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frank@invalid.org: Dec 18 03:40PM > some pictures on the net. > One of them is the DCD model AC.350.OM (where probably OM stands for > Originate, as it doesn't have any Orig/Answ switch).   If anyone is interested, I produced a few video from all the repair process of this 1974's acoustic coupler:   https://www.youtube.com/watch?v=ZAICCy4OC-8 https://www.youtube.com/watch?v=4-StGVDZzXA https://www.youtube.com/watch?v=V3nH4li8MjA   Frank IZ8DWF

Chuck <ch@dejanews.net>: Dec 17 11:11AM -0600 >material.   >So, any recommendations for a small set of tiny >torx bits that actually hold up under use? https://www.homedepot.com/p/Husky-8-in-1-Precision-Torx-Screwdriver-Set-70381H/302735271?cm_mmc=Shopping%7CG%7CBase%7CD25T%7C25-1_HAND+TOOLS%7CNA%7CLIA%7c71700000043839315%7c58700004592003384%7c92700038837660276&gclid=Cj0KCQiAr93gBRDSARIsADvHiOr22bosM03LkORdK-56Md4_lLjurzMk1XXpf59T6jah8gsyPLPJULsaAmZHEALw_wcB&gclsrc=aw.ds have held up well for me.

mike <ham789@netzero.net>: Dec 17 02:08PM -0800 On 12/17/2018 12:22 PM, Jeff Liebermann wrote: > if you disclose if you are stripping the bit or the mating screw? You > might be dealing with a poor fit, bad metalurgy, or excessive force > (torque).   I misunderstood. Thought you were discussing the handle and how it didn't hold the bits well.   If you're not using an impact driver, there ain't no such thing as excessive torque. You apply enough torque to loosen the screw. Anything less is useless. If the bit rounds off or breaks before the screw turns, it's not an acceptable tool. If it damages the screw in the process, you've got problems well in excess of a $2 screwdriver bit.   Since I don't have any of the tiny bits, my experience is with T7 to T10. I found the shiny bits round off very easily. The dull grey or black bits hold up better.   I have shattered bits with the impact driver, but that's not the issue when taking apart a phone.

Jeff Liebermann <jeffl@cruzio.com>: Dec 17 05:22PM -0800 On Mon, 17 Dec 2018 11:42:52 -0600, Fox's Mercantile <jdangus@att.net> wrote:   >Who is Husky and where did they come from?   These might help:   "Who owns what brands" <https://pow-jrk.netdna-ssl.com/wp-content/uploads/2017/01/Tool-Brand-Behemoths-Tool-Companies-Who-Owns-What-Brands.jpg> Husky is in the lower right corner.   Currently, the Husky name is owned by Home Despot: <http://tmsearch.uspto.gov/bin/showfield?f=doc&state=4807:kigunh.2.7> There are multiple listings under the Husky trademark, one for each type of tool sold by Home Depot. My guess is about 300 listings.   Husky tools now have a lifetime warranty. <https://toolguyd.com/husky-tools-forever-guarantee/> Since the quality of Husky tools seems to be going downhill, it's cheaper for Home Despot to offer a lifetime warranty to replace those few tools that are returned as defective, than to fix the quality problems for everyone.   More: <https://en.wikipedia.org/wiki/Husky_(tools)> <https://pressurewashr.com/tool-industry-behemoths/>     -- 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>: Dec 17 06:33PM -0800 >I misunderstood. Thought you were discussing the handle and how it >didn't hold the bits well.   No. It's the way the bit is made that's the problem. Torx drivers and screw heads have a torque limit: <https://www.wihatools.com/torx-sizes> Exceed the torque limit and bad things happen. However, this table assumes that the bit and screw head are perfectly mated fit, with no air gap anywhere on surfaces perpendicular to the direction of applied force. If there's an air gap, the force (torque) will be applied to a much smaller area than with a perfect fit. It doesn't take much of an air gap, especially small screw heads which don't have much mating area anyway. That's why the tapered sides of the new and not-so-improved Husky bits are a problem. There is quite a reduction in contact area near the too narrow tip, and quite an air gap due to the tapered fit.   >If you're not using an impact driver, there ain't no such thing as >excessive torque.   I beg to differ. Look at the max torque specs at the above URL and test your ability to apply torque with some kind of torsion torque tester. This one should cover T2 to T10 screws: <https://www.ebay.com/itm/392178731130> I just tried it with a small torque wrench and found that I could do about 8 ft-lbs or about 11 newton-meters. That's sufficient to hit maximum for a T20 screw head far more than necessary to strip out the tiny screws found in cell phones.   >If the bit rounds off or breaks before the screw >turns, it's not an acceptable tool.   Maybe. If the bit was a good mating fit for the screw head, then yes, it's probably junk. However, if it was a sloppy fit and/or had air gaps, I could also blame the screw or bit depending on which one was poorly made. There's also a question of metallurgy. If the bit were properly heat treated, only the outside surface would be hardened and annealed, while the core would be softer steel. That would give the maximum hardness to protect the surface from gouging, and a somewhat flexible core to give the bit strength. However, as the bit becomes smaller and smaller, more of the material becomes hardened and annealed steel, until the tip becomes very hard and very brittle. Do anything wrong while driving this type of brittle bit, and it's going to break.   >If it damages the screw in the process, you've got problems >well in excess of a $2 screwdriver bit.   I have a collection of screw extractors and center drilling jigs. I rarely need them.   >is with T7 to T10. I found the shiny bits >round off very easily. The dull grey or black >bits hold up better.   Most of the bits are electroplated with some kind of chromium anti-rust compound. In the past, screwdriver tips were hardened giving them a darkish color. This was the symbol of quality for Proto, SK, and other quality screwdrivers. Now, every manufacturer does this, except there's no hardening and the darkish color is either an acid etch or paint.   >I have shattered bits with the impact driver, but >that's not the issue when taking apart a phone.   Hint: If you feel the need to use an impact driver to remove a screw, it's probably a left handed screw thread. (e.g. early Motorola DynaTac and MicroTac).   Suggestions: 1. Don't use driver bits. There's nothing really wrong with them except that the handles are too large for smaller size Torx screws. 2. I have a few of these "precision" Wiha Torx tools: <https://www.wihatools.com/torx-tools/precision-screwdrivers> which I use for working on smartphones. They work very nicely. 3. Test the fit of whatever driver you purchase against the screw head before applying main force. There are some really weird screw heads out there.   -- 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

stratus46@yahoo.com: Dec 17 08:44PM -0800 > And, by doing so, you are voting with your feet and wallet that your neighbor's job and well-being are meaningless to you.   > Peter Wieck > Melrose Park, PA   OK, you're making a fuss about Harbor Freight and I get your point BUT there are times where I want something I'm only going to use a few times and cheapo is good enough. BTW that Husky tool for $6 from Home Depot includes front/back photos of the package which clearly says Made in China.   G²

"pfjw@aol.com" <peterwieck33@gmail.com>: Dec 18 07:16AM -0800 On Monday, December 17, 2018 at 6:14:15 PM UTC-5, stra...@yahoo.com wrote: c   > I also use Wiha drivers at work but Peter will still be unhappy. While they are not made in China, they are also not made in USA. They are German.   > I used to use Xcelite made in USA but hey are poor quality compared to Wiha and to add insult, they cost more.     Not so much on the German or Swiss stuff. That will be premium, and I concede that need for those that need that level of ultra-reliability. When I was working as a machinist - and signing off on aircraft parts (full signature, not initials), the tools I used were either Swiss, German, or Starrett-level American. And those things that measured got calibrated every quarter.   Point being that if one needs tools of that quality, one has few choices.   Peter Wieck Melrose Park, PA

Big Bad Bob <BigBadBob-at-mrp3-dot-com@testing.local>: Dec 17 10:18PM -0800 On 12/01/18 23:57, Sjouke Burry wrote: >> will fit?   > buy a few garage sale radios, A lot of them use the same pot/switch. > Also found in other old audio stuff.   another possibility is guitar amplifier parts, like at 'amplifiedparts.com'   this search resulted in several hits, maybe one will work? https://www.amplifiedparts.com/search/node/switch?cats%5B0%5D=147     -- (aka 'Bombastic Bob' in case you wondered)   'Feeling with my fingers, and thinking with my brain' - me

Big Bad Bob <BigBadBob-at-mrp3-dot-com@testing.local>: Dec 17 10:09PM -0800 > worked with one of these in many years, and never had to replace one in > the old days. My meter was climbing, probably from the filter caps. > during this test.   forward/back resistance with a basic ohm meter should be around 100:1 or better as I recall, and you might have to use a resistance bridge of some kind (or other measuring circuit) with a voltage potential of several volts for the higher voltage selenium rectifiers.   Selenium rectifiers might have a voltage drop of several volts during normal operation. So maybe a test circuit would work better...   You could drive normal AC power through it, into a (safe) resistive load (no capacitors), and then look at the downstream waveform on an o-scope. It should be half wave AC at a reasonable peak voltage, into a reasonable resistive load (let's say a 10k or 20k several-watt resistor).   I assume it's for a radio that runs on 110V [or maybe 220/240V for EU and AU radios]. So you'll see a half-wave 50/60 cycle waveform that peaks at around 1.4 times the input voltage.   If you look at it with an o-scope and see too much on the negative cycle, you'll know it's bad. Otherwise it should be ok to use it as long as the resulting output voltage is correct.     -- (aka 'Bombastic Bob' in case you wondered)   'Feeling with my fingers, and thinking with my brain' - me

Big Bad Bob <BigBadBob-at-mrp3-dot-com@testing.local>: Dec 17 10:12PM -0800 >> are extremely fussy about that.   > I plan to leave it on the chassis for looks, but replace it. > My voltage is real low, so it seems it's weak or worse....   right they'll probably short out when they fail and blow the filter caps.   You could try a resistive load (10k-20k, several watt resistor) and disconnect it from the filter capacitors when you do it. Then look at the waveform. (I suggested this in a different post already, just summarizing)     -- (aka 'Bombastic Bob' in case you wondered)   'Feeling with my fingers, and thinking with my brain' - me

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