More on Det Cans

[E4ODnut]

I'm still trying to find what kind of Det Can design works best for me. This is important, because as far as I know, any electronic knock sensor device has to be calibrated, tuned, dialed in, or what ever term you prefer. In order to to this you have to be able to compare an audible signal to the electronic output. As I mentioned in a previous post, the recommended 3/8 air hose and modified ear protectors design just didn't work for me. Could be an age thing.

Best for me was to be right beside the engine. Not always practical. So I got to thinking about sound transfer theory. The old "voice tube" communication on ships worked rather well. Just a long tube from the Bridge to the Engine Room or where ever. From what I've seen in museums, this tube was between 2" and 3" in diameter. So, I figure bigger is better. I substituted my 5/8" heater hose for a 1 5/8" bilge pump discharge hose (light, flexible, cheap) and tried that. Good results. Then I plumbed it into my ear protectors. I just use the right side because it turns out that my hearing is better on that side, so why waste energy on the poor receiving side? The results were very good. Kind of loud, but the ping came through about the same as being right beside the engine.

This might not work for everyone, but it works for me.