Subsea camera cables carry all camera power supply, control and video feeds inside one long multi core cable with no real problems although the voltage and current is low, usually 12V DC @ aprox 1A (at the surface end anyway). The video coax is in the centre of the cable with the other cores twisting around it. AC at mains potential might be a different story but that would be insanity anyway.
I often ended up with mains cables running parallel to signal cables in my HIFI setups with no apparent problems.
I often ended up with mains cables running parallel to signal cables in my HIFI setups with no apparent problems.
Stands to reason that you either have a very large head, or a superior olive in your martini (msoc, not vsop) to catch a 1.2 uS ITD in real life.
(easier than finding a decent shirt with a 20'' collar size, we all have our tiny problems)
The subsea cable guys run an amp or so from one continent to another, -5kV at one end, +1 Amp at the other, with occasional up to 300 volt steps as the earths magnetic field twitches...
😱 I bet the maths gets complicated. No wonder they like to use fibre optic cables nowadays.
You can actually purchase cable made up like that in the pro industry.
I attended a three day emc seminar put on by a lab maybe 10 years ago and learned a bunch but then realized I actually did know much of it with a bit of thought. I did leave and purchase some test equipment, spectrum analyzer antennas and various pickups. I like to measure.
I attended a three day emc seminar put on by a lab maybe 10 years ago and learned a bunch but then realized I actually did know much of it with a bit of thought. I did leave and purchase some test equipment, spectrum analyzer antennas and various pickups. I like to measure.
Wayne,
Yes you can purchase some nice snakes for pro audio but I just assumed that everything internal was twisted pairs and such with lots of shielding. They can get rather expensive. I still to this day do an over under figure-8 when I wind cables to keep from breaking any wires, something so many don't seem to have ever been taught when winding a cable. Nothing like seeing someone wind a mic cable around their arm and tie a knot or tie them up like a power cable for construction.
Yes you can purchase some nice snakes for pro audio but I just assumed that everything internal was twisted pairs and such with lots of shielding. They can get rather expensive. I still to this day do an over under figure-8 when I wind cables to keep from breaking any wires, something so many don't seem to have ever been taught when winding a cable. Nothing like seeing someone wind a mic cable around their arm and tie a knot or tie them up like a power cable for construction.
Anhydrous ethanol, not something you are going to see often and it won't stay that way long as soon as it is exposed to air. I distilled some once from a starter of 151 rum and wasn't about to taste the final product. Used it for a solvent extraction at the time.
Sy,
I guess you just place an order with Edmonds Scientific or Merck or someone and you have your dry martini!
I guess you just place an order with Edmonds Scientific or Merck or someone and you have your dry martini!
Indeed if it’s not measured it has no value and you know what you do when you know what you measure.
In our case acc to Nelson Pass “the ear is not a microphone”, so for to validate what we measure, we have to make a link with the way we perceive what we hear, thus:
A turntable’s Wow&Flutter linked to music and psychoacoustic effects:
Rotational speed variations rates higher than 1.5Hz start to be perceived as timing variations.
Rotational speed variations rates of 4-7Hz are readily noticeable (4Hz=tremolo optimum, 6-7Hz =vibrato optimum)
Rotational speed variations rates of 11-15Hz are perceived as damaging the melodic tone sequence and the proper dying-out of music tones. (This falls into the “echo window” range (50mms-100ms)
Rotational speed variation rates higher than 25-30Hz produce the perception of roughness at mid freq tones. This falls into the “Haas effect” range (5ms-35ms)
George
You could adapt an optical rotary encoder to capture the speed of he turntable with virtually no additional drag. Something like this and a little 1/4" tubing would do the job New Incremental Rotary Encoder 400P R 6mm Shaft 5 24VDC | eBay It doesn't have the same number of pulses as a test tone but it would be around 200 Hz, enough to see the variations adequately. There are higher resolution encoders for more money on eBay. On a direct drive you could hack into the existing pickup.
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