2nd section center to 3rd section shield.
2nd section shield to 3rd section center.
Basically, you are alternating from center to shield, shield to center as you add sections. Hopefully, this all makes sense.
Another way of thinking of it is the shield of the transmission line "reflects" the main signal carried by the center conductor. So by swapping the two in the 1st section, the center conductor becomes the signals reflector forcing the signal out and away from the center in an omni-directional pattern. It's really difficult to explain all the physics involves (especially since I don't understand them all myself). The credit for the design actually goes to one of the top antenna designers in the U.S.A. who saw my Typhoon and the antenna limitations / requirements. When I get my transmitter back from being modified (right now it's on an aircraft band) I'll be testing in the jacuzzi! Maybe I can even get the blond next door to be an underwater camera model!

Best, Ed

[tang]

I was pondering the use

I was pondering the use of a wireless fish finder as a way to "see" underwater. There is a Hummingbird unit that transmits at 115kHz. It's intended to float while transmitting. I would imagine it wouldn't have enough range once submerged, but I'm not knowledgeble enought to make a proper guesstimate.

Can anyone offer some advice on these devices?

p.s.- One of the drawbacks to these are the limited view. On most models, they only offer a 90degree downward facing view.

[wingtip]

i have looked into this

i have looked into this device as well... looks like it would be fun to tinker with...

as for the underwater cam try this link they have some heavy duty stuff and some ready to go miniature stuff

http://www.deepsea.com/camera.html

and check out their SS35C

"Color mini video and lighting system. Only 3.47cm (1.37 in) in diameter. Extremely durable. Crisp, wide-angle image. Rated to 400 meters."

[bcliffe]

Tang,

Your guesstimate is correct, the

Tang,

Your guesstimate is correct, the SmartCast fish finder is designed for surface use only. The wireless signal is lost once the tansducer is submerged in only inches of water.

It is a great toy for hunting submarines though.

Cheers
BC

[fbradasc]

I am actually trying to

[color=#000000]

I am actually trying to create a reliable way to control the sub via acoustic transmissions. The range difference between acoutsic, and radio, is quite big.

If anyone else has done research on this, help would be greatly appreciated.

Interpol, I'm thinking to control the sub model by acoustic signals too.

I've tought two ways to do that]

[tang]

Ooooooooh WOW That sounds much

Ooooooooh WOW That sounds much too much exciting for you guys to hide on your emails. Please consider hashing out those details in a thread here on subcommittee!!!!!