Digest for sci.electronics.repair@googlegroups.com - 13 updates in 4 topics

adrian@poppyrecords.invalid.invalid (Adrian Tuddenham): Nov 13 11:31PM

> by the ADC's filters.
 
> Is this .WAV exactly as it came out of the recorder, or did you adjust
> it (e.g. gain-boost for visibility) in any way?
 
Exactly as downloaded.
 
 
--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk
John-Del <ohger1s@gmail.com>: Nov 14 05:05AM -0800

On Tuesday, November 13, 2018 at 6:31:29 PM UTC-5, Adrian Tuddenham wrote:
 
> ...or add a sub-audio signal.
 
> ...or never turn the recording gain right down and let the pre-amp noise
> floor take care of it..
\
 
That's true, but if my solution works, it won't require any intervention to prevent that spurious noise.
 
Years ago, I had a customer with a Vizio flat TV that would start, run five seconds, and shut down. Turns out it was set to the PC input awaiting a timing signal, and when finding none, shut down as most computer monitors will. There was no way to change the input during the short time it was on. I connected a PC to it, it stayed on, and I put it back on "TV" mode and sent it back with instructions to be careful about switching inputs.
 
A month later, it was back with the same problem. Seems when switching inputs to watch a DVD, they again paused over the PC input and the TV shut down.
 
I ended up finding a timing signal on the board, cap coupled it to a transistor, and fed that to the back of the PC jack to fool it to think an active PC was connected. That fixed that. From then on, it would stay on regardless of where the input was set.
 
A software change would have fixed it, but there was no help from Vizio.
 
 
> I haven't looked to see if new software is downloadable for that model -
> but I suspect this is more likely to be a hardware fault.
 
Did you contact them? It does kind of sound like it's a software issue. Maybe when it detects zero signal, it may do something odd, like recycle one of the ICs.
 
 
makolber@yahoo.com: Nov 14 07:23AM -0800

> > > > connected to anything, for it to happen. If there is any sound on the
> > > > channel, the noise immediately stops, but re-starts about one second
> > > > after complete silence returns.
 
try connecting an audio signal generator do create say a 1 kHz sine tone.
 
slowly drop the level.
at some level the clicks will start.
 
observe the tone during the clicks for clues. Does the tone change in anyway due to the clicks?
 
Also with the external input connected to nothing, do the clicks change depending on if the external input is open vs shorted or terminated?
 
These recorders often apply a few volts of DC power to the input to power mics.
 
Put a scope on the input line and see if the spikes are actually present on the input line. Or connect the input to another audio input that you can listen to , do the spikes come OUT the audio input?
 
If you apply a small DC signal to the input through a current limiting resistor , will that stop the spikes? Try both polarities?
 
Is there a schematic available?
 
mark
makolber@yahoo.com: Nov 14 07:34AM -0800


> If you apply a small DC signal to the input through a current limiting resistor , will that stop the spikes? Try both polarities?
 
> Is there a schematic available?
 
> mark
 
also, the wave file posted shows clicks in both L and R, is it bot or just L?
 
Also the clicks in the wav file are alternating polarity, up then down then up etc. might mean something to you
 
mark
N_Cook <diverse@tcp.co.uk>: Nov 14 04:08PM

Can you read the IC numbers relating to preamps, then perhaps find a
generic operational problem with it, outside of Tascam. A datasheet
would let you find the main rails and perhaps there is some space to add
some chip caps across the rails in that arra.
Fox's Mercantile <jdangus@att.net>: Nov 14 05:52AM -0600

On 11/13/18 9:37 PM, JoeF wrote:
> Still interested after all these years? I've got one.
 
> JF3
 
email me, with a valid email return address.
 
Jeff
 
 
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
Fox's Mercantile <jdangus@att.net>: Nov 14 08:17AM -0600

On 11/14/18 5:52 AM, Fox's Mercantile wrote:
 
> email me, with a valid email return address.
 
> Jeff
 
Thanks Joe
 
 
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
tabbypurr@gmail.com: Nov 14 03:42AM -0800

On Wednesday, 14 November 2018 08:45:04 UTC, Phil Allison wrote:
 
> > Expecting people to be mind readers is rather silly.
 
> ** Never expecting that.
 
> You a lack the ability to follow the context.
 
your bullsht lately is tiresome
Phil Allison <pallison49@gmail.com>: Nov 14 04:03AM -0800


> > ** Never expecting that.
 
> > You a lack the ability to follow the context.
 
> your bullsht lately is tiresome
 
 
 
** Piss off to hell - you PITA damn troll.
Phil Allison <pallison49@gmail.com>: Nov 14 04:28AM -0800

GS wrote:
 
> Also check tinsel condition. A DC voltage and moving them should
> have no noise.
 
** Not too long ago, I had a small woofer that was quite silent.
 
An ohm meter test showed the voice oil was shorted - however the cone moved back and forth freely under finger pressure. No burnt smell either.
 
Then I saw it, the tinsel leads had welded themselves together requiring some effort to pull them apart. Later, when the woofer was driven hard on test, the leads vibrated *towards* each other, eventual making a horrible noise when they began touching !!!
 
Shortening both tinselleads by a couple of cm and twisting them 90 degrees in the solder terminals fixed the problem.
 
A similar problem happens when both tinsel leads are able to contact the speaker's steel frame in use. Tinsel leads have to be just the right length and oriented correctly.
 
 
> When done apply low frequency sine wave and listen or any
> noises.
 
** Agreed.
 
 
 
..... Phil
Look165 <look165@numericable.fr>: Nov 14 01:34PM +0100

Try this :
 
http://www.goodhifi.com/
 
They are super, rubber rings, diaphragm, special glue.
 
The prices are quite nice.
 
 
John-Del a écrit :
brix <matlab.user@gmx.com>: Nov 14 10:16AM +0100

On 10/11/2018 10:41, brix wrote:
> I have to take these arbitrations. There is the figure the city and the
> referee judge of the organization. Who can help me?
 
there is an update. Another city and a person of uk.legal that is taking
the arbitrates
€ 2.000.000.000 Zaragoza (foot)
€ 1.500.000.000 Paris (hand)
€ 30.000.000 Turin (foot)
€ 25.800.000 Modena (hand)
€ 17.600.000 Rome (penis)
€ 17.000.000 Rovigo (hand)
€ 16.000.000 Gorizia (hand)
€ 13.500.000 Milan (hand)
€ 6.000.000 Cremona (foot)
€ 2.700.000 Cuneo (foot)
€ 2.500.000 Fermo (foot)
€ 2.400.000 Ravenna (hand)
€ 2.200.000 Rimini (hand)
€ 2.000.000 Ascoli Piceno (hand)
€ 1.500.000 Chieti (foot)
€ 1.500.000 Siena (ax)
€ 800.000 Bari (foot)
€ 700.000 Verona (foot)
€ 650.000 Ferrara (hand)
€ 340.000 Ancona (foot)
€ 3.643.190.000 Total
Fox's Mercantile <jdangus@att.net>: Nov 14 05:51AM -0600

On 11/14/18 3:16 AM, brix wrote:
>> referee judge of the organization. Who can help me?
 
> there is an update. Another city and a person of uk.legal that is taking
> the arbitrates
 
Here's an update for you:
Take you stupid pointless shit somewhere else.
Nobody here gives a flying fuck.
 
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
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