Recent content by DKGrimm

The word goniometer has yet another use. In radio direction fining receivers, it is a set of coils -- two fixed and one movable -- used to combine signals from two perpendicular receiving antennas to measure the arrival angle of the signal. It was invented jointly by Ettore Bellini and...

Your question takes me way outside my field. I'm sure others can give a better answer. My read on what I googled on the subject is that a theodolite is an optical goniometer that can measure angles between visible objects in both the horizontal plane and can also measure elevation angles. A...

Nostalgia strikes again. I put a lot of miles on a planimeter measuring crop acreages an aerial photos for the Wells County Agriculture Stabilization Committee during summers when I was in high school. We had a quality control process where we essentially had to measure each field three times...

And to think I've gone through almost my entire life thinking that I was the only one who always struggled with keeping views consistent -- and have a bunch of mistakes to prove it. Don

Just happened to remember, the S/G driver has a blocking diode on the power input to block negative voltage swings. Also, try clipping the scope input lead to the S/G driver GROUND and test it again. Does the pulse go away? The pulse could easily be coupling into the scope lead or the scope...

Hmmmm. sounds to me like something that could be induced by coupling from the spark wiring. I've even seen this magnitude of pulse coupled into other circuits, even the ground. Does a spark plug resistor of 10 kohms or so make it go away?

Peter, I've spent quite a bit of time with the Sage-Gedde driver; I even made my own circuit boards and bought parts for six of them. I used that driver for most of the coil testing I did. I see you were part of the discussions in the thread "Tests of CID Ignition Modules," and this question...

Never had that happen while running but did several times when starting. My startup routine now is to spin the engine by hand for about 20 cycles with gas on and ignition off, then switch on the ignition while it is still spinning.

Perhaps it is not a coincidence that I took courses in lightning protection and had that as one of my jobs for a time. It's amazing what a 100,000 amp lightning pulse can do. If you ever want a job with a surprise around every corner, that would be a good choice. Don

As far as this very fast pulse when the spark first fires, I don't think the source of the spark would make any difference. I was working as a mechanic in my dad's garage when resistor plugs or resistor harnesses were introduced to the automotive world. Cars all had AM radios; FM had not been...

Petertha, You raise a very interesting and important question. . . . but not an easy one. I bought a 1Ghz sampling scope and tried to do a little research. I found out early on that the noise from the spark current coupled into grounds and wires and even into the scope itself, and I really...

Oh, yes; ignition. I had no end of problems with conventional points and coil. I kept getting sparks from contact bounce at bad times and got very erratic firing. I ended up with an extension of the slide valve underneath the base with a hall sensor and a "buzz coil" CDI. It fires while the...

Thanks for your comments, raveney. The story of the reamer is that I originally set up with a double-length boring bar between centers in the lathe to bore the cylinder, but I just could not get it to quit chattering, so I mad and ordered the reamer. Then I lapped the cylinder to make it...

I love this engine. Here's some construction pictures from my build in 2006. Cylinder is cast iron, drilled and reamed and lapped to size. Still take it to every engine show.