- Can someone explain to me how you lose (and then find) a satellite? - 10 Updates
- Help, electronics on Craftsman Radial Arm Saw. - 1 Update
- ESR meter trap - 7 Updates
| ultred ragnusen <ultred@ragnusen.com>: Feb 01 09:23PM -0800 Can someone explain to me how you lose (and then find) a satellite? https://www.washingtonpost.com/news/inspired-life/wp/2018/02/01/this-amateur-astronomer-found-a-satellite-lost-in-space/ Since the thing is orbiting earth, why can't NASA just look up in the sky with a telescope to find it? |
| jurb6006@gmail.com: Feb 01 09:51PM -0800 >"Since the thing is orbiting earth, why can't NASA just look up in the sky with a telescope to find it?" Good question. But I do know that when you aim at something 22,000 miles away you have to be pretty close. the band over the equator where geosynchronous satellites can orbit is about 82,000 miles in circumference, so that is alot of area. Plus we don't know it was geosynchronous. Satellites can go every which way. The can be 22,000 miles up and do the same speed as the surface of the Earth at the equator, but they can go any way. But then you have to track them to communicate with them. There are also an infinite number of planes at which a satellite can orbit, the closer to the Earth the faster it must move, the farther the slower. So it can indeed be like finding a needle in a haystack, and I mean without a magnet. Normally the tracking system can follow the signal, but not if it stops transmitting. If it is not in geosynchronous orbit it can be extremely hard to find. Count this up to luck. If NASA couldn't find it even knowing where it was supposed to be odds are about like hitting the lotto. But then people do... |
| robin <none@home.com.invalid>: Feb 02 01:32AM -0600 On Thu, 1 Feb 2018 21:23:59 -0800, ultred ragnusen <ultred@ragnusen.com> wrote: >https://www.washingtonpost.com/news/inspired-life/wp/2018/02/01/this-amateur-astronomer-found-a-satellite-lost-in-space/ >Since the thing is orbiting earth, why can't NASA just look up in the sky >with a telescope to find it? Did you read the article? Start there, then come back if you still have questions. |
| N_Cook <diverse@tcp.co.uk>: Feb 02 08:49AM On 02/02/2018 05:23, ultred ragnusen wrote: > https://www.washingtonpost.com/news/inspired-life/wp/2018/02/01/this-amateur-astronomer-found-a-satellite-lost-in-space/ > Since the thing is orbiting earth, why can't NASA just look up in the sky > with a telescope to find it? Considering they can track things as small as a glove, to monitor space junk, for collision avoidance. |
| gregz <zekor@comcast.net>: Feb 02 09:00AM > https://www.washingtonpost.com/news/inspired-life/wp/2018/02/01/this-amateur-astronomer-found-a-satellite-lost-in-space/ > Since the thing is orbiting earth, why can't NASA just look up in the sky > with a telescope to find it? LOL. When they were trying to regain Skylab communication, we could see it. Try pointing am 85 foot dish at it. That's what we were doing, pointing at it. We almost got it. Later another agency sent proper position data. Greg |
| Phil Allison <pallison49@gmail.com>: Feb 02 01:33AM -0800 ultred ragnusen wrote: ----------------------- > https://www.washingtonpost.com/news/inspired-life/wp/2018/02/01/this-amateur-astronomer-found-a-satellite-lost-in-space/ > Since the thing is orbiting earth, why can't NASA just look up in the sky > with a telescope to find it? ** How would you identify which one it was ?? Only finding a characteristic radio signal does that. Satellites moving across the night sky look much the same. .... Phil |
| amdx <nojunk@knology.net>: Feb 02 07:34AM -0600 On 2/1/2018 11:23 PM, ultred ragnusen wrote: > https://www.washingtonpost.com/news/inspired-life/wp/2018/02/01/this-amateur-astronomer-found-a-satellite-lost-in-space/ > Since the thing is orbiting earth, why can't NASA just look up in the sky > with a telescope to find it? It's like your keys, you lose them, you look for them, find them, cause they were there all along! |
| Stephen Wolstenholme <steve@easynn.com>: Feb 02 01:50PM >> with a telescope to find it? > It's like your keys, you lose them, you look for them, find them, >cause they were there all along! I got a key finder from Object Locator. It don't finds satellites! Steve -- http://www.npsnn.com |
| Fox's Mercantile <jdangus@att.net>: Feb 02 08:07AM -0600 On 2/1/18 11:23 PM, ultred ragnusen wrote: > Can someone explain to me how you lose (and then find) a satellite? You realize this is that bonehead Harry Newton again. -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com |
| "Mr. Man-wai Chang" <toylet.toylet@gmail.com>: Feb 03 12:07AM +0800 > Normally the tracking system can follow the signal, but not if > it stops transmitting..... Could it suddenly use the wrong frequency to transmit due to software or hardware bug? -- @~@ Remain silent! Drink, Blink, Stretch! Live long and prosper!! / v \ Simplicity is Beauty! /( _ )\ May the Force and farces be with you! ^ ^ (x86_64 Ubuntu 9.10) Linux 2.6.39.3 不借貸! 不詐騙! 不援交! 不打交! 不打劫! 不自殺! 請考慮綜援 (CSSA): http://www.swd.gov.hk/tc/index/site_pubsvc/page_socsecu/sub_addressesa |
| Terry Schwartz <tschw10117@aol.com>: Feb 02 08:05AM -0800 On Wednesday, January 31, 2018 at 6:40:51 PM UTC-6, Ivan Vegvary wrote: > Just rebuilt this saw. Electronics worked when purchased used in 2005. Now, with new battery, nothing on the display. Total of 4 encoders should be read/displayed. Any help on finding schematic etc. appreciated. Sears no longer has parts. Thanks! Perhaps a model number would help. |
| "Gareth Magennis" <soundserviceleeds@outlook.com>: Feb 01 08:21PM "Phil Allison" wrote in message news:880bbfb4-6afb-4945-a441-caa38bafd0ab@googlegroups.com... Hi, few here would disagree that using an ESR meter is the fastest and surest way to find bad electros. If the meter reading is several times or more higher than normal, that electro must go. This week, I saw a Fender tube amp with pretty obvious filter electro trouble that almost caught me trusting my (Bob Parker) ESR meter too much. Under a steel cover were five, "IC" brand 22uF, 500V axial electros - from the symptoms I figured ones immediately following the rectifiers diodes must be bad. The ESR meter agreed, giving open ( >100ohms) ESR readings for two and good readings for the remaining three. While extracting the bad pair from the PCB, I realised they were wired in parallel. The electros looked in good condition so my suspicions raised, I peeled back the case with nippers to loosen rubber bung and take peek inside. Turned out there was NO metallic connection between the positive lead and the rest of the capacitor. The bung and lead stub simply fell off. I opened the other three and found two more in the same condition while the last was perfectly OK with all its connections in place. The electros concerned are exactly like the ones in this pic: http://www5.austlii.edu.au/au/legis/qld/consol_act/cc189994/s268.html The ESR meter was fooled by the fact (except for one) the caps had NOT gone high ESR, but had suffered severe corrosion of the plus leads where they entered the cap roll. I have to agree with the author of the linked page, Illinois Capacitors have produced a bad batch and full replacement is the only smart option. .... Phil *********************************************** I had a Fender Hotrod Deluxe in a couple of months ago with an identical problem. All 3 of the 22uF caps were leaking and measured bad ESR. The 47uF were fine. I figured at the time it must have been a faulty batch of IC capacitors. They weren't THAT old, and ALL of them suffered the same fate. This amp was motorboating like crazy, but only on the distortion channel. Gareth. |
| "Gareth Magennis" <soundserviceleeds@outlook.com>: Feb 01 10:29PM "Gareth Magennis" wrote in message news:YEKcC.637430$fg4.510296@fx08.am4... "Phil Allison" wrote in message news:880bbfb4-6afb-4945-a441-caa38bafd0ab@googlegroups.com... Hi, few here would disagree that using an ESR meter is the fastest and surest way to find bad electros. If the meter reading is several times or more higher than normal, that electro must go. This week, I saw a Fender tube amp with pretty obvious filter electro trouble that almost caught me trusting my (Bob Parker) ESR meter too much. Under a steel cover were five, "IC" brand 22uF, 500V axial electros - from the symptoms I figured ones immediately following the rectifiers diodes must be bad. The ESR meter agreed, giving open ( >100ohms) ESR readings for two and good readings for the remaining three. While extracting the bad pair from the PCB, I realised they were wired in parallel. The electros looked in good condition so my suspicions raised, I peeled back the case with nippers to loosen rubber bung and take peek inside. Turned out there was NO metallic connection between the positive lead and the rest of the capacitor. The bung and lead stub simply fell off. I opened the other three and found two more in the same condition while the last was perfectly OK with all its connections in place. The electros concerned are exactly like the ones in this pic: http://www5.austlii.edu.au/au/legis/qld/consol_act/cc189994/s268.html The ESR meter was fooled by the fact (except for one) the caps had NOT gone high ESR, but had suffered severe corrosion of the plus leads where they entered the cap roll. I have to agree with the author of the linked page, Illinois Capacitors have produced a bad batch and full replacement is the only smart option. .... Phil *********************************************** I had a Fender Hotrod Deluxe in a couple of months ago with an identical problem. All 3 of the 22uF caps were leaking and measured bad ESR. The 47uF were fine. I figured at the time it must have been a faulty batch of IC capacitors. They weren't THAT old, and ALL of them suffered the same fate. This amp was motorboating like crazy, but only on the distortion channel. Gareth. ******************************** Maybe there is a polarity difference between clean and distortion channels, haven't checked. Gareth. |
| Phil Allison <pallison49@gmail.com>: Feb 01 08:39PM -0800 Gareth Magennis wrote: ---------------------- > I figured at the time it must have been a faulty batch of IC capacitors. > They weren't THAT old, and ALL of them suffered the same fate. > This amp was motorboating like crazy, but only on the distortion channel. ** Like this one ? https://www.youtube.com/watch?v=iDeXlQIvqco FYI: My service notes show that the same Fender amp was here in July last year, with no external signs of trouble with any electros. .... Phil |
| jurb6006@gmail.com: Feb 01 09:59PM -0800 On Thursday, February 1, 2018 at 3:38:52 AM UTC-5, Phil Allison wrote: > ** The good reading was **misleading** you fucking moron. > .... Phil Actually I saw the >100 ohms and assumed that means bad. I read too fast and thought too slow. You could have worded it differently and I wouldn't have missed part of it. Anyway, I have also heard of ESR meters being used as a low low ohmmeter to locate a short on a power supply where evereything is just hooked together. I do have a Fluke DVM capable of that but not everyone does. i wonder if the ESR function is a bit better than that though because it might be able to pick up on some inductance. Maybe, never thought about it much. I just use a scope for ESR. |
| "Gareth Magennis" <soundserviceleeds@outlook.com>: Feb 02 09:05AM "Phil Allison" wrote in message news:4487eeeb-f346-42e8-a565-df1711569ead@googlegroups.com... Gareth Magennis wrote: ---------------------- > I figured at the time it must have been a faulty batch of IC capacitors. > They weren't THAT old, and ALL of them suffered the same fate. > This amp was motorboating like crazy, but only on the distortion channel. ** Like this one ? https://www.youtube.com/watch?v=iDeXlQIvqco ************************************ Identical! Gareth. |
| Phil Allison <pallison49@gmail.com>: Feb 02 01:19AM -0800 jurb...@gmail.com wrote: ------------------------ > Actually I saw the >100 ohms and assumed that means bad. > I read too fast and thought too slow. You could have worded it > differently and I wouldn't have missed part of it. ** The Bob Parker ESR meter has an auto-ranging, two digit display that over flows above 99 ohms. It shows ESR values from 0.01 ohms to 99 ohms. The black button zeros the reading before measurements and also cycles the meter on and off. http://i44.photobucket.com/albums/f9/akuhon/esr-caps-pic/DSCF0045-86.jpg The "good" 22uF, 500V electros showed readings close to 1.5 ohms while the "bad" ones were completely open. In reality, 2 of the 3 "good" electros were just about to fail open circuit. Electro caps normally dry out and go high ESR fairly slowly, ones that test perfect one day and go DEAD the next are not playing fair. .... Phil |
| Tim R <timothy42b@aol.com>: Feb 02 05:54AM -0800 On Friday, February 2, 2018 at 4:19:20 AM UTC-5, Phil Allison wrote: ones that test perfect one day and go DEAD the next are not playing fair. > .... Phil Hate it when that happens. But it's the reason we were required to Live Dead Live in the factory where I worked, to be sure power was off before doing a repair. Live (testing a powered circuit) proves your meter works. Dead proves your locked out circuit is safe, provided your meter didn't die in between. Live again proves your meter was okay. |
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