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"Peter W." <peterwieck33@gmail.com>: Jul 18 01:15PM -0700 Just to make it clear, these are Acoustech Model X *Solid State* self-powered electrostatic speakers, about two meters high (more than 6') and just under 75 cm wide.   They are silent. As in not even a pop, click or hiss. They have been so for ten (10) years. -Fuses are good. -Capacitors are good under LV test. -Relay is good. -Power Transformer is good. -Transistors are good. - There is no evidence of physical, water, or similar damage or abuse.   These were my brother's who used them for many years until he stopped. He just moved into a rather small apartment, and they had to go.   There are two (2) potted transformers that feed from the driver section onto the speaker itself. Seven (7) leads connect to the speaker. From the back left-to-right: 1. Silicon Red wire to larger potted tranny 2. Silicon Red wire to larger potted tranny 3. Small yellow wire to smaller potted tranny 4. Small blue/black wire to smaller potted tranny 5. Small black wire to smaller potted tranny 6. Small black wire to smaller potted tranny 7. Silicon Red Wire to Fat Flat Wire on speaker to smaller potted tranny   I can get continuity from 1-2 that makes sense. I can get continuity from 3 - 6 that also seem to make sense. I cannot get continuity from 7 to anywhere either on the chassis, other transformer leads nor any other point that I can trace.   I have a very bad schematic from HiFi Engine that speaks to a shield. But its origin(s) and destination(s) are not clear.   This condition is extant on both (2x) speakers.   Any one out there who has had experience on these beasts? Any thoughts? If not, I will treat them as landfill and flog them as-is and with a very accurate description on the usual auction site, pick-up only. Otherwise, if there is hope, I am up for the work.   Thanks in advance!   Peter Wieck Melrose Park, PA

Phil Allison <pallison49@gmail.com>: Jul 18 06:53PM -0700 Peter Wanker dribbled:   =================: > Just to make it clear, these are Acoustech Model X *Solid State* self-powered > electrostatic speakers, about two meters high (more than 6') and just under 75 cm wide.   ----------------------------------------------------------------------------------------   ** The model was marketed briefly by Koss in *1965*.   Each speaker was bi-amped - at a time when most SS amps used Germanium transistors. Each amplifier feeds an output transformer, to boost the voltage maybe 100 times. If the HT ( 2kV at least) supply fails, an ES speaker goes silent.   Moisture and dust ingress destroys ES speakers over time.     ..... Phil

"Peter W." <peterwieck33@gmail.com>: Jul 19 05:53AM -0700 a) All the transistors are silicon. The output devices are in-place are 2N4348 in a TO3 package. https://alltransistors.com/crsearch.php?mat=Si&struct=NPN&pc=120&ucb=140&uce=120&ueb=7&ic=30&tj=200&ft=0.8&hfe=15&caps=TO3 b) There are three (3) transformers: the main power transformer being one and verified as having no open coils and no internal shorts. c) There are two (2) potted transformers commonly connected to the main board through a single eight (8) conductor plug (Cinch-Jones). d) Of these two transformers, one appears to be HV only (two red silicon leads to the speaker). e) The other has five (5) leads to the speaker, one of which is also red silicon. And that is the one that is floating as far as I can test. f) The available schematic does NOT show a diagram of the potted transformers. If I had that, I would not be here.   Again, before I apply power for the first time in over ten years, I would like to understand what is connected to which and to explain the 7th speaker connection with no discernable ''other end".   Peter Wieck Melrose Park, PA

Rob <nomail@example.com>: Jul 19 05:13PM +0200 > Again, before I apply power for the first time in over ten years, I would like to understand what is connected to which and to explain the 7th speaker connection with no discernable ''other end".   > Peter Wieck > Melrose Park, PA   I would recommend to first forget about those transformers and their connections and focus on the power supply and amplifiers. Unless there are blown fuses, the transformers are likely OK, but the power supplies and amplifiers could suffer from bad caps or other component failure.   Likely best is to isolate the poweramp from the transformer (unplug it and replace with a resistive load, like 50 ohms) and run the amplifiers separately, watching their output on a 'scope. Check for DC setpoint of the amplifiers and see if they output the audio. When that is OK, connect the transformers and measure on their output (being careful because of the HV)

"Peter W." <peterwieck33@gmail.com>: Jul 19 08:26AM -0700 > Check for DC setpoint of the amplifiers and see if they output the audio. > When that is OK, connect the transformers and measure on their output > (being careful because of the HV)   a) No blown fuses. Fuses are not new. b) I have not yet plugged them in. I am generally resistant to plugging in a stranger until I understand its functions and antecedents. If I were to have a diagram of the potted transformers, I would be much more sanguine about applying power. c) I can isolate the potted transformers from the rest of the system. Theoretically, I could then determine if the amps are passing audio. d) But I would REALLY like to know what is going on inside all that elephant snot.... e) And the main power transformer shows no shorted windings or internal shorts, and the secondary windings make sense as to the schematic.   Peter Wieck Melrose Park, PA

Rob <nomail@example.com>: Jul 19 05:46PM +0200 >> (being careful because of the HV)   > a) No blown fuses. Fuses are not new. > b) I have not yet plugged them in. I am generally resistant to plugging in a stranger until I understand its functions and antecedents. If I were to have a diagram of the potted transformers, I would be much more sanguine about applying power.   Power them up with a light bulb in series with the mains.   I have made a special wiring harness with a male and female mains plug and a standard E27 lamp socket that allows me to insert a light bulb (40, 60, 100W) in series with any device, to reduce the maximal current. When available, use a VARIAC to slowly increase the voltage and have a multimeter attached to some point of interest (e.g. the DC output of the powersupply) to see what happens.

"Peter W." <peterwieck33@gmail.com>: Jul 19 09:14AM -0700 I have a very nice metered Variac. https://www.byan-roper.org/steve/steve-at-play/antique-electronics-and-2/heathkit-ip-5220-variable.html like that.   Again: I do not understand clearly what is going on or should be going on. And all I have is the nameplate in terms of anticipated current. I am trying to get to where I can align the actual current to the anticipated current before I apply power.   Related: I just heard from David Janzen, the son of the designer of these beasts, and still in the business. He is looking to see if he has a diagram of the potted trannys. That will be immensely helpful.   Peter Wieck Melrose Park, PA

bruce bowser <bruce2bowser@gmail.com>: Jul 18 03:32PM -0700 On Wednesday, July 14, 2021 at 4:53:53 PM UTC-4, Boris wrote in alt.home.repair: > her home. She has no idea if the units she's looking at, which draw 4.9 > amps (115v), would overload any particular circuit. Without mapping the > circuits, is there any way to know, other than plugging the unit in?   What else is plugged into the circuit?

Michael Trew <mt999999@ymail.com>: Jul 18 08:48PM -0400 On 7/18/2021 6:32 PM, bruce bowser wrote: >> amps (115v), would overload any particular circuit. Without mapping the >> circuits, is there any way to know, other than plugging the unit in?   > What else is plugged into the circuit?     Yes, you'd have to know what else is plugged in, and it's not a good idea to have them both on the same circuit.

Rheilly Phoull <rheilly@bigslong.com>: Jul 19 08:52AM +0800 On 19/07/2021 8:48 am, Michael Trew wrote:   >> What else is plugged into the circuit?   > Yes, you'd have to know what else is plugged in, and it's not a good > idea to have them both on the same circuit.   Yup, and the ratings of the circuits etc.

bruce bowser <bruce2bowser@gmail.com>: Jul 19 09:14AM -0700 On Sunday, July 18, 2021 at 8:52:20 PM UTC-4, Rheilly Phoull wrote:   > > Yes, you'd have to know what else is plugged in, and it's not a good > > idea to have them both on the same circuit. > Yup, and the ratings of the circuits etc.   Including the distance covered by the wires? from the service's interface to the outlet?

N_Cook <diverse@tcp.co.uk>: Jul 19 04:54PM +0100 On 04/02/2021 13:42, Branislav Drengubiak wrote: > Display datasheet is available www.amega.sk/brano/Displej.pdf > driver ST7567A   > code (STM32 spi client ) is www.amega.sk/brano/main.c   Interesting info , I've downloaded for later . Just got back to this tide-gauge project, the optics part of it anyway. The bored hole through the lens has to be offset from centre by the half-inch of the separation of the laser output port and the centre of the large lens. Also covering over the small inset lens, so as not to confuse the range setting procedure. Some stainless steel "reusable drinks straws" I found for guiding the laser thru the lens without side-scatter being returned to the receiving lens. Just trying out a pan of water , shrouded against false returns, to check out over 20 metres initially. For real over tidal water comes later.   -- Global sea level rise to 2100 from curve-fitted existing altimetry data <http://diverse.4mg.com/slr.htm>

Jeroni Paul <JERONI.PAUL@terra.es>: Jul 18 04:30PM -0700 > caused by replacing the print cartridge while the printer power was > turned on. Notice how close the contact pads are on the cartridge:   The cartridge is supposed to be changed with the printer on, otherwise it is parked. Output connections are supposed to be properly current limited and if this is really what happens maybe a diode or fuse resistor went open, may be repairable.

Jeroni Paul <JERONI.PAUL@terra.es>: Jul 18 04:23PM -0700 > I have a microwave from the mid 2000s that failed on me. It uses basic circuitry: transformer, diode, cap, magnetron....not an inverter type or anything fancy like that. One morning it seemed to mostly work, but the output rapidly dropped over a few minutes. No bang, no smoke. Just stopped heating.   I repaired a similar case and it was the faston type plugs did not make good electrical connection to the magnetron. I cleaned surfaces and it came back to life.

Jeff Liebermann <jeffl@cruzio.com>: Jul 18 10:00AM -0700 On Sun, 18 Jul 2021 08:28:48 -0700, David Farber >one hand, I could easily rotate the plug end with the other hand. Only >one of those loose plugs had issues with cutting out. Do all of these >plugs need replacing?   Speaker cable is usually a pair of large gauge stranded wire. The usual problem is that one strand from the bundle is not soldered in place or there's no shrink tube insulation. As the cable is moved around, that strand could short to the other speaker wire. If the 1/4" phone plug has a metal casing, it could also short to ground. Rotating the connector is just another way of rotating the cable inside the phone plug.   At the very least, resolder the connections, add shrink tube insulation if possible, look for loose wire strands, etc. If these are not possible or practical, put some insulation between the two connections on the plug.   Also, if it's a cheap phone plug, I've had problem with the rivet that holds the lug to the phone plug tip connection. They are sometimes loose. Soldering it in place fixes that problems.     -- Jeff Liebermann jeffl@cruzio.com PO Box 272 http://www.LearnByDestroying.com Ben Lomond CA 95005-0272 Skype: JeffLiebermann AE6KS 831-336-2558

David Farber <farberbear.unspam@aol.com>: Jul 18 10:16AM -0700 On 7/18/2021 9:08 AM, KenW wrote: > Usually the 'tarnish' cannot be seen. Doing that now with 1/8" on an > Intel NUC computer.   > KenW   Hi KenW,   I don't think you understood my question. If I hold the plug end in one hand and the common terminal at the back end with the other hand, is it normal to be able to rotate the plug while holding the back end steady? Most of the plugs are rigid and cannot be rotated in this fashion.   Thanks for your reply. -- David Farber Los Osos, CA

David Farber <farberbear.unspam@aol.com>: Jul 18 10:59AM -0700 On 7/18/2021 10:00 AM, Jeff Liebermann wrote:   > Also, if it's a cheap phone plug, I've had problem with the rivet that > holds the lug to the phone plug tip connection. They are sometimes > loose. Soldering it in place fixes that problems.   Hi Jeff,   I think it is your closing paragraph that applies here:   Also, if it's a cheap phone plug, I've had problem with the rivet that > holds the lug to the phone plug tip connection. They are sometimes > loose. Soldering it in place fixes that problems.   The rivet is not doing its job. I'll see if resoldering it does the trick but if not...   Regarding this: > Rotating the connector is just another way of rotating the cable > inside the phone plug.   That is what's supposed to happen when the rivet is holding everything together but in this instance, you can rotate the plug without twisting anything at the opposite end. Is this a decent quality replacement plug? https://www.digikey.com/en/products/detail/neutrik/568-NP2X-B/10488987   Thanks for your reply. -- David Farber Los Osos, CA

Jeff Liebermann <jeffl@cruzio.com>: Jul 18 01:04PM -0700 On Sun, 18 Jul 2021 10:59:55 -0700, David Farber   >That is what's supposed to happen when the rivet is holding everything >together but in this instance, you can rotate the plug without twisting >anything at the opposite end.   Ideally, the rivet and tip (center) lug should NOT rotate. If you tear apart a connector (necessary sacrifice to the connector gods), you'll find that the rivet is not a separate component but rather is part of the wire that eventually goes to the connector tip (center). I can usually grab the solder lug with pliers and rotate the lug relative to the rivet with some force. However, lug should NOT be flopping around loose. Try beating on the rivet with a drift punch to get a better connection. If that doesn't play, solder the rivet to the solder lug.   >Is this a decent quality replacement plug? >https://www.digikey.com/en/products/detail/neutrik/568-NP2X-B/10488987   I have no idea. The data sheet doesn't show the internals and there's no usable photo. At $6/ea, it would seem overpriced. Also, I don't like dissimilar metals in connectors. The description has this oddity: 6.35mm (0.250", 1/4") - Headphone Phono (RCA) Plug Mono Connector Solder That's not an RCA phono plug.   In my never humble opinion, you don't need an overprice designer phone plug. Just something that was correctly assembled. Even the best of connectors might have a few rejects.   I don't know what to recommend. You didn't provide any info on cable dimensions so I can't be sure it will fit in the shell hole. Since you don't seem to need too many, buy an assortment of likely and cheap connectors and use what seems best: <https://www.ebay.com/sch/i.html?_nkw=1%2F4+in+phone+plug> If you have money to burn, Switchcraft is usually good: <https://www.switchcraft.com/Category.aspx?Parent=42> <https://www.switchcraft.com/Category.aspx?Parent=1253> -- Jeff Liebermann jeffl@cruzio.com PO Box 272 http://www.LearnByDestroying.com Ben Lomond CA 95005-0272 Skype: JeffLiebermann AE6KS 831-336-2558

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