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ggherold@gmail.com: Jun 21 01:08PM -0700 I've got a Fluke 189 DMM. The banana jack inputs are getting flaky. With the probes or input pushed up or down they sometimes loose continuity. I opened it up and looked at the solder joints... they look fine. The banana jacks are encased in plastic so it's hard to see exactly. I tried squeezing them in some, it's maybe a bit better, but no one wants even a bit of flaky in their test gear. Any ideas? (about how I might fix it.)   George H.

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Jun 21 04:30PM -0400 > wants even a bit of flaky in their test gear. Any ideas? (about how I might > fix it.)   > George H.   You might drop $17 for a set of ProbeMaster 8000 series leads   http://probemaster.com/8000-series-test-leads-only/   All gold-plated, soft silicone leads, lots of accessories available. Gorgeous.   Even if it turns out to be the meter that's broken, you'll be glad to have the leads for the next one!   Cheers   Phil Hobbs   -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510   http://electrooptical.net http://hobbs-eo.com

N_Cook <diverse@tcp.co.uk>: Jun 21 09:52PM +0100 > wants even a bit of flaky in their test gear. Any ideas? (about how I might > fix it.)   > George H.   Usually a break in the condutor. If + cross-section form of the male part then at least try generally cleaning male & female and insert razor blade forcibly each way in the + splits .

Jeff Liebermann <jeffl@cruzio.com>: Jun 21 02:42PM -0700 >I tried squeezing them in some, it's maybe a bit better, but no one >wants even a bit of flaky in their test gear. Any ideas? (about how I might >fix it.)   If the banana jacks really are intermittent, replacement are available: <https://www.ebay.com/sch/i.html?_nkw=fluke+187+jacks> Judging by the number sold (247+105) it seems to be a common problem.   More Fluke parts, from Fluke: <https://www.ebay.com/sch/fluke-usa/m.html?_nkw=> Now we know what usually breaks on a Fluke meter.   Hints: 1. Beware of new and improved. 2. That which is most difficult to replace, is usually the problem. 3. When all else has been replaced, that which remains, no matter how improbable, is the culprit.       -- 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

"jfeng@my-deja.com" <jfeng@my-deja.com>: Jun 21 02:55PM -0700 On Thursday, June 21, 2018 at 1:53:02 PM UTC-7, N_Cook wrote: > Usually a break in the conductor. The cheapest way to test this hypothesis is to get one of the free DMMs from Harbor Freight and use their leads on your Fluke. If this fixes the problem, you can confidently buy something of higher quality. Most banana jacks and plugs are interchangeable.

ggherold@gmail.com: Jun 22 06:22AM -0700 On Thursday, June 21, 2018 at 4:31:02 PM UTC-4, Phil Hobbs wrote: > Briarcliff Manor NY 10510   > http://electrooptical.net > http://hobbs-eo.com   No whatever banana I stick in there is intermittent. (I use a lot of BNC to dual banana plug adapters.. then I can watch the fast stuff on the 'scope at the same time.)   GH

ggherold@gmail.com: Jun 22 06:34AM -0700 On Thursday, June 21, 2018 at 5:42:14 PM UTC-4, Jeff Liebermann wrote:   > More Fluke parts, from Fluke: > <https://www.ebay.com/sch/fluke-usa/m.html?_nkw=> > Now we know what usually breaks on a Fluke meter.   Thanks Jeff, looks like I'll be ordering one of those. (As you can see it's hard to get inside the plastic.)   George H.   > 2. That which is most difficult to replace, is usually the problem. > 3. When all else has been replaced, that which remains, no matter how > improbable, is the culprit. Grin, for number three I had this circuit that was leaking ~1 Meg ohm, I couldn't figure it out, I'm ripping out everything. I finally pull out the toggle switch. Bingo! We had a box full of toggle switches of which ~10% had a resistance in the meg ohm region when 'open'. (Hmm that might count for #2 also.)   GH.

"pfjw@aol.com" <peterwieck33@gmail.com>: Jun 22 06:35AM -0700 > (I use a lot of BNC to dual banana plug adapters.. then I can watch > the fast stuff on the 'scope at the same time.)   > GH   Then it is in the meter. You may be able to tighten up the contacts with a dental-pick, or you will have to take it apart and look for a broken solder joint or some such.   Peter Wieck Melrose Park, PA

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Jun 22 10:28AM -0400 > No whatever banana I stick in there is intermittent. > (I use a lot of BNC to dual banana plug adapters.. then I can watch > the fast stuff on the 'scope at the same time.)   Ah. Those put a lot of torque on the solder joints, of course.   Cheers   Phil Hobbs   -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics   160 North State Road #203 Briarcliff Manor NY 10510   hobbs at electrooptical dot net http://electrooptical.net

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Jun 22 10:30AM -0400 On 06/21/2018 05:42 PM, Jeff Liebermann wrote: > 2. That which is most difficult to replace, is usually the problem. > 3. When all else has been replaced, that which remains, no matter how > improbable, is the culprit.   Except that while replacing all that stuff, the real fault blew up several of the replacements, so it's quite possible to replace everything and still not fix it!   Cheers   Phil Hobbs   -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics   160 North State Road #203 Briarcliff Manor NY 10510   hobbs at electrooptical dot net http://electrooptical.net

Tim R <timothy42b@aol.com>: Jun 22 08:05AM -0700 > > 2. That which is most difficult to replace, is usually the problem. > > 3. When all else has been replaced, that which remains, no matter how > > improbable, is the culprit.   I agree with that but you're using a misleading singular.   THAT.......is THE problem.......... falsely implies only one thing is wrong. I've been fooled a number of times because two things were bad simultaneously. Sometimes one caused the other but sometimes it's just random.   In fact there is no theoretical limit to how many things can go wrong at once.

Jeff Liebermann <jeffl@cruzio.com>: Jun 22 08:50AM -0700 On Fri, 22 Jun 2018 10:30:36 -0400, Phil Hobbs >everything and still not fix it! >Cheers >Phil Hobbs   4. When everything has been replaced, and nothing remains to replace, it's time to give up.   I have a multiyear example of that happening to me. I am the not so proud owner of an IFR1500 service monitor. Over the years, the power supply had become more and more intermittent and refused to function on 117VAC input. However, the 12VDC input does work. In multiple attempts to fix the problem, I have systematically replaced every part in the switching power supply section except the magnetics at least 3 times. The last time, I replaced everything with all new parts before applying power. Something blew up anyway, so I gave up and have been running it on a 12VDC bench supply for about 5 years.   At one point, I even thought I had found the culprit: <http://www.learnbydestroying.com/jeffl/IFR-1500%20Power%20Supply%20Repair/IFR-1500%20power%20supply%20repair.html> However, the celebration was premature. It died again in about a month.   My current strategy is to find a 117VAC +5V/+12V only "brick" power supply and replace the entire power supply. I can live without battery operation and DC power. However, I can't seem to find something suitable in a form factor that will fit. My latest scheme is separate +5V and +12V bricks, which hopefully will fit.   At least I'm in good company: <http://www.repeater-builder.com/test-equipment/aeroflex/aeroflex-index.html> "Also, many old IFRs are having power supply problems. If anyone would like to do an article on troubleshooting and repair we'd be happy to put it here."   -- 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

dplatt@coop.radagast.org (Dave Platt): Jun 21 05:14PM -0700 In article <q36mid99k9epbqpk1qcqdh2crjcdv1gush@4ax.com>,   >You should have taken my advice and glued the cracked gear back >together with epoxy.   I may well do that, to put my existing gears back in usable condition.   >Well, not quite. The last one I did, I either got the mixture wrong >on the epoxy, or used some ancient tube of epoxy which refused to >harden.   I've made a lot of use of G-Flex epoxy for jobs like this - it works very well on most plastics, and also on metal.   >in half. Most will break at the set screw with very little pressure. >Might as well have it break now, rather than while you're using the >generator.   Both of the larger gears with set-screws are cracked, and will need repair. The third large gear (the one which normally free-wheels on the shaft) isn't cracked, and I don't think it has a set-screw hole, but I suspect the nylon has probably shrunk and is putting the plastic under tension/compression. Might be worth it to deliberately split it between teeth, and give it the same file-and-epoxy treatment.   >>repair it isn't gripping the shaft well enough to prevent slipping.   >I haven't seen that yet. I'll take a look at the two I have when the >bench is clear. That might explain some backlash in the shaft.   Looking at pictures on the net, I suspect that at least part of this problem exists only on the "old" switch-and-gear assemblies - the ones made with real wafer switches. The "new" switch-and-gear assemblies that use the PC-board-style switches with the plastic-disc-and-finger contactors, may use a different type of shaft for the planetary gears; the photos I've seen show the use of a metal tube with metal axles, rather than plastic.   It's quite possible that the rear plastic part (the coupler) simply doesn't exist at all in the "new" assembly, since the rear switch section seems to be another of the PC-board type rather than a stack of three wafers.   So, the whole "bad plastic tube and coupler" problem may not exist at all on a lot of the 8640Bs.   >adequate, but not great. If anything, the plastic shaft has SHRUNK >making a loose fit more likely than a tight fit. I can measure mine >if you need a comparison.   I'd appreciate that - thanks@   > I would bet the hole has burrs, shavings, >or is undersized.   I think it may be both... that is, some burrs, possibly undersized (although the other two did fit OK onto the metal shafts of the switches), and maybe some changes in the plastic.   Here's what I got when I measured everything with a Miyutoyo digital caliper:   Central rod .1120-.1125 Shaft ID .129 Shaft OD .2470 at the tail, as much as .2505 next to the axles. Gear ID .2490 to .2500 Axles .124-.125 Planetary gear center .125   So, the shaft does seem to be a bit over-size where the gear is supposed to rotate on it - possibly some damage there - I should be able to smooth it down. I've already burnished the inside of the gear to get rid of any burrs that might have been there.   I suspect that the two plastic planetary gears may have shrunk a bit with age, just as the plastic parts of the three big gears did - I need to open the holes up a bit to get them to rotate easily on the axles.   >>gears, and a composite or Delrin assembly in back) and might try >>fabricating something if I can't get the existing plastic parts back >>into service.   It looks as if I'd be able to use some fairly "stock" metal parts to make the shaft... 1/4" OD fairly-thick-wall brass tube, and 1/8" brass rod. The trickiest part would be mounting the 1/8" axle rods... I'd probably have to drill slightly-undersized holes in the sides of the tube, press-fit the axle rods into place, and then maybe silver-solder them. Gotta talk to my machinist friend about this.   >Can you generate the G code needed to make the part?   Maybe after six months teaching myself how to use a CAD program :-)   >all the teeth will need to be shaped with a small end mill. That's >slow and not fun. It would almost be easier to make a silicone rubber >mold and cast the gears from resin.   I _think_ the gears I have will work out - either the plastic ones (repaired) or the new brass ones I bought (maybe after some burnishing or other tweaking). It's the center tube and planetary-gear drive that I'd need, and I'm not sure CNC milling would be the way to go.   I did find a supplier who sells Delrin rod with a slightly-oversized 1/4" diameter and a slightly-undersized 1/8" central opening. This might work, if I drilled out the inside to a bit more than 1/8", and then machined down the OD to .125". Unfortunately I haven't found anybody who sells this particular variant in small quantities.

"Ron D." <ron.dozier@gmail.com>: Jun 21 10:19AM -0700 For info on the elestometric connector look for "zebra strip".   I had moderate success in repairing watch LCD's. They don't like water. Sometimes you can take a pair of polarized sunglasses and rotate them and the image will come back through the polarizer. At one point I found the polarizing material.   In a Seiko watch I really loved had a non round watch crystal. I had the ability at work to actually cut a piece of quartz on a diamond saw and make a watch crystal.   There is a Timex close to the Seiko, so I have to settle for that,   My problems were not the connector. Once you know how the connector works, you can likely re-position. Just think of fine wires of a certain pitch embedded into insulating rubber. There is other ways of doing the connector too e.g. alternating layers of a conductive elastomer.

"Miguel Giménez" <me@privacy.net>: Jun 21 06:50PM +0200 I am looking for a free Aiwa XR-M35EZ service manual.   My device was pissed by a cat just over the main motherboard, and almost all FPC cables and connectors got badly corroded. The rest of the board is fine. I have changed cables and connectors, but I want to check some things with the service manual before powering up.   Thank you.   -- Greetings Miguel Giménez

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