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root <NoEMail@home.org>: Jun 16 04:19PM I was looking through an old copy of Seely's book. My favorite tube (on the basis of clever design) was the Phantastron. Really slick.

jhewitt03041976@gmail.com: Jun 16 07:45AM -0700 On Wednesday, June 17, 1998 at 2:00:00 AM UTC-5, VPR wrote:   > anybody know where to get em or how to build it?   > -- > remove no_spam_ when replying   Yes, electronic hobbyists used to call these devices "boxes", there were bunches and depending on the function, the code name would have a "color" in front of it, A "Blue Box" would tell AT&T or Ma-Bell that you would hang up before the call is answered, a "Black Boxes", Red, blue, Green, just about any color of the rainbow.....and yes, they "DID" work, but in this day of digital perfection, all those "Boxes" are paperweights in the modern world, they just don't work anymore, the companies who were getting hacked figured out why these boxes worked and fixed the issues, the only place devices like these work now are backwards countries whose "modern" technology is 30+ years old. Sorry

"pfjw@aol.com" <peterwieck33@gmail.com>: Jun 16 08:24AM -0700 You responded to a 22 year old post.   Peter Wieck Melrose Park, PA

Adrian Caspersz <email@here.invalid>: Jun 16 04:46PM +0100 > You responded to a 22 year old post.   The OP's jail sentence has probably expired, he might be able to follow up on the wisdom of his bill dodging investigation?   -- Adrian C

Fox's Mercantile <jdangus@att.net>: Jun 16 11:04AM -0500 Facebook is flooded with ads for "The electric companies hate these" Goodies about the size of a pack of cigarettes that are supposed to lower your bill by at least 50%. Just plug them into any convenient wall outlet.   Watt meters are simple, they expect the load to look like +R(ohms) +J(inductance). If they see +R -J they will slow down or run backwards if the capacitance across the line (on the load side) is high enough.   But, capacitors big enough to accomplish that are the size of a 5 gallon Jerry can.     -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

Tim R <timothy42b@aol.com>: Jun 16 05:59AM -0700 On Friday, March 27, 2020 at 8:02:55 PM UTC-4, amdx wrote:   > Marantz or Macintosh? But really in the end, you have to have a pretty > poor amplifier for the speakers not to be the limiting factor.   > IMHO, Mikek   This. Given the effects of speakers, room acoustics, and whatever you're using for input, the quality of the amplifier is likely down in the undetectable range.   But, consider another complicating factor. The spectral response of your ears has to be vastly different from what it was a couple decades back. If you found that identical amp somehow preserved without any degradation, I doubt it would sound the same, now that so much of your high frequency hearing has disappeared.

"pfjw@aol.com" <peterwieck33@gmail.com>: Jun 16 07:52AM -0700 Amplifiers..... I have waited this long. But here goes:   a) With a very broad brush, the single significant characteristic of any given amplifier is Headroom. How much unclipped power can it deliver, for how long. b) Speaker power ratings are not based on what an amplifier can deliver, but on how much power the speaker can absorb continuously over what spectrum. So a speaker rated at 50 amps (theoretically) can absorb 50 watt of power continuously of a standard spectrum. A 50-watt continuous sine wave, for instance would pretty much melt any driver it was directed to in short order. c) The single most significant aspect of any signal is Peak-to-Average. So, most (not all) heavy metal has a P/A of about 10 dB. Well recorded classical music will have a P/A of about 20 dB, with some (Saint-Saens Organ Symphony) as much as 30 dB (again, well recorded). d) An amplifier, theoretically, is not to add or remove artifacts to the signal. Most, if even reasonably well designed, achieve that status fairly well.   Cutting to the chase: I keep and use regularly, three significantly different styles of speakers. They are all 'rated' at about 50 watts. They are all relatively inefficient at 85 dB at one meter at one watt. Two of the three pairs are driven by what is best described as brute-force amps (more than 200 wpc/rms) and are in large rooms. The last is a sub/sat system driven by a 17 wpc/rms tube amp in a very small room.   In every case, the limitation on the volume I can achieve is the amplifier headroom, not the speakers. The one brute-force amp is *adequate* to drive the Maggies playing the aforementioned Organ Symphony at below-ear-bleed volumes. It would clip if played any louder, whereas the speakers would be fine but-for the clipping (and for the record, most solid-state amps clip badly). The baby Dynaco (ST-35) does well enough at far-below ear-bleed levels in a small room. As it is tube, I do not worry about clipping damage if I go over-the-top on volume.   The AR3as make up the third-most-used set, also driven by a brute-force amp, and also do nicely in a medium room. And, yes, I do moderate so as not to clip.   Cutting to the chase, headroom is singularly critical to decent sound reproduction.   Peter Wieck Melrose Park, PA

Tim R <timothy42b@aol.com>: Jun 16 08:12AM -0700 > d) An amplifier, theoretically, is not to add or remove artifacts to the signal. Most, if even reasonably well designed, achieve that status fairly well.   (and for the record, most solid-state amps clip badly). The baby Dynaco (ST-   > Cutting to the chase, headroom is singularly critical to decent sound reproduction.   Okay, trying to make sense for my uses, I think you're saying: 1. most amps don't distort 2. unless you use enough power to clip   and I never do, so for my purposes, amplifiers are not the weak point.   3. But if you want to play really loud, which you might need to do when your music has a wide dynamic range, you need lots of power in the amp.   And the corollary might be that given enough watts per channel, decent amplifiers are equivalent.   Did I get that right?

"pfjw@aol.com" <peterwieck33@gmail.com>: Jun 16 09:02AM -0700 Pretty much got it right, yes.   Amplifiers are very seldom the weak point, unless driven to clipping on a regular basis.   Peter Wieck Melrose Park, PA

John Robertson <spam@flippers.com>: Jun 15 10:17AM -0700 On 2020/06/08 7:44 p.m., Mike S wrote:   > Farberware Classic 1.1 cu. ft .1000-Watt Microwave Oven $99.99 > Farberware Classic 0.9 cu. ft. 900-Watt Microwave Oven $89.99   > https://www.hsn.com/shop/50-99-ranges-and-microwaves/ho0514-6664   The question is, how long would these MWs last under the same usage as the original Panasonic? I suspect perhaps 5 years...so repairing a machine that lasted 10 years, might cost $100 - and give it another ten years. Vs. replacing it with a cheaper design that may last 1/2 the time? Is that really a better deal? Plus you have saved landfill.   John :-#)#

Jeff Liebermann <jeffl@cruzio.com>: Jun 15 11:08AM -0700 >blown. Microwave wouldn't start cooking so I ran it for a moment with >the cover off, transformer did a light and smoke display and now it >smells like fireworks.   Impressive. I know how you feel: <http://www.learnbydestroying.com/jeffl/pics/drivel/#burned-yam.jpg> That's what happened when I cooked a yam (potatoe) for 16 minutes instead of 6 minutes. It was glowing bright red inside just before I opened the door. The inside of my Panasonic NN-S533WF (Sensor 1300w) microwave oven changed from white to yam colored. I tried to clean it, but the yam color is permanently baked into the paint. The S/N label says made in 2003. I think I received it as a present in 2005, making it 15 years old. It works as well today as it did in 2005 with no change in output level. That's one of the benefits of an inverter oven.   >I made sure the magnetron was discharged and between the two connections >I am getting 0 ohms, but I only have a basic multimeter. Between those >and the casing is open.   Try measuring again with a much better ohmmeter or preferably an ESR meter, which will measure resistances below 1 ohm. The two terminals on the magottron are the filament wires. Less than 1 ohm is typical and is easily mistaken for a short circuit. "Magnetron Test for Opens, shorts or Insufficient Power" <https://www.microwavespecialties.com/pdfs/E10-2010-06%20Mag%20Test%20Bulletin.pdf> The instructions are for a commerical oven, which may have more than one magnetron inside, but the methods are the same for a home microwave oven with only one magnetron.   >This microwave is at least 10 years old with a lot of use, so how likely >is it that the transformer has just gone by itself vs the magnetron or >the small mains input board dying and taking the transformer with it?   Near zero. I haven't repaired too many microwave ovens and only one inverter oven. Mostly, what I find are (in order of frequency): 1. Blown high voltage diodes. 2. Blown high voltage capacitor. 3. Blown thermal protection fuse. 4. Filthy and intermittent door interlock switch. 5. Low magentron output or dead magnetron. I would guess I've fixed about 20 mw ovens and have yet to see a blown high voltage transformer. If the enamel coating on the torroid are discoulored from overheating, you might have a problem with the transformer. If it looks normal, it's something else.   You might want to try searching on YouTube for videos on how to diagnose and repair microwave ovens. This looks like a good start: <https://www.youtube.com/watch?v=hBJJU4ZRh7U>   >can be used with an A66454T05AP or F66454T07AP board, which do look the >same as mine, so are they just a different revision or something or are >the differences going to be bigger?   What you're seeing are differences in part number because the manufacturer sourced their magnetron from multiple (Chinese) sources. Each source has a different part number, but are functionally and mechanically identical. The NN-A554W is a 1000 watt oven, so any 1000 watt magnetron that mechanically fits is likely to work.   >a part that would work in many different models, even different brands, >if only I knew which one to look for (it seems there are no parts for my >model).   No parts? Google is your friend: <https://www.google.com/search?q=NN-A554W+oven+parts> Hmmm... are you in the UK? The Panasonic model number seems to be a UK only 230VAC oven?   >Am worried about replacing it and having the new one get instantly blown >up though.   Well, if you want an exact replacement, it would helpful if you would supply the full model number. Is it NN-A554WB or NN-A554WF ?   If you have no clue what you're doing, and are lacking in basic test equipment, I would recommend: 1. Checking the magnetron with an ohms guesser. 2. If ok, replace the Hi-V diodes and Hi-V capacitor. 3. If that doesn't fix it, don't replace the magnetron. Instead by a replacement inverter board. It's one of these: <https://www.kitchenwareonline.com/panasonic-microwave-oven-hv-inverter-m3ffzz000bp-c2x13938345> <https://www.kitchenwareonline.com/panasonic-hv-inverter-for-microwave-ovens-z606yba00gp-c2x15619538> 4. If that doesn't fix it, it MIGHT be the magnetron, but I doublt it. Magnetrons usually fade away slowly, where cooking takes longer and longer, until it doesn't cook. It does not die suddenly or belch fire. If you bought a replacement board, you've probably spend more on the repair than the oven is worth. I suggest you cut your losses and just buy a new oven.   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

"pfjw@aol.com" <peterwieck33@gmail.com>: Jun 15 11:26AM -0700 The longevity of any given appliance is a factor. But, in one's choice of appliances, longevity is only one (1) factor. If one looks at the life-cycle cost, the factors are:   a) Cost to produce, market, transport and sell. b) Cost of energy used over the life of the appliance (and, technically, the source of that energy). c) Cost of disposal when 'used up'.   Then, there are wearing parts: hinges & latches, microwave safe internal finishes, bearings and so forth. Investing in repair parts might not give that further ten years.   So, if one assumes that the typical microwave lasts around ten years, and is in actual use for (low end for this purpose) one full hour per week, that comes to 520 hours of operation. A magnetron tube is about 65% efficient these days. Assume all microwaves are a (mere) 700 watts. Assume the US national average cost pr KWH of $0.1331. The equation looks like this:   ((700/0.65) x 520)/1,000)=560. 560 x 0.1331 = 74.536. So, it will use $74.54 in electricity in those 10 years at that rate. A modern inverter stands to use, on average, 50% less energy. So use $37 as the 'advantage' per ten years to the inverter technology.   I dunno... It has been my experience that modern microwaves are largely made of parts made by robots, assembled mostly by robots, tested by robots and (maybe) visually inspected and packed by a exceedingly bored human.   https://www.midea-group.com/About-Us/manufacturing/kitchen-appliances   http://www.midea-gy.com/files/images/shebei/02.jpg   Chances for human error are minuscule. Finishes are far better. Parts variability is far less. And so on. As cheaply made and looking as these things might feel, with proper care and feeding, there is no reason why that $89 dollar device might not last that 10 years and beyond.   Fully agreed on the landfill - we are privileged that most scrap metal from our township is recycled to Acelor Mittal:   https://usa.arcelormittal.com/our-operations/steelmaking/coatesville Which has been in continuous, uninterrupted operation (including wars, depressions, holidays and so forth) since 1810.   It is a process.   Peter Wieck Melrose Park, PA

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