sci.electronics.repair@googlegroups.com

Google Groups

jurb6006@gmail.com: Jan 24 06:37PM -0800 >"I will try to put in the drop box."   Too bad. Dropbox doesn't want to display for me. It might be because I used to be a member ad gave it up. I am currently looking for free hosting that is compatible with my browser.   I don't mind an ad or two but I don't want people to have to sign up or sign in and that is what it is doing for me.

Ralph Mowery <rmowery28146@earthlink.net>: Jan 24 11:23PM -0500 In article <37301d83-be37-4233-9918-209e49cec2b1@googlegroups.com>, pfjw@aol.com says... > > works OK except for 1000...   > As already noted, there are almost as many codes as makers. In my (very) old Centerlab Catalog, I did find references to W-Taper pots, but nothing conclusive at all on K or k taper as a specific reference.   > With the additional hint of this being a slider, further googling got me to drill bits, but nothing on pots, linear or rotary.   All that is what makes things 'interisting'. I believe the K is for Kelvin temperature and that made them use the k for 1000.   Too bad that many companies seem ot use their own code for part numbers. I really hate the companies that use their part number on standard parts and if you need to replace them, you are almost forced to go to the origional company or one of their repair man. Friend in the auto repair business told me that often a luxulary car part would be the same as a less expensive model. They use a different number and higher price.

rickman <gnuarm.deletethisbit@gmail.com>: Jan 25 12:05AM -0500 Phil Allison wrote on 1/23/2018 10:29 PM:   > The code letters used varied alarmingly, A originally meant linear and C =log. Pots coming from Asia used A = audio taper with B = linear and D = log.   > The code letter "E" referred to a "reverse log" pot, useful in instrumentation where the actual gain of a amplification stage must be varied smoothly.   > Strangely, I have not come across a reverse linear pot anywhere.   If you give it a thought, you will realize a linear pot is its own reverse. The reverse doesn't refer to whether the resistance goes up or down, it refers to which direction the log curve goes, a log taper or an exponential taper. A linear taper is the same either way... it's linear.   --   Rick C   Viewed the eclipse at Wintercrest Farms, on the centerline of totality since 1998

whit3rd <whit3rd@gmail.com>: Jan 24 11:28PM -0800 On Wednesday, January 24, 2018 at 9:05:17 PM UTC-8, rickman wrote:   > If you give it a thought, you will realize a linear pot is its own reverse. > The reverse doesn't refer to whether the resistance goes up or down, it > refers to which direction the log curve goes...   Log taper means mimicing log(d) where the deflection (d) goes from 1 to 100 or somesuch. Inverse log taper means mimicing log(1/d) = - log(d)   So, linear taper can mimic 'd', and its inverse can be '-d', as you say. Or, linear taper can be 'd', and its inverse can be '1/d'.   The '1/d' taper would be a way to make an adjustable attenuator, linear in inverse gain going from '1' meaning full signal, to '2' meaning 1/2, ... '10' meaning 1/10

rickman <gnuarm.deletethisbit@gmail.com>: Jan 25 02:57AM -0500 whit3rd wrote on 1/25/2018 2:28 AM: > Or, linear taper can be 'd', and its inverse can be '1/d'.   > The '1/d' taper would be a way to make an adjustable attenuator, linear in inverse gain > going from '1' meaning full signal, to '2' meaning 1/2, ... '10' meaning 1/10   Then it is no longer linear.   --   Rick C   Viewed the eclipse at Wintercrest Farms, on the centerline of totality since 1998

Fox's Mercantile <jdangus@att.net>: Jan 25 01:58AM -0600 On 1/24/18 11:05 PM, rickman wrote: > reverse. The reverse doesn't refer to whether the resistance goes up or > down, it refers to which direction the log curve goes, a log taper or an > exponential taper.  A linear taper is the same either way... it's linear.   Congratulations, not only are you ignorant, you have no sense of humor.       -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

tabbypurr@gmail.com: Jan 25 12:22AM -0800 On Thursday, 25 January 2018 05:05:17 UTC, rickman wrote: > The reverse doesn't refer to whether the resistance goes up or down, it > refers to which direction the log curve goes, a log taper or an exponential > taper. A linear taper is the same either way... it's linear.   I would very much expect he didn't need to 'give it a thought' to work out something so obvious.     NT

"pfjw@aol.com" <pfjw@aol.com>: Jan 25 04:13AM -0800 > >"I will try to put in the > drop box."   > Too bad. Dropbox doesn't want to display for me. It might be because I used to be a member ad gave it up. I am currently looking for free hosting that is compatible with my browser.   Dropbox does not support Samsung devices for what that is worth. Or so they tell me.   Peter Wieck Melrose Park, PA

rickman <gnuarm.deletethisbit@gmail.com>: Jan 25 08:06AM -0500 >> refers to which direction the log curve goes, a log taper or an exponential >> taper. A linear taper is the same either way... it's linear.   > I would very much expect he didn't need to 'give it a thought' to work out something so obvious.   And yet, he mentions he has never seen a reverse linear taper.   --   Rick C   Viewed the eclipse at Wintercrest Farms, on the centerline of totality since 1998

"pfjw@aol.com" <pfjw@aol.com>: Jan 25 05:22AM -0800 On Thursday, January 25, 2018 at 8:06:29 AM UTC-5, rickman wrote: > And yet, he mentions he has never seen a reverse linear taper.   Back when I was a journeyman electrician, and therefore was privileged to haze the apprentices, I asked one to fetch me (amongst many other things) a combo-plate from the warehouse like this: https://cdn.gescan.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/b/ibv97532-2.jpg   And when he brought me this:   https://images.homedepot-static.com/productImages/5849af02-96ef-4c79-9192-37a8464488aa/svn/stainless-steel-legrand-pass-seymour-combination-wall-plates-sl18cc5-64_1000.jpg   I sent him back, stating I needed the receptacle on the left.   He got as far as the door before he caught on. And it never happened to him again. Others got all the way to the counter at the warehouse.   Peter Wieck Melrose Park, PA

amdx <nojunk@knology.net>: Jan 25 08:00AM -0600 > JB Weld is your best friend. Get a soda-straw or heat-shrink tubing about the same diameter as the shaft, either use the broken piece or a suitable bit of solid material to extend the shaft to the correct length. Mix up the *SLOW* JB Weld epoxy, and use the straw/tubing to hold the shebang together and vertical, but out of the pot, until the epoxy sets up. Let the epoxy fill any voids. The result will be stronger than the original.   > Peter Wieck > Melrose Park, PA   I have repaired many broken plastic parts. I have a kit with 0.025" and 0.035" drill bits and matching steel rods. I put the parts together, then drill through where inserting a steel pin will give it the most strength. I epoxy the joint and the pin and put it all together. I use a Dremel tool to drill the hole and and cut the steel pin off, after the epoxy sets. The epoxy I have is Huntsman Fastweld 10, (ex. Ciba-Geigy Araldite) It is a 5 minute set 24 hour cure.   Mikek

amdx <nojunk@knology.net>: Jan 25 08:15AM -0600 > He got as far as the door before he caught on. And it never happened to him again. Others got all the way to the counter at the warehouse.   > Peter Wieck > Melrose Park, PA   In my late teens a father bought his daughter a Volkswagen Beetle, the first thing he did was send her to go to the gas station* and have them check the water in the radiator.   Mikek   * back when they had service at gas stations.

rickman <gnuarm.deletethisbit@gmail.com>: Jan 24 11:57PM -0500 > On Monday, 22 January 2018 20:56:52 UTC, Terry Schwartz wrote: >> At my last company, I spent the better part of my last 4 or 5 years dealing with water conductivity issues. We produced machines that electrolyzed water into base and acid components in order to produce cleaning chemicals. <<< snip >>> > I'd be interested to find out about the production of the cleaning chemicals.   I can tell you it wasn't from electrolysis of water. That produces hydrogen (H2) and oxygen (O2), not acid and base. Anything else would have to come from additives to the water.   --   Rick C   Viewed the eclipse at Wintercrest Farms, on the centerline of totality since 1998

tabbypurr@gmail.com: Jan 25 12:15AM -0800 On Thursday, 25 January 2018 04:58:09 UTC, rickman wrote:   > I can tell you it wasn't from electrolysis of water. That produces hydrogen > (H2) and oxygen (O2), not acid and base. Anything else would have to come > from additives to the water.   it's saltwater.   I'm curious when this was patented, if it was.     NT

rickman <gnuarm.deletethisbit@gmail.com>: Jan 25 08:11AM -0500 >> (H2) and oxygen (O2), not acid and base. Anything else would have to come >> from additives to the water.   > it's saltwater.   Not really. All water has contaminants. The water he has mentioned was fresh water with more or less contaminants. Still, it wouldn't be described as electrolysis of (salt)water if the interesting part was the contaminants. It would be described as the interesting bits dissolved in water.   --   Rick C   Viewed the eclipse at Wintercrest Farms, on the centerline of totality since 1998

"pfjw@aol.com" <pfjw@aol.com>: Jan 25 05:36AM -0800 Apropos electrolysis and water, way back in the day in high-school, my chemistry teacher showed us how to make Hydrogen peroxide using electrolysis. It was crude and not very efficient, and wasteful of resources.   Today, not so much.   https://link.springer.com/article/10.1023/A%3A1017588221369   Under controlled conditions, other products are also possible. I suspect that is what Tennant was doing.   Side Note: This teacher partnered with several of the history teachers. He had us collect 'night soil' to make gunpowder when we were studying the Civil War, we had to learn the 'secret code' whereby one could identify an American anywhere, any time (this _was_ the 1960s, remember), and we had to learn the ten (10) reindeer. In any case, a lot of very basic and very useful chemistry and applied science has stuck with me over the years.   Peter Wieck Melrose Park, PA

Terry Schwartz <tschw10117@aol.com>: Jan 25 06:06AM -0800 Apparently anyone can be an expert on things they do not understand.

whit3rd <whit3rd@gmail.com>: Jan 24 05:26PM -0800 On Wednesday, January 24, 2018 at 9:18:36 AM UTC-8, KenO wrote:   > A while ago put a number of HDDs in storage.   > Recently tried to use and noticed that some do Not spin up (all were working when put in storage).   > Had read that sometimes the heads will stick or other factors like lube will cause the disk from spinning.   Yes, motor power is sometimes a problem: first thing to do is listen very hard. If it IS spinning, don't hit it... but if it isn't, the motor control will shut down a second after power is applied, so what you want to do is give the drive a brisk twist just after applying power. Set the drive on a horizontal surface, flip on power and quickly rap one corner so as to make the drive twist position slightly... try both directions. You must switch the power off and wait a few seconds between each trial. Give it a dozen tries (use a stick, no sense getting bruised).   Apply heat (hair dryer is fine) to warm the case, wait a few minutes, and try again. You just want the aluminum parts warm so the lubricant softens.   If that doesn't work, examine the drive electronics, sometimes it's just a shorted diode on the power pins. And, sometimes there's a scorched odor and a crater in one of the black plastic rectangles...

tabbypurr@gmail.com: Jan 25 12:11AM -0800 On Thursday, 25 January 2018 00:02:21 UTC, Clifford Heath wrote: > a Fujitsu Eagle hard drive. Pretty difficult; it took two > strong people to coordinate a twist on a 60kg drive without > dropping it.   how many platters did that have?? Even the original 2' wide rusty platter stack didn't come in at 60kg iirc.     NT

tabbypurr@gmail.com: Jan 25 12:14AM -0800 On Thursday, 25 January 2018 08:11:54 UTC, tabby wrote:   > how many platters did that have?? > Even the original 2' wide rusty platter stack didn't come in at 60kg iirc.   > NT   11x 10.5" platters, 4k rpm, 30 second spin-up time.     NT

Clifford Heath <no.spam@please.net>: Jan 25 07:44AM +1100 >> how many platters did that have?? >> Even the original 2' wide rusty platter stack didn't come in at 60kg iirc. > 11x 10.5" platters, 4k rpm, 30 second spin-up time.   I never weighed one, just took a guess. It was a difficult thing to lift and apply power then a rapid rotational jerk to however. Then gently lift it back into the rack to avoid crashing anything. 540MB if I recall - I don't even have a thumb drive that small any more.

jack4747@gmail.com: Jan 25 02:06AM -0800 Il giorno mercoledì 24 gennaio 2018 18:18:36 UTC+1, KenO ha scritto:   > A while ago put a number of HDDs in storage.   > Recently tried to use and noticed that some do Not spin up (all were working when put in storage).   > Had read that sometimes the heads will stick or other factors like lube will cause the disk from spinning.   when the disk is powered off the heads are parked, and if the heads touch the platters then you can throw the HD in the trash.   If it doesn't spin up it's because the bearings of the motor are stuck. A gentle but firm poke on the side of the disk should help. Also putting the HD in vertical instead of horizontal position when it power up may help. Or shaking it a little.   Bye Jack

"Rick" <rike22@bellsouth.net>: Jan 25 05:12AM -0600 "John Robertson" <spam@flippers.com> wrote in message news:mZidnWkj6PCjhvTHnZ2dnUU7-L2dnZ2d@giganews.com... > (604)872-5757 (Pinballs, Jukes, Video Games) > www.flippers.com > "Old pinballers never die, they just flip out."   http://www.alps.com/prod/info/E/PDF/Potentiometer/TAPER.pdf

tabbypurr@gmail.com: Jan 25 03:31AM -0800 On Thursday, 25 January 2018 09:45:34 UTC, Clifford Heath wrote: > Then gently lift it back into the rack to avoid crashing anything. > 540MB if I recall - I don't even have a thumb drive that small any > more.   sounds like an improvement on: 1956 IBM 350. fifty 24-inch (0.6 m) platters, total capacity (3.75 megabytes).     NT

Harold Newton <harold@example.com>: Jan 25 02:50AM On Wed, 24 Jan 2018 09:46:53 -0800, Jeff Liebermann wrote:   > T-Mobile doesn't claim to have service, I have not idea if they will > thank you for improving their footprint, disconnect your service, or > something in between. Good luck.   Hi Jeff, Thanks for that input.   It's not a big deal because I was answering the question for "The Real Bev", where I'm pretty sure (but not positive) the answer is thus.   1. Repater 2. Femtocell   The Repeater "probably" does not report back to the cellular provider anything as it's likely just a "bridge" of sorts that just passes the MAC address (among other things) straight through.   In that case, the cellular provider probably can't tell that you moved the repeater because it likely doesn't even know that the repeater is involved.   The Femtocell is *completely* different.   They know *everything* about the Femtocell; so it's interesting you were able to move it. Perhaps the IP geolocation isn't great enough, in your test, to flag their "movement" algorithm.   Thanks!

You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.