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afonsogageiro@gmail.com: May 30 06:28AM -0700 Hello from Portugal   Where is the tuning button (or equivalent) on a National L15EN VCR? I can't find it anywhere!   Best regards, Afonso Gageiro

amdx <nojunk@knology.net>: May 30 10:13AM -0500 > Where is the tuning button (or equivalent) on a National L15EN VCR? I can't find it anywhere!   > Best regards, > Afonso Gageiro   Never heard of a National VCR, can you post a picture? How old is it? Is anyone manufacturing VCRs anymore? I made a living repairing VCRs for about 14 years of my life, but that was over 21 years ago.   Mikek     --- This email has been checked for viruses by Avast antivirus software. http://www.avast.com

N_Cook <diverse@tcp.co.uk>: May 30 05:02PM +0100 On 30/05/2015 16:13, amdx wrote:   > --- > This email has been checked for viruses by Avast antivirus software. > http://www.avast.com   Probably called Panasonic NV L15 (various suffixes) in other countries

bud-- <null@void.com>: May 29 12:19PM -0600 On 5/26/2015 5:12 PM, KenO wrote:   Excellent information on surges and surge protection is at: http://www.lightningsafety.com/nlsi_lhm/IEEE_Guide.pdf - "How to protect your house and its contents from lightning: IEEE guide for surge protection of equipment connected to AC power and communication circuits" published by the IEEE in 2005 (the IEEE is a major organization of electrical and electronic engineers). And also: http://pml.nist.gov/spd-anthology/files/Surges_happen!.pdf - "NIST recommended practice guide: Surges Happen!: how to protect the appliances in your home" published by the US National Institute of Standards and Technology in 2001   Both guides are from reliable sources.   The IEEE surge guide is more technical.   > A friend recently had her audio system damaged from an AC Power Surge.   > Would like to prevent this so Googled using AC Power Surge Protection and found "The Best Surge Protector by Brent Butterworth. > http://thewirecutter.com/reviews/best-surge-protector/   I wouldn't rely on the testing that was done. There are standard tests for surge protectors - 600V is not one of them (6,000V is). And I have no idea if their test is representative of a surge. There is related information on UL testing in the IEEE surge guide under "2.2.3 Surge Limiting Voltage"     > Read link "Surge Protectors ??? (Brickwall, Zero Surge, Furman, SurgeX," http://www.avsforum.com/forum/40-oled-technology-flat-panels-general/1146963-surge-protectors-brickwall-zero-surge-furman-surgex-etc.html   The vast majority of surge protectors use MOVs as the voltage limiting element (over 90% according to the IEEE surge guide). These protectors do not use MOVs. I have not seen them evaluated by a reliable independent agency, and I would not use them. They, of course, claim to be better than the MOV based ones. Some of their arguments are downright stupid.     > Then did a Forum search and found some very long discussions such as: > Surge Protectors https://groups.google.com/forum/#!searchin/sci.electronics.repair/AC$20Power$20Surge$20Protection%7Csort:relevance/sci.electronics.repair/mkLpyahIKNk/3GvjxW9LrrsJ   Westom is an internet nut that googles for "surge" to spread his ideas about protection. He has joined an astonishing number of forums to spread his ideas. Some of them are good, some not-so-good, and some are complete nonsense. Everything he says about plug-in protectors is complete nonsense. How can you tell? Westom says plug in protectors don't work. Both the IEEE and NIST guides say they are effective.   I am "bud". I got tired of westom's crap after seeing it on several Usenet groups I watch over a short period. I have nothing to do with the surge protection industry other than I am using a couple protectors. A lot of what I wrote here comes from the IEEE and NIST surge guides     > Surge protector fuse blown https://groups.google.com/forum/#!searchin/sci.electronics.repair/AC$20Power$20Surge$20Protection%7Csort:relevance/sci.electronics.repair/iUffPhXZsNA/Ay8058Ba46QJ   w_tom is a name that westom used to use. More nonsense.   I have not read either of these threads.     > Would like to use your advice to build a cost effective audio protection system.   > Thanks   > Ken   If using a plug-in protector all interconnected equipment needs to be connected to the same protector. External connections, like coax also must go through the protector. As explained in the IEEE surge guide (starting page 30) plug-in protectors work primarily by limiting the voltage from each wire to the ground at the protector. To do that all wires must go through the protector.   The NIST surge guide suggests most equipment damage is from high voltage between power and signal (phone, cable,...) wires. Computer and video equipment is likely more at risk than audio. And it depends on where you are. Some parts of the US have significant surge exposure. The major cause of damaging surges is lightning. Normal and abnormal utility operations can also cause damaging surges.   The author of the NIST surge guide looked at the surge current that might come in on power wiring (US). The source was a 100,000A lightning strike to a utility pole adjacent to a house with typical urban overhead power distribution. Only 5% of strikes are more powerful and this is, for practical purposes, the worst case. The surge current was 10,000A per wire. Service panel protectors with much higher ratings are readily available. High ratings mean long life. A service panel protector is likely to protect anything connected only to power wiring (most audio systems?)   The author of the NIST surge guide also investigated how much energy might be absorbed in a MOV in a plug-in protector. Branch circuits were 10m and longer, and the surge on incoming power wires was up to 10,000A (wort case, as above). The maximum energy at the MOV was a surprisingly small 35 joules. In 13 of 15 cases it was 1 joule or less. There are a couple simple reasons the energy is so low (one of which may be particular to US wiring). Any UL listed protector in the US will have ratings higher than that, and much higher ratings are readily available (as in your first link). Again high ratings mean long life.   (Neither service panel or plug-in protectors protect by absorbing a surge. They do absorb some energy in the process of protecting. And protection from a direct strike to a building requires lightning rods.)   In the US, since 1998 UL has required thermal disconnects for overheating MOVs. (With world markets they are probably included by all competent manufacturers everywhere.) APC had an engineering error resulting in a recall.   The IEEE surge guide describes how the protected equipment can be connected across the MOVs, or be connected across the incoming power wires. If connected across the MOVs, the protected equipment will be disconnected on failure. (That is one reason why manufacturers can have protected equipment warranties.) I think the IEEE surge guide says UL requires protectors to state if they do not disconnect the protected load with the MOVs.)   It would be nice if you could compare protectors based on joule rating. The IEEE surge guide explains that (US) there is not a standard way of measuring this, so some manufacturers have misleading ratings. Some other (reliable) manufacturers responded by not including joule ratings.

Cydrome Leader <presence@MUNGEpanix.com>: May 29 05:38PM >> A friend recently had her audio system damaged from an AC Power Surge.   > ** AC power voltage surges damaging audio gear are so rare that I cannot accept it as true without convincing evidence.   > The DC power supply inside each piece of audio gear usually contains a transformer, rectifier and filter electros - a combination that eliminates AC voltage spikes/surges better than anything you can possibly buy or build.   That may be true if the stereo or whatever is not attached to other devices. Once you connect things together, damage from power surges starts to happen.   It's quite common with computer network gear. Interconnected ports fail, while the main switch chassis or network attached printer or computer continue to work.   Service entrance surge surpressors protect against this sort of issue.   > OTOH, the term "power surge" is regularly used to explain away sudden failures in almost any electronic device - when the real cause is simply a bad component.   power surges and the damage they cause are very real problems.   FWIW somebod mentioned powervar and Oneac devices, it wasn't clear what these devices were, but if they were isolation/filter units, they work great.   Stuff from tripplite is pure junk, had many of their devices catch on fire, without surges. It was always caused by poor crimps and junky power switches or bad assembly.   APC power strips are better, never had one self destruct yet.

Phil Allison <pallison49@gmail.com>: May 29 07:37PM -0700 Cydrome Leader wrote:     > That may be true if the stereo or whatever is not attached to other > devices. Once you connect things together, damage from power surges starts > to happen.     ** My comments were intended to exclude the effects of a lightning strikes hitting the ground.   AC supply voltage spikes are normally caused by inductive loads going on and off.     > > OTOH, the term "power surge" is regularly used to explain away sudden failures in almost any electronic device - when the real cause is simply a bad component.   > power surges and the damage they cause are very real problems.     ** If by 'power surge' you actually you mean lightning strike.         ... Phil

Phil Allison <pallison49@gmail.com>: May 29 08:06PM -0700 bud-- wrote:     > As explained in the IEEE surge guide > (starting page 30) plug-in protectors work primarily by limiting the > voltage from each wire to the ground at the protector.   ** Connecting MOVs to ground like that in a *plug-in device* is prohibited on safety grounds under EU and similar regulations as followed in most 230/240 V places - like Australia where I am.   MOVs either have or can develop after some use leakage currents well in excess of the maximum permitted, which is only a milliamp or so for most categories of appliances.   The only components that may be so connected are agency approved " Y caps " with values like 4.7nF - while MOVs and " X caps" always go across the line.       ... Phil

"Gareth Magennis" <sound.service@btconnect.com>: May 30 07:59AM +0100 "Phil Allison" wrote in message news:85f11b0e-85bd-4d2c-8db0-c6bbee864ad3@googlegroups.com...   bud-- wrote:     > As explained in the IEEE surge guide > (starting page 30) plug-in protectors work primarily by limiting the > voltage from each wire to the ground at the protector.   ** Connecting MOVs to ground like that in a *plug-in device* is prohibited on safety grounds under EU and similar regulations as followed in most 230/240 V places - like Australia where I am.   MOVs either have or can develop after some use leakage currents well in excess of the maximum permitted, which is only a milliamp or so for most categories of appliances.   The only components that may be so connected are agency approved " Y caps " with values like 4.7nF - while MOVs and " X caps" always go across the line.       ... Phil       Slightly OT but ..... In the UK you can buy "surge protected" multi outlet extensions like this: http://www.amazon.co.uk/Sivitec-Switched-Extension-Protection-Indicator/dp/B00DVHK7IY/ref=sr_1_1?ie=UTF8&qid=1432969032&sr=8-1&keywords=4+gang+surge+protection   Problem is, these can't be tested with a typical PAT Tester, as they fail the test every time, being as there is circuitry between live and ground.       Gareth.

Phil Allison <pallison49@gmail.com>: May 30 05:30AM -0700 Gareth Magennis wrote:   > http://www.amazon.co.uk/Sivitec-Switched-Extension-Protection-Indicator/dp/B00DVHK7IY/ref=sr_1_1?ie=UTF8&qid=1432969032&sr=8-1&keywords=4+gang+surge+protection   > Problem is, these can't be tested with a typical PAT Tester, as they fail > the test every time, being as there is circuitry between live and ground.     ** Really? You read this somewhere on the net, right?   I bet they CAN be tested, passing all the tests is the issue. FYI:   A customer, who runs a hire business, brought in his "Megger 4DV" PAT tester recently for a check over - so I got to see exactly what it did and how.   Some tests involved normal AC power being applied to the device, others used high voltage DC and another low voltage AC at high current to check earth conductor resistance.   AC leakage current and insulation resistance are the main things checked - the pass /fail threshold was user adjustable to suit the type of appliance under test. Class 1 and class 2 ( double insulated ) appliances follow different rules.   The operator is also expected to carry out a thorough visual inspection too, so needs to be familiar with electrical appliance safety.   If a new product failed one of the tests, that would be VERY alarming and should be reported to the supplier immediately.       ... Phil

"Gareth Magennis" <sound.service@btconnect.com>: May 30 04:09PM +0100 "Phil Allison" wrote in message news:408a078a-4d5b-4474-aad2-dfd233176312@googlegroups.com...   Gareth Magennis wrote:   > http://www.amazon.co.uk/Sivitec-Switched-Extension-Protection-Indicator/dp/B00DVHK7IY/ref=sr_1_1?ie=UTF8&qid=1432969032&sr=8-1&keywords=4+gang+surge+protection   > Problem is, these can't be tested with a typical PAT Tester, as they fail > the test every time, being as there is circuitry between live and ground.     ** Really? You read this somewhere on the net, right?           No, I have a PAT Tester and PAT Test all the sound and lighting equipment for a music festival.   I was told by an electrician that you have to test these as Class 2, and put a sticker on them to say so.     Gareth.

bud-- <null@void.com>: May 30 10:15AM -0600 On 5/29/2015 9:06 PM, Phil Allison wrote:   > MOVs either have or can develop after some use leakage currents well in excess of the maximum permitted, which is only a milliamp or so for most categories of appliances.   > The only components that may be so connected are agency approved " Y caps " with values like 4.7nF - while MOVs and " X caps" always go across the line.   > ... Phil   I think the US-UL permitted leakage for "appliances" is 0.5mA (which of course is at 120V).   Standard practice in the US for plug-in protectors is MOVs from H-N, H-G, N-G. And if signal wires go through the protector, they are limited to ground also.   One of the reasons the energy at a MOV in a protector is so low (US) is that at about 6kV there is arc-over between service panel busbars and the enclosure. This appears to be an intentional feature. (The voltage across the established arc is hundreds of volts. Since the enclosure is connected to the earthing system that dumps most of the surge energy to earth. And a required N-G bond at the service limits the N surge voltage.)   A significant (and likely major) cause of surge damage to equipment is high voltage between power and signal wires. If MOVs are only connected H-N and there is a large surge the voltage drop on H & N will likely increase the voltage between power and signal wires (6kV at the service would result in about 2kV from the H & N to the 'ground' reference at the service panel). It then would be inadvisable to use plug-in protectors on equipment that has both power and signal wires.   The normal failure mode for MOVs is after sufficient energy hits they start to conduct at lower voltages, eventually conduct at 'normal' voltages, and go into thermal runaway. Thermal disconnects then operate(at least in the US). I would think a H-N MOV with 1mA leakage @230V would be near thermal runaway.   I don't know how surge protection is done down-under. It works here. Some features here may be from the relatively high exposure to thunderstorms in parts of the country. They are uncommon or nonexistent in many parts of the globe.

"David Farber" <farberbear.unspam@aol.com>: May 29 11:15PM -0700 David Farber wrote:   > I just bought the 852D model shown on eBay for under $60.. You make a > good point about using a microscope. I'll look into that as well.   > Thanks for your reply.   My rework station arrived a couple of days ago. I watched several instructional videos to get an idea of how to use it properly. I found that using the smallest diameter air flow nozzle and a temperature of around 280C worked very well on the leaking caps. I had to remind myself to be patient until the solder was hot enough before attempting to pull the cap off of the board. I also noticed that if you increase the temperature too much, it's quite easy to unintentionally remove neighboring components. All in all, this is a big time saver and a very safe way to keep the pads from getting ruined.   Thanks for your replies. -- David Farber Los Osos, CA

jurb6006@gmail.com: May 29 05:14PM -0700 On Tuesday, May 26, 2015 at 3:46:05 PM UTC-5, Glenn Russell wrote: > My vintage Sony Trinitron model KV-19TS20 goes wacky after inly a few seconds. screen has jagged lines and makes a noise that changes in pitch from low to high. Can somebody please help me?   What about the bad connections at the coils to the IF chip. Nobody mentioned that.

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