sci.electronics.repair - 26 new messages in 9 topics - digest

sci.electronics.repair
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Today's topics:

==============================================================================
TOPIC: Fluke Scopemeter 199
http://groups.google.com/group/sci.electronics.repair/t/0cfaff10705fe0ca?hl=en
==============================================================================

== 1 of 2 ==
Date: Wed, May 19 2010 8:56 am
From: Merciadri Luca

On May 19, 9:33 am, Pat Jordan <mymailgene...@gmail.com> wrote:
> On May 18, 6:33 pm, Merciadri Luca <merciadril...@gmail.com> wrote:> On May 18, 4:07 pm, Pat Jordan <mymailgene...@gmail.com> wrote:
>
> CHB voltage fluctuates greatly with nothing attached. Suspect Philips
> 000262HL N1E5Y9 HSH0144 i.c but cannot find a reference to this semi
> on the web. Cost of repair is ridiculously high - could buy a
> competitors scope for the cost quoted for repair! Any ideas?
>
>
>
> > The fact is that, as you know, Fluke is some kind of trustmark. It'd
> > be better to replace the defective component than to go for a
> > competitor main unit. For the rest, I cannot tell you more about how
> > to find a solution.
>
> Thanks Merciadi Luca, I have several thousand Euros worth of Fluke
> test equipment as I believed they were dependable.
So, why would you look in the concurrence?

== 2 of 2 ==
Date: Wed, May 19 2010 4:31 pm
From: Jamie

Pat Jordan wrote:
> On May 18, 6:33 pm, Merciadri Luca <merciadril...@gmail.com> wrote:
>
>>On May 18, 4:07 pm, Pat Jordan <mymailgene...@gmail.com> wrote:
>>
>
> CHB voltage fluctuates greatly with nothing attached. Suspect Philips
> 000262HL N1E5Y9 HSH0144 i.c but cannot find a reference to this semi
> on the web. Cost of repair is ridiculously high - could buy a
> competitors scope for the cost quoted for repair! Any ideas?
>
>
>>The fact is that, as you know, Fluke is some kind of trustmark. It'd
>>be better to replace the defective component than to go for a
>>competitor main unit. For the rest, I cannot tell you more about how
>>to find a solution.
>
>
> Thanks Merciadi Luca, I have several thousand Euros worth of Fluke
> test equipment as I believed they were dependable.
Really, I just filed, in its proper place, A fluke 787 process DMM..

Its now has a proper resting place, the garbage can.

jamie.

==============================================================================
TOPIC: cheap LCD/LED on the way
http://groups.google.com/group/sci.electronics.repair/t/08ed0981300ac43b?hl=en
==============================================================================

== 1 of 1 ==
Date: Wed, May 19 2010 8:57 am
From: bob

http://xrl.in/5e60

bob

==============================================================================
TOPIC: OT: card storage
http://groups.google.com/group/sci.electronics.repair/t/1faee31fa35fe26a?hl=en
==============================================================================

== 1 of 1 ==
Date: Wed, May 19 2010 9:21 am
From: Jeff Liebermann

On Tue, 18 May 2010 13:54:33 -0700 (PDT), Rich Grise on Google groups
<richardgrise@yahoo.com> wrote:

>On May 18, 9:43 am, Jeff Liebermann <je...@cruzio.com> wrote:
>> scanner, printer, etc conglomeration. Here's a video clip of it
>> scanning both sides of service manual:
>> <http://802.11junk.com/jeffl/crud/CanonImageRunner5000.wmv>
>
>Man, that's a looooooong download for 15 seconds of video.

Sorry. I didn't bother to reduce it down to YouTube minimalist
standards of blurriness, smear, pixelation, and tiny size. I did note
that it was 4MBytes big. Unless you're on dialup, it should have been
all that slow (about 45 seconds on my 1.5Mbit/sec DSL line).

However, I lied a little. It is scanning both sides on the fly, but
it's not reading (make searchable in PDF) either side. That was done
later with the e-Copy program from Canon. It took about 90 seconds to
do the entire 180 pages.
<http://www.ecopy.com/Products-eCopy-ShareScan-Essentials.asp>

--
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

==============================================================================
TOPIC: BWS688 is dead
http://groups.google.com/group/sci.electronics.repair/t/b88c19d1c4c5cfb2?hl=en
==============================================================================

== 1 of 5 ==
Date: Wed, May 19 2010 11:13 am
From: "Vale"

"Merciadri Luca" <merciadriluca@gmail.com> ha scritto nel messaggio
news:bf873332-81d6-4c08-8219-b82e32fd3d28@e21g2000vbl.googlegroups.com...
On May 18, 9:40 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> On Tue, 18 May 2010 12:23:14 -0700, Merciadri Luca wrote:
> > On May 18, 8:28 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> >> On Tue, 18 May 2010 10:56:56 -0700, Merciadri Luca wrote:
> >> > On May 18, 7:53 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> >> >> On Tue, 18 May 2010 10:49:02 -0700, Merciadri Luca wrote:
> >> >> > On May 18, 7:44 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> >> >> >> Sorry to hear one BWS688 isn't working.
>
> >> >> Oh,you wanted to go further? I just thought you were describing some
> >> >> equipment you had and how it did or didn't operate. What further did
> >> >> you want to know?

Luca, I know well enough Meat Plow, don't take him for a "rude" person.
Still remember some answers given to another It ,an accountist who wanted to
become an expert electronic tech in a couple of days.
Was really fun to read his questions and M.P answers.
Meat Plow, I guess, is the kind of person who deals with electronics after a
lifetime of work and study and, just like me, gets irritaded from
silly/ingenuous questions.
Have a try, ask your questions on it.hobby.elettronica.riparazioni.
You'll have less troubles in explaining the problem.
Buona fortuna

== 2 of 5 ==
Date: Wed, May 19 2010 11:44 am
From: Meat Plow

On Wed, 19 May 2010 20:13:16 +0200, Vale wrote:

> "Merciadri Luca" <merciadriluca@gmail.com> ha scritto nel messaggio
> news:bf873332-81d6-4c08-8219-
b82e32fd3d28@e21g2000vbl.googlegroups.com...
> On May 18, 9:40 pm, Meat Plow <mhyw...@yahoo.com> wrote:
>> On Tue, 18 May 2010 12:23:14 -0700, Merciadri Luca wrote:
>> > On May 18, 8:28 pm, Meat Plow <mhyw...@yahoo.com> wrote:
>> >> On Tue, 18 May 2010 10:56:56 -0700, Merciadri Luca wrote:
>> >> > On May 18, 7:53 pm, Meat Plow <mhyw...@yahoo.com> wrote:
>> >> >> On Tue, 18 May 2010 10:49:02 -0700, Merciadri Luca wrote:
>> >> >> > On May 18, 7:44 pm, Meat Plow <mhyw...@yahoo.com> wrote:
>> >> >> >> Sorry to hear one BWS688 isn't working.
>>
>> >> >> Oh,you wanted to go further? I just thought you were describing
>> >> >> some equipment you had and how it did or didn't operate. What
>> >> >> further did you want to know?
>
> Luca, I know well enough Meat Plow, don't take him for a "rude" person.
> Still remember some answers given to another It ,an accountist who
> wanted to become an expert electronic tech in a couple of days. Was
> really fun to read his questions and M.P answers. Meat Plow, I guess, is
> the kind of person who deals with electronics after a lifetime of work
> and study and, just like me, gets irritaded from silly/ingenuous
> questions.
> Have a try, ask your questions on it.hobby.elettronica.riparazioni.
> You'll have less troubles in explaining the problem. Buona fortuna

I wasn't trying to be rude or disingenuous I was using a little
psychology. I don't know Mr. Luca or his technical abilities and he
doesn't seem to understand the process of being as precise as possible
when seeking some tech information. I did research his Blue Sky weather
apparatus but I couldn't find enough info on it in English to be of help.
Even if I were able to find english tech literature I don't think Mr.
Luca has the skill set to sort out the problem with the proper
references. I mentioned how I would go about evaluation and possibly
repair to demonstrate the procedure and let him make up his mind if he was
up to the task.

== 3 of 5 ==
Date: Wed, May 19 2010 1:59 pm
From: Merciadri Luca

On May 19, 8:44 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> On Wed, 19 May 2010 20:13:16 +0200, Vale wrote:
> > "Merciadri Luca" <merciadril...@gmail.com> ha scritto nel messaggio
> > news:bf873332-81d6-4c08-8219-
>
> b82e32fd3...@e21g2000vbl.googlegroups.com...
>
>
>
> > On May 18, 9:40 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> >> On Tue, 18 May 2010 12:23:14 -0700, Merciadri Luca wrote:
> >> > On May 18, 8:28 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> >> >> On Tue, 18 May 2010 10:56:56 -0700, Merciadri Luca wrote:
> >> >> > On May 18, 7:53 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> >> >> >> On Tue, 18 May 2010 10:49:02 -0700, Merciadri Luca wrote:
> >> >> >> > On May 18, 7:44 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> >> >> >> >> Sorry to hear one BWS688 isn't working.
>
> >> >> >> Oh,you wanted to go further? I just thought you were describing
> >> >> >> some equipment you had and how it did or didn't operate. What
> >> >> >> further did you want to know?
>
> > Luca, I know well enough Meat Plow, don't take him for a "rude" person.
> > Still remember some answers given to another It ,an accountist who
> > wanted to become an expert electronic tech in a couple of days. Was
> > really fun to read his questions and M.P answers. Meat Plow, I guess, is
> > the kind of person who deals with electronics after a lifetime of work
> > and study and, just like me, gets irritaded from silly/ingenuous
> > questions.
> > Have a try, ask your questions on it.hobby.elettronica.riparazioni.
> > You'll have less troubles in explaining the problem. Buona fortuna
>
> I wasn't trying to be rude or disingenuous I was using a little
> psychology. I don't know Mr. Luca or his technical abilities and he
> doesn't seem to understand the process of being as precise as possible
> when seeking some tech information. I did research his Blue Sky weather
> apparatus but I couldn't find enough info on it in English to be of help.
> Even if I were able to find english tech literature I don't think Mr.
> Luca has the skill set to sort out the problem with the proper
> references. I mentioned how I would go about evaluation and possibly
> repair to demonstrate the procedure and let him make up his mind if he was
> up to the task.

No problem. The fact is that I'm not an electronic guru, sure. Note
that I'm not Italian, and that I consequently can't write topics in
Italian.

== 4 of 5 ==
Date: Wed, May 19 2010 2:13 pm
From: Meat Plow

On Wed, 19 May 2010 13:59:46 -0700, Merciadri Luca wrote:

> On May 19, 8:44 pm, Meat Plow <mhyw...@yahoo.com> wrote:
>> On Wed, 19 May 2010 20:13:16 +0200, Vale wrote:
>> > "Merciadri Luca" <merciadril...@gmail.com> ha scritto nel messaggio
>> > news:bf873332-81d6-4c08-8219-
>>
>> b82e32fd3...@e21g2000vbl.googlegroups.com...
>>
>>
>>
>> > On May 18, 9:40 pm, Meat Plow <mhyw...@yahoo.com> wrote:
>> >> On Tue, 18 May 2010 12:23:14 -0700, Merciadri Luca wrote:
>> >> > On May 18, 8:28 pm, Meat Plow <mhyw...@yahoo.com> wrote:
>> >> >> On Tue, 18 May 2010 10:56:56 -0700, Merciadri Luca wrote:
>> >> >> > On May 18, 7:53 pm, Meat Plow <mhyw...@yahoo.com> wrote:
>> >> >> >> On Tue, 18 May 2010 10:49:02 -0700, Merciadri Luca wrote:
>> >> >> >> > On May 18, 7:44 pm, Meat Plow <mhyw...@yahoo.com> wrote:
>> >> >> >> >> Sorry to hear one BWS688 isn't working.
>>
>> >> >> >> Oh,you wanted to go further? I just thought you were
>> >> >> >> describing some equipment you had and how it did or didn't
>> >> >> >> operate. What further did you want to know?
>>
>> > Luca, I know well enough Meat Plow, don't take him for a "rude"
>> > person. Still remember some answers given to another It ,an
>> > accountist who wanted to become an expert electronic tech in a couple
>> > of days. Was really fun to read his questions and M.P answers. Meat
>> > Plow, I guess, is the kind of person who deals with electronics after
>> > a lifetime of work and study and, just like me, gets irritaded from
>> > silly/ingenuous questions.
>> > Have a try, ask your questions on it.hobby.elettronica.riparazioni.
>> > You'll have less troubles in explaining the problem. Buona fortuna
>>
>> I wasn't trying to be rude or disingenuous I was using a little
>> psychology. I don't know Mr. Luca or his technical abilities and he
>> doesn't seem to understand the process of being as precise as possible
>> when seeking some tech information. I did research his Blue Sky weather
>> apparatus but I couldn't find enough info on it in English to be of
>> help. Even if I were able to find english tech literature I don't think
>> Mr. Luca has the skill set to sort out the problem with the proper
>> references. I mentioned how I would go about evaluation and possibly
>> repair to demonstrate the procedure and let him make up his mind if he
>> was up to the task.
>
> No problem. The fact is that I'm not an electronic guru, sure. Note that
> I'm not Italian, and that I consequently can't write topics in Italian.

I wouldn't consider myself a guru on anything but older( vintage) tube
style guitar amps. It's hard to keep abreast of the wildly evolving
technology unless you deal with it as employment and are sent to school
on the stuff as a part of your job continuing education. That's why I'm
stuck in the 60s,70s, and 80s. I'm now a hobby repair making a few spare
bucks spending money but at times quite in demand for all sorts of
vintage gizmos and amps. I like dealing with point to point wiring,
standard PC board construction and don't like surface mount parts.
Some say it's never too late to learn but the zeal of new technology
service has long faded for me.

== 5 of 5 ==
Date: Wed, May 19 2010 2:36 pm
From: "Vale"

"Merciadri Luca" <merciadriluca@gmail.com> ha scritto nel messaggio
news:82a3b96d-e49f-4306-97ed-747f46d7ad7f@m4g2000vbl.googlegroups.com...
On May 19, 8:44 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> On Wed, 19 May 2010 20:13:16 +0200, Vale wrote:
> > "Merciadri Luca" <merciadril...@gmail.com> ha scritto nel messaggio
> > news:bf873332-81d6-4c08-8219-
>
> b82e32fd3...@e21g2000vbl.googlegroups.com...
>
>
>
> > On May 18, 9:40 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> >> On Tue, 18 May 2010 12:23:14 -0700, Merciadri Luca wrote:
> >> > On May 18, 8:28 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> >> >> On Tue, 18 May 2010 10:56:56 -0700, Merciadri Luca wrote:
> >> >> > On May 18, 7:53 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> >> >> >> On Tue, 18 May 2010 10:49:02 -0700, Merciadri Luca wrote:
> >> >> >> > On May 18, 7:44 pm, Meat Plow <mhyw...@yahoo.com> wrote:
> >> >> >> >> Sorry to hear one BWS688 isn't working.
>

No problem. The fact is that I'm not an electronic guru, sure. Note
that I'm not Italian, and that I consequently can't write topics in
Italian.

Sorry Luca, your name & surname looks like just as mine, Italian.
Go ahead, get passionated in electronics and for shure you'll became as
expert as Meat Plow....
Can't help you with your gizmo, but it looks like it just doesn't transmit.
You will need some skill to investigate the power out RF stage as well as
the typical other basic circuits involved in p.s.
Good luck!

==============================================================================
TOPIC: technics amp SU-Z200 low volume problem
http://groups.google.com/group/sci.electronics.repair/t/9e0b05e00f883d65?hl=en
==============================================================================

== 1 of 3 ==
Date: Wed, May 19 2010 1:44 pm
From: b

On 19 mayo, 00:24, Franc Zabkar <fzab...@iinternode.on.net> wrote:
> On Tue, 18 May 2010 15:04:03 -0700 (PDT), b
> <reverend_rog...@yahoo.com> put finger to keyboard and composed:
>
> >It uses an STK 4152 II, pretty typical design of the period.
>
> FWIW, there is application circuit in the datasheet:http://www.datasheetarchive.com/pdf-datasheets/Datasheets-316/586035.pdfhttp://www.acust.narod.ru/files/PDF/STK4152.PDF

took a look at that, thanks. Unfortunately there is nothing connected
to the mute pin (6) on this amp, so that ruled out a relatively easy
line to pursue.
I've changed most of the caps around the subcircuits of the IC to no
avail. It's looking as if the IC is shot, and it seesm to be NLA.....
-B

== 2 of 3 ==
Date: Wed, May 19 2010 2:07 pm
From: Archon

On 5/19/2010 4:44 PM, b wrote:
> On 19 mayo, 00:24, Franc Zabkar<fzab...@iinternode.on.net> wrote:
>> On Tue, 18 May 2010 15:04:03 -0700 (PDT), b
>> <reverend_rog...@yahoo.com> put finger to keyboard and composed:
>>
>>> It uses an STK 4152 II, pretty typical design of the period.
>>
>> FWIW, there is application circuit in the datasheet:http://www.datasheetarchive.com/pdf-datasheets/Datasheets-316/586035.pdfhttp://www.acust.narod.ru/files/PDF/STK4152.PDF
>
> took a look at that, thanks. Unfortunately there is nothing connected
> to the mute pin (6) on this amp, so that ruled out a relatively easy
> line to pursue.
> I've changed most of the caps around the subcircuits of the IC to no
> avail. It's looking as if the IC is shot, and it seesm to be NLA.....
> -B
>
Ebay #380189378364

== 3 of 3 ==
Date: Wed, May 19 2010 2:13 pm
From: "Dave M"

Archon wrote:
> On 5/19/2010 4:44 PM, b wrote:
>> On 19 mayo, 00:24, Franc Zabkar<fzab...@iinternode.on.net> wrote:
>>> On Tue, 18 May 2010 15:04:03 -0700 (PDT), b
>>> <reverend_rog...@yahoo.com> put finger to keyboard and composed:
>>>
>>>> It uses an STK 4152 II, pretty typical design of the period.
>>>
>>> FWIW, there is application circuit in the
>>> datasheet:http://www.datasheetarchive.com/pdf-datasheets/Datasheets-316/586035.pdfhttp://www.acust.narod.ru/files/PDF/STK4152.PDF
>>
>> took a look at that, thanks. Unfortunately there is nothing connected
>> to the mute pin (6) on this amp, so that ruled out a relatively easy
>> line to pursue.
>> I've changed most of the caps around the subcircuits of the IC to no
>> avail. It's looking as if the IC is shot, and it seesm to be NLA.....
>> -B
>>
> Ebay #380189378364
>
> JC

Also available from Consolidated Electronics at
http://www.ceitron.com/semi/semi.phtml?part=STK4152

--
David
dgminala at mediacombb dot net

==============================================================================
TOPIC: Rega RB300 turntable...
http://groups.google.com/group/sci.electronics.repair/t/6fe769494aca3a1c?hl=en
==============================================================================

== 1 of 4 ==
Date: Wed, May 19 2010 2:11 pm
From: "Ian Iveson"

Roger Thorpe wrote:

> William Sommerwerck wrote:
>> Many turntables have a line resistor. It "does something"
>> (that I don't
>> understand) to improve speed stability. Or torque. Or
>> something. It's not to
>> reduce the line voltage.
>>
>>
> It's a while since I looked, and I could be wrong but:
> The Rega planar motor is a pair of multi pole two phase
> synchronous pancake motors sandwiched together with the
> poles interleaved.
> The resistor and capacitor are there to change the phase
> (lag or lead?) of one motor so that the assemlby turns in
> the right direction when it is started.
> Incidentally mine is a Rega 2 and the resistor burnt out
> too. A day after a short friendly 'phone conversation with
> the company the postman handed me an envelope containing a
> new resistor (with a higher power rating).
> --

I read it that the resistor is in series with the whole
motor. How could that introduce a relative phase shift
between the two halves?

I looked at the site someone linked to, at the circuit for a
simple synchronous motor. When a resistor is used to drop
the supply voltage, the value of the recommended cap remains
the same. I didn't mention phase, therefore, not because I
know it's not significant, but that I have no evidence to
suggest that a resistor in series makes any difference.

Motors are something of a black art, AFAIK. Two motors in
parallel sharing a cap and resistor is about as black as art
can get. How can a symmetrical circuit favour one direction?
In what way is the circuit not symmetrical? Are you sure
that direction isn't determined by geometry?

Actually, this isn't a good place to explain such a thing.
If you have a name for the type of motor arrangement, maybe
I could look it up?

Ian

== 2 of 4 ==
Date: Wed, May 19 2010 3:00 pm
From: "Ian Iveson"

"Jim Lesurf" <noise@audiomisc.co.uk> wrote in message
news:5119e3ce32noise@audiomisc.co.uk...
> In article
> <ht0nne$fa8$1@corncockle-nntp.csv.warwick.ac.uk>, Roger
> Thorpe
> <myinitial.mysurname@warwick.ac.uk> wrote:
>> William Sommerwerck wrote:
>> > Many turntables have a line resistor. It "does
>> > something" (that I
>> > don't understand) to improve speed stability. Or
>> > torque. Or something.
>> > It's not to reduce the line voltage.
>> >
>> >
>> It's a while since I looked, and I could be wrong but:
>> The Rega planar
>> motor is a pair of multi pole two phase synchronous
>> pancake motors
>> sandwiched together with the poles interleaved. The
>> resistor and
>> capacitor are there to change the phase (lag or lead?) of
>> one motor so
>> that the assemlby turns in the right direction when it is
>> started.
>
> That chimes with my understanding, based purely on having
> had to 'fix' a
> similar problem with a friend's Rega a few years ago.
> Haven't commented
> previously as I don't know the full details.

Now, since you have now commented, you *do* have the full
details, presumably?

> I just replaced the burnt out
> resistor with one rated at a higher power. And have since
> forgotten the
> value.

Oh...maybe not

> Must admit I was less than impressed with the circuit at
> the time. From
> this thread it does look like this resistor is prone to
> burning. Although
> perhaps that is made worse by the risk of the motor being
> stalled or
> loaded.

Perhaps? Certainly, surely?

Is it really likely, do you think, that the manufacturer
would continue to fit an inappropriate resistor for so long?
It's not like resistor power rating is complicated or
arcane. Cost difference can't be that significant, and
there's no shortage of space.

It would be interesting to know how the winding resistance
compares with the impedance of an up-to-speed motor. If the
difference is great enough, it could be that all those
burned-out resistors are a result of stalled motors or
increased drag, or even the fitting of heavy platters. It's
also possible that every burned-out resistor has saved a
motor winding, in which case a higher-rated resistor would
be a liability.

Ian

== 3 of 4 ==
Date: Wed, May 19 2010 2:44 pm
From: "Ian Iveson"

"PeterD" <peter2@hipson.net> wrote in message
news:61l7v5l6jvohh6pqk7d38gpk6oql1t4c3r@4ax.com...
> On Wed, 19 May 2010 12:33:27 +0100, "Ian Iveson"
> <IanIveson.home@blueyonder.co.uk> wrote:
>
>>Arfa Daily wrote:
>>
>>> Thanks Adam. It is indeed a Planar 3. I had in fact
>>> already been on that site, and seen the reference to the
>>> 150 ohm resistor. I suppose it's possible that there
>>> might
>>> be more than one value having been fitted over the life
>>> of
>>> production, because given 40 odd years of looking at
>>> burnt
>>> and discoloured resistor stripes, I definitely would not
>>> have said that the middle one was originally green, but
>>> who knows ? (well, hopefully someone on one of these
>>> groups does ! ) I was pretty sure that the first two
>>> were
>>> brown and red for 1- 2 - something. I was just concerned
>>> that if the final band was red, or even orange, I didn't
>>> want to be putting 120 ohms in there ...
>>
>>What's the resistor for? Assuming the motor draws tens of
>>mA
>>when running normally, the resistor would need to be a few
>>k
>>if its purpose is to drop from 240 to 120V.
>>
>>If it is to drop from UK mains to 220V, then 120 or 150
>>ohms
>>would be the right order of magnitude.
>
> Well the turntable draws about 4 watts according the the
> OP (or
> someone else in this thread). So that's 30 MA. To drop 120
> volts (240
> to 120)at that current and power you would have to use a
> resistor of
> 4K. But since half that power is the motor, and half is
> the resistor,
> twice the value (8K) is more appropriate. 120 ohms would
> result in a
> current draw at 120 volts of hundreds of watts!

I've read this a few times but....perhaps you misunderstood.
I was entertaining the theory that the 120 ohm resistor
drops the difference between 220V (or whatever the motor
hopes for) and UK mains, i.e. 10 or 15V, whatever it was
when the deck was made. If that difference has increased by,
say 25% from 12V to 15V, then the change that has been
mentioned, from 120 to 150 ohms, makes sense, roughly.
Everything that Arthur has said seems to fit this theory.
It's simple, too.

Anyway, as I understand it, Arthur's worried because if it's
supposed to be a much higher value, he might do some damage.
That's why I homed in on the voltage dropping issue.
Whatever else it might do, a resistor in series will
certainly drop voltage. If the value is much too low, then
it could result in a burnout. This is true whatever its
effect on direction, speed, torque and lots of other stuff I
don't know about but probably everyone else does but didn't
fancy saying so until now.

I wonder if he's tried it yet?

Ian

>>If an increase in
>>value is advisable, then that should reflect a
>>proportional
>>increase in the difference between 220 and UK mains, so an
>>increase from 120 to 150 ohms would be reasonable.
>>
>>It's common for motor drivers to use fuse resistors to
>>save
>>the motor from burning out if it stalls or jams. It could
>>be
>>that, in your case, the choice of resistor power rating
>>suitable for protecting the motor is such that the
>>resistor
>>runs habitually hot, and fails occasionally. I guess a
>>higher power rating, in combination with a higher
>>temperature coefficient, might protect the motor equally
>>well, whilst not burning out so quick under normal
>>conditions.

== 4 of 4 ==
Date: Wed, May 19 2010 6:23 pm
From: "Arfa Daily"

"Ian Iveson" <IanIveson.home@blueyonder.co.uk> wrote in message
news:RbZIn.6126$ea4.5138@newsfe29.ams2...
> Roger Thorpe wrote:
>
>> William Sommerwerck wrote:
>>> Many turntables have a line resistor. It "does something" (that I don't
>>> understand) to improve speed stability. Or torque. Or something. It's
>>> not to
>>> reduce the line voltage.
>>>
>>>
>> It's a while since I looked, and I could be wrong but:
>> The Rega planar motor is a pair of multi pole two phase synchronous
>> pancake motors sandwiched together with the poles interleaved.
>> The resistor and capacitor are there to change the phase (lag or lead?)
>> of one motor so that the assemlby turns in the right direction when it is
>> started.
>> Incidentally mine is a Rega 2 and the resistor burnt out too. A day after
>> a short friendly 'phone conversation with the company the postman handed
>> me an envelope containing a new resistor (with a higher power rating).
>> --
>
> I read it that the resistor is in series with the whole motor. How could
> that introduce a relative phase shift between the two halves?
>
> I looked at the site someone linked to, at the circuit for a simple
> synchronous motor. When a resistor is used to drop the supply voltage, the
> value of the recommended cap remains the same. I didn't mention phase,
> therefore, not because I know it's not significant, but that I have no
> evidence to suggest that a resistor in series makes any difference.
>
> Motors are something of a black art, AFAIK. Two motors in parallel sharing
> a cap and resistor is about as black as art can get. How can a symmetrical
> circuit favour one direction? In what way is the circuit not symmetrical?
> Are you sure that direction isn't determined by geometry?
>
> Actually, this isn't a good place to explain such a thing. If you have a
> name for the type of motor arrangement, maybe I could look it up?
>
> Ian
>
>

Ian. See my later post regarding the correct value, and how it all performed
when fitted. I think that I'm down the same road as Jim was when he did his
mate's one, and judging by what someone else said about Rega sending them a
shiny new resistor of increased power rating, that would seem to be the
right road, if their answer is also upping the rating from what they
originally designed in. Also, its primary function does seem to be that of a
simple dropper to get the 240v mains supply down to something closer to the
110v rating of the motor. My replacement R resulted in 240v in, 98v out
across the motor. I would say that the 0.22uF cap is there to introduce
phase shift between the two stacked windings, to ensure startup, and as
someone else suggested, correct rotational direction. I'm not sure that
stalling is a big current-draw issue for a synchronous motor like it would
be for AC or DC brushgear types. Anyone actually know ?

Arfa

==============================================================================
TOPIC: What caps is this?
http://groups.google.com/group/sci.electronics.repair/t/f138da91a9286cb2?hl=en
==============================================================================

== 1 of 7 ==
Date: Wed, May 19 2010 4:17 pm
From: Paul Conners

<http://i50.tinypic.com/14jtc0l.jpg>

Electrolytic? Tantalum?

Manufacturer? Data sheet?

Thanks.

== 2 of 7 ==
Date: Wed, May 19 2010 4:57 pm
From: Jeffrey D Angus

Paul Conners wrote:
> <http://i50.tinypic.com/14jtc0l.jpg>
>
> Electrolytic? Tantalum?
>
> Manufacturer? Data sheet?
>
> Thanks.
>
Siemens. At least from the trademark.
Possibly 1 UF at 40 VDC

Jeff

--
"Egotism is the anesthetic that dulls the pain of stupidity."
Frank Leahy, Head coach, Notre Dame 1941-1954

http://www.stay-connect.com

== 3 of 7 ==
Date: Wed, May 19 2010 4:57 pm
From: John Larkin

On Wed, 19 May 2010 16:17:22 -0700, Paul Conners
<pconners98@gUSmail.com> wrote:

><http://i50.tinypic.com/14jtc0l.jpg>
>
>Electrolytic? Tantalum?
>
>Manufacturer? Data sheet?
>
>Thanks.

Siemens logo.

John

== 4 of 7 ==
Date: Wed, May 19 2010 5:09 pm
From: Paul Conners

> Paul Conners wrote:
>> <http://i50.tinypic.com/14jtc0l.jpg>
>>
>> Electrolytic? Tantalum?
>>
>> Manufacturer? Data sheet?

> Siemens. At least from the trademark.
> Possibly 1 UF at 40 VDC
>
> Jeff

Type?

== 5 of 7 ==
Date: Wed, May 19 2010 6:25 pm
From: Jeff Liebermann

On Wed, 19 May 2010 17:09:05 -0700, Paul Conners
<pconners98@gUSmail.com> wrote:

>> Paul Conners wrote:
>>> <http://i50.tinypic.com/14jtc0l.jpg>
>>>
>>> Electrolytic? Tantalum?
>>>
>>> Manufacturer? Data sheet?
>
>> Siemens. At least from the trademark.
>> Possibly 1 UF at 40 VDC
>>
>> Jeff
>
>Type?

Nice photo. Dimensions would have been helpful.

My guess(tm) is Tantalum. It's not ceramic as it appears to be
polarized. It's not metalized film, for the same reason. It's too
small for electrolytic. That leaves tantalum.

Siemens sold their cazapitor division to EPCOS:
<http://www.epcos.com>
I couldn't find anything on the site resembling that capacitor.

I recall using similarly packaged caps back in the 1970's from Kemet.
I couldn't find any Epoxy B packaged tantalums on the Kemet site, but
there are similar packages with what looks like the right lead
spacing. See:
<http://www.kemet.com/kemet/web/homepage/kechome.nsf/weben/014FB383A945D0938525751600535A31/$file/F3296_ProductSelection.pdf#page=3>
and look for "Tantalum Molded Radial" on Page 7. If you have a
Digikey or Mouser printed catalog, you might want to skim through the
pages and see if there's something similar. I'm too lazy to do it
right now.

--
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

== 6 of 7 ==
Date: Wed, May 19 2010 8:17 pm
From: "Phil Allison"

"Paul Conners"

>>> <http://i50.tinypic.com/14jtc0l.jpg>
>>>
>>> Electrolytic? Tantalum?
>>>
>>> Manufacturer? Data sheet?
>
>> Siemens. At least from the trademark.
>> Possibly 1 UF at 40 VDC
>>
>
> Type?

** Looks very much like some German made " long life " electros I see in
audio equipment made by Quad in the UK in the late 1970s and 1980s. Normal
electros, airtight sealed in a plastic housing.

Funny thing is, they nearly all failed ( high ESR or open) after 10 to 15
years.

.... Phil

== 7 of 7 ==
Date: Wed, May 19 2010 10:05 pm
From: Paul Conners

> Nice photo.

Thank you Canon! (A620, handheld.)

> Dimensions would have been helpful.

7 mm H, 4 mm W & D.

> My guess(tm) is Tantalum. It's not ceramic as it appears to be
> polarized. It's not metalized film, for the same reason. It's too
> small for electrolytic. That leaves tantalum.

Being molded plastic, does this automatically rule out electrolytic?

> Siemens sold their cazapitor division to EPCOS:

>
<http://www.kemet.com/kemet/web/homepage/kechome.nsf/weben/014FB383A945D093852

> 5751600535A31/$file/F3296_ProductSelection.pdf#page=3>
> and look for "Tantalum Molded Radial" on Page 7.

Resemblance? Color?

The originals are black and beveled at the front corners. None of these are.
Other than physical, not much to go on...

Thanks.

==============================================================================
TOPIC: Warrior PA ...
http://groups.google.com/group/sci.electronics.repair/t/d16e1cfd9002a7f7?hl=en
==============================================================================

== 1 of 1 ==
Date: Wed, May 19 2010 6:26 pm
From: "Arfa Daily"

Bit of a long shot, but has anyone by any chance got shematics for a Warrior
IS 1000 PA amp ? I've currently got a query in this regard out with the
importers, but I'm not holding my breath ...

TIA

Arfa

==============================================================================
TOPIC: Allah, CREATED THE UNIVERSE FROM NOTHING
http://groups.google.com/group/sci.electronics.repair/t/d304b0e66e9026f0?hl=en
==============================================================================

== 1 of 2 ==
Date: Wed, May 19 2010 7:13 pm
From: Mark Allread

Jeff Liebermann wrote:
> On Mon, 17 May 2010 15:02:14 -0500, Jeffrey D Angus
> <jangus@suddenlink.net> wrote:
>
>> Jeff Liebermann wrote:
>>> Anyway, this is really 4th of Sivan, 5770 years after creation.
>>
>> So we don't have to worry about Y6K for another 230 years then?
>
> We've been through 5 similar Y2K type events in the past, so a 6th one
> should not be a problem.
>
> However, I think you might enjoy the Hebrew calendar's "leap months"
> <http://en.wikipedia.org/wiki/Hebrew_calendar#Leap_months>
> which features 12 years with 12 months, and then 7 years with 13
> months.
>
>> Probably the same people that elected this guy:
>> http://www.youtube.com/watch?v=u1WSs9B4H5s
>
> I noticed that the audience didn't react to his comment, which
> suggests that they were either asleep, or that such comments were
> fairly normal and nothing unusual.
>
When I hear dogs barking, I don't bark back.
I wouldn't have seen that post, but for you replying to it.
Now I'll have to add you to my filter as well.

== 2 of 2 ==
Date: Wed, May 19 2010 8:48 pm
From: Jeff Liebermann

On Wed, 19 May 2010 19:13:38 -0700, Mark Allread <markA@once.org>
wrote:

>When I hear dogs barking, I don't bark back.

That's because you're not a werewolf:
<http://802.11junk.com/jeffl/pics/jeffl/slides/jeffl-wolf.html>
(Give it some time to load).

>I wouldn't have seen that post, but for you replying to it.

I hate to tell you this, but I trimmed the original boring rant about
Allah. Only "Sparky" didn't have the sense to trim the massive
quotes. Please complain to the original poster or to "Sparky".

Hopefully, you're not referring to my comments about the Hebrew
calendar leap months.

>Now I'll have to add you to my filter as well.

Be sure to add both jeffl@cruzio.com and jeffl@comix.santa-cruz.ca.us
to your filter. I also use a gmail.com account but not in
sci.electronics.repair.

--
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

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