Hi Richard, that Extech ground tester looks like a very useful device....any ideas of how it works ?....possible diy ?.
Dan.
Dan.
The extech 382357 replacement for the 56 is only 1359 USD . I like your idea Max !
🙂
Look like a clamp Meter.
Fluke Clamp Meters, Amp Meters and Clamp On Ammeters
Just it measure by comparing the currents from a single source to earth through 3 different serial resistances.
You can do the same with a single multimeter.
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It works by inducing power into the ground system and measuring the current flow. It assumes that there is more than one path to ground to complete the loop.
For many ground tests the method was to connect a 40 amp fuse between the 120 volt AC power line and the safety ground. If the fuse blew the ground connection was adequate. Really!!!
Of course if you gave a bare ground wire you can measure the voltage across it and the current through it.
For many ground tests the method was to connect a 40 amp fuse between the 120 volt AC power line and the safety ground. If the fuse blew the ground connection was adequate. Really!!!
Of course if you gave a bare ground wire you can measure the voltage across it and the current through it.
I now know 🙂, that the magic is called stakeless earth testing.
The clamp on head has two coils...one induces current into an earth conductor, and the second coil measures the induced current, the smarts works out the effective loop resistance of the circuit under test.
Might be useful for identifying ''Pin 1"' problems.
Megger DET14C - APPLICATION NOTE is a good primer.
Dan.
Harlan Ellison wrote an interesting story about such a TV in the possession of
a child. Of course it wasn't the TV that was doing the trick...
I started to say nice story but I wouldn't want to give the wrong impression
about Ellison's approach to stories.
😎
Correction: Google had it http://en.wikipedia.org/wiki/Jeffty_Is_Five
and it was a radio.
a child. Of course it wasn't the TV that was doing the trick...
I started to say nice story but I wouldn't want to give the wrong impression
about Ellison's approach to stories.
😎
Correction: Google had it http://en.wikipedia.org/wiki/Jeffty_Is_Five
and it was a radio.
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Seems like just the right type of TV to watch old shows like Perry Mason and other black and white vintage shows. Gives that vintage feel to an old show that was never in color.
But the tube is supposed to be round with a rectangular mask! The rectangular tubes are from the later 50's.
Do you know how hard it was to get a working BW tube to begin with!
It is loaded with 500 hours of shows replayed in random order. Goes through the entire list before repeating. I still need to mount the rabbit ears.
Defiately looks 50's, I've been cathching up on Boris Karloff's "Thriller" lately. The oldest Perry Mason's are quite a surprise too.
My oldest is Captain Midnight. Newest is the first season of Man from UNCLE. I also got some Captain Gallant and Sgt Preston. The most time was ripping the files. Most were 30 minutes which take 15 to rip! Disc is 1T.
Yes, but does it have the commercials too? Those are part of the experience.
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