- Will two table radios always be in phase, out of phase/ - 8 Updates
- Looking for Schematic for L&R T-9B Ultrasonic cleaner - 1 Update
- Harman Kardan AVR1700 Rcvr BCO update - 2 Updates
| Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Jan 02 01:28PM -0500 John Larkin wrote: >> will vary at infrasonic or low-audio rates. > Table radios aren't SSB! What's worse is that unlocked SSB shifts > the audio frequencies, which mangles all the harmonics. Well, maybe _your_ table radio isn't. ;) If I even possessed a table radio, I'd certainly want something like a Hammarlund Super Pro or a National HRO or a Hallicrafters SX-122. ;) > delayed about a nanosecond. Every foot your ear moves from the > speaker, the sound is delayed about a millisecond. > 1 million to one often matters. Sure. The point I was bringing up is that in heterodyning, the difference in the carrier phases comes out in the baseband signal. In optics the wavelength contrast is even more stark. An AM radio uses the unsuppressed carrier as the phase reference for the detector (which can therefore be as simple as a single diode), so you need a hell of a d phi / df (aka group delay) to make much of a difference there. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com |
| wmartin <wwm@wwmartin.net>: Jan 02 10:31AM -0800 On 1/2/23 07:01, Phil Hobbs wrote: > infrasonic or low-audio rates. > Cheers > Phil Hobbs Infrasonic? OIC... we need a SSB decoder for radio bigfoot! |
| Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Jan 02 05:07PM -0500 wmartin wrote: >> Cheers >> Phil Hobbs > Infrasonic? OIC... we need a SSB decoder for radio bigfoot! ;) The phase changes at the beat frequency between the BFO and the place where the carrier would be if it were still there. You want that to be slow, because it's annoying if it's in the audio range. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com |
| Brian Gregory <void-invalid-dead-dontuse@email.invalid>: Jan 03 02:30AM On 02/01/2023 13:48, Rink wrote: > If from two speakers at the some radio (left and right), one is wrong > connected, you can hear that at exactly the middle between the speakers > where there is a fase-out for all audio frequencies. I've never heard an audible null between out of phase speakers. It usually just ruins the stereo effect, makes it sound almost like two separate lots of music (or whatever). -- Brian Gregory (in England). |
| Clive Arthur <clive@nowaytoday.co.uk>: Jan 03 10:10AM On 03/01/2023 02:30, Brian Gregory wrote: > I've never heard an audible null between out of phase speakers. It > usually just ruins the stereo effect, makes it sound almost like two > separate lots of music (or whatever). With a mono source (ie both channels the same phase) you lose a lot of bass in the centre. Block one ear and the effect is clearer and at higher frequencies too. A long time ago, when stereo records were often mixed with the vocals in the middle and other instruments to the sides, inverting one channel and adding it to the other channel (ie subtracting it) could do a not-too-bad job of removing the vocals for karaoke. -- Cheers Clive |
| Arie de Muijnck <eternal.september@ademu.com>: Jan 03 03:24PM +0100 On 2023-01-03 11:10, Clive Arthur wrote: >> I've never heard an audible null between out of phase speakers. It usually just ruins the stereo effect, makes it sound almost like two separate lots of music (or whatever). > With a mono source (ie both channels the same phase) you lose a lot of bass in the centre. Block one ear and the effect is clearer and at higher frequencies too. > A long time ago, when stereo records were often mixed with the vocals in the middle and other instruments to the sides, inverting one channel and adding it to the other channel (ie subtracting it) could do a not-too-bad job of removing the vocals for karaoke. Yesterday I tried to check if the internal pick-off from my new TV to better speaker boxes was properly wired. Hard to hear. Left/right check was no problem, but phasing was hard to hear (I'm deaf, -60 dB on one ear). Even with a single speaker, and a swept tone, I got dead spots from wall reflections. An old trick solved the problem: put the two boxes very close, front to front, and test with a mono signal. Improper phasing removes most of the sound, proper phasing gives full volume. Arie |
| sticks <wolverine01@charter.net>: Jan 03 09:39AM -0600 On 1/3/2023 8:24 AM, Arie de Muijnck wrote: |
| sticks <wolverine01@charter.net>: Jan 03 10:04AM -0600 On 1/3/2023 9:39 AM, sticks wrote: |
| Steve <nospam@nowhere.org>: Jan 02 06:56PM -0500 I am looking for a schematic for L&R T-9B ultrasonic cleaner. I have searched the web, but cannot find one. Can anyone help me. I have the cleaner, but it doesn't turn on. Steve |
| "Víctor Paúl Shiguiyama Kobashigawa" <victor.shiguiyama@udem.edu>: Jan 02 10:23AM -0800 El viernes, 5 de julio de 2013 a las 14:30:28 UTC-5, root escribió: > There is nothing in the user manual about this problem. > Any help? > TIA Disconnect the unit until all lights go off. The reconnect the unit and should work. I did it with mine and worked. -- AVISO DE CONFIDENCIALIDAD. El contenido de este correo electrónico, incluyendo cualquier documento adjunto es confidencial y puede contener información privilegiada propiedad de la Universidad de Monterrey y/o entidades relacionadas. Se entiende dirigido y para uso exclusivo del destinatario, si usted ha recibido este mensaje por error o no le compete, está prohibida su difusión, transmisión, alteración, explotación, impresión o copia. Por favor inmediatamente avise al remitente y elimine el original. Para mayor información sobre nuestro Aviso de confidencialidad y exención - Confidential notice and legal advice disclaimer consulte: www.udem.edu.mx/disclaimer <https://admin.google.com/www.udem.edu.mx/disclaimer> |
| Victor Shiguiyama <vshiguiyama@gmail.com>: Jan 02 10:30AM -0800 Just unplug the unit until the lights go out. Then everything works again. It worked for me. |
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