Jeroen Belleman worked out some spiffy non-reflective constant-resistance lowpass filters
and they work (well simulate) beautifully in a thing I'm struggling with.
On Sun, 20 Dec 2015 20:30:54 -0800, John Larkin Gave us:
Some really sad soldering practice there. Also are those X7R caps? Unless they are NPO it will not be very stable.
Another thing is that the ideal spacing (pitch) between turns on a coil is the wire diameter, so the gap between each turn should be a one wire width space. A small piece of anything rigid and drops of epoxy will lock them in place.
A good way to achieve the spacing is with teflon tubing on the mag wire. A lot harder to lock onto a fixture 'bar' though with teflon. Shrink tubing also works. Especially if you are not going to be pushing any power through them.
Looks like a take-off on constant-k design...you just lost host status on Romper Room.
It might look like that to an amateur without access to Wikipedia.
Constant-K was an ancient (1922) way to design mediocre filters, before computers were available. A constant-K filter is NOT a reflectionless, constant-resistance filter. Not that you have any use for filters.
A few people sell constant-resistance filters. It was nice of Jeroen to publish his work. Compared to a conventional LC filter, these are amazing in my circuit.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
Constant K is reflectionless in the passband when properly terminated.
Let me see if I understand your arrogance. We have a filter class invention in use for over 90 years now with what has to be tens of millions of installations, and you call this mediocre, crude and amateur? You're something else.
Of course, I forgot the whole world revolves around your circuit. I don't think Jeroen's criteria of "plenty good enough" is rigorous enough for anything more than ideas for design.
Jeroen's filter is constant-resistance *inside and outside of the passband*, which is the entire point. By conservation of energy, all pure-LC filters must either pass incoming energy or reflect it. Read his PDF.
Mine sure does. We plan to build it and sell it. And it couldn't be sold if I used a conventional lossless filter.
It looks perfect in simulation, with his values scaled to my frequency and impedance. It absorbs anything thrown at it. It's damned good, limited by part tolerances much more than by any of his approximations.
Why are you such a downer? That can't be much fun.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
Yeah, it's not constant-k or m-derived, it's full on network synthesis or computational minimization. (Meaning, the coefficients in the table are derived from the theoretical polynomials for their respective characteristics, at least those for the filter part.)
Tim
-- Seven Transistor Labs Electrical Engineering Consultation Website: http://seventransistorlabs.com
Go away you pretentious little mental midget...
Gee Fred, you always seem so unhappy. Not to put too fine a point on it, but I've heard that you can buy shotguns with flavored barrels nowadays.
Sno-o-o-ort... the perfect Christmas gift for Fred, and DecadentLoser, and... >:-} ...Jim Thompson
--
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I love to cook with wine. Sometimes I even put it in the food.
On Wed, 23 Dec 2015 07:11:34 -0700, Jim Thompson Gave us:
Perhaps... except that it would be you I would be giving "the tasting" to.
Of course you would then not be able to give the review or choose the number of stars it rated.
Some of you retarded bastards are as stupid and uncouth as it gets.
Uncouth? We certainly don't want any uncouth people in this newsgroup.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
If John Larkin were sincere about that, we'd be deprived of our most prolific poster. Jim Thompson - who can be equally uncouth - had posted almost as much as John Larkin when I last looked.
"Couth" isn't exactly the flavour of the month around here. Joey Hey wants us to "respect" his ill-informed opinions, which is equally hopeful, and quite as far out of touch with reality.
-- Bill Sloman, Sydney
This is new from MiniCircuits
I wish I could use them but, for obscure reasons, I probably want reflectionless on one port only. Might try them anyhow.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
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