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frank <frank@invalid.net>: Jul 06 07:15AM > Maybe Barkhausen oscillation (aka the Barkhausen-Kurtz effect). This > used to show up in old-fashioned incandescent light bulbs that were > evacuated instead of argon-filled.   according to a wikipedia article, the Barkhausen-Kurz oscillator used triodes. So I'm still puzzled. I'll try to make a test setup with constant current on a GDT and try to measure the frequency of the oscillation.   Frank

ggherold@gmail.com: Jul 06 05:35AM -0700 On Thursday, July 6, 2017 at 3:19:34 AM UTC-4, frank wrote: > I'll try to make a test setup with constant current on a GDT and try > to measure the frequency of the oscillation.   > Frank   Not knowing Barkhausen-Kurz from Berkinstocks, I think Phil means it has to do with the time delay. Enough gain and a time delay leads to oscillations. (hmm just like in thermal control loops.)   George H.

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Jul 06 09:48AM -0400 On 07/06/2017 03:15 AM, frank wrote: > I'll try to make a test setup with constant current on a GDT and try > to measure the frequency of the oscillation.   > Frank   You can get Barkhausen oscillations in light bulbs, as I said. If you have a spectrum analyzer, you can find out pretty fast.   Cheers   Phil Hobbs   -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics   160 North State Road #203 Briarcliff Manor NY 10510   hobbs at electrooptical dot net http://electrooptical.net

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Jul 06 09:51AM -0400 > has to do with the time delay. Enough gain and a time delay leads to > oscillations. (hmm just like in thermal control loops.)   > George H.   No, it's a coupled plasma/surface effect. It's really cool. It peaks down around a few tenths of a millitorr, but it's still appreciable at higher pressures.   The light bulb thing was discovered by somebody turning on an incandescent lamp and wiping out his reception.   I don't know if the pressure in the transient suppressor is low enough for Barkhausen--if not, it's probably the neon bulb oscillation as others have said.   Cheers   Phil Hobbs   -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics   160 North State Road #203 Briarcliff Manor NY 10510   hobbs at electrooptical dot net http://electrooptical.net

frank <frank@invalid.net>: Jul 06 04:12PM > You can get Barkhausen oscillations in light bulbs, as I said. If you > have a spectrum analyzer, you can find out pretty fast.   I do have one (of course, I'd say). My radio reception (hamradio bands) has never been disturbed by incandescent lights though (and it's about the only electric thing that doesn't make any RF nowadays). In the next days (as I find time) I'll try to run the transient suppressor with a small dc current and see if it oscillates (and at what frequency).   Thanks Frank IZ8DWF

mhooker32@gmail.com: Jul 05 10:00PM -0700 > > "Old pinballers never die, they just flip out."   > its an IC, an LA7833( nte1773) . i'll change it out and see what happens. i did change out every cap, and it was exactly the same. no better, no worse.   > thanks much   just got done replacing the vertical IC, la7833. no change in the image. no better, no worse.

John Robertson <spam@flippers.com>: Jul 05 11:57PM -0700 >> its an IC, an LA7833( nte1773) . i'll change it out and see what happens. i did change out every cap, and it was exactly the same. no better, no worse.   >> thanks much   > just got done replacing the vertical IC, la7833. no change in the image. no better, no worse.   Any schematic you can provide a link to? Someone suggested a bad yoke, which is possible if the bottom half of the vertical deflection shorted out. Maybe. However a schematic would help.   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."

rickman <gnuarm@gmail.com>: Jul 06 07:17AM -0400 >> its an IC, an LA7833( nte1773) . i'll change it out and see what happens. i did change out every cap, and it was exactly the same. no better, no worse.   >> thanks much   > just got done replacing the vertical IC, la7833. no change in the image. no better, no worse.   Looks like the 24 volt supply is generated by doubling the 12 volt supply. Measure the 24 volt supply at pin 6. I bet something is wrong that this is only 12 volts, maybe the diode?   --   Rick C

mhooker32@gmail.com: Jul 06 08:18AM -0700 On Thursday, July 6, 2017 at 7:17:12 AM UTC-4, rickman wrote: > only 12 volts, maybe the diode?   > --   > Rick C     https://na.suzohapp.com/pdf/service_pdfs/support/visionpro/49-1329-vp2_manual.pdf   https://na.suzohapp.com/pdf/service_pdfs/support/visionpro/49-1329-vp2_schematic.pdf   B+ is 12v3, 12V and 24V good. i was thinking yoke, but they ohm out good, and look like brand new. no physical damage. looks like a few transistors are after the vertical ic, i'm looking at them now. not real good at following this schematic, so any help is appreciated.   thanks

rickman <gnuarm@gmail.com>: Jul 06 12:01PM -0400 > https://na.suzohapp.com/pdf/service_pdfs/support/visionpro/49-1329-vp2_manual.pdf   > https://na.suzohapp.com/pdf/service_pdfs/support/visionpro/49-1329-vp2_schematic.pdf   > B+ is 12v3, 12V and 24V good. i was thinking yoke, but they ohm out good, and look like brand new. no physical damage. looks like a few transistors are after the vertical ic, i'm looking at them now. not real good at following this schematic, so any help is appreciated.   I'm not so good at following this schematic myself. It looks like W402 is the connector to the yoke. If so, I would say Q404 sets the vertical position. Q360 and D307 link the vertical drive signal to I201, the color gun controller. Perhaps this is creating too large a load from a bad part, so the drive is clipped?   Did you say I302 pin 2 has a square wave on it? Shouldn't that be a sawtooth?   --   Rick C

Madness <madness.mail@gmail.com>: Jul 06 09:20AM -0400 On 7/1/2017 8:14 PM, Jon Elson wrote: > They are for cell phone headsets and other connections to a phone (like a > car). Left and right audio out, and microphone. Blame Apple.   > Jon   I could be wrong, but I think I read somewhere that the Brits used to use similar plugs for their (landline) phones. Think they called it, "plug-and-jack (or -socket)?"

"pfjw@aol.com" <pfjw@aol.com>: Jul 06 07:14AM -0700 On Thursday, July 6, 2017 at 9:20:24 AM UTC-4, Madness wrote:   > I could be wrong, but I think I read somewhere that the Brits used to > use similar plugs for their (landline) phones. Think they called it, > "plug-and-jack (or -socket)?"   Back in the day, Bell System phones were 4-wire, and all 4 had some function. Most of the world (back then) used 4 wires - Poland, apparently, used 5.   Peter Wieck Melrose Park, PA

rickman <gnuarm@gmail.com>: Jul 06 10:30AM -0400 >> use similar plugs for their (landline) phones. Think they called it, >> "plug-and-jack (or -socket)?"   > Back in the day, Bell System phones were 4-wire, and all 4 had some function. Most of the world (back then) used 4 wires - Poland, apparently, used 5.   The Bell System used two wires for the phone line and if you had a Princess phone the other two were used to supply power for the lighted dial. Otherwise the other two were for your second extension line. This has nothing to do with the four way plugs and jacks the OP is talking about.   --   Rick C

"pfjw@aol.com" <pfjw@aol.com>: Jul 06 08:55AM -0700 On Thursday, July 6, 2017 at 10:30:43 AM UTC-4, rickman wrote:   > phone the other two were used to supply power for the lighted dial. > Otherwise the other two were for your second extension line. This has > nothing to do with the four way plugs and jacks the OP is talking about.   Bell System:   Up to 1930 - three active wires: Voice/Ringer/Ground From 1930 well into the 1960s, up until touch-tone *in some regions* and with some providers: Four active wires: Voice/Ringer/Side-Tone Suppression/Ground   At some point, the side-tone suppression function was served by a small capacitor - this took a few years to become universal. A diode allowed all functions to be handled by only two wires. After which the additional wires could serve such niceties as lighting. BUT - those functions required a local wall-wart type power-supply feeding a jack for proper distribution.   Peter Wieck Melrose Park, PA

amdx <nojunk@knology.net>: Jul 06 09:53AM -0500 > A lot of people do their own diagnosing or follow someone's (alleged) success on youtube and always assume their TV has the same issue. What happens is they buy the wrong board, or the TV doesn't need a board at all if the display itself is bad or has an open LED in the display or a wiring issue inside.   > Recent Samsungs are known for LED failures. It would not surprise me if you don't get a return request on one or both of those boards. My dad always told me not to count my chickens before they're hatched.   > Good luck.   After I sold the first two pcb's I decided to list the third pcb. It sold, but, it happened, the third pcb I sold is being returned. Customer (a TV repair shop) says 'did not fix backlight problem' The board worked when I removed it. I suspect poor trouble shooting or I'm getting back a bad pcb. I did mark my pcb with my intials, so I'll know if I get the same pcb back. I posted a picture of my markings to ABSE and to my dropbox account, this morning I also made a Ebay listing showing the picture of my markings on the pcb. I used a very high price so no one will bid. I hope I get back a different pcb. Today is the last day the seller is supposed to ship it. No notice of shipping, I provided notice to return on 6-28-17, he has had 6 business days to return. Mikek

amdx <nojunk@knology.net>: Jul 06 09:20AM -0500 I have a Sony Bravia TV and a digital cable box.   My kids (23 and 25 yrs old) visited this weekend. They left and I came home from work and turned on the TV. It had no sound, I turned the volume up to max, nothing, I checked all the cables, still nothing. I called my son, no answer, I called my daughter, no answer. A couple minutes later my daughter called back, I ask if she did anything to the TV, it has no sound. "Did you turn up the volume on the TV?" So I grabbed the TV remote (that we never use) and turned the volume up. Yes it works. A few minutes later my son returned my call, I told him I didn't have any sound on the TV, but your sister fixed it. he said, "did you turn the sound up on the TV" As I said I never use the TV remote but the kids, ignored the Cable Box remote and turned down the sound on the TV. I later texted them and told them to quit laughing at your dad!   Mikek

rickman <gnuarm@gmail.com>: Jul 06 10:32AM -0400 amdx wrote on 7/6/2017 10:20 AM: > As I said I never use the TV remote but the kids, ignored the Cable Box > remote and turned down the sound on the TV. > I later texted them and told them to quit laughing at your dad!   With remotes the rule is, "If some is good and more is better, then too much is just enough". Unfortunately two is one too many.   --   Rick C

"John Smith" <invalid@invalid.invalid>: Jul 05 09:03PM -0400 It hums, said the customer. I'll take a look, I said.   After a cleanup I tested it and couldn't find anything electrically wrong.   But with nothing except power connected there always seemed to be a faint hum from the speaker.   Probably normal I thought. It doesn't seem to be the highest quality design.   But then I noticed that the bench seemed to be vibrating a little. And when I disconnected the speaker the hum remained.   It's actually caused by the power transformer. Pushing hard on the back of the unit by the transformer eliminates the hum. Perhaps tightening the transformer bolts will fix it.

Phil Allison <pallison49@gmail.com>: Jul 05 06:19PM -0700 John Smith wrote:   > It's actually caused by the power transformer. > Pushing hard on the back of the unit by the transformer eliminates the hum. > Perhaps tightening the transformer bolts will fix it.   ** There are a whole bunch of Fender SS amps built the same way - and I have seen one or two that hummed due to vibration from the AC transformer.   Tightening the mounting bolts might help.     .... Phil

N_Cook <diverse@tcp.co.uk>: Jul 06 08:31AM +0100 On 06/07/2017 02:03, John Smith wrote:   > It's actually caused by the power transformer. > Pushing hard on the back of the unit by the transformer eliminates the hum. > Perhaps tightening the transformer bolts will fix it.   Before tightening the bolts, slacken a bit and introduce thinned lacquer all around the E&I soft iron plates. Check soldering at the input socket ground lines as well.

Bob F <bobnospam@gmail.com>: Jul 05 11:37AM -0700 On 7/5/2017 8:43 AM, Geo wrote: >> file, or anywhere else to find it. Does anyone have any suggestions?   > You have to be signed-in for the download button to appear between the > File frame and the Author frame.   I thought about that, but I didn't see anything in the FAQ's that said that, in a list of things you did need to sign in for, so I didn't expect it. Thanks for making it clear. And for the quick response.

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