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tabbypurr@gmail.com: Feb 18 02:32AM -0800 On Saturday, 16 February 2019 23:29:11 UTC, Ralph Mowery wrote:   > Looks to me they should have the same amp rating at all voltages. The > do not specify any kind of load like something that would draw a larger > current at startup with a higher voltage.   higher voltage means more energy in the arc for a given current. It also means more ability to sustain the arc. DC is more able to sustain an arc than ac, for the same v,i.     NT

tabbypurr@gmail.com: Feb 18 02:28AM -0800 On Saturday, 16 February 2019 07:05:08 UTC, Phil Allison wrote:   > > > ** So they were offering to PAY you to take the POS away ?   > > Vintage scopes have market value for collectors.   > ** Still a POS   yep   > and you are no collector.   lol     > > > Audio is ELECTRONICS, not sound.   > > no kidding   > ** Asinine reply, from an utter ass.   yours was indeed     > > I'd call those radio myself   > ** Another asinine reply.   > Folk who service "audio" are expected to do each of them.   but the fact is it is radio   > > > Faulty ( or badly designed / built ) audio amplifiers may exhibit oscillation upto 50MHz.   > > which can be found on a low speed scope with a capacitor & diode   > ** Completely irrelevant.   heh, hardly     > > > Digital audio seems to know no bounds.   > > though it doesn't normally tax any sane scope.   > ** As if a bullshitting troll like you would know.   feel free to show us some digital audio that a sane scope can't handle     > NT = nutcase troll.   > Fuck off.   PA = personality-problem ass. Grow up. If you have any facts show us.

Fox's Mercantile <jdangus@att.net>: Feb 17 04:12PM -0600 > Yes, the original question was which caps are BEST, but much of my > concern is based on the failed motherboards, which only lasted a year or > so.   Which, as usual, you didn't make at the beginning.   The Failed motherboards were, Dell. Their "Lets buy cheap shit" almost put them out of business. And that was almost 20 years ago.   -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

Phil Allison <pallison49@gmail.com>: Feb 17 03:05PM -0800 Fox's Mercantile wrote:   > The Failed motherboards were, Dell. > Their "Lets buy cheap shit" almost put them out of business. > And that was almost 20 years ago.   ** This old Wiki has the story:   https://en.wikipedia.org/wiki/Capacitor_plague   The brands of capacitor involved were previously unknown and unable to be linked to any of the well known makers.   AFAIK the issue never involved electros that might be used in restoration of vintage tube gear.   "tubeguy" is a fuckwit - see " top definition " :   https://www.urbandictionary.com/define.php?term=fuckwit       .... Phil

Michael Black <mblack@pubnix.net>: Feb 17 06:37PM -0500 On Sun, 17 Feb 2019, Phil Allison wrote:     > The brands of capacitor involved were previously unknown and unable to be linked to any of the well known makers.   > AFAIK the issue never involved electros that might be used in restoration of vintage tube gear.   > "tubeguy" is a fuckwit - see " top definition " :   A little knowledge can be a dangerous thing.   People hear the stories, but don't grasp the details. Modern use of electrolytics is different from the tube days. Not only have values gone up as size got smaller, but they are often expected to handle much higher frequencies than 60 or 120Hz in the days of tubes. Electrolytics are also a lot more common in the days of solid state. In tube days, a bad one would mean low voltage, or hum, or low audio gain, but there were a handful of electrolytics. Now they are everywhere, a shift to low impedance so larger values needed, and that means electrolytics. The circuitry is now more complicated and a bad capacitor may not be so obvious as in the old days.   Michael

whit3rd <whit3rd@gmail.com>: Feb 17 05:05PM -0800 On Sunday, February 17, 2019 at 2:13:03 PM UTC-8, Fox's Mercantile wrote:   > The Failed motherboards were, Dell. > Their "Lets buy cheap shit" almost put them out of business.   Oh, no, it's not that simple. Dell was publiclly traded, and made formal notice in their stockholder report one quarter, and that was big news. But, Apple had similar problems (trust me, I own a couple or three), as did everyone else.   The faulty technology was widely rebranded and even given counterfeit labeling, and wasn't purged from inventories for some years.   The bad capacitors weren't significantly less expensive than any others on the market, and turned bad only after a year or so (so incoming tests couldn't catch the problem).

Ralph Mowery <rmowery28146@earthlink.net>: Feb 18 12:02AM -0500 In article <d1189f6f-4996-46ef-a3bf-5981483d3f6a@googlegroups.com>, whit3rd@gmail.com says...   > The bad capacitors weren't significantly less expensive than any others on > the market, and turned bad only after a year or so (so incoming tests couldn't > catch the problem).   Yes, it was not only Dell,but other companies. I and a friend had a mother boards that were bought as boards and were not Dell that the capacitors went bad. Those boards were highly recommended before the capacitor problems showed up. Just lucky it was less than a year and under warrenty. I had a video card or two that had the capacitor problem.

Fox's Mercantile <jdangus@att.net>: Feb 17 04:20PM -0600 > voltage return, (knowing that spark plugs complete the circuit by being > connected to the engine block, which is connected to the battery > GROUND).   The internal resistance of a car battery is close to zero ohms. When the points open, the magnetic field from the primary collapses. This causes a huge inductive kick voltage spike. The condenser across the points acts like a tuned circuit to sustain the high voltage by acting like a tuned circuit. The secondary being in series with the primary acts like a auto-transformer and increases the high voltage oscillations to a value high enough to create a solid, hot, spark across the electrode of the spark plug.   The fact that the return is via the positive terminal of the battery doesn't mean shit.     -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

etpm@whidbey.com: Feb 17 03:53PM -0800 On Sun, 17 Feb 2019 16:20:16 -0600, Fox's Mercantile <jdangus@att.net> wrote:   >across the electrode of the spark plug.   >The fact that the return is via the positive terminal of the battery >doesn't mean shit. I was taught years ago that the condenser was to prevent arcing at the points. It was not until recently I learned that its more important function is to be part of a tuned resonant circuit. This makes so much sense. About 40 years ago I had a motorcycle ignition problem that was fixed by replacing the condenser and I never knew why. I still don't know why Lucas ignitions used a rising field ignition instead of the usual collapsing field. And I knew lots of guys who converted their British bikes to rising field ignitions for the better spark. Me included. Eric

+++ATH0 <news@ringpiece.local>: Feb 17 04:54PM -0800 > fixed by replacing the condenser and I never knew why. I still don't > know why Lucas ignitions used a rising field ignition instead of the > usual collapsing field.   Nonsense. This type of ignition is initiated by the points opening and breaking the primary (LT) current.   The HT voltage achieved depends on the rate of change of primary current, and failure of the condensor causes the interruption of the primary current to be much slower because of arcing at the points, which also wastes energy in the coil which should end up in the spark at the plug, not to mention destroying the points in hosrt order.   The condensor functions by carrying the primary current for long enough for the points to separate without an arc being initiated.   If the engine does start and run, the usual symptom of condensor failure is misfiring at wide throttle openings (when cylinder pressure at the point of ignition is higher, increasing the breakdown voltage across the spark plug points) and difficulty starting.

etpm@whidbey.com: Feb 17 03:37PM -0800 On Fri, 15 Feb 2019 19:02:44 -0800, Jeff Liebermann <jeffl@cruzio.com> wrote:     >The link in the video to EEVblog doesn't work. This does: >"EEVblog #453 - Mysteries of x1 Oscilloscope Probes Revealed" ><http://www.eevblog.com/forum/blog/eevblog-453-mysteries-of-x1-oscilloscope-probes-revealed/?all> Thanks again Jeff. I have watched EEVblog several times and haven't had time yet to check out completely the episode mentioned. I looked for it and just got it started when the dryer belt broke. Anyway, when I spoke above about .1mS I meant that the overshoot lasts that long. So there is a peak at the beginning of the square wave and then the trace curves down to become flat. And the time it takes to become flat is about .1 mS. The computer I am posting from is running XP and so I can't use Dropbox. I should look for another easy to post to picture site. Eric

technowb <pietrarca@gmail.com>: Feb 17 09:35AM -0800 Thank you! I've read everything, and I searched for the exact magnetron; unfortunately I have to go for an "80% compatibile model" since everytime I find a website listing the correct model it's either out of stock or the website fails under a 404 error.   I have one more question, since I noticed a difference between apparently the same model by different manufacturers:   Does the shape of the hole of the "microwaves cannon" make some difference? I can't find one with the exact shape of my original model (square): the available shapes of the alternatives are circle and triangle.. should I go for one of those randomly or there are better chances of compatibility if I choose one over the other?   Thank you again

Look165 <look165@numericable.fr>: Feb 17 07:00PM +0100 Try https://www.cdiscount.com/electromenager/r-magnetron+panasonic+2m236-m42.html#_his_   technowb a écrit le 12/02/2019 à 22:41 :

"pfjw@aol.com" <peterwieck33@gmail.com>: Feb 17 08:49AM -0800 Both the white shell, and the (usually grey) infill are fired ceramics. Different composition gives different hardening temperatures.   Peter Wieck Melrose Park, PA

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