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How can I find my old posts & old threads 2 years ago?

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gary350

Well-Known Member
I have moved 4 times in the past 1.5 to 2 years now I am 2000 miles away in the 4th house opening boxes looking for my electronic parts and papers trying to set up my electronic workshop. I have lost all my circuit notes and some of the projects that I built too. If I can find my old posts and old threads all the circuits and notes are probably there?
 

JimB

Super Moderator
Most Helpful Member
Or, at the top right hand corner of the page, use the mouse or whatever to point to your user name (Gary350) and a box of options will appear, click on Your Content and all your posts will be listed.

JimB
 

gary350

Well-Known Member
I found these 2 circuits. I don't remember which one I built but it was probably the 9v project I remember using a 9v battery and an ear phone. The 9v project has a PC drawing top right and bottom this is probably the one I built. I connected the ear phone and battery it worked good but never got to experiment with it. I am trying to build an indicator that detected the sound of an engine as it runs by holding the microphone against the engine. I need to be able to hear every time the engine fires. If the engine is set to run at a speed where it fires 200 times per second I need the detector to read that to verify it really is running at 200. If it is not running at 200 then I need to know what it is running at. The math says engine should be running at 200 but it might be running at 208 or 210 or 194 or 198. The test is to make sure the valves run at the same speed as the engine.



 
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Tony Stewart

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Most Helpful Member
if the valves run at a different "speed" than the Pistons, then the valves will hit the piston.
If the timing is off then. the timing chain is wrong.
If the ignition timing is wrong then adjust the distributor or vacuum advance.
 

gary350

Well-Known Member
if the valves run at a different "speed" than the Pistons, then the valves will hit the piston.
If the timing is off then. the timing chain is wrong.
If the ignition timing is wrong then adjust the distributor or vacuum advance.
It is a pulse jet engine it has no pistons. Only moving part are the valves. Everything has a frequency the engine is a tube 11 times longer than the diameter a formula can be used to find the resonance Hz but being an engine with valves that changes things a bit. The math says 200 Hz but it will not run exactly 200Hz even if the valves are turned to 200 Hz too. It runs plus or minus 2 to 4 all the time and some times as much as 10. The engine runs at average 197 to 203 Hz 99% of the time. I can use the formulas to build an engine but I have to use the University Engineering Lab to test the Hz. I would like to do testing at home just a double check to know what I really have. I received an email today from someone telling me to buy a certain tool it is a laser device I can shine inside the engine as it runs that will read the Hz. I need to check into that.

Watch the video.

 
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MrAl

Well-Known Member
Most Helpful Member
Hi,

With these low frequency circuits you can get a solderless breadboard and wire them both up and test both of them, then see which one you like the best. Solderless breadboards are available all over the place these days, online anyway like at Amazon, etc.
 
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