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mogulah@hotmail.com: Apr 11 08:04AM -0700 On Tuesday, April 7, 2015 at 8:25:07 AM UTC-4, Bruce Esquibel wrote in sci.electronics.repair:   >This is just a stupid comment that crossed my mind, but are you > sure the remote for the radio is actually an infared and not > rf or bluetooth or something else?   And more importantly, would he even be able to tell without using a microscope?

"Bob F" <bobnospam@gmail.com>: Apr 11 09:36AM -0700 >> rf or bluetooth or something else?   > And more importantly, would he even be able to tell without using a > microscope?   Would an LED on the end of the remote that shows light only through a digital camera when the unit is operated be a clue? No visable light using only my eyes. That plus the fact that the learning remote said "success" with each key I asked it to learn.   The problem is that the learning remote does not seem to operate the device at all.   A new data item. The JVC remote causes my computer IR receivers to flash with each keypress, again indicating IR transmission. Interestingly, it works across the room just fine, which suggests that it has a strong signal, and the JVC receiver must be desensitized. Trying my learning remote very close to the JVC receiver does not help. Perhaps the JVC remote is particularly strong, even though tiny with a small button cell battery.   Do learning remotes transmit exactly the same signal it "learned" no matter which device it is selected for? I programmed buttons associated with the "AUX" button, which by default is a Sony unknown something.

Cydrome Leader <presence@MUNGEpanix.com>: Apr 10 06:46PM > ** Where there are two technician at work?   >> or can they be hooked up together to provide 1KVA supply?   > ** If the output voltages are *identical*, you can wire them in parallel and double the current rating.   well, and the %Z must match too if you want to get real serious, otherwise one transformer may still be doing more work as it takes more of the load.

Cursitor Doom <curd@notformail.com>: Apr 10 09:16PM On Thu, 09 Apr 2015 20:15:04 -0700, Phil Allison wrote:     > To safely parallel the pair, the primaries must be wired to the SAME AC > plug - cos using two plugs means one will have exposed live pins.   > ... Phil   Thanks, Phil. Best I hang on to the pair of 'em then, just in case...

Phil Allison <pallison49@gmail.com>: Apr 10 04:13PM -0700 Cydrome Leader wrote:   > >> or can they be hooked up together to provide 1KVA supply?   > > ** If the output voltages are *identical*, you can wire them in parallel and double the current rating.   > well, and the %Z must match too if you want to get real serious, otherwise one transformer may still be doing more work as it takes more of the load.     ** Both transformers are stated to be rated at 500VA so the input and output voltages should match exactly at that load to comply with the 240:240 spec.   So the extra condition that the off load voltages also match nails the voltage regulation characteristic for resistive loads.   Ideally, the trannys should be of the same design, ie both e-core, c-core or both toroidal.       ... Phil

mike <ham789@netzero.net>: Apr 10 09:44PM -0700 On 4/10/2015 11:46 AM, Cydrome Leader wrote:   >> ** If the output voltages are *identical*, you can wire them in parallel and double the current rating.   > well, and the %Z must match too if you want to get real serious, otherwise one transformer may > still be doing more work as it takes more of the load.   Simple test. Parallel the primaries. Measure the input POWER (loss). Parallel the secondaries. Measure the input power again. All that power is heat in the transformers. The increase is due to voltage mismatch across the impedance. Notice, I didn't say measure current. I said measure REAL power. That should give you some idea of how long before the smoke gets out.   Pass that test? Move on to load tests and measure the currents in each secondary winding. Easy way to do that is run the individual secondaries in opposite directions thru your current probe. Result should be zero if the load is shared equally.

Phil Allison <pallison49@gmail.com>: Apr 10 11:05PM -0700 mike wrote:       > Simple test.   ** Really ???     > Easy way to do that is run the individual secondaries in opposite > directions thru your current probe. Result should be zero if the load > is shared equally.     ** That process looks like the HARD way and needs test gear most do not have.       ... Phil

mike <ham789@netzero.net>: Apr 10 11:39PM -0700 On 4/10/2015 11:05 PM, Phil Allison wrote: >> directions thru your current probe. Result should be zero if the load >> is shared equally.   > ** That process looks like the HARD way and needs test gear most do not have.   Well, the default test is to just parallel them and wait for smoke. No smoke, you're good to go. Smoke, you're done.   > ... Phil   Your choice. You can get some indication of the input power by putting an incandescent light bulb in series with the input.   I'd argue that there are a lot of reasons not to just hang two transformers in parallel.   If I had two transformers with a nameplate that claimed they were each 500W and isolation, I'd not even think about paralleling them without making some measurements.   Advising someone who'd ask that kind of question to do it is irresponsible.

Phil Allison <pallison49@gmail.com>: Apr 10 11:57PM -0700 mike wrote:   > > ** That process looks like the HARD way and needs > > test gear most do not have.   > Well, the default test is to just parallel them and wait for smoke.   ** No it isn't.     > No smoke, you're good to go. Smoke, you're done.     ** Absolutely idiotic "straw man" pile of bullshit.     > I'd argue that there are a lot of reasons not to just hang > two transformers in parallel.     ** Then you'd be arguing with yourself.   > If I had two transformers with a nameplate that claimed > they were each 500W and isolation, I'd not even think > about paralleling them without making some measurements.     ** Tell me, did you read my posts at all ??   Rhetorical question, the answer is obvious.     > Advising someone who'd ask that kind of question to do it > is irresponsible   ** It would be.   But has not happened here.     ... Phil

mogulah@hotmail.com: Apr 11 07:51AM -0700 On Thursday, April 9, 2015 at 11:15:11 PM UTC-4, Phil Allison wrote in sci.electronics.repair: > > one off I thought I'd best check whether there are any circumstances in > > electronic repair when it's really handy to actually have two of them   > ** Where there are two technician at work?   Whoa, whoa wait a minute now, there's an idea. Isn't that what they teach you in electronics school? Always work with a helper, so if you're injured then, maybe at least SOME ONE will know to call for help.

Cursitor Doom <curd@notformail.com>: Apr 11 04:23PM On Sat, 11 Apr 2015 07:51:21 -0700, mogulah wrote:   > Whoa, whoa wait a minute now, there's an idea. Isn't that what they > teach you in electronics school? Always work with a helper, so if > you're injured then, maybe at least SOME ONE will know to call for help.   All too often not possible, I'm afraid.

jurb6006@gmail.com: Apr 10 07:29PM -0700 One wierd thing about this one also is that from the voltage readings on the good (in fact both) channels, it uses bipolars but with the base or emitter in the middle. You can see the construction there, they mirrored it but flipped one side upside down. However input and all that are on one side. Why the hell didn't they just mirror it the other way ?   Anyway, I doubt it needs outputs from the readings, but it seems the outputs have the base (or maybe the emitter) in the middle, not the collector. And they are all the same polarity. I can't see the numbers and I am not taking that part of it apart unless necessary. But on one side they got like -100V on two pins and 0 on the other. On the other ones they got +100V on one pin but 0 on the other two. The difference is that the other is on the end instead of the middle.   Anyway, here are some pictures (higher res available on request) :   https://dl.dropboxusercontent.com/u/29948706/piox/pi01.jpg   https://dl.dropboxusercontent.com/u/29948706/piox/pi02.jpg   https://dl.dropboxusercontent.com/u/29948706/piox/pi03.jpg   https://dl.dropboxusercontent.com/u/29948706/piox/pi04.jpg   https://dl.dropboxusercontent.com/u/29948706/piox/pi05.jpg   https://dl.dropboxusercontent.com/u/29948706/piox/pi06.jpg   https://dl.dropboxusercontent.com/u/29948706/piox/pi07.jpg   It may be a little hard to see in those pictures but it is a two sided board which makes any reverse engineeering alot harder. If I could just find a print it would help.   I got no output on the right channel, or B or whatever. It is not in protection. The readings look the same as the other channel.   Any idea what it is ? Any help is appreciated. If not I gotta tear into it blind because you really can't get to much. Anything, even the model number might help. I doubt any idiot ripped the numbers off because it was hot because the serial number is still there.

Jeff Liebermann <jeffl@cruzio.com>: Apr 10 10:41PM -0700 >Any idea what it is ? Any help is appreciated. If not I gotta tear into it blind because you really can't get to much. Anything, even the model number might help. I doubt any idiot ripped the numbers off because it was hot because the serial number is still there.   Well, the sticker says that it's made by Pioneer: <https://dl.dropboxusercontent.com/u/29948706/piox/pi03.jpg> but is sure doesn't look like anything made by Pioneer. It also says made in 2004 but looks older. I also don't recall anything by Pioneer with a fan (although I may have missed something).   I did some image searching, but couldn't find anything by Pioneer that looked even close: <https://www.google.com/search?tbm=isch&q=pioneer+amplifier>   My guess(tm) is that it's either a counterfeit, or someone just stuck the Pioneer name on some other device in order to enhance its resale value.   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

Phil Allison <pallison49@gmail.com>: Apr 10 11:02PM -0700 > It may be a little hard to see in those pictures but it is a two sided board which makes any reverse engineeering alot harder. If I could just find a print it would help.   > I got no output on the right channel, or B or whatever. It is not in protection. The readings look the same as the other channel.   > Any idea what it is ? Any help is appreciated. If not I gotta tear into it blind because you really can't get to much. Anything, even the model number might help. I doubt any idiot ripped the numbers off because it was hot because the serial number is still there.     ** That is a USA made amplifier - not Pioneer.   FYI: Asian electronic gear has metric thread bolts and I but that POS has Yankee ones.   If the middle pin on a large flyt pak is not a collector, then the devices are lateral Mosfets.     ... Phil

jurb6006@gmail.com: Apr 11 12:40AM -0700 >My guess(tm) is that it's either a counterfeit, or someone just stuck >the Pioneer name on some other device in order to enhance its resale >value. "   I had serious doubts about it being a Pioneer and I appreciate the confirmation. As far as enhancing its value, it has probably more power than most Pioneers. (I just looked and now they are into class D3 at alot more power, but this thing is not new)   I doubt a company would just stick the nameplates on there, it may have been a seller. I will have to query this guy to find out where he got it but I wouldn't count on that going too far. It was in his stash. He owns a bar and his soundguy walked off and took his toys so this dude is hooking up his own toys. He already has two 1,300 watt QSCs which do sound damn good. I hooked them up and phased the speakers.   But now he has this other amp and more speakers because the hairs in the kids' cochleas have been shaved off a bit. So they need more. Actually they are into bass bigtime and bass is not so bad for the ears.   But anyway, the thing doesn't seem to have any shorted outputs, it is not even in protection.   I might just have to do it the old fashioned way. Problemm is, I am not breaking the seal between those heatsinks and transistors.   Hm, on a side note, I get involved with the hifi crowd from time to time and I found out that some of them in restoring an old piece, actually take the outputs out and clean it all down and put new virdshit (heatsink cmpound) on them. I think this is crazy. It is settled in real nice. the thermal contact is probably the best it'l ever be and better then it'll ever need to be. What's more if you have mica insulators and stress them wrong they delineate. And I bet they do not check for that. I have mentioned it but got no answers back. I guess you could do that if you want it to look nice, but use new insulators then if you want to have a boat in your livingroom. (boat = hole in water to throw money in)   And I bet they spread it too, instad of putting it evenly at the main force to squeeze it out so there are no air pockets. I told a coworker that 1,000 times and he wouldn't listen. I tried and tried, it makes sense dude, WTF is wrong with you ? Nothing. Ignorance and I bet willful. My old source of this bad information is better than what you say about it that actually makes sense - even though my credentials are better.   Fucking people amaze me. Gotta watch Dr. Hoo. Or wait, not Dr., Inspector or something. It is an ep of Get Smart, which is one of the best of all time BTW. I got a bunch of them. At least after watching them I might be able to put a little insanity into the insanity and enjoy it a bit.   Sorry for the rant. But then, it's Friday.

jurb6006@gmail.com: Apr 11 01:24AM -0700 >"** That is a USA made amplifier - not Pioneer.   >FYI: Asian electronic gear has metric thread bolts and I but that POS has >Yankee ones. "   How could you tell that from the picures ? those aren't even the hi res ones. (not that they're all that good)   >"If the middle pin on a large flyt pak is not a collector, then the devices are >lateral Mosfets."   Never heard of them befroe but oww tht I had a look around the net I se that possible. they said the bias rquirements are similar to bipolar, I assume that means voltage ? I mean, if you have to drive it with current then youo are back where you started. Regardless I did nmeasure about the same voltage on two adjacent pins and a far awy voltage on the other end in all cases. I found the coil whee it comes out and it has no offsaet. The relays are separate fro each channels and I hear them both click in. There is no heavy drain. ust a surge when it comes on. It is pretty hard for it to be anythoing but someting in the signal path rather than the power amps themselves.   I might just have to figure it out myself. But now I am even more adamant about not breaking the seals on those outputs. If I have to pull that channel I will get them but other than that fuck it. The other channel I am leaving alone of course.   I am almost intereted in seeng the actual curves n shit on these lateral FETs. I doubt I'll ever use one purposely in a circuit, but it is nice to know. Like when you read a Tektronix manual and it explains all about tunnel diodes and unijunction transistors. Actually worht the read but, once.

John-Del <ohger1s@aol.com>: Apr 11 04:33AM -0700 On Saturday, April 11, 2015 at 1:40:56 AM UTC-4, Jeff Liebermann wrote:   I also don't recall anything by Pioneer > with a fan (although I may have missed something).   I guess you missed the joy of the low end Pioneer receivers that had what we call the "music to smoke converter" module. It was a Borg type cube that had all the outputs plus the two driver boards stuffed into a chimney with an exhaust fan that would blow the smoke from the inevitable failure quickly out the back.   http://s753.photobucket.com/user/ronrap2009/media/Receivers-01/Pioneer-M-790-Pwr-Amp-003.jpg.html

dansabrservices@yahoo.com: Apr 11 05:08AM -0700 This unit looks to me like an older Crest amp. They usually have markings on the front, but this one may have either worn off or been removed. Crest systems don't usually have the name on the back either.   The Pioneer name on the back looks like someone added it on.   Dan

"Mark Zacharias" <mark_zacharias@labolgcbs.net>: Apr 11 07:35AM -0500 "Jeff Liebermann" <jeffl@cruzio.com> wrote in message news:gubhiap50n52ujm0ud0vs3trj7t0onth5j@4ax.com... > 150 Felker St #D http://www.LearnByDestroying.com > Santa Cruz CA 95060 http://802.11junk.com > Skype: JeffLiebermann AE6KS 831-336-2558     Looks like a legit serial number sticker but I need more pics of the unit itself.   Inside pics would help too.   Mark Z.

jurb6006@gmail.com: Apr 10 08:25PM -0700 johnny, look at the dates when responding to threads. this one is 16 years old.

Allodoxaphobia <knock_yourself_out@example.net>: Apr 10 05:05PM > Yes, if I ordered two of those extensions, the second one would > put the end connector back in "phase".   > I did not know there are two types of extensions until now.   heh... The Electronics Industry has taken a page from the Plumbing Industry -- and you'll find there are WAY more than "two types of extensions".   Jonesy

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