GEB

[Chet]

Hi Green
It makes more sense now. Before I didn't understand the added amplification and saturation that was occurring.
Thank you,
Chet

[green]

I charted some aluminum test targets in another thread awhile back. Charted to 60usec, I said they charted the same. Was wondering if they were the same at a longer decay time. Charted to 500usec, the smaller targets tail off a little more. Charted some threaded aluminum balls and lead weights to 200usec to see the size effect. Charted integrator out with the targets sitting on a 70mm spacer. The delay and sample times are what I had set awhile back. Checked to see if they still canceled ground, they did. Thought GEB might cancel the small lead more than it did. Tx time usec not sec. on chart.

[green]

[The exact timing requirements depend on a lot of things, like coil inductance, damping, and preamp compensation] Carl's reply from Hammerhead, ground balance #82

I've found Tx time and shape effect ground decay also. Charted some target decays with different GEB delay and sample times. Want to try changing some more. Is there something I should add to the chart before I do? Based on Carl's reply trying different timing is something each one needs to do to see what works best. Documenting the tests with the needed information is important. Increasing GEB sample time looks better for the targets I used. Taking an EF sample, not stated on chart. 200mm o0o coil.

[green]

Another target decay chart.

[green]

Reply #49 I entered a -1377 for the nickel in the GEB column. Should have been +1377. The GEB target signals were quite a bit lower for the 15usec target delay so I ran another with a 15usec delay with a longer GEB delay and corrected the - sign for the nickel. I entered the delay and sample times in the Excel simulator and changed ground slope until the ground canceled. Got -1.48, -1.487, -1.44, and -1.485 for the four runs, ball park of what I get when I chart ground decay on a log log chart.