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oldschool@tubes.com: May 03 04:14PM -0400 I have a commercial mid 1980s solid state stereo preamp/mixer, which has a dual LED Bar Meter. (about 6 green on the bottom, two yellow above that, and a red on the top).   The preamp/mixer works well, but the LED meter is flakey. I have never worked with one of these, so before I tear into it, I want to know if these are all complete units, and are they fed off the actual preamp, or do they have a separate amp of their own?   What it's doing: One channel lights up every so often, and moves like it should. Then it goes off for awhile. The other channel does not light at all.   However, both channels do momentarily light up the red LED for a split second when I turn on the power to this preamp. So, that tells me that there is obviously power going to this LED meter, and that the meter LEDs do work.   I'll begin by looking for any loose connections, but what is the way to troubleshoot these if all connections are tight? If I measure voltages with my VOM, what sort of voltage would be normal?   (I have not been able to find a schematic for this device, so I'm on my own).

Phil Allison <pallison49@gmail.com>: May 03 03:49PM -0700 The olds moron wrote...   > I have a commercial mid 1980s solid state stereo preamp/mixer,   ** So the make / model is a HUGE secret is it ??   Wot a PITA moron.       > What it's doing: > One channel lights up every so often, and moves like it should. Then it > goes off for awhile. The other channel does not light at all.       ** Check the leds first, cracked solder on the legs is very common and so are dead leds.       .... Phil

dplatt@coop.radagast.org (Dave Platt): May 03 04:35PM -0700 In article <vndkgcdp111c70tgb174dv29l8era9itj7@4ax.com>,   >If I measure voltages with my VOM, what sort of voltage would be normal?   >(I have not been able to find a schematic for this device, so I'm on my >own).   A lot of these meters use an LM3914 (linear) or LM3915 (logarithmic) dot/bar display driver IC, or an equivalent. They take in a signal voltage, accept a "reference" voltage to set the full-scale reading, and drive LEDs or other display elements.   If one of these is what your device uses, it probably wouldn't need a separate preamp circuit - it ought to be able to sample the audio voltage on the main bus (or output) directly. Their might be a half- or full-wave peak detector circuit between the input and the display-driver IC.   The data sheets for these ICs are instructive.

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: May 04 10:32AM +1000 > If I measure voltages with my VOM, what sort of voltage would be normal?   > (I have not been able to find a schematic for this device, so I'm on my > own).   **Since you have elected not to tell us what the brand on model of the device is, any assistance can only be of a generic nature. LED failures are common, but it could be a connector. Who knows? Without more information, it is impossible to say.   -- Trevor Wilson www.rageaudio.com.au

Phil Allison <pallison49@gmail.com>: May 03 05:44PM -0700 Trevor Wilson wrote: > device is, any assistance can only be of a generic nature. LED failures > are common, but it could be a connector. Who knows? Without more > information, it is impossible to say.   ** I know I have seen LED ramps where OC failure of one LED disables all the ones beneath it. Maybe in some Soundcrafts ?   Not ones that use the LM3914/5.     .... Phil

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: May 04 10:59AM +1000 On 4/05/2017 10:44 AM, Phil Allison wrote:   > ** I know I have seen LED ramps where OC failure of one LED disables > all the ones beneath it. Maybe in some Soundcrafts ?   > Not ones that use the LM3914/5.   **I used to see it in early cassette decks that used LEDs. As you said, the failure of one LED usually condemned all below.     -- Trevor Wilson www.rageaudio.com.au

oldschool@tubes.com: May 03 03:35PM -0400 I have an older pair of Fisher 3 Way Speakers. They are good speakers, except on of the tweeters is blown and sounds horrid. Fisher is out of business, so I cant buy an original replacement tweeter.   I am looking on speaker websites and ebay, trying to find a replacement.   I realize that I will need to replace the tweeter in BOTH speaker cabinets so they match.   Obviously I need something that will fit the hole in the cabinet. I also need to match the impedense (8 ohm), and get tweeters rated at the same of higher power rating for these cabinets, (each cabinet is rated at 120W).   I have heard that the Pizeo tweeters are good, and can handle a lot of power, plus they are fairly inexpensive.   However, I may be wrong, but I recall hearing something years ago, that the Pizeo speakers should not be connected to a crossover system, and need to be run direct. (I do not know if this is correct).   These cabinets DO have a crossover.   Of the non-pizeo types, I am seeing a lot of terms that I dont fully understand. There are "Bullet Horn Tweeters", "Titanium tweeters", "Fluid Enhanced Voice Coil", and more....   Some have huge magnets and are rated at extreme wattages, like 1500W (but I'm sure that highly exaggerated, and not true or RMS power).   Some also list the frequency range. I dont really know what the crossover points are, and doubt I can really find that out.   My question is this: Do I need to be real critical, or will most any tweeter work? I will avoid the Pizeo types if they wont perform properly with the crossover.   Do the "Bullet" types perform better, or is that just a decorative thing? What is Titanium? Is that the magnet type, or what?   I do intend to buy something that can handle power, since these speakers do get driven hard at times.   One other thing, are there any brands to avoid, and any brands that are considered to be the best? I'm seeing a lot of brands, but the brands I see most are Pyle, Pyramid, Orien, Pioneer, AudioQuest and Alpine. (The Alpine seem to all be for cars, but it probably dont matter what they are used for).   Any tips or suggestions?   Thanks in advance.

"pfjw@aol.com" <pfjw@aol.com>: May 03 01:56PM -0700 > I have an older pair of Fisher 3 Way Speakers. They are good speakers.   These two statements are mutually contradictory.   With that in mind, seriously:   a) any tweeter that will fit will be remarkably better than what started there back in the day. b) Rebuild the crossover (if any), at least replace *all* the capacitors. Use screened non-polarized caps of the correct value. No guessing. c) Piezo speakers are, in a single word, manure.   So, look on-line at any of several sources (one attached).   https://www.parts-express.com/cat/tweeters/17   $10 or so should be your upper, upper limit per each, whatever fits and is approximately the same impedance as the existing unit - which, unless it is open can be measured. When in doubt, use nominal 4-ohms.   If it fits, this one will do fine:   https://www.parts-express.com/grs-1tm-4-1-mylar-tweeter-4-ohm--292-438   Peter Wieck Melrose Park, PA

"pfjw@aol.com" <pfjw@aol.com>: May 03 02:07PM -0700 > I have an older pair of Fisher 3 Way Speakers. They are good speakers,   On Wednesday, May 3, 2017 at 4:36:37 PM UTC-4, olds...@tubes.com wrote:   > I have an older pair of Fisher 3 Way Speakers. They are good speakers.   These two statements are mutually contradictory.   With that in mind, seriously:   a) any tweeter that will fit will be remarkably better than what started there back in the day. b) Rebuild the crossover (if any), at least replace *all* the capacitors. Use screened non-polarized caps of the correct value. No guessing. c) Piezo speakers are, in a single word, manure.   So, look on-line at any of several sources (one attached).   https://www.parts-express.com/cat/tweeters/17   $10 or so should be your upper, upper limit per each, whatever fits and is approximately the same impedance as the existing unit - which, unless it is open can be measured. When in doubt, use nominal 4-ohms.   If it fits, this one will do fine:   https://www.parts-express.com/grs-1td1-8-1-dome-tweeter-8-ohm--292-462   You need to understand how speakers are rated. If you were to run a steady-state 120 watts of power into those speakers for say.... 20 minutes at a reasonable frequency mix, they would be a slagged mess. At a specific frequency, a slagged mess in 3 minutes or less. Music does not play that way.   I have a pair of speakers "rated" at 125 watts, but they are extremely inefficient. 1 watt makes 83 dB at 1 meter. I feed it with a 225-watt amplifier that will make a peak (without clipping) of about 1,000 watts for one (1) second.   Which means that if my *average* volume is 83 dB, I will be able to handle a 30 dB Peak-to-Average signal, without clipping, as long as the peaks do not exceed 1 second (most really do not). Would I be worried about pumping 1,000 watts into these speakers? Not hardly. And were the signal to be longer than 1 second, the safety circuits would kick in and shut it all down anyway. But in 40 years I have not blown a speaker (due to volume, anyway) yet.   Would I be comfortable running either of my brute-force amps into those Fishers? No, I would not. Into my little AR4xs? Every day.   Peter Wieck Melrose Park, PA

amdx <nojunk@knology.net>: May 03 04:25PM -0500 > On Wednesday, May 3, 2017 at 4:36:37 PM UTC-4, olds...@tubes.com wrote:   >> I have an older pair of Fisher 3 Way Speakers. They are good speakers.   > These two statements are mutually contradictory.   You just couldn't restrain yourself could you? :-)   I used to work in a consumer electronics repair shop. Authorized repair for about 100 brands, but we made a lot of money on Fisher products.   Mikek

ohger1s@gmail.com: May 03 02:57PM -0700 On Wednesday, May 3, 2017 at 5:25:21 PM UTC-4, amdx wrote: > Authorized repair for about 100 brands, but we made a > lot of money on Fisher products.   > Mikek         I can't count how many of those Darlington STK ICs I changed in the 80s. As bad as they were, they were nowhere near as bad as the Pioneer amps with the "suicide" line to "protect" the speakers. The good thing is that they used a fan in the tunnel to conveniently let the smoke out the back.

Clifford Heath <no.spam@please.net>: May 04 08:54AM +1000 > 120W).   > I have heard that the Pizeo tweeters are good, and can handle a lot of > power, plus they are fairly inexpensive.   Two out of three ain't bad. But piezo tweeters are. They have a vast array of mechanical resonant modes so you just can't get a flat response. Throw them in the trash where they belong and buy modern Kevlar domes or something, depending how much you care.

mike <ham789@netzero.net>: May 03 04:11PM -0700 > (but I'm sure that highly exaggerated, and not true or RMS power).   > Some also list the frequency range. I dont really know what the > crossover points are, and doubt I can really find that out. If you can read or measure the component values, you can calculate it. There are spectrum analyzer apps for Android. Connect and disconnect the tweeter on the good one and see how the shape of the signal changes. Would be more precise with another phone and a signal or white noise generator to drive the amp. > are used for).   > Any tips or suggestions?   > Thanks in advance.   There are a huge number of issues. There should be a lot of overlap in the frequency response of your woofers and tweeters, so the precise crossover may not matter much. BUT, the sensitivity of the tweeter needs to match.     I bought a subwoofer with built-in crossover at a garage sale. It's about the size of a coffee table. Puts out a LOT of bass. Problem is that I never found any speakers that would work with it. Sure, there's bass, but the response is not flat because the sensitivity of the speakers doesn't match the design of the crossover. There's a big step in the frequency response plot.   Still works as a coffee table. And the Klipsch Korner Horns still work as speakers. I don't use 'em, should sell 'em.

oldschool@tubes.com: May 03 06:55PM -0400 >Authorized repair for about 100 brands, but we made a >lot of money on Fisher products.   > Mikek   I recall back in the 80s I had a woman friend with a Fisher solid state receiver. She had spent a lot of money getting that thing repaired when she blew out the audio output ICs. A few months later she blew them again. When she learned that I had previously worked on electronics, she wanted me to fix it. At the time I did not have much left for test gear, and I hated working on IC devices. But as a friend, I tried. Those ICs were blown, along with some other diodes and stuff. I could not find replacements for those ICs anyhow. I talked her into buying a separate power amp. I cut the power to that output board, and she just used the Fisher receiver as a tuner/preamp, and fed the sound to the new power amp. I was NOT impressed by that receiver.   I never owned any Fisher tube gear, but I heard it was built well. That's all I know about that, except it sells for big $$$ now.   As far as my Fisher speakers, they have decent 15" woofers, and sounded good till I connected up my new 600W (300 per channel) commercial power amp. I'm only running it at about 1/3 full power, and the woofers sound great. The mids are ok too, but I blew that tweeter almost instantly.   However, I just learned why. I removed both tweeters and found that the one that blew is a Radio Shack replacement rated at 25W. I guess there is no need to explain this further, since I'm pumping at least 100W into them and that was a 25W speaker....

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: May 04 10:45AM +1000 > 120W).   > I have heard that the Pizeo tweeters are good, and can handle a lot of > power, plus they are fairly inexpensive.   **Nope. They're shit. Look at how the things are built. They use levers and pivots and all manner of bits and pieces. Tweeters should be simple. Voice coil, magnet and a dome or a cone. That's all you need. More power? Find one that employs ferro-fluid cooling.     > However, I may be wrong, but I recall hearing something years ago, that > the Pizeo speakers should not be connected to a crossover system, and > need to be run direct. (I do not know if this is correct).   **Incorrect. Just parallel an 8 Ohm, 10 Watt resistor with the piezo 'voice coil' and the crossover will operate (more or less) correctly. Contrary to a lot of common-knowledge, piezos should always be used with some kind of crossover.   > "Fluid Enhanced Voice Coil", and more....   > Some have huge magnets and are rated at extreme wattages, like 1500W > (but I'm sure that highly exaggerated, and not true or RMS power).   **Of course. Just use your noodle. A REALLY efficient tweeter is about 10% efficient. IOW: 90% of the input power is converted into heat. Think any tweeter can dissipate more than 100 Watts?   Correct. They cannot. Most tweeters can deal with between 5 and 30 Watts of continuous power (there is no such thing as 'RMS power'). After that the voice coil fails.   > with the crossover.   > Do the "Bullet" types perform better, or is that just a decorative > thing? What is Titanium? Is that the magnet type, or what?   **'Bullet' types drivers tend to be more efficient. Not necessarily better. Titanium refers to the cone/dome material. Modern titanium drivers are pretty good. But so are modern plastic ones.     > I do intend to buy something that can handle power, since these speakers > do get driven hard at times.   **Find a driver that uses ferro-fluid cooling and/or one that is efficient. That way you can pad it back.   > are used for).   > Any tips or suggestions?   > Thanks in advance.   **If you care about sound quality, avoid piezos.     -- Trevor Wilson www.rageaudio.com.au

Phil Allison <pallison49@gmail.com>: May 03 05:52PM -0700 Trevor Wilson wrote:   > 'voice coil' and the crossover will operate (more or less) correctly. > Contrary to a lot of common-knowledge, piezos should always be used with > some kind of crossover.   ** Having no need for a x-over was a big selling point for piezos - but it's complete bullshit   Running them without low frequency attenuation is the MAIN cause of burn outs - due to BASS frequencies exceeding the VOLTAGE limit of the piezo element.   I always added a parallel resistor and series film cap to roll of the input below 5kHz to stop that nonsense.   FYI: for use in cheap foldback boxes with Etone guitar woofers.     .... Phil

"Ron D." <ron.dozier@gmail.com>: May 03 11:52AM -0700 Nice mess. In the daze of analog TV VSB (vestigial sideband), the frequency of a TV channel was by the carrier frequency. This worked because the signal was asymmetrical. Symmetrical modulation schemes, such as FM, used the center frequency. SSB continued to use the carrier frequency. Meanwhile, the FCC uses the center frequency for most everything. Along came DTV, without a carrier frequency, so it was decided to use the center frequency. That generally satisfied the tech types.   I totally agree. I do have equipment that can measure BER and signal strength, but it was an early adopter sort of thing and not convenient to use.   So, rotators are really foreign to Samsung.   That tuner is just plain weird because I need the physical channel re-scan for virtual channels and it only reports the center frequency. In the ATSC specs there is a center frequency field and sometimes it's wrong.   The $1000 tuner can;t do Daylight Savings Time properly, nor can it do the EPG properly. Incidentally, this http://auroramultimedia.com/products/vtune-pro-4k/ is the high end tuner. It has other quirks too.   I think a big issue for them is cable cards fell out of favor or don't exist anymore.   It's grand scheme of things is to put the output on an IPTV/RF modulator so I can watch on my laptop. I just haven't got there yet.   As another ASIDE (sorry), I want a way to take analog L/R and upconvert to AC3 5.1 in a "Audio Only" TV mode over HDMI, so I can put an AM/FM tuner on an ATSC channel.

Jeff Liebermann <jeffl@cruzio.com>: May 03 05:25PM -0700 On Wed, 3 May 2017 11:52:37 -0700 (PDT), "Ron D."   >So, rotators are really foreign to Samsung.   Yep. I fired up my Samsung P2570HD TV and got an unpleasant surprise: <https://www.newegg.com/Product/Product.aspx?Item=N82E16824001335> When I scanned for active channels, it didn't find any channels. I tried it several times, on several antennas, and got the same results. No channels. Since the HDMI, composite, VGA, and DVI inputs all work normally, my guess(tm) is the tuner is blown.   Looking at the available scan settings, it gets even stranger. I can add a channel manually, but there doesn't seem to be any way to remove a channel. Of course, since I can't test it, I'm sure about this. Offhand, I would say you're correct, that Samsung doesn't make it easy to use a rotator or multiple antennas.   >re-scan for virtual channels and it only reports the center frequency. >In the ATSC specs there is a center frequency field and sometimes >it's wrong.   Is the virtual channel number correct? Does it even have a virtual channel number?   >The $1000 tuner can;t do Daylight Savings Time properly,   The US congress critters tweaked the beginning and end of DST in order to somehow save energy in 2007. Many devices didn't clean up their DST act for many years after that.   > nor can it do the EPG properly. Incidentally, this > http://auroramultimedia.com/products/vtune-pro-4k/ is the high > end tuner. It has other quirks too.   If it does IPTV, it must surely do NTP (network time protocol) which includes proper DST shifts. I don't think there's a single device available that does EPG (electronic program guide) without bugs, added monthly costs, or both. However, don't blame the guide vendor. Stations often change their programming at the last moment for odd reasons (sponsor pressure, current events, ongoing disaster coverage, etc).   > I think a big issue for them is cable cards fell out of favor or > don't exist anymore.   It didn't "fall out of favor". It was massacred by the cable companies, who preferred to rake in the cash from equipment leases than to allow the GUM (great unwashed masses) to own their own equipment. Never mind that the FCC ordered the availability of user owned cable equipment. Comcast also made it look like a frontal attack on Tivo, who is the major beneficiary in CableCard based installations. Incidentally, Comast raised the price of them allowing a CableCard from about $2/month to $10 or $15/month (I couldn't find the exact price) so as to be equal with the cost of leasing a set top box. So much for affordable.   > It's grand scheme of things is to put the output on an IPTV/RF > modulator so I can watch on my laptop. I just haven't got there yet.   RF Modulator? That's rather low quality video if fed from composite video. What most users want is the ability to record HD programming without DRM issues. A CableCard in a tuner can do that if digitized video can be delivered via ethernet (thus avoiding the encrypted HDMI problem). No, I won't tell you how to do it.   > As another ASIDE (sorry), I want a way to take analog L/R and > upconvert to AC3 5.1 in a "Audio Only" TV mode over HDMI, so I > can put an AM/FM tuner on an ATSC channel.   Why bother? Most OTA radio stations also stream over the internet. Just point your web browsers to the stations URL and you have streaming AM/FM audio on the laptop. However, if you do find a station that does NOT stream, just plug an RTL2832U plus R820T2 SDR receiver dongle into a USB port, run one of a dozen receiver control programs, and you have an AM/FM/ham/WX/scanner/whatever receiver. <https://learn.adafruit.com/getting-started-with-rtl-sdr-and-sdr-sharp/sdr-number-fm-radio>   Sigh. Topic drift at it's best.   -- 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

John Robertson <spam@flippers.com>: May 03 05:13PM -0700 On 2017/05/02 5:27 AM, James Doyle wrote: > need a ribbon cable for display board, wave radio AWR1-1W .. > jim nc4fl@hotmail.com   Depending on the type of ribbon cable and plugs, if a wire is broken where it just comes out of the plug you can sometimes separate the housing and carefully release and then move the wire inwards 3/8" or so to get a fresh connection when re-pressed.   Assuming there is enough slack...   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

Phil Allison <pallison49@gmail.com>: May 03 03:44PM -0700 > > It's always good to see Phil at the top of his game.   > Sure is. His fulminations are typically in inverse proportion to > the correctness of his position.   ** One can learn a lot from the Wieck troll - by just taking the opposite of everything he posts.       > I keep WD-40 by the unpressurized gallon,     ** So fucking what ?   You know fuck all about the topic of this thread and yet insist on posting more meaningless concertos for solo trumpet.   Hurry up and die, you vile autistic old troll.         .... Phil

mjb@signal11.invalid (Mike): May 03 11:26PM +0100 >not safe to use without checking the materials in use. There are many >products that are specifically intended as contact cleaners which don't >cause these problems.   Bizarrely, there are contact cleaners designed for that which DO cause problems. A can of RS "Switch cleaner" made a bit of a mess of the inside of the plastic case of an old radio, by melting the black plastic into runny black goo.   Cleaned the wave-band switch a treat, but I'm glad it only puddled in the inside corner, and not so much the outside!   -- --------------------------------------+------------------------------------ Mike Brown: mjb[-at-]signal11.org.uk | http://www.signal11.org.uk

Phil Allison <pallison49@gmail.com>: May 03 04:14PM -0700 Mike wrote:   > cause problems. A can of RS "Switch cleaner" made a bit of a mess of the > inside of the plastic case of an old radio, by melting the black plastic > into runny black goo.   ** This the one?   http://au.rs-online.com/web/p/precision-cleaners-degreasers/0180831/   That is a strong grease solvent, meant for mechanical stuff.     FYI:   Here is a spray can with the title:   "Contact Cleaner and Protector" http://au.rs-online.com/web/p/contact-cleaners/3883814/   Far as I can tell from the data sheets, its WD-40 under another name.     .... Phil

oldschool@tubes.com: May 03 03:00PM -0400 On Wed, 3 May 2017 10:00:50 +0100, Adrian Caspersz <email@here.invalid> wrote:     >> I tried "three dimensional picture", that did not work. I tried >> "changing picture", that did not work either.   >https://en.wikipedia.org/wiki/Lenticular_printing   Thank You.   After asking everyone I know, I finally posted this on here.   I've seen these pictures in several forms and even saw the small Cracker Jack ones many years ago, but I never knew what they were called. (Or how they work).   This article answered everything.   Appreciated!

ohger1s@gmail.com: May 03 01:30PM -0700 Pardon my ignorance but are these the same pictures that have been available for decades, or is this something new?

amdx <nojunk@knology.net>: May 03 05:30PM -0500 > "changing picture", that did not work either.   > Anyone know?   > Thanks   Wifi Digital Picture Frame :-)   Mikek

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