Re: Transducer Cable had an oopsie.
I can tell by your connector selection that you must be an audio guy.
I suggested audio connectors because fish/depth finders use sound waves, and because they are widely available. Both RCA and XLR connectors are capable of passing signals at 200kHz.
In this application the sheilding is pretty much irrelvent. The cable in question is nothing more than a two conductor with foil cover shield. The transducer is running off pulsed AC. No temp or speed signals to isolate. Could have used wire nuts and it would have worked just fine.
Sound waves are AC signals and are susceptible to interference. This isn't so important during the pulse/output part of the cycle as it is when the device is "listening". Unamplified audio inputs need to be shielded.
There are two types of AC signal cables: balanced and unbalanced.
An unbalanced cable has one center conductor and either a foil wrap with a bare "drain" wire or braids/wraps that serve as both shield and ground connection. This is the type that I believe Joel described. It's identical to that found on an RCA home stereo cable.
A balanced cable has two center conductors in a twisted-pair configuration. If it is shielded it has a third conductor -- either foil or braid w/drain wire.
In both types, the outer metal sleeves of the connectors allow the shield to be continuous and protect the inner conductor.
