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John Robertson <spam@flippers.com>: Nov 02 01:00PM -0700 On 2018/11/01 6:28 AM, John-Del wrote:   > I like the advice that they are either jukebox amps or theater amps. Since you described them as physically large, I think a theater amplifier would make sense. The fact that the electros were easily replaceable seem to indicate that they are specifically built to be serviced quickly and on-site, which again favors both jukebox or theater amp.   > We have a resident jukebox expert here (John Roberson?) who might be able to add some thoughts.   > In the meantime, can you post pictures of these amps to a hosting site?   I know of no jukebox amp that had plug in capacitors. I agree that a theatre amp is most likely - I too would enjoy seeing photos of these amps you have!   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

Terry Schwartz <tschw10117@aol.com>: Nov 02 04:24PM -0700 I recall some old intercom/PA amps that had both plug-in capacitors and plug-in relays. Everything was socketed.   Terry

Phil Allison <pallison49@gmail.com>: Nov 02 05:07PM -0700 John Robertson wrote:     > I know of no jukebox amp that had plug in capacitors. I agree that a > theatre amp is most likely - I too would enjoy seeing photos of these > amps you have!   ** The idea of using high voltage, plug-in electros seems quite unsafe.   At the very least, the outside metal case would have to be well insulated so a user would not receive a serious shock if a charged cap was withdrawn from the socket.   Even then, some of the octal pins would be hot while others would be connected to the metal case.   Sounds like some amp builder's ones clever idea that is a bit too clever.       .... Phil

John-Del <ohger1s@gmail.com>: Nov 02 07:23PM -0700 On Friday, November 2, 2018 at 8:07:28 PM UTC-4, Phil Allison wrote:   > Sounds like some amp builder's ones clever idea that is a bit too clever.   > .... Phil     Using bleeders would reduce any shock potential. A big commercial amp would have plenty of room for them. As long as some novice didn't pull the electro with the amp powered up a loaded cap wouldn't be a problem.   A way of making them safer would be to use longer pins on the ground connections (or deeper socket pins for the B+ connections) so the B+ would break before the ground disconnected in case someone pulled one out of a powered up chassis. The cap would remain charged but the tech wouldn't be connected to the live B+ through the cap.   In any case, I do remember in the old tube/valve TV days when low end TVs that didn't use power transformers did have a hot electro on an isolated phenolic base. Those electros had heavy cardboard sleeves well bonded to the can for safety reasons. Never saw one of those come apart.

tabbypurr@gmail.com: Nov 02 09:01PM -0700 On Saturday, 3 November 2018 00:07:28 UTC, Phil Allison wrote:   > Even then, some of the octal pins would be hot while others would be connected to the metal case.   > Sounds like some amp builder's ones clever idea that is a bit too clever.   > .... Phil   it wouldn't have been any great concern back then though. Expectations have much changed. Bare live bits are frowned on now.     NT

Phil Allison <pallison49@gmail.com>: Nov 02 11:10PM -0700 > it wouldn't have been any great concern back then though. > Expectations have much changed. Bare live bits are frowned on now.   ** Tubes have long been user replaceable items, sold direct to the public. Biggest risk is the glass breaks or you plug it in out of key.   Building an electro with octal plug on the end makes it appear just like a tube, so just as safe. So it has to be.   .... Phil

tabbypurr@gmail.com: Nov 03 03:14AM -0700 On Saturday, 3 November 2018 06:10:09 UTC, Phil Allison wrote:   > ** Tubes have long been user replaceable items, sold direct to the public. Biggest risk is the glass breaks or you plug it in out of key.   > Building an electro with octal plug on the end makes it appear just like a tube, so just as safe. So it has to be.   > .... Phil   now there's a non sequitur     NT

John-Del <ohger1s@gmail.com>: Nov 03 04:38AM -0700 > > .... Phil   > now there's a non sequitur   > NT     Well, I'm sure he's being sarcastic..   Still, a theater amp wouldn't generally be serviced by a novice as common radios and TVs were by consumers. A professional technician would hopefully be aware of the dangers of hot-swapping an electro just as he should be about using any line powered test equipment on a hot chassis without isolation. If it meant getting a theater amp running quickly I guess it made sense.

tabbypurr@gmail.com: Nov 03 09:10AM -0700 On Saturday, 3 November 2018 11:38:28 UTC, John-Del wrote:   > > NT   > Well, I'm sure he's being sarcastic..   > Still, a theater amp wouldn't generally be serviced by a novice as common radios and TVs were by consumers. A professional technician would hopefully be aware of the dangers of hot-swapping an electro just as he should be about using any line powered test equipment on a hot chassis without isolation. If it meant getting a theater amp running quickly I guess it made sense.     I've used 2 lots of cinema equipment from the 1930s. The small setup was reasonably safe, the full size one was another matter. Safety was not high on the list of concerns of whoever designed it, and it was top quality equipment (Kalee). If you opened the side of the thing and caught a glimpse of the carbon arc you wouldn't be seeing anything for a while. There was no latch, let alone a lock or interlock. Needless to say one needed to open the thing regularly to do the job.   There was also no easy way to check if the extractor fan was removing the arc combustion products, and of course no monitoring or interlock and no other vents etc. There were also zero precautions available for nitrate film. And lots of mercury in the rectifiers. The projection booth was all fireproofed though - but the fire extinguishing equipment totalled a single 1kg chemical extinguisher. A cap that might have killed someone that messed with it without knowing what they were doing would not have raised any concerns.     NT

Ivan Vegvary <ivanvegvary@gmail.com>: Nov 02 09:43PM -0700 Purchased used Variac. Good action, very smooth from 0 to 140V AC. Question: Input and output are both 2 prong, no ground. Should I modify it to three prong with ground? BTW, I do also own a functioning isolation transformer. Should the IXformer be placed between the mains and the Variac? Please advise as to best procedure. Thanks. Main use of Variac will be to power up ancient tube equipment. Thank you!

John Robertson <spam@flippers.com>: Nov 02 10:20PM -0700 On 2018/11/02 9:43 PM, Ivan Vegvary wrote: > BTW, I do also own a functioning isolation transformer. > Should the IXformer be placed between the mains and the Variac? Please advise as to best procedure. Thanks. Main use of Variac will be to power up ancient tube equipment. > Thank you!   As long as the variac passes basic eletrical leakage test fine and the powre cord and internal wiring are in good condition there is little sense in trying to upgrade it to three conductor wiring.   In fact I recall reading somewhere (can't find the link) that it is against the electrical safety regulations to convert two conductor products to three conductor. This could be incorrect, until I can find the reference take it with a grain of salt. However many items wired for two conductor would need to be modified for three conductor beyond just adding a ground - in pinball and jukeboxes the older two conductor items correctly had the power switch on one side of the line and the line fuse on the other - this is totally wrong on three wire setups!   So use the isolation Xformer to be safe.   Also, I trust you are aware of the series lamp (25 to 100W bulb depending on the load) test for powering up gear that you aren't sure hasn't a problem (shorted winding, cap, rectifier, etc.)...   John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

Phil Allison <pallison49@gmail.com>: Nov 02 10:57PM -0700 John Robertson wrote:     > As long as the variac passes basic eletrical leakage test fine and the > powre cord and internal wiring are in good condition there is little > sense in trying to upgrade it to three conductor wiring.   ** To maintain the safety of equipment that normally uses a ground conductor with a 3 pin plug - earth continuity must remain intact.     > In fact I recall reading somewhere (can't find the link) that it is > against the electrical safety regulations to convert two conductor > products to three conductor.   ** If the product as originally sold was of Double Insulated (aka class2) design, this may be true. Earthing a Class 2 shaver is silly.   But I would not hesitate to add a 3 conductor cable to any guitar amp, powered desk or similar I found that did not have it.     > adding a ground - in pinball and jukeboxes the older two conductor items > correctly had the power switch on one side of the line and the line fuse > on the other - this is totally wrong on three wire setups!   ** Sounds easy enough to correct, as it is to remove the infamous "death cap" fitted to many 2 wire guitar amps not so long ago.       .... Phil

Phil Allison <pallison49@gmail.com>: Nov 02 10:57PM -0700 Ivan Vegvary wrote:   > Purchased used Variac. Good action, very smooth from 0 to 140V AC.   > Question: Input and output are both 2 prong, no ground. > Should I modify it to three prong with ground?   ** Yes - all modern ones are made like that. It is not safe to de-earth an appliance just because you need to use a Variac with it.     > BTW, I do also own a functioning isolation transformer. > Should the IXformer be placed between the mains and the Variac? > Please advise as to best procedure.   ** Either way works, feeding 140VAC to the Iso may get it a bit hot though.     > Main use of Variac will be to power up ancient tube equipment.     ** I use mine for almost everything.   Cos I hate blowing fuses at switch-on.     .... Phil

tabbypurr@gmail.com: Nov 03 03:13AM -0700 On Saturday, 3 November 2018 04:43:21 UTC, Ivan Vegvary wrote:   > Purchased used Variac. Good action, very smooth from 0 to 140V AC. > Question: Input and output are both 2 prong, no ground. Should I modify it to three prong with ground?   it's safer to   > BTW, I do also own a functioning isolation transformer. > Should the IXformer be placed between the mains and the Variac? Please advise as to best procedure. Thanks. Main use of Variac will be to power up ancient tube equipment. > Thank you!   that works, but don't assume you won't then get a shock from a live wire. Safer & easier now to use an RCD/GFCI.     NT

Cursitor Doom <curd@notformail.com>: Nov 03 12:37PM On Fri, 02 Nov 2018 21:43:18 -0700, Ivan Vegvary wrote:   > Purchased used Variac. Good action, very smooth from 0 to 140V AC. > Question: Input and output are both 2 prong, no ground. Should I modify > it to three prong with ground?   I certainly would.     > advise as to best procedure. Thanks. Main use of Variac will be to > power up ancient tube equipment. > Thank you!   The isolation transformer should always power the *device under test* to remove the Earth reference from it.         -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition.

Ralph Mowery <rmowery28146@earthlink.net>: Nov 03 10:37AM -0400 In article <X-WdneIGd9CSrUDGnZ2dnUU7-XHNnZ2d@giganews.com>, spam@flippers.com says... > adding a ground - in pinball and jukeboxes the older two conductor items > correctly had the power switch on one side of the line and the line fuse > on the other - this is totally wrong on three wire setups!   In just the last few years I have been looking at the older equipment ( some in the mid 1960s) and they were 2 wire devices. They had the switch on one side of the transformer and the fuse on the other side. I don't know about the code or why it was done that way. I would have thought the fuse would come first on the hot wire and then the switch. Much of the equipment is ham radio related and most users would have a good connection of the chassis to the earth ground.

Fox's Mercantile <jdangus@att.net>: Nov 03 10:05AM -0500 On 11/3/18 9:37 AM, Ralph Mowery wrote: > thought the fuse would come first on the hot wire and then the switch. > Much of the equipment is ham radio related and most users would have a > good connection of the chassis to the earth ground.   Because in the end, it's a series circuit. It doesn't make a damn bit of difference.   Primarily, it was done from a "Is this the cheapest and easyist (also cheapest) way to do it this way?"         -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

Phil Allison <pallison49@gmail.com>: Nov 02 11:24PM -0700 M Philbrook wrote:   > Currently what I have found it the control transformer to P3 plug seems > not correct to me.... It is using a 230v primary in a 120 V system and > is part of the supply rails for the 5, 15+ and 15- post regulators..   ** That tranny HAS to be 240V rated so it can cope with accidental ues with 240VAC power.   https://www.sweetwater.com/store/detail/AR1220--furman-ar-1220-ac-line-voltage-regulator   > Its only getting to 10VDC after the bridge on the average and of course > that isn't enough for proper reg..   ** May not matter, TL084s have a wide operating voltage range.     > sagging on the 15 volt supplies.. These supplies are to take care of the > TLO84 quod op-amp and thus the way they are now tells me the 15 volt regs > are nothing more than limiters not regulators...   ** That is likely exactly how it works.       .... Phil

jurb6006@gmail.com: Nov 02 03:32PM -0700 I don't normally do this but - that VCR is not a Sony and it is a piece of shit. I think the really last good Sony VCRs were like the SLV920HF, and I have one, and the SLV100HF. they do things right, they don't put the rubber pinch roller on the oxide side of the tape, which was known to be a nono since the sales of wire recorders dropped...   It is better to take those head cleaners out, they get dirty and unclean the heads. Use a coffee filter, place it on the drum and keep it stationary and rotate the upper drum. On the one you'll probably have to remove the drum motor from the top to do it. Use 91 or 99% isopropyl alcohol. Don't forget to clean the lower drum as well.   It looked like the head stalled, if so it is an extremely dirty head drum or tape. That could cause shutdown as well if it is trying to move the tape and doesn't get reel sensor pulses because it is stuck.   The next generation of Sony VHS was like the SLV780HF. Not bad for tape handling but can be a bitch to work on, in fact I got two of them I suspect the uProcessors in, but it is too hard to confirm, and I am not changing them anyway. I mean I am NOT changing them, one belongs to my Mother and I am not changing them.

John-Del <ohger1s@gmail.com>: Nov 02 04:24PM -0700 > I don't normally do this but - that VCR is not a Sony and it is a piece of shit. I think the really last good Sony VCRs were like the SLV920HF, and I have one, and the SLV100HF. they do things right, they don't put the rubber pinch roller on the oxide side of the tape, which was known to be a nono since the sales of wire recorders dropped...   > It is better to take those head cleaners out, they get dirty and unclean the heads. Use a coffee filter, place it on the drum and keep it stationary and rotate the upper drum. On the one you'll probably have to remove the drum motor from the top to do it. Use 91 or 99% isopropyl alcohol. Don't forget to clean the lower drum as well.   > It looked like the head stalled, if so it is an extremely dirty head drum or tape. That could cause shutdown as well if it is trying to move the tape and doesn't get reel sensor pulses because it is stuck.   If you watch the whole video (it's long), you will see the head spin up normally later on. It sure looks like the head was still damp from cleaning when she attempted to load the tape, sticking the tape to the upper head cylinder.   Yep, it looks like an Orion transport, but it's been many years since I really played with a VCR. Definitely not a Sony built transport.   I think she broke the heads cleaning them. Once the upper cylinder dried off and the tape started to move, she had no signal on her monitor. It's possible that the wet upper cylinder may have transferred tape particles to the head chips and it needs to be cleaned again, but I think she smote them. People who have never cleaned a helical scanned head aren't aware that you can break them without even feeling them go.   I left some comments on her youtube video but she probably tossed the machine. At the end of her video, she goes into a rant about Sony not supporting an old VHS anymore.

"pfjw@aol.com" <peterwieck33@gmail.com>: Nov 02 10:13AM -0700 You just fed the troll.

Fox's Mercantile <jdangus@att.net>: Nov 02 03:42PM -0500 > You just fed the troll.   Yes I did. And I wanted everyone on all three news groups to know what a worthless piece of shit he is.     -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

sheydamirlou@gmail.com: Nov 02 01:25PM -0700 > contact me to : mattosbw1@gmail.com mattosbw1(at)gmail.com   > Are available a lot of solution manuals/test banks (it is just a partial list). Then if you need a solutions manual/test bank just send me an email. Change the (at) for @   > ___________________________________________________________________________________________________ HELLO I'd appreciate if you could send me Mechanic of cells by David boal solution. Thank you Mirlou

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