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bruce2bowser@gmail.com: Nov 15 10:55PM -0800 From 1969 to at least 1994, the US Embassy in Russia had listening devices (in-depth).

John-Del <ohger1s@gmail.com>: Nov 16 04:07AM -0800 > From 1969 to at least 1994, the US Embassy in Russia had listening devices (in-depth).   There have always been listening devices and there always will be.   I remember reading the clever way the Russians were snooping on the Americans with no bugs within half a mile of the room: they targeted a laser on a window pane of the room they were spying on. The window pane acted like a microphone diaphragm. They then demodulated the return signal which had the room audio modulated on it. Probably not hifi but I'll bet it was usable.   Gotta give them props for that trick.

Phil Allison <pallison49@gmail.com>: Nov 16 04:29AM -0800 John-Del wrote:   ------------------   > There have always been listening devices and there always will be.   > I remember reading the clever way the Russians were snooping on the Americans with no bugs within half a mile of the room: they targeted a laser on a window pane of the room they were spying on. The window pane acted like a microphone diaphragm. They then demodulated the return signal which had the room audio modulated on it. Probably not hifi but I'll bet it was usable.     ** By all accounts, bouncing a IR laser off a widow is not practical. The beam has to be precisely aligned *square on* to the window and the resulting sound quality is abysmal.   OTOH this simple Soviet invention worked well and had no such issues:   https://en.wikipedia.org/wiki/The_Thing_(listening_device)       .... Phil

N_Cook <diverse@tcp.co.uk>: Nov 16 02:17PM On 16/11/2017 12:07, John-Del wrote:   > There have always been listening devices and there always will be.   > I remember reading the clever way the Russians were snooping on the Americans with no bugs within half a mile of the room: they targeted a laser on a window pane of the room they were spying on. The window pane acted like a microphone diaphragm. They then demodulated the return signal which had the room audio modulated on it. Probably not hifi but I'll bet it was usable.   > Gotta give them props for that trick.   Reminds me of a project , I never got around to trying. I had a pot of those glass beads that are used in the paint of road traffic signs. Since originally thinking about the idea , paint-ball guns are now around. But the idea was to somehow propel a blob of white paste and beads upwards and then down, to splat onto a window pane, leaving a simulated bird shit hit. Then try a laser beam at any angle onto the bird shit and monitor the return.

"pfjw@aol.com" <pfjw@aol.com>: Nov 16 04:38AM -0800 http://www.surplusshed.com/pages/item/r3043.html   Those of you looking for vintage parts, or into DYI may find some use for this source. They ship promptly and their parts are exactly as described.   Peter Wieck Melrose Park, PA

"Gareth Magennis" <soundserviceleeds@outlook.com>: Nov 16 08:48AM wrote in message news:d590f407-6862-49bc-b878-c4efa33dd17d@googlegroups.com...   Greetings-   I have an HK 680i from the 80s on which the volume cuts out. When I first turn it on there is sometimes sound output, but after several seconds it goes silent. If I turn the volume way up the sound will come back, but at ear-splitting levels; when I turn it lower, it goes silent again. I'm wondering if there are any simple ideas I might try? I have a can of Deoxit D5 and a bit of patience.   TIA.         *****************************************************     I would try headphones first, this socket often incorporates a switch that cuts the main speakers.   (You don't specifically mention whether both left and right have the same problem at the same time, or whether it is the same or OK on headphones)       Gareth.

bruce2bowser@gmail.com: Nov 15 10:59PM -0800 On June 24, 2017 2:18PM, Dimitrij Klingbeil wrote:   > Whatever generates the timing ...   It depends upon both the hardware and software (wanted and not wanted).

Jeff Liebermann <jeffl@cruzio.com>: Nov 15 07:32PM -0800 On Wed, 15 Nov 2017 18:52:06 -0000, "Ian Field" >> <https://www.youtube.com/watch?v=IhUtKvCV6fs> >> <https://www.youtube.com/watch?v=1w3Tv1Jg0ps>   >Every day is a school day.   That's another variation on my "Learn by Destroying". If you haven't destroyed it, you don't understand it. My skool education was very much like that. I would break something, and then take it apart to see how it works. The skool would frown upon me taking apart something that was still working, but offered little resistance if I took apart something that was broken.   >I might have to rummage those cells out of the bin and do an autopsy - but >conscious enough of potential hazards to not bother re using them though.   Bin? Don't you have a local recycling facility that takes batteries?   >Plenty replacements to hand, I just assembled another battery pack - but >that seems to answer my question; what happened.   It might answer what happened, but not why. I've had brand new battery packs, assembled by a reputable and experienced rebuilder, trip the protector for no obvious reason. I recently had one go open circuit during charging, which might offer a clue.   -- 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

Jeff Liebermann <jeffl@cruzio.com>: Nov 15 07:56PM -0800 >Or you can get the ones not specified as battery extenders >https://www.ebay.com/itm/N35Super-Strong-Round-Disc-10x1mm-10x2mm-Magnets-Rare-Earth-Neodymium-N35/361874792648> >for 3-cents each in hundreds.   Nice price. However, 10mm wide is MUCH too large for a button top replacement. The eBay offering did not mention the size, but measuring the one's I'm using produced: 6mm diameter x 0.84 mm thick.   Measuring the normal size of the stock button top on a typical 18650 cell, I get: 6mm diameter at the base x 2.5 mm thick.   >solder a wire or put a clip on it. Works for charging all types >of batteries with magnet-attractive connection points. And the current >doesn't go through the magnet or depend on the surface plating.   I don't have much of a problem with current going through the magnet. Perhaps if I were using the cells for a high discharge application, but not for the typical small flashlight (about 1 amp) or E cigarette application (about 2 amps max).   My ESR meter is in my office so I can't measure the resistance of the battery right now. I'll try to remember to check tomorrow.       -- 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

mike <ham789@netzero.net>: Nov 15 08:07PM -0800 On 11/15/2017 7:56 PM, Jeff Liebermann wrote:     > Measuring the normal size of the stock button top on a typical 18650 > cell, I get: > 6mm diameter at the base x 2.5 mm thick.   click the size selector on that page.

Jeff Liebermann <jeffl@cruzio.com>: Nov 15 09:22PM -0800 >> cell, I get: >> 6mm diameter at the base x 2.5 mm thick.   >click the size selector on that page.   Thanks. I missed that. Looks like 6mm x 1mm is available very cheap. 1pc for $1.08 and 100 pcs for $2.99. I just ordered 100 each of 6mm dia x 1mm and 2mm thick magnets. Total price was $7.01 (which was about what I paid for 10 magnets from the previous vendor).   I managed to lose the magnet that I was measuring. It's probably stuck to something on my desk, but I can't find it. Grumble.       -- 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

Phil Allison <pallison49@gmail.com>: Nov 15 06:02PM -0800 tabb...@gmail.com wrote:   ---------------------------   Prickman complete moron wrote:     > > > which might or might not be a problem.   > > ** FFS - do you *read* posts at all????   > yes   ** But then ignore them and all context.     > > How is that relevant to the Prickman's bullshit claim ?   > it's relevant to the OP's situation     ** You ignored the question and the context, again.   Wot a tenth-wit.         .... Phil

Jeff Liebermann <jeffl@cruzio.com>: Nov 15 08:26PM -0800 >All the electronics are are potted into the reg case   If it's an epoxy potting compound (usually hard and black), you can soften it with commercial epoxy paint remover (methanol and methylene chloride). <http://www.jasco-help.com/product/premium-paint-epoxy-remover> Or, you can use a hot air SMT desoldering thing: <https://www.youtube.com/watch?v=Oiyg6jIZg_w>   >cap in question is 220 MFD 250 volt. I will be replacing it with one >that has a higher voltage rating. >Eric   Much depends on at what frequency the regulator is operating.   12 inches of wire = 31 cm I'll assume #16 AWG wire, which is 1.3 mm in diameter. 1 ft of #16 AWG has a resistance of about 4 milliohms, which is much smaller than the capacitor ESR and can be ignored. I'll assume that the voltage regulator uses some kind of switcher running at 1 MHz.   Plugging all that into: <http://chemandy.com/calculators/round-wire-inductance-calculator.htm> I get 378 nano-henrys inductance. At 1 MHz, that 0.421 ohms.   You didn't supply the original capacitor value, voltage, manufacturer, and type, so I can't calculate what the ESR should be. For 250 uF and 25v, my guess(tm) would be about 2 ohms (at 100KHz).   Therefore, adding 12 inches of #16 AWG wire to the filter increases its ESR by about 25%. That's not a huge amount and will probably work, but I would increase the voltage rating of the capacitor in order to get something with a lower ESR.   I don't suppose you could disclose the maker and model of the generator, possibly a guess as to the original capacitor specs, and perhaps a photo of the regulator?   -- 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

Jeff Liebermann <jeffl@cruzio.com>: Nov 15 08:38PM -0800 >The voltage from my generator drooped so much that a 3500 watt >generator would no longer start a 1/4 hp motor.   I wonder what caused the capacitor to bulge? Mostly, I find that it's the ripple current, where a small amount of AC voltage ripple is impressed across a filter capacitor. This causes a high current to flow through the capacitor, which causes heating, which causes the electrolyte to boil, which eventually blows the lid off the capacitor.   So, what would cause AC to flow through the capacitor? Well, the generator will do that if the output from each of the presumably two phases is different. That could be caused by having a radically different load on each of the two phases. A two phase 3500 watt generator is really a dual 1750 watt generator, where each phase can only supply 1750 watts. If you try to load all 3500 watts across one phase, bad things will happen. Another possibility is a shorted turn on one winding. I have a few other guesses, but can offer much without a clue as to how its wired, which might be available once you disclose the maker and model number.     -- 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

Jon Elson <elson@pico-systems.com>: Nov 15 10:04PM -0600 My mother in law has an original Amana RadarRange that still works! If it ever breaks, we will have to find out what museums want it.   Jon

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