- Some customers... - 8 Updates
- magnifier - 14 Updates
- Rusting satellite dish - 3 Updates
| MJC <gravity@mjcoon.plus.com>: Mar 25 05:35PM In article <d53c2fdd-65ec-4489-ba91-1c3c8c6de636@googlegroups.com>, dansabrservices@yahoo.com says... > I questioned what manufaturing defect "caused" this problem and did not get an answer... > Dan Portable devices do have to be robust to be fit for purpose... Mike. |
| Cydrome Leader <presence@MUNGEpanix.com>: Mar 25 06:33PM > bring in his speakers. He had wired both the plus and minus leads to > the center connector on both speaker plugs. I kept a straight face > but unfortunately one of my techs went off on him. the RCA speaker outputs were as silly as the preamp to amp shunts stuck into the RCA jacks at the factory. Anybody ever remove one of those? Was never able to pull out out with my bare hands, didn't care enough to try with pliers. |
| jurb6006@gmail.com: Mar 25 11:55AM -0700 >"the RCA speaker outputs were as silly as the preamp to amp shunts >stuck >into the RCA jacks at the factory. " I would actually like to have a switch on the front panel of an amp to switch the pre out/main in loop rather than their jumpers. Too easy to lose. And then my buddy got this Marantz, a really nice one, 2325. It has the type of jack where you plug something in and it breaks the connection. I'd much rather have a switch, even if it is on the back and many of them are. Another thing I noticed about those shunts is ain't none of the MFs ever the same size. I have had a drawerfull of them and still had to make shunts out of 12 gauge wire because none of them fit. |
| Jeff Liebermann <jeffl@cruzio.com>: Mar 25 07:22PM -0700 On Fri, 25 Mar 2016 05:48:15 -0500, "Mark Zacharias" >Cautioned him on speaker hook-ups, gave him our hand-out sheet explaining >speaker connections, >which also contains explicit warnings about shorting wires etc. Put a 0.5 ohm xx watt resistor in series with each speaker. Paint the resistors with whatever concoction generates the most noxious smoke possible[1]. Then he shorts the leads again, the resistor(s) will get hot, smoke, stink, and NOT blow up the output stages. There will be a loss in output power, which presumably he won't notice unless he's running low impedance or low efficiency speakers. [1] Cotton soaked in propylene glycol or white mineral oil which is what we used for wind tunnel airflow visualization. Propylene glycol doesn't stink very much, but white mineral oil really reeks. -- 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 |
| John Heath <heathjohn2@gmail.com>: Mar 25 08:52PM -0700 On Friday, March 25, 2016 at 10:23:01 PM UTC-4, Jeff Liebermann wrote: > 150 Felker St #D http://www.LearnByDestroying.com > Santa Cruz CA 95060 http://802.11junk.com > Skype: JeffLiebermann AE6KS 831-336-2558 I have heard this argument too many times as if the costumer is responsible for electrical engineering issues. The customer paid for the amplifier leading a profit for the manufacturer. It is the manufacturer that is responsible to made sure the amplifier is idiot proof. Amplifiers have current limiting circuits which means you can sort the outputs all day long without any damage. If the manufacturer can not be bothered to be responsible for their own engineering leading to output transistor failure than they are in the wrong business. There is no such thing as a costumer that is wrong as he is the one that is paying the money. The failure is always up stream from the costumer. I will now get of my soap box. |
| Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Mar 26 05:34PM +1100 On 25/03/2016 9:48 PM, Mark Zacharias wrote: > I'm reminded of Chevy Chase's rant in Christmas Vacation... > Mark Z. **I'm suprised that the shitbox Yammy can't handle a short. Part of the test procedure for all the old 1970s Marantz amps, was to throw a short circuit across the outputs. If it didn't survive, it would not be given back to the owner (until it did). -- Trevor Wilson www.rageaudio.com.au --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
| "Mark Zacharias" <mark_zacharias@sbcglobal.net>: Mar 26 06:11AM -0500 "Jeff Liebermann" <jeffl@cruzio.com> wrote in message news:m4sbfbtj3k3b1hcjnca9t86o566tel84o4@4ax.com... > 150 Felker St #D http://www.LearnByDestroying.com > Santa Cruz CA 95060 http://802.11junk.com > Skype: JeffLiebermann AE6KS 831-336-2558 You, sir - are an evil Genius! mz |
| "Mark Zacharias" <mark_zacharias@sbcglobal.net>: Mar 26 06:15AM -0500 "Trevor Wilson" <trevor@SPAMBLOCKrageaudio.com.au> wrote in message news:dlmorsFg49tU2@mid.individual.net... > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus Not sure it was purely a direct short, or if it was a one-off. The emitter resistor showed signs of longer term overheating. He's sure as hell doing something wrong though. can't rule out a bad speaker either. The whole thing requires further investigation. He live a ways our of town from my location so a service call is at the least inconvenient for me. At the least I need to have him bring me the speakers and wires for evaluation. Mark Z. |
| Jeff Liebermann <jeffl@cruzio.com>: Mar 25 10:17AM -0700 On Thu, 24 Mar 2016 19:51:14 -0700 (PDT), captainvideo462009@gmail.com wrote: > TV camera with a varifocal 3.5 to 8 mm lens but it doesn't > make the image large enough. I was wondering what people > are using to do this. Thanks, Lenny You can enlarge your video image with the appropriate software. You may end up seeing scan lines and have focus problems, but it will be larger. I have some software that came with a microscope camera that does this quite well. I don't recall the name right now. I have fair collection of vision aids. All of them work for specific functions, but none of them work for every possible situation. Here's my list: 1. 3.25 diopter reading glasses. I get these at the dollar store for ummm.... $1/ea. They're junk and are treated accordingly. They're what I use most when I want to inspect a PCB. I also have some other power reading glasses for reading. 2. Surgical or dental loupe binoculars: <http://www.ebay.com/itm/281832405417> I have a similar 3.5x-420mm binoculars that fit over my $1 reading glasses. They're also available in: 2.5x-320mm 3.5x-320mm 2.5x-420mm 3.5x-420mm and maybe some other sizes. I also have an LED light that clips onto the glasses (or my hat). 3. USB camera/microscope something like this: <http://www.ebay.com/itm/351620052002> Most of the specs are lies. Mine is 640x480. Here's some sample pics: <http://802.11junk.com/jeffl/pics/USB%20Camera/640x480/index.html> What's important is the LED ring light, which produces shadow free illumination. I also have a ring light for my microscope. 4. Trincocular microscope. The 3rd pipe is for the USB camera. Be sure to get a camera with a 0.5x expander. <http://802.11junk.com/jeffl/pics/white-plastic-rot/slides/microscope-setup.html> <http://802.11junk.com/jeffl/pics/drivel/slides/Olympus-BHC-Microscope.html> 5. Inspection type binocular microscope. This one has about 2" working distance and should be usable for soldering SMT parts. However, I'm short on eye pieces, the boom needs work, and the optics need cleaning. No photos. 6. Assortment of Fresnel and convex magnifier lenses and hand magnifiers. Also, a few illuminated jewelers loops. I keep these in the car for service calls, where the larger devices would get in the way. 7. Various digital cameras with macro lenses or built in macro features. It's often easier to inspect or enhance a digital photo, than try to see detail through the lens. Good luck... -- 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>: Mar 25 10:22AM -0700 On Fri, 25 Mar 2016 11:08:04 -0400, "Ralph Mowery" >one and for some work it is ok, but for fine work something else is needed. >After about 3x the lenses put your eye so close to the work it is difficult >to get the soldering equipment in without getting burnt. See: <http://www.ebay.com/itm/281832405417> 3.5x with a 420 mm (16.5") working distance. You can get them in other working distances. -- 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 |
| whit3rd <whit3rd@gmail.com>: Mar 25 11:12AM -0700 > On Thursday, March 24, 2016 at 10:51:18 PM UTC-4, captainvi...@gmail.com wrote: > > I need to purchase a magnifier so that I'll be able to ...le are using to do this. Thanks, Lenny > The dentist wears a headset rig that allows him to work from at least an arms length away. I've seen pictures of doctors wearing similar magnifiers. Those are wide-field opera glasses; two small telescopes, mounted accurately to an eyeglass frame. It's a bit expensive, and you MUST have them custom-fitted, so it's hard to try before you buy. Designs for Vision is a supplier. <http://www.designsforvision.com/> |
| John-Del <ohger1s@aol.com>: Mar 25 11:28AM -0700 |
| John-Del <ohger1s@aol.com>: Mar 25 11:36AM -0700 > On Thursday, March 24, 2016 at 10:51:18 PM UTC-4, captainvi...@gmail.com wrote: > > I need to purchase a magnifier so that I'll be able to do things like replace eproms and other small SMT's. I'm not looking to do LSI's with 150 pins Etc. Just mostly smaller stuff. For instance I currently have a board that needs an 8 pin Eprom replaced. I thought that I could do it with the magnifiers I have but the stuff is Just too small. I tried using a high res TV camera with a varifocal 3.5 to 8 mm lens but it doesn't make the image large enough. I was wondering what people are using to do this. Thanks, Lenny > The dentist wears a headset rig that allows him to work from at least an arms length away. I've seen pictures of doctors wearing similar magnifiers. I don't know what the magnification of these things are though. Anyone know the specifics on those? Lenny I bought a pair of those many years ago on ebay. They are 6.5X 420mm loupes, and I've used them for inspection, but not for soldering. The working distance is at least a foot, but the image is darker than the Opti-Visors I have and I just can't get used to working at that far a distance. Between the long distance between my eyes and my hands and the jittery aspect of them I just leave them in their wooden felt lined box. Maybe if I used them more I can get used to them as a dentist would (he can't get inside a mouth after all). It's possible they may simply be too strong for what I need. |
| "Ralph Mowery" <rmowery28146@earthlink.net>: Mar 25 03:33PM -0400 <captainvideo462009@gmail.com> wrote in message news:29a361eb-b2f1-4886-9cba-afe21278b218@googlegroups.com... I need to purchase a magnifier so that I'll be able to do things like replace eproms and other small SMT's. I'm not looking to do LSI's with 150 pins Etc. Just mostly smaller stuff. For instance I currently have a board that needs an 8 pin Eprom replaced. I thought that I could do it with the magnifiers I have but the stuff is Just too small. I tried using a high res TV camera with a varifocal 3.5 to 8 mm lens but it doesn't make the image large enough. I was wondering what people are using to do this. Thanks, Lenny A good bright light helps a lot. I often use one of the LED types that replace the common light bulb. I put in one of the reflectors that has a clamp on it . The LED puts out lots of light and is not hot like a 60 watt bulb would be. |
| "Dave M" <dgminala@mediacombb.net>: Mar 25 02:31PM -0500 Jeff Liebermann wrote: > features. It's often easier to inspect or enhance a digital photo, > than try to see detail through the lens. > Good luck... Funny that this subject has come up at the same time that I'm looking for a hobbyist-priced stereo microscope for SMD assembly and rework. A good stereo microscope seems indispensible now that almost everything electronic is getting so small that only robots are capable of handling and assembling it. I've been looking at the AmScope line of stereo microscopes, which are available directly form AmScope and Ebay, for similar prices. The ones I'm interested in are the model SE400X 5X-10X Stereo Boom Arm Microscope (Ebay item 140927802323) and the 7X-45X Trinocular Articulating Zoom Microscope + Ring Light (SKU: SM-6T-FRL on AmScope.com). The latter unit is on sale right now; regular price is $1100, sale price is $530. Pretty good discount. It's a trinocular microscope, with a port for a video camera. I'm trying to get some recommendations as to the camera resolution needed for SMD electronics work (megapixels). The former unit is advertised to have a 9" working distance (from lens to work). Reviews for the AmScope units seem to indicate that the 10X magnification is best for electronics work; higher magnification results in too small field of view. The trinocular unit from AmScope is a zoom unit, with 7X-40X magnification, well suited for a wide range of applications. I haven't decided which model I want to buy yet... But AmScope seems to be the best bang for the buck for me. Cheers, Dave M |
| MJC <gravity@mjcoon.plus.com>: Mar 25 07:57PM In article <e381a4e0-b2dc-4507-9bcc-ef5108d78e1e@googlegroups.com>, whit3rd@gmail.com says... > > The dentist wears a headset rig that allows him to work from at > > least an arms length away. I can understand a dentist wanting to be as far away as possible, but further than an arms's length? Mike. |
| dansabrservices@yahoo.com: Mar 25 01:39PM -0700 I picked up an AM-Scope from Ebay a few years ago and use it all the time. Works great!! This particular unit has up to 80X with a different insert. I've only used the higher mag once but it was useful for the task. These take a little practice, but are best for SMD work. Dan |
| Jon Elson <jmelson@wustl.edu>: Mar 25 05:15PM -0500 Dave M wrote: >> 4. Trincocular microscope. The 3rd pipe is for the USB camera. Be >> sure to get a camera with a 0.5x expander. >> <http://802.11junk.com/jeffl/pics/white-plastic-rot/slides/microscope- setup.html> >> <http://802.11junk.com/jeffl/pics/drivel/slides/Olympus-BHC- Microscope.html> > electronic is getting so small that only robots are capable of handling > and assembling it. > I've been looking at the AmScope line of stereo microscopes, We have this one at work : eBay 400429169541 although we have a different stand for it. It has two long (maybe 600mm) horizontal rods that link the scope to the base. But, the scope is the same. They also sell a fluorescent ring light that is just dumb, it cuts the working distance in half, and totally gets in the way. I ended up making my own LED ring light, which surrounds the nose of the scope, so it doesn't get in the way at all. The magnification is maybe just a HAIR too much at minimum, but really does well. I take my glasses off, so I can get my eyes really close to the eyepieces, they you get a wider field of view. I have an old Olympus at home, the AmScope at work, and we also have an ancient American Optical. They all work about equally well. Here's the same boom stand we have on ours. I think it is a very good stand for bench electronics work. eBay # 201537233463 Jon |
| Jon Elson <jmelson@wustl.edu>: Mar 25 05:21PM -0500 Dave M wrote: >> 4. Trincocular microscope. The 3rd pipe is for the USB camera. Be >> sure to get a camera with a 0.5x expander. >> <http://802.11junk.com/jeffl/pics/white-plastic-rot/slides/microscope- setup.html> >> <http://802.11junk.com/jeffl/pics/drivel/slides/Olympus-BHC- Microscope.html> > (Ebay item 140927802323) and the 7X-45X Trinocular Articulating Zoom > Microscope + > Ring Light (SKU: SM-6T-FRL on AmScope.com). Check eBay # 400334443106 This is the same size as the crummy fluorescent ring light we got, it sticks about one whole INCH below the rest of the microscope, and also is almost 2" wider in diameter than that part of the scope. Really gets in the way of working on things. So, I do not recommend this specific light. What you want is one that fits up higher around that black conical part, just under the white ring with the thumbscrew in the first picture. Jon |
| Jeff Liebermann <jeffl@cruzio.com>: Mar 25 05:40PM -0700 On Fri, 25 Mar 2016 10:17:23 -0700, Jeff Liebermann <jeffl@cruzio.com> wrote: >may end up seeing scan lines and have focus problems, but it will be >larger. I have some software that came with a microscope camera that >does this quite well. I don't recall the name right now. It's called AmScope from the company AmScope: <https://www.amscope.com/software-download> <https://unitedscopellc.wordpress.com/> <http://www.scopetek.com/download/download.html> I just noticed that I'm using a really old version. I guess I should try something later. -- 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>: Mar 25 06:04PM -0700 On Fri, 25 Mar 2016 13:39:54 -0700 (PDT), dansabrservices@yahoo.com wrote: >I've only used the higher mag once but it was useful for the task. >These take a little practice, but are best for SMD work. >Dan Yep. I just ran a screen capture of an SMD device with the cheap 640x480 USB camera placed as close to the PCB as possible. Illuminination is by the LED ring built into the USB camera: <http://802.11junk.com/jeffl/pics/USB%20Camera/AmScope/> The small photo is 640x480 as captured by the AmScope 3.7 software. The large photo is a screen grab of the program, with a few menus showing, and the image expanded 2x (fit to window). Not too horrible for a $12 camera: <http://www.ebay.com/itm/351620052002> The down side is that the gimbal mount is impossible to tighten enough to keep the assembly from falling over, the clamp around the camera body had to be glued in place to keep it from falling off, and the LED's are intermittent (bang on case to operate). -- 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>: Mar 25 07:08PM -0700 On Fri, 25 Mar 2016 17:21:34 -0500, Jon Elson <jmelson@wustl.edu> wrote: >this specific light. What you want is one that fits up higher around that >black conical part, just under the white ring with the thumbscrew in the >first picture. This is the one that I bought for my various microscopes and cameras: <http://www.ebay.com/itm/311570447425> I wanted variable intensity and as much junk away from the ring as possible and a double ring of LEDs to help reduce shadows even further. The hole size is 60mm ID. -- 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 |
| Tim R <timothy42b@aol.com>: Mar 25 11:16AM -0700 On Friday, March 25, 2016 at 12:00:00 PM UTC-4, Jeff Liebermann wrote: > mirror finish, when the sun goes behind the satellite belt twice each > year, the reflected light would burn up the LNB. I've had it happen > on larger dishes. If the dish were painted flat black, it would Hmm. OT maybe, but........ a little bit ago we needed to measure a large number of throws of Frisbee golf discs. I had one of those big reflective round traffic signs, about the size of a good size satellite disc. It was a No Entry One Way (but the international symbol, not words). That thing really reflects, my little LED headlamp will light it up two blocks away. The back of it is just gray sheet metal but the front, wow, that reflective paint is great stuff. So the plan was have the kids throw from where the sign was set up, then go to where each disc lands and shoot back to the sign with my laser range finder. Surprise. The range finder won't read off a reflective sign at all, at any distance. Turned the sign around and it read fine off the unpainted back. I hadn't expected that. |
| whit3rd <whit3rd@gmail.com>: Mar 25 11:21AM -0700 On Friday, March 25, 2016 at 5:35:51 AM UTC-7, N_Cook wrote: > No reception problems , even in heavy rain, but presumably will do some > time. > If the dish completely rusts over ... Oh, there's a solution for that, from the world of architecture. Plant ivy. Seriously, there's very little effect unless the dish changes shape; the Arecibo telescope doesn't look like a shiny-new dish, and it focuses radio just fine. And a thin layer of paint won't keep the underlying metal from blocking the passage of radio waves, so it'll still reflect if you decide to apply some finish. |
| MJC <gravity@mjcoon.plus.com>: Mar 25 08:02PM In article <328070ca-dfe1-4038-ab54-edaa1a93171f@googlegroups.com>, timothy42b@aol.com says... > Surprise. The range finder won't read off a reflective sign at all, > at any distance. Turned the sign around and it read fine off the > unpainted back. I hadn't expected that. That's a surprise to me too. I thought the laser range-finding to the Moon was done using a retro-reflector placed there specially by visitors. But maybe they did not use a road-sign... Mike. |
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