http://groups.google.com/group/sci.electronics.repair?hl=en
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Today's topics:
* Annoying Clock on Microwave - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/408849711f765a28?hl=en
* three pin multi colour led to two pin led - 6 messages, 4 authors
http://groups.google.com/group/sci.electronics.repair/t/f2426227629ec773?hl=en
* Old style filament lamps? - 8 messages, 7 authors
http://groups.google.com/group/sci.electronics.repair/t/8b70a4142ec9c2ec?hl=en
* Has anyone tried this product for heat-sink compound? - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/6163429af05daf16?hl=en
* Vietnamese Marshall - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/83dfedaa7815fcd1?hl=en
* Found: E book stash. - 4 messages, 3 authors
http://groups.google.com/group/sci.electronics.repair/t/e957cecc59313da7?hl=en
* Triple ganged pots - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/0db7c3a79a7550cb?hl=en
* Lead free solder - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/7ff46ef49e9b7de3?hl=en
==============================================================================
TOPIC: Annoying Clock on Microwave
http://groups.google.com/group/sci.electronics.repair/t/408849711f765a28?hl=en
==============================================================================
== 1 of 1 ==
Date: Thurs, Apr 28 2011 10:28 am
From: josephkk
On Wed, 27 Apr 2011 06:50:05 -0700 (PDT), KR <kenreed1999@gmail.com>
wrote:
>On Apr 25, 9:05 pm, "William Sommerwerck" <grizzledgee...@comcast.net>
>wrote:
>> >> I find it impossible to believe that /any/ microwave oven
>> >> would use a crystal or resonator -- which costs money --
>> >> when the power frequency is /right there/, and free.
>> > They would use the same crystal as the microprocessor,
>> > and run the clock in software.
>>
>> I was, of course, referring to a separate crystal (he said, retro-conning
>> the issue).
>
>
>It is possible to have a second crystal, as I have seen a custom IC
>that included an RTC inside have its own separate 3.579mhz
>crystal in addition to the crystal for the CPU function. Both
>connected to the same IC on separate pins.
>In this case though, this second crystal would be just for the RTC
>function,
>as the low speed would save power, and also the rest of the chip would
>likely be shut down also to save power hence no software clock.
>This was an early 1990s design
>
>
>
>As microwaves don't have a RTC in them (that I have seen) and simply
>reset to 12:00 or whatever after a power failure,
>there is no need for the more sophisticated system described above.
>
That IS a RTC. It just has no battery backup to ride through power
outages.
>
>I agree with Michael A Terrell,
>
>There wouldn't be a separate crystal for the clock in a modern
>microwave,
>The "clock" and processor would be incorporated into a single chip,
>and the timekeeping would
>be surely a software function. The chip would very likely have a
>single crystal
>or resonator.
>
>In my original comment, I suggested looking for a trimmer cap
>across the crystal and trimming it to fine adjust the clock if the
>inaccuracy is a real issue for the OP .
>
>You also can check the value of the crystal, there is also a very very
>remote possibility that there was the wrong value, but very close
>installed at the factory - something like a 3.562 MHZ instead of a
>3.579545 MHZ
It would save a lot more power at 32,786 Hz, which is also standard for
the application.
>for example, but without sitting and working out the inaccuracy this
>would cause, this might not be right and might make too big a
>difference to be the problem.
>
>
>It will not hurt the rest of the system to run a tiny fraction faster/
>slower.
>
>
>
==============================================================================
TOPIC: three pin multi colour led to two pin led
http://groups.google.com/group/sci.electronics.repair/t/f2426227629ec773?hl=en
==============================================================================
== 1 of 6 ==
Date: Thurs, Apr 28 2011 10:56 am
From: tom
Hello. I've never done this before so I just want to make sure I'm
doing this correctly. I want to change a three pin multi colour led
activity light on a dvd drive to a two pin blue led. I'm guessing I
need to join the two cathode inputs on the circuit board together?
Makes sense to me but I don't want to screw anything up. Thanks
== 2 of 6 ==
Date: Thurs, Apr 28 2011 11:12 am
From: mike
tom wrote:
> Hello. I've never done this before so I just want to make sure I'm
> doing this correctly. I want to change a three pin multi colour led
> activity light on a dvd drive to a two pin blue led. I'm guessing I
> need to join the two cathode inputs on the circuit board together?
> Makes sense to me but I don't want to screw anything up. Thanks
Look at the circuit diagram or reverse-engineer it.
Tying pins together might work just fine...maybe...or it may let the
smoke out. I can't count the number if times I assumed the designer
was logical and F'd something up.
Depending on how clever the original designer, there's more than one
way to connect stuff. Tying pins together is a risky thing to do.
Might be safer to replace with two blue led's.
Or, since you're throwing away one indication, use one led and forget the
other.
What's the cost of a new drive? How badly do you want the blue light?
The thing has two colors for a reason.
I don't remember the Shakespeare quote, but to goes somehthing
like, "if it bothers you, stick tape over it."
Or just Leave it alone and train yourself to ignore it!!!
If you have to ask the question, leaving it alone is appropriate.
== 3 of 6 ==
Date: Thurs, Apr 28 2011 11:58 am
From: spamtrap1888
On Apr 28, 10:56 am, tom <tomi...@gmail.com> wrote:
> Hello. I've never done this before so I just want to make sure I'm
> doing this correctly. I want to change a three pin multi colour led
> activity light on a dvd drive to a two pin blue led. I'm guessing I
> need to join the two cathode inputs on the circuit board together?
> Makes sense to me but I don't want to screw anything up. Thanks
Assuming for discussion the three-pin is a red/green LED, one circuit
powers the red LED while another circuit powers the green LED. Are
these circuits suitable for wired-OR operation? How is the LED current
limited?
== 4 of 6 ==
Date: Thurs, Apr 28 2011 12:18 pm
From: Ken
mike wrote:
> tom wrote:
>> Hello. I've never done this before so I just want to make sure I'm
>> doing this correctly. I want to change a three pin multi colour led
>> activity light on a dvd drive to a two pin blue led. I'm guessing I
>> need to join the two cathode inputs on the circuit board together?
>> Makes sense to me but I don't want to screw anything up. Thanks
>
> Look at the circuit diagram or reverse-engineer it.
> Tying pins together might work just fine...maybe...or it may let the
> smoke out. I can't count the number if times I assumed the designer
> was logical and F'd something up.
>
> Depending on how clever the original designer, there's more than one
> way to connect stuff. Tying pins together is a risky thing to do.
> Might be safer to replace with two blue led's.
> Or, since you're throwing away one indication, use one led and forget the
> other.
>
> What's the cost of a new drive? How badly do you want the blue light?
>
> The thing has two colors for a reason.
> I don't remember the Shakespeare quote, but to goes somehthing
> like, "if it bothers you, stick tape over it."
> Or just Leave it alone and train yourself to ignore it!!!
> If you have to ask the question, leaving it alone is appropriate.
He might also try installing a diode between each input lead and the
controlling lead of the LED. This would provide isolation and possibly
damage to the other control circuit.
== 5 of 6 ==
Date: Thurs, Apr 28 2011 2:29 pm
From: tom
On Apr 28, 3:18 pm, Ken <K...@invalid.com> wrote:
> mike wrote:
> > tom wrote:
> >> Hello. I've never done this before so I just want to make sure I'm
> >> doing this correctly. I want to change a three pin multi colour led
> >> activity light on a dvd drive to a two pin blue led. I'm guessing I
> >> need to join the two cathode inputs on the circuit board together?
> >> Makes sense to me but I don't want to screw anything up. Thanks
>
> > Look at the circuit diagram or reverse-engineer it.
> > Tying pins together might work just fine...maybe...or it may let the
> > smoke out. I can't count the number if times I assumed the designer
> > was logical and F'd something up.
>
> > Depending on how clever the original designer, there's more than one
> > way to connect stuff. Tying pins together is a risky thing to do.
> > Might be safer to replace with two blue led's.
> > Or, since you're throwing away one indication, use one led and forget the
> > other.
>
> > What's the cost of a new drive? How badly do you want the blue light?
>
> > The thing has two colors for a reason.
> > I don't remember the Shakespeare quote, but to goes somehthing
> > like, "if it bothers you, stick tape over it."
> > Or just Leave it alone and train yourself to ignore it!!!
> > If you have to ask the question, leaving it alone is appropriate.
>
> He might also try installing a diode between each input lead and the
> controlling lead of the LED. This would provide isolation and possibly
> damage to the other control circuit.
Thanks for the replies. There's a schematic on the board and it looks
like this. http://tinypic.com/r/29ynsrq/7 Currently the top three
connections are being used for the led.
== 6 of 6 ==
Date: Thurs, Apr 28 2011 3:09 pm
From: mike
tom wrote:
> On Apr 28, 3:18 pm, Ken <K...@invalid.com> wrote:
>> mike wrote:
>>> tom wrote:
>>>> Hello. I've never done this before so I just want to make sure I'm
>>>> doing this correctly. I want to change a three pin multi colour led
>>>> activity light on a dvd drive to a two pin blue led. I'm guessing I
>>>> need to join the two cathode inputs on the circuit board together?
>>>> Makes sense to me but I don't want to screw anything up. Thanks
>>> Look at the circuit diagram or reverse-engineer it.
>>> Tying pins together might work just fine...maybe...or it may let the
>>> smoke out. I can't count the number if times I assumed the designer
>>> was logical and F'd something up.
>>> Depending on how clever the original designer, there's more than one
>>> way to connect stuff. Tying pins together is a risky thing to do.
>>> Might be safer to replace with two blue led's.
>>> Or, since you're throwing away one indication, use one led and forget the
>>> other.
>>> What's the cost of a new drive? How badly do you want the blue light?
>>> The thing has two colors for a reason.
>>> I don't remember the Shakespeare quote, but to goes somehthing
>>> like, "if it bothers you, stick tape over it."
>>> Or just Leave it alone and train yourself to ignore it!!!
>>> If you have to ask the question, leaving it alone is appropriate.
>> He might also try installing a diode between each input lead and the
>> controlling lead of the LED. This would provide isolation and possibly
>> damage to the other control circuit.
>
> Thanks for the replies. There's a schematic on the board and it looks
> like this. http://tinypic.com/r/29ynsrq/7 Currently the top three
> connections are being used for the led.
Your schematic is missing ALL the critical parts.
What drives the leds?
Likely comes out of some chip somewhere and you probably still won't
know what drives the leds unless you reverse-engineer the circuit and/or
the chip, depending on what documentation is available.
Put two blue leds and be done with it.
I am kinda curious what's so important about this that you'd risk
blowing up the drive??
==============================================================================
TOPIC: Old style filament lamps?
http://groups.google.com/group/sci.electronics.repair/t/8b70a4142ec9c2ec?hl=en
==============================================================================
== 1 of 8 ==
Date: Thurs, Apr 28 2011 10:56 am
From: adrian@poppyrecords.invalid.invalid (Adrian Tuddenham)
Phil Allison <phil_a@tpg.com.au> wrote:
> "Adrian Tuddenham"
>
> > http://www.wrightshardware.co.uk/Eaccess.htm
>
>
> ** Have you rung the phone number?
>
> Does ma or pa Wright answer ??
Thursday is early closing day in Bath; it's when he goes to the
wholesalers to stock up. Try again tomorrow.
> Looks like a ghost web site to me.
Nope - just under delayed construction. I'm the webmaster and I'm
waiting for more info.
--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk
== 2 of 8 ==
Date: Thurs, Apr 28 2011 11:13 am
From: Terry Pinnell
adrian@poppyrecords.invalid.invalid (Adrian Tuddenham) wrote:
>Terry Pinnell <terrypingm@DELETEgmail.com> wrote:
>
>> (Re-posted from the lower traffic sci.electronics.misc group.)
>>
>> Does anyone know where I can buy 'normal' filament lamp bulbs in the UK
>> please? I just cannot get on with the new economy type. My remaining stock
>> of 60W and 100W is dwindling rapidly.
>
>http://www.wrightshardware.co.uk/Eaccess.htm
Thanks Adrian. Phoned at 7pm but I see they're closed all day Thursdays
anyway. I'll try again on Saturday after the Wedding. Doesn't look like
they have any online ordering but presumably they will despatch? Bath's a
little too far to justify the trip!
--
Terry, East Grinstead, UK
== 3 of 8 ==
Date: Thurs, Apr 28 2011 11:59 am
From: Meat Plow
On Thu, 28 Apr 2011 17:19:10 +1000, Phil Allison wrote:
> "Terry Pinnell"
>
>> Does anyone know where I can buy 'normal' filament lamp bulbs in the UK
>> please? I just cannot get on with the new economy type. My remaining
>> stock of 60W and 100W is dwindling rapidly.
>
>
> ** AFAIK- even if you came across a stock it is illegal now for anyone
> to
> sell them to you.
>
> Have a look for the high efficiency halogen bulbs that are made in the
> same style as regular BC and ES 40 watt and 60 watt bulbs. Rated at
> 2000 hours and bit whiter light but rather more expensive.
>
> Legally on sale all over Australia, but not sure about the UK.
Who is going to arrest you for selling incandescent bulbs? The bulb
police?
--
Live Fast Die Young, Leave A Pretty Corpse
== 4 of 8 ==
Date: Thurs, Apr 28 2011 12:02 pm
From: spamtrap1888
On Apr 28, 11:59 am, Meat Plow <mhywa...@yahoo.com> wrote:
> On Thu, 28 Apr 2011 17:19:10 +1000, Phil Allison wrote:
> > "Terry Pinnell"
>
> >> Does anyone know where I can buy 'normal' filament lamp bulbs in the UK
> >> please? I just cannot get on with the new economy type. My remaining
> >> stock of 60W and 100W is dwindling rapidly.
>
> > ** AFAIK- even if you came across a stock it is illegal now for anyone
> > to
> > sell them to you.
>
> > Have a look for the high efficiency halogen bulbs that are made in the
> > same style as regular BC and ES 40 watt and 60 watt bulbs. Rated at
> > 2000 hours and bit whiter light but rather more expensive.
>
> > Legally on sale all over Australia, but not sure about the UK.
>
> Who is going to arrest you for selling incandescent bulbs? The bulb
> police?
>
I remember when Detroiters would cross into Canada to buy 5 gallon
flush toilets. Good times.
== 5 of 8 ==
Date: Thurs, Apr 28 2011 1:00 pm
From: adrian@poppyrecords.invalid.invalid (Adrian Tuddenham)
Terry Pinnell <terrypingm@DELETEgmail.com> wrote:
> adrian@poppyrecords.invalid.invalid (Adrian Tuddenham) wrote:
>
> >Terry Pinnell <terrypingm@DELETEgmail.com> wrote:
> >
> >> (Re-posted from the lower traffic sci.electronics.misc group.)
> >>
> >> Does anyone know where I can buy 'normal' filament lamp bulbs in the UK
> >> please? I just cannot get on with the new economy type. My remaining stock
> >> of 60W and 100W is dwindling rapidly.
> >
> >http://www.wrightshardware.co.uk/Eaccess.htm
>
> Thanks Adrian. Phoned at 7pm but I see they're closed all day Thursdays
> anyway. I'll try again on Saturday after the Wedding. Doesn't look like
> they have any online ordering but presumably they will despatch? Bath's a
> little too far to justify the trip!
He told me he intends to open the shop tomorrow (Friday).
I warned him that, if he had a website, people would expect him to do
mail order, but I don't know if he is ready for it yet.
--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk
== 6 of 8 ==
Date: Thurs, Apr 28 2011 7:49 am
From: M.Joshi
'Terry Pinnell[_3_ Wrote:
> ;2636067'](Re-posted from the lower traffic sci.electronics.misc
> group.)
>
> Does anyone know where I can buy 'normal' filament lamp bulbs in the UK
> please? I just cannot get on with the new economy type. My remaining
> stock
> of 60W and 100W is dwindling rapidly.
>
> --
> Terry, East Grinstead, UK
Do you mean that your light fittings cannot accomodate the larger
compact fluorescent bulbs?
If so, there are halogen bulbs available in the same form factor as the
old incandescent filament bulbs. These are classed as lower energy than
a standard incandescent and can be purchased from most supermarkets and
DIY stores. See the link below:
They give you full brightness at switch on unlike compact fluorescents
that take time to warm-up.
--
M.Joshi
== 7 of 8 ==
Date: Thurs, Apr 28 2011 2:30 pm
From: "William Sommerwerck"
> They give you full brightness at switch on, unlike
> compact fluorescents that take time to warm-up.
Yes, but...
The better CFLs are quite bright at turn-on -- bright enough that you don't
feel you bought a defective lamp.
== 8 of 8 ==
Date: Thurs, Apr 28 2011 3:14 pm
From: Andrew Rossmann
In article <ipbnl5$if2$1@dont-email.me>, grizzledgeezer@comcast.net
says...
> British CFLs must be of very poor quality, because you can get
excellent
> ones in the US. They come instantly -- faster than incandescent -- and have
> good color balance.
>
> I've replaced all but the miniature "decorative" lamps in my condo with
> CFLs. I would never go back to incandescent.
>
> I'm writing this in my den. The light is from a 100W-equivalent Home Depot
> CFL in an IKEA shade. The /only/ way you can tell it's not incandescent is
> by looking under the shade.
Although many CFL's list the color temperature (2700K is roughly
equivalent to incandescent), they rarely list the CRI (Color Rendering
Index). That gives an idea on how well a bulb displays all colors.
http://en.wikipedia.org/wiki/Color_rendering_index
--
If there is a no_junk in my address, please REMOVE it before replying!
All junk mail senders will be prosecuted to the fullest extent of the
law!!
http://home.comcast.net/~andyross
==============================================================================
TOPIC: Has anyone tried this product for heat-sink compound?
http://groups.google.com/group/sci.electronics.repair/t/6163429af05daf16?hl=en
==============================================================================
== 1 of 1 ==
Date: Thurs, Apr 28 2011 11:01 am
From: josephkk
On Sun, 24 Apr 2011 23:07:52 -0400, "Barry" <none@nospam.org> wrote:
>
>Working around chemists, I had easy access to silicone vacuum stopcock
>grease. I have used it in a pinch for thermal grease and it worked well.
>You can find a similar grease in the plumbing department of Lowes and
>Home Depot. It is used to lubricate valve stems, rubber seals, and those
>ungodly expensive ceramic Price-Pfister faucets. It will work far better
>than any Permatex product as a heat transfer grease.
>
>Oh, and one other reason to not use Permatex in this application. This
>silicone is an acetoxy cure which means it releases corrosive acetic acid
>when it cures.
Ahem, not any more.
>
> Dr. Barry L. Ornitz WA4VZQ ham_call_letters at live.com
>
Only the very old version from thee 1960s were acetoxy cure. I had a lot
of corroded connections to learn my lesson about that. Then in the early
1970s GE came out with the thixotropic variants which use atmospheric
moisture as an initiator. No more acid release as a byproduct of cure.
Please get up to date.
==============================================================================
TOPIC: Vietnamese Marshall
http://groups.google.com/group/sci.electronics.repair/t/83dfedaa7815fcd1?hl=en
==============================================================================
== 1 of 2 ==
Date: Thurs, Apr 28 2011 11:02 am
From: boardjunkie1
On Apr 28, 1:39 pm, "Phil Allison" <phi...@tpg.com.au> wrote:
> ** A rather new looking Marshall " MA100H " valve head landed on my bench
> today - but it looked a bit different. On the back it says " Made in Vietnam
> " - so this is the first non UK made ( ie assembled) Marshall, at least
> that I have ever seen.
>
> The amp was silent, valves all lit up but no output whatsoever and no extra
> current draw when the Standby switch was closed. OK - so where is the damn
> HT fuse ? Nothing on the back so it must be inside - another first for a
> Marshall valve amp. On the PCB is a 630mA delay fuse - very blown -
> fitting a new one got the amp running.
>
> Bit of poking about finds that both 1/4 inch QCs on the PCB used for output
> valve grid drive are very loose - easy fixed. But was this the cause of
> fuse blowing? Nope.
>
> That 630 mA HT fuse should be 1 amp at least, since it is fitted in the
> secondary of the PT. On test, the fuse had to pass just over 1 amp rms when
> the amp is over-driven. The primary AC current draw is 2 amps rms at the
> same time ( ie 480VA) .
>
> On sine wave test, there is significant crossover distortion on the CRO
> screen at 1/2 output and above. The bias setting seemed OK - there are two
> trims inside and a pair of 1 ohm resistors in each pair of output valve
> cathodes.
>
> On checking the screen B+ supply, the cause is simple. There is no filter
> choke of course ( what are they ?) and instead a 470 ohm ,7W resistor. So
> the screen B+ supply falls like a rock soon as the amp is driven. Guess
> this helps the crappy Chinese EL34s to survive overdriving.
>
> Besides the above bad points, there are lots more.
>
> The AC tranny is undersized - it looks like a 250VA type and needs to be
> 400VA to withstand hard use in this amp. Even sitting on the bench with a
> 605mA idle current from the AC supply, the internal temp rise is almost 40
> degrees C. A couple of hours of heavy metal on a warm night will see it off.
>
> The same * ridiculously fragile* plastic shaft pots as used on other recent
> Marshalls have been fitted - one light bump on the knob = nasty
> intermittent fault.
>
> There is no AC voltage selector fitted and no internal option either,
> another first in a Marshall valve head. All the fasteners are metric too,
> not one single concession in sight to the brand's UK origin.
>
> There ARE two small screw-in bulbs ( labelled 12V ) fitted inside the
> cabinet that illuminate the whole chassis and the "Marshall" logo through
> the open weave cloth. These are not ordinary 12 volt dial lamps but special
> dual, orange LEDs - one chip connected for each polarity when fed with AC.
>
> Next the these is a non Accutronics ( Belton ?) reverb tank.
>
> All the jack sockets ( 7 of them ) are very fragile, PCB mount types.
>
> Every single part in the amp looks like it came either from China, Korea or
> Taiwan and then assembled in Vietnam.
>
> Good points:
> --------------
>
> The 4 x EL34 output valves and the 12AX7 PI are on ceramic sockets, hand
> wired to the two trannys and the PCB.
>
> The main PCB looks like it is easy to get lose and invert for servicing.
>
> The amp is pretty cheap to buy.
>
> But a used example from the 1980s is a way better product, full of UK made
> transformers and other parts that have proved their ability to survive in a
> Marshall.
>
> .... Phil
Good info. Haven't had one of these cross my path yet. Just finished
up on a DSL100 that had to have the main pcb replaced due to the bias
instability issue caused by crappy board material. The replacements
look to be FR4 or similar good quality stuff.
== 2 of 2 ==
Date: Thurs, Apr 28 2011 12:49 pm
From: "Gareth Magennis"
"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:91t5gtFsmpU1@mid.individual.net...
>
> ** A rather new looking Marshall " MA100H " valve head landed on my bench
> today - but it looked a bit different. On the back it says " Made in
> Vietnam " - so this is the first non UK made ( ie assembled) Marshall,
> at least that I have ever seen.
>
> The amp was silent, valves all lit up but no output whatsoever and no
> extra current draw when the Standby switch was closed. OK - so where is
> the damn HT fuse ? Nothing on the back so it must be inside - another
> first for a Marshall valve amp. On the PCB is a 630mA delay fuse - very
> blown - fitting a new one got the amp running.
>
> Bit of poking about finds that both 1/4 inch QCs on the PCB used for
> output valve grid drive are very loose - easy fixed. But was this the
> cause of fuse blowing? Nope.
>
> That 630 mA HT fuse should be 1 amp at least, since it is fitted in the
> secondary of the PT. On test, the fuse had to pass just over 1 amp rms
> when the amp is over-driven. The primary AC current draw is 2 amps rms at
> the same time ( ie 480VA) .
>
> On sine wave test, there is significant crossover distortion on the CRO
> screen at 1/2 output and above. The bias setting seemed OK - there are
> two trims inside and a pair of 1 ohm resistors in each pair of output
> valve cathodes.
>
> On checking the screen B+ supply, the cause is simple. There is no filter
> choke of course ( what are they ?) and instead a 470 ohm ,7W resistor. So
> the screen B+ supply falls like a rock soon as the amp is driven. Guess
> this helps the crappy Chinese EL34s to survive overdriving.
>
> Besides the above bad points, there are lots more.
>
> The AC tranny is undersized - it looks like a 250VA type and needs to be
> 400VA to withstand hard use in this amp. Even sitting on the bench with a
> 605mA idle current from the AC supply, the internal temp rise is almost 40
> degrees C. A couple of hours of heavy metal on a warm night will see it
> off.
>
> The same * ridiculously fragile* plastic shaft pots as used on other
> recent Marshalls have been fitted - one light bump on the knob = nasty
> intermittent fault.
>
> There is no AC voltage selector fitted and no internal option either,
> another first in a Marshall valve head. All the fasteners are metric too,
> not one single concession in sight to the brand's UK origin.
>
> There ARE two small screw-in bulbs ( labelled 12V ) fitted inside the
> cabinet that illuminate the whole chassis and the "Marshall" logo through
> the open weave cloth. These are not ordinary 12 volt dial lamps but
> special dual, orange LEDs - one chip connected for each polarity when fed
> with AC.
>
> Next the these is a non Accutronics ( Belton ?) reverb tank.
>
> All the jack sockets ( 7 of them ) are very fragile, PCB mount types.
>
> Every single part in the amp looks like it came either from China, Korea
> or Taiwan and then assembled in Vietnam.
>
> Good points:
> --------------
>
> The 4 x EL34 output valves and the 12AX7 PI are on ceramic sockets, hand
> wired to the two trannys and the PCB.
>
> The main PCB looks like it is easy to get lose and invert for servicing.
>
> The amp is pretty cheap to buy.
>
> But a used example from the 1980s is a way better product, full of UK made
> transformers and other parts that have proved their ability to survive in
> a Marshall.
>
>
>
> .... Phil
>
>
>
>
>
I've an Ampeg SVT Classic here thats "manufactured in Vietnam".
Have to say the build quality seems good. The pots and sockets even seem to
be the retro style chunky Western parts.
I've seen quite a few of these now, never noticed the Vietnam connection
before, but they have always seemed to be solidly built.
I got 340 Watts out of the 6 x Sovtek 6550's today.
Gareth.
==============================================================================
TOPIC: Found: E book stash.
http://groups.google.com/group/sci.electronics.repair/t/e957cecc59313da7?hl=en
==============================================================================
== 1 of 4 ==
Date: Thurs, Apr 28 2011 1:42 pm
From: atec77
On 28/04/2011 10:02 PM, Gagi-9a6aag wrote:
> "Barry OGrady"<atheist@hotmail.com.au> wrote
>> but what does it mean?
>>
>
> what part you didnt understand?!?!
> part that such link is welcome or part i did repost that link to Croatian
> electronics news group?!
>
>
He generally doesn't understand
everything
--
X-No-Archive: Yes
== 2 of 4 ==
Date: Thurs, Apr 28 2011 1:45 pm
From: Adrian C
On 25/04/2011 16:36, Ian Field wrote:
> http://www.unhas.ac...
I sometimes get a little annoyed by all this. The western and central
world looks to bookshops and libraries to study college disciplines. The
eastern and middle eastern world just look to unscrupulous piracy.
I occasionally service computers bought here (UK) by overseas folks that
actually *pay* their eastern brethren good local money to install the
latest hooky stuff. So apart from Microsoft product keys failing WGA, so
that the machine quickly becomes very unpatched, open for exploit and
then (satisfying for me) broken, *everything* installable is delivered
in multiple directories, hacked, cracked, trojaned, you name it. The
real price of that software normally outvalues the cost of the hardware
by the ratio 1000:1.
I had one Indian fellow who is taking up a science teaching post over
here, completely fail to understand exactly why most of his hard drive
stored training materials, ill-licensed computer programs, video
captures, and ebook texts would be wholly inappropriate to share with
pupils and use in the classroom within the school IT infrastructure.
Very wrong, all of this IMO :-(
--
Adrian C
== 3 of 4 ==
Date: Thurs, Apr 28 2011 3:54 pm
From: "Gagi-9a6aag"
"Adrian C" <email@here.invalid> wrote
> Very wrong, all of this IMO :-(
well, Adrian,...generally speaking i totally agre with you...and i support
such way of thinking like yours...but...tell me, how do you think i am able
to buy a damn XP OS licence that was/is around 120Euros (or 100 UK pounds)
when i have month salary of 350 euros...my flat and bills (minimum ones)
takes around 150-200 euros a month, a food, underaverage ingridiets (meat
slice maybe once a week) takes at last 150-200euros as well...so, to buy a
simple shoes, pair of jeans or shirt is like a mission impossible if you
idnt plan ti at least 2-3 months in advance to save some extra money for
it...and then, besie that, to have a car is MUST HAVE as well...and i was
driving a car i bought for 600euros...and 1 liter of fuel is 1.5
euros....and safety licence and insurance takes around 400euros a
year....etc..etc...to manage just a basic life needs you must be a
economy/financial master to succeed sucessfully manage all the costs and
minimum needs.....and usually everything is solved with some long term loans
hoping some better days will come ahead....
people here are buying FOOD with damn loan...can you imagine that?!!?...that
even food is payed with loaned money...what means people cant earn enough
just for minimum of daily life standards.....so, to have a PC is
LUXURY....and to have internet (ADSL 2gbit DL and 256kbit Up) means you own
a world....and to buy a licence for some software like Win XP...it would
mean you lost your mind or your parents are relatives of Donald Trump,
Rockefeller...or somone like that...
of course...things are not so depressive, bad and black....there are many
who can afford themselves all of mentioned above plus vacation at Ibiza at
summer time or ski vacation at winter time....but those are just minority...
there is no middle class anymore...people are low rich, mid rich or sick
rich and all those can afford themselves everythign mentioned and a bit more
....while on other side completely poor and to buy a PC for 200 euros with
old CRT screen seems like a dream to them...
look for example; i live only 120km or like 70 miles away form sea
side...for last 7 years i cant affrod myself vacation at seaside for even 3
days to stay at coast.....WHY?!?!....simple...coz the prices for some
average apartment is around 50-70 euros a day....so, just 3 days would cost
me half of my month salary....i will need ther eat least 10 euros a day to
eat something...plus aprox aprox 25-30euros for fuel there and back (without
driving a lot around) and dont forget i need to spend aprox 150 euros for my
monthly bills and falt no matter where i am....
so, after all this...and this is just a simple example and there are dozens
of more examples....my only question is; would you let me use pirat OS and
be able to participate in global communication and development of IT world
and new generation of people.....or you will rather make us all
informatically stupid and undeveloped just coz we cant afford ourselves
licenced software....
you must remember one thing, and that is; the fact your country standard
makes you easier able to buy some software doesnt mean you worth more then
some Indian or Croatian who cant afford it but can use it and understand it
maybe even better then you...(in sense of mentality over reaching the pirat
things)
i am not saying you are the one like that judging...but i have met some like
that...
anyway...i have been hanging with Americans, Canadians, French even UK's for
years and i asure you so the rest of people form this gorup how there is a
lot higher number of people from those countries that are using pirat
materials then the statistical reports are showing...
for example...pirate movies are ordinary thing in USA....i can name 90% of
my friends from states (and i know aprox 100-120 people from states) all
using "torrents" to download movies hits...so, this West - East piracy
estimation is just a story for CNN....reality is something completely
different...i am prety sure in that...
or by other words...if prices of software are like 50% of average month
salary of USA....trust me; 90% of USA citizens would NEVER buy a single
Windwos licence....and MS Office not even in madness :))
hmm..average USA salaray a month around 2005. - 2006. was aprox 1800US$ (in
range of 1400 up to 2200US$ class which takes a majority of USA citizens)
so, now imagine that Win XP licence price was/is 900US$....pffft...entire
USA would be piratized with Win OS...thats not a presumption, but fact...
== 4 of 4 ==
Date: Thurs, Apr 28 2011 3:55 pm
From: "Gagi-9a6aag"
"atec77" <atec77@hotmail.com> wrote
> He generally doesn't understand
> everything
yes, i realized that :)
==============================================================================
TOPIC: Triple ganged pots
http://groups.google.com/group/sci.electronics.repair/t/0db7c3a79a7550cb?hl=en
==============================================================================
== 1 of 1 ==
Date: Thurs, Apr 28 2011 2:11 pm
From: "caius"
"spamtrap1888" <spamtrap1888@gmail.com> ha scritto nel messaggio
news:ef7e1ca7-7806-48fa-ad18-6eed4d346405@s34g2000prg.googlegroups.com...
>You could start at potentiometers.com. I see they have >KKK triple gang
>pots, as well as modular pots that go eight deep.
Thanks.Sadly they accept only order from a minimum of 50 pieces and each
piece of the KKK pot is 50$..
==============================================================================
TOPIC: Lead free solder
http://groups.google.com/group/sci.electronics.repair/t/7ff46ef49e9b7de3?hl=en
==============================================================================
== 1 of 1 ==
Date: Thurs, Apr 28 2011 3:48 pm
From: "Charles"
"Father Haskell" wrote in message
news:8149b5cb-636f-481c-8684-e6b9123c7ac4@dr5g2000vbb.googlegroups.com...
On Apr 21, 5:07 pm, "Charles" <charlesschu...@comcast.net> wrote:
> Has this had any impact on repair and rework of electronic devices and
> equipment?
If it's as bad as the lead-free plumbing solder, expect
poor wetting and tendency to set cold. 63/37 tin-lead
can't be beat. Fast, and joints look like they're soldered
with Sterling silver.
The eutectic 63/37 alloy is still easy to buy. Perhaps the repair industry
is dodging the bullet fired at the manufacturing industry. Or, as several
have pointed out, it is impossible to enforce lead-free rules on the
repairers.
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