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ehsjr <ehsjr@mverizon.net>: Oct 27 11:03PM -0400 On 10/21/2017 8:50 PM, Clifford Heath wrote: > friction pad touches it. You could try getting some Penetrene > into the bearings, but the right fix is to disassemble, clean > and lubricate it.   Here's a video on the motor clutch - it might help: https://www.youtube.com/watch?v=WfZS7hHBd7s   Ed

Ivan Vegvary <ivanvegvary@gmail.com>: Oct 28 06:38AM -0700 Back in the late '70s I was paying $12-1300 for used selectrics. Those were real dollars. Hurts to see them at garage sales for $5-10. Wonderful machines!

Foxs Mercantile <jdangus@att.net>: Oct 28 09:14AM -0500 On 10/28/2017 8:38 AM, Ivan Vegvary wrote: > Back in the late '70s I was paying $12-1300 for used > selectrics. Those were real dollars. Hurts to see > them at garage sales for $5-10. Wonderful machines!   Some time ago, I read a wonderful article about them. "The invention nobody needed."   After their introduction, it seemed like EVERY office in the US replaced their old mechanical typewriters.   In my Junior year in high school I took a typing class. Being good at it I was allowed to use one of the IBM Selectrics. 65 WPM here we come!   You'll never fully appreciate doing a two column full justification on a PC unless you've done it by hand with a typewriter and a red pencil. ;-)       -- Jeff-1.0 wa6fwi http://www.foxsmercantile.com

Tim R <timothy42b@aol.com>: Oct 27 05:24PM -0700 > >> of space in comparison to optical or laser levelling to good old benchmarks.   > >Unless you have a warm air layer in between refracting your line of sight.   > Working near a very, very hot room and opening the doors to the cold, cold outside can cause that visual effect.   There is a rather famous case where tunnels were supposed to meet from each side of a mountain, but didn't. Analysis showed they'd relied on a laser level, and it had been bent by a warm air layer in the path.

Ivan Vegvary <ivanvegvary@gmail.com>: Oct 28 06:50AM -0700 Any surveyor can calibrate quickly with no instrumentation. Set level tripod almost exactly between two objects approximately 200ft apart. Make a mark on each object (rotate 180deg back and forth). Said marks will be exactly at the same elevation. Move level (4-5ft) close to one mark, sight it, rotate to second mark (200ft away) and hope to read the same relationship. Adjust bubble accordingly, and repeat entire procedure.

bruce2bowser@gmail.com: Oct 28 07:10AM -0700 I think that imaging using electromagnetic radiation or waves has come quite a ways, too.

dplatt@coop.radagast.org (Dave Platt): Oct 27 11:09AM -0700 >did the hum not show up immediately upon turning on the receiver rather >than after 1/2 hour? I enjoy solving a problem, but I always like to >fully understand it. Thanks.   At a guess, the caps probably undergo some amount of thermal cycling as the receiver warms up (when turned on) and cools down (when turned off). The temperature changes cause the material of the caps (and the leads) to expand and contract, creating a temperature-dependent physical stress on the cap body (the leads are soldered down and their ends can't move, and so stress is created where the leads enter the body and where the leads are soldered to the board).   Over time, this repeated stress ended up weakening and cracking something in the caps - possibly the dielectric itself, possibly the dielectric-to-wire bonds. It's also common for the component itself to be OK, but for a stress crack to occur in the solder joint where its leads connect to the PC board or solder terminals.   Apparently, when the receiver warms up, the thermal expansion is enough to cause this crack to open up. When the receiver down, the cracked junction is pressed back together enough to "close the circuit" again.   Replacing the parts with known-good subsitutes, after cleaning off the older solder from the junction, and re-soldering carefully with the right type of solder and (often useful) some extra liquid solder flux, is the right fix.   Problems of this sort can sometimes be found by tapping various components gently with a wooden chopstick... when you find the area of the cracked component or solder joint, a test speaker hooked to the receiver will start making dreadful popping and banging noises, or the problem will appear and disappear. Don't do this with a speaker you care about :-)

Ken <Ken@invalid.com>: Oct 27 02:03PM -0500 Dave Platt wrote: > receiver will start making dreadful popping and banging noises, or the > problem will appear and disappear. Don't do this with a speaker you > care about :-)   I figured it must be heat related, but your explanation was precise and probably correct. Thanks.

jurb6006@gmail.com: Oct 27 12:26PM -0700 Actually lytics are worse when cold, the opposite of your situation.

Ken <Ken@invalid.com>: Oct 27 08:25PM -0500 > Actually lytics are worse when cold, the opposite of your situation.   The caps I was thinking of were disc caps across the diodes, not electrolytics elsewhere in the circuit. What puzzled me about the 30 minute delay was that electrolytic DO behave that way. If the problem was the caps across the diodes, that would make sense since they seem to be the source of the noise.

Peabody <waybackNO584SPAM44@yahoo.com>: Oct 27 12:00PM -0500 It's an old Sears garage door opener. The schematic shows a 50 ufd start capacitor. What's in there now is 43-52 ufd. What I've found locall to replace it is 53-64 ufd. Will that work?

Fred Smith <fred@thejanitor.corp>: Oct 27 10:27PM > It's an old Sears garage door opener. The schematic shows a 50 ufd start > capacitor. What's in there now is 43-52 ufd. What I've found locall to > replace it is 53-64 ufd. Will that work?   Probably... But the wrong capacitor value may make the motor not spin up at all, or go in reverse instead.

M Philbrook <jamie_ka1lpa@charter.net>: Oct 27 07:18PM -0400 In article <20171027-170008.854.0@Peabody.ssl.astraweb.com>, waybackNO584SPAM44@yahoo.com says...   > It's an old Sears garage door opener. The schematic shows a 50 ufd start > capacitor. What's in there now is 43-52 ufd. What I've found locall to > replace it is 53-64 ufd. Will that work?   YES Those values are not critical for that application.

Foxs Mercantile <jdangus@att.net>: Oct 27 06:51PM -0500 On 10/27/2017 6:18 PM, M Philbrook wrote: >> replace it is 53-64 ufd. Will that work?   > YES > Those values are not critical for that application.   Right. A start capacitor has a minimum value at which it work work. The ones that are critical are the run capacitors. And even then, 10-20% will usually work, 100% might, but the motor will run hot.   -- Jeff-1.0 wa6fwi http://www.foxsmercantile.com

micky <NONONOmisc07@bigfoot.com>: Oct 27 12:58PM -0400 In sci.electronics.repair, on Thu, 26 Oct 2017 22:26:38 -0700, mike >I'm sure you will never let anyone else drive your car...until it >happens. The person who buys it at your estate sale might be surprised >when he accidentally pops the top at highway speed.   One more thing. Every car I've had except one 47 years ago (that I sold because my brother gave me a convertible) and my immediately preceding car, that I still have, has gone to the junk man after it left me. Even the one I still have, I might not be able to find someone who will both buy and repair.   I was going to list this as the first reason there is no danger in my cutting the wire from the speedometer to the top motor, but I'll admit that maybe I'll raise my standard of living by the time I'm 75 and not drive my car until it falls apart, like I always have. And of course if I die, there's no special reason to think the car will be a junker then, but my plan is to live much longer than this car will last. ;-)   (Of course and otoh, even if I outlive this car, I'll cut the same wire on the next four cars, every 5 years instead of 7 like it's been, if I still have the strength to do it. It was tedious and tiring to kneel on the ground for a total of an hour or more and twist my body to look at the wires behind the kick panel, but all in all, it was still easy. I hear a time is coming when I'm 90 or 95 that I won't be able to do this. Maybe I could hire someone, but that is so expensive. ;-) )

micky <NONONOmisc07@bigfoot.com>: Oct 27 01:14PM -0400 In sci.electronics.repair, on Fri, 27 Oct 2017 12:23:14 -0400, Tom Biasi >> little [bit of a scratch], but memory plays tricks on mpeople. And it didn't tear the >> cloth but it still scratched, and that surprised me.   >That's why they make strap wrenches.   I didn't know about that in those days. I only had the tools and parts my father had bought when he was alive. We went to the hardware store some times but I never even looked in the tool section.   When the battery on the '52 Hudson was dead every night, and I had to take my mother's car to my summer job, the only test equipment I had was a socket with a 110 volt light bulb, lamp cord, and an ice pick. It actually was enough, and since there were no transistors then (1964), at least not in cars, not in 1952 cars, I didn't hurt anything.   There were also no quick connectors so every time I had to disconnect a wire, I had to unscrew something, all of it under the dash.

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