sci.electronics.repair - 25 new messages in 8 topics - digest

sci.electronics.repair
http://groups.google.com/group/sci.electronics.repair?hl=en

sci.electronics.repair@googlegroups.com

Today's topics:

==============================================================================
TOPIC: AVO 8 Mk 4 ...
http://groups.google.com/group/sci.electronics.repair/t/a0ca6d125e6a7e97?hl=en
==============================================================================

== 1 of 4 ==
Date: Sun, Apr 3 2011 12:31 am
From: Ian Jackson

In message <vCPlp.3200$Dj5.343@newsfe10.ams2>, Arfa Daily
<arfa.daily@ntlworld.com> writes
>
>
>"Robin" <see@sig.sep> wrote in message
>news:iaHlp.2408$Ir.2384@newsfe13.ams2...
>>> I just went and looked at a BAMA mirror site, and lo ! I have found a
>>> file that says it's for the Mk IV. I've downloaded it, but now need
>>> to find some software to open it. It says that it is .DJVU format ??
>>>
>> The site has links to viewers: see eg
>>http://bama.edebris.com/manuals/avo FWIW I use Irfan. And you will
>>need then the djvu plug-in (from the same site). But I am sorry to
>>have to tell you that if you have downloaded mk4elect.djvu it is the
>>manual for the Avo Electronic Testmeter Mark 4. (I know 'cos I got
>>some of my manuals from BAMA and looked there yesterday when you
>>first asked: I am *really* looking for excuses not to get back to
>>crawling around in the loft!)
>>
>> -- Robin
>> PM may be sent to rbw0{at}hotmail{dot}com
>>
>
>I got me a viewer (I actually have Irfan as well, but didn't realise it
>did these djvu's) and yes, you are quite right, it is the wrong one,
>even though it appears to be listed as one of the 8's. Anyways, meter
>is now fixed - see my later post ! :-)
>
You can get your own DJVU maker (+viewer) here (and several other
interesting things):
http://www.tuberadio.it/
http://www.tuberadio.it/utils.htm
http://www.tuberadio.it/download/dvs31.exe
--
Ian

== 2 of 4 ==
Date: Sun, Apr 3 2011 5:53 am
From: "Ian Field"

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:vCPlp.3200$Dj5.343@newsfe10.ams2...
>
>
> "Robin" <see@sig.sep> wrote in message
> news:iaHlp.2408$Ir.2384@newsfe13.ams2...
>>> I just went and looked at a BAMA mirror site, and lo ! I have found a
>>> file that says it's for the Mk IV. I've downloaded it, but now need
>>> to find some software to open it. It says that it is .DJVU format ??
>>>
>> The site has links to viewers: see eg http://bama.edebris.com/manuals/avo
>> FWIW I use Irfan. And you will need then the djvu plug-in (from the same
>> site). But I am sorry to have to tell you that if you have downloaded
>> mk4elect.djvu it is the manual for the Avo Electronic Testmeter Mark 4.
>> (I know 'cos I got some of my manuals from BAMA and looked there
>> yesterday when you first asked: I am *really* looking for excuses not to
>> get back to crawling around in the loft!)
>>
>> --
>> Robin
>> PM may be sent to rbw0{at}hotmail{dot}com
>>
>
> I got me a viewer (I actually have Irfan as well, but didn't realise it
> did these djvu's)

Can't remember the exact reason why I stopped using Irfanview for DJVU and
went back to the original publishers browser pluggin but the most recent
download of DJVU certainly works much better than earlier versions.

== 3 of 4 ==
Date: Sun, Apr 3 2011 5:59 am
From: "Ian Field"

"H. Neary" <£££nearyh£££@clara.co.uk> wrote in message
news:10jfp69d6r5mh7p469i0cuas3igjo2aa7a@4ax.com...
> On Sun, 3 Apr 2011 02:02:32 +0100, "Arfa Daily"
> <arfa.daily@ntlworld.com> wrote:
>
>>
>>
>>"Meat Plow" <mhywattt@yahoo.com> wrote in message
>>news:pan.2011.04.02.17.56.07@lmao.lol.lol...
>>> On Sat, 02 Apr 2011 10:45:22 +0100, Arfa Daily wrote:
>>>
>>>> "Meat Plow" <mhywattt@yahoo.com> wrote in message
>>>> news:pan.2011.04.01.21.02.25@lmao.lol.lol...
>>>>> On Fri, 01 Apr 2011 21:46:53 +0100, Arfa Daily wrote:
>>>>>
>>>>>> "Robin" <see@sig.sep> wrote in message
>>>>>> news:97olp.1305$bT6.318@newsfe05.ams2...
>>>>>>> Arfa Daily wrote:
>>>>>>>> Anybody got a copy of the schematic that's in the back of the user
>>>>>>>> guide that they can scan for me, please ? I've searched all my
>>>>>>>> files
>>>>>>>> and drawers high and low, and can't find my book anywhere ... I
>>>>>>>> thought that the 'net would be awash with copies of the schematic,
>>>>>>>> but it seems only for the Mk 2, which is totally different to the
>>>>>>>> MK
>>>>>>>> 4. TIA
>>>>>>>>
>>>>>>> Is it the circuit diagram at
>>>>>>> http://www.radiomuseum.org/r/avo_universal_avometer_8_mk_i.html ?
>>>>>>> (Registration necessary for download. I have not done it as mine's
>>>>>>> a
>>>>>>> Mk II.)
>>>>>>> --
>>>>>>> Robin
>>>>>>> PM may be sent to rbw0{at}hotmail{dot}com
>>>>>>>
>>>>>>>
>>>>>> Hi Robin, thanks for that. It would appear to be the correct one.
>>>>>> Looks as though you need to pay to become a member, so I will hold
>>>>>> off
>>>>>> for now until all the feelers that I have out, run dry. It's really
>>>>>> annoying because I have owned the meter from new when I was an
>>>>>> apprentice, and I have the book, which has the schematic in it,
>>>>>> carefully filed away somewhere, but I'm buggered if I can now find
>>>>>> it.
>>>>>> It is in a box file, but said boxfile is not where I know it should
>>>>>> be. Even more annoying is that I have damaged the meter by my own
>>>>>> stupidity, so now have the need to fix it ... :-(
>>>>>>
>>>>>> Arfa
>>>>>
>>>>> That's too bad. I have some old gear I used as an apprentice that have
>>>>> a high value in the nostalgia department. An old EICO 232 VTVM, B&K
>>>>> 1801 freq. counter, Beckman Tech 310 DVM, Amprobe Amp Clamp and some
>>>>> other things that I can't think of right now.
>>>>>
>>>>>
>>>>>
>>>>>
>>>> Yes, Meat. It's very frustrating. I cut my 'professional' teeth with
>>>> that meter, and it has served me faithfully over the years without
>>>> serious mishap. It is still in weekly use, but not quite the daily use
>>>> that it once was. For some types of repair, the swinging needle of a
>>>> quality instrument like this, is so much more appropriate than a
>>>> digital
>>>> type ...
>>>>
>>>> Arfa
>>>>> --
>>>
>>> I got used to the LCD after using one for 25 years but it took awhile
>>> after using the EICO and a Simpson. The Beckman 310 was the first LCD I
>>> owned. I found a benchtop Beckman with LED's back in the 90's I used for
>>> several years before it failed beyond repair. Now using my faithful
>>> Fluke
>>> 77. This is one that had a touch hold button in the middle of the
>>> selector. It's hard to put aside the tools you've learned to trust after
>>> decades.
>>>
>>>
>>
>>Indeed it is. I have a hand portable DMM that is now the main workshop
>>workhorse, and I am very easy with it. I also have a bench true RMS 6
>>digit
>>job that is used fairly rarely. The AVO still gets used where I feel it is
>>the appropriate instrument for the job. I tend to be happier using it
>>around
>>tube circuitry for measuring volts, and I prefer its ohms ranges for
>>measuring semiconductor junctions, even though the DMM has a diode test
>>facility
>>
>>Arfa
>
> It's what you are used to. I started out with an AVO 7 I think it
> was 500 Ohms per Volt. It certainly had an effect on circuits even in
> the days before CMOS.
>
> I could turn on transistors and generally interact with circuits using
> it. Although a tool no doubt aimed at Electrical Engineers it proved a
> useful diagnostic instrument in an electronics environment.
>
> Oddly enough the AVO eight was potentially more accurate than todays
> digital afferings. At 20 K to the Volt, The AVO took half the current
> of the modern DMM.
>
> It was a dashed big needle to shift too.
>
>
> My gripe with the AVO was that although it was a robust instrument,
> you could buy around fifteen less robust meters for the same price.
> Similar accuracy, smaller scale though and at a major price reduction.
> Plus of course the fact that you could buy batteries to keep the Ohm
> fires burning at your local newsagent. I seem to recollect tht The AVO
> needed some kind of battery / inverter replacement when Ever Ready
> stopped producing their very expensive box of volts.

Had that problem with my Taylor meter - I wound a blocking oscillator coil
on a small toroid and simply shunted the output with a 30V zener, its
connected via a pushbutton to the 1.5V low Ohms battery.

== 4 of 4 ==
Date: Sun, Apr 3 2011 6:08 am
From: "Ian Field"

"Windmill" <spam-no-spam@Onetel.net.uk.invalid> wrote in message
news:LJ29u8.5vD@freebie.onetel.net.uk...
> Mike Tomlinson <mike@jasper.org.uk> writes:
>
>>In article <5Rqlp.4508$o81.2161@newsfe28.ams2>, Arfa Daily
>><arfa.daily@ntlworld.com> writes
>>> Even more annoying is that I have damaged the
>>>meter by my own stupidity
>>Measured the resistance of the mains?
>
> You too, eh?
> But they are indeed tough beasts; apart from a shaky ohms-adjust pot
> it's still working 25 years later.
>
> Doubtful if you could do that with a modern DVM and get away with it.

My first ever DMM was fished out of the bin where I worked at the time, Ohms
& ACV didn't work.

When I opened it there was an OP-AMP in the middle of the PCB - it was sort
of easiest to try replacing that and it actually fixed the fault!

The employer very kindly loaned me a recently calibrated instrument and an
assortment of adjustable PSUs and resistance decade boxes so I could make
the neccessary adjustments to the presets next to the OP-AMP.

I still have it but its been relegated to the shed for occasional automotive
work.

==============================================================================
TOPIC: Foregoing warranty rights
http://groups.google.com/group/sci.electronics.repair/t/db33289fb500ca5c?hl=en
==============================================================================

== 1 of 13 ==
Date: Sun, Apr 3 2011 1:11 am
From: Jeff Urban

"The rounded corner distributes the inpact load over a larger
area of the case than it would if it were more box shaped."

You are an engineer somewhere ? I am not being sarcastic, maybe you
should be if you aren't. That's the way to think. Look at how some
things, bigger things are built. You might scratch your head and say "
What, did they think it was going to fall up ? ". Well that is exactly
what they were thinking.

I can design simple stuff, test fixtures and all that, apply a signal
and watch the result through a current resistor, shit like that, but I
am not an employable engineer, except by myself and a few others. But
I can think of it from their viewpoint. All they care is get it on the
shelves intact working and sellable. After that the minimum warranty
possible, anything goes under US law. Got to watch it in Europe, their
governments seem to work for the people there. We're working on that.
But the US government works for us.

Think I'm fucking kidding ?

== 2 of 13 ==
Date: Sun, Apr 3 2011 5:08 am
From: "William Sommerwerck"

> Best one IMHO was the directions I got
> with a stainless steel coffee percolator:
> "Do Not Use In A Microwave Oven."

That isn't quite so stupid as it sounds. Even though I had a good grasp of
electronics as a teenager, I didn't understand this.

== 3 of 13 ==
Date: Sun, Apr 3 2011 5:29 am
From: "Geoffrey S. Mendelson"

William Sommerwerck wrote:

> That isn't quite so stupid as it sounds. Even though I had a good grasp of
> electronics as a teenager, I didn't understand this.

I can understand this, but anyone born after 1970 probably had their bottles
heated in a microwave and have grown up with one. That makes it likely
that they were taught as infants you never put metal into a microwave,
and although there are some exceptions (they probably don't know them)

In fact, anyone with a computer capable of playing youtube videos or a tv
with the discovery channel has seen the effect of a microwave on a CD.

On the other hand, a coffee percolator is not a young person's device,
only people who drank their coffee before Mr. Coffee, Melita filters,
and Starbucks would even think of using one. I'm sure there are a lot of
older people out there who would buy one but have never quite grasped
the concept of no metal in a micro. :-)

Geoff.

--
Geoffrey S. Mendelson N3OWJ/4X1GM
Those who cannot remember the past are condemned to misquote it.

== 4 of 13 ==
Date: Sun, Apr 3 2011 5:32 am
From: "William Sommerwerck"

> Why is it that no maker ever gives advice on what to do
> if your pocket digital wonder gets accidentally immersed
> or suffers a spillage?

It's common knowledge in the electronics industry that if the "soiled" item
is thoroughly flushed in/with distilled water, then allowed to dry (or
forcibly dried), it will often recover. If the manufacturer advises the
consumer to do this, and the device remains dead, the manufacturer could
find itself liable for a free replacement. * In many cases, a customer could
visit the nearest cell phone store and get a replacement in less time.

Nikon once ran an ad about a photographer in India who'd accidentally dunked
his F. He carried it some distance in a bucket of fresh water (which was
then standard for photo equipment -- you kept the camera wet until you got
it to a service tech), periodically removing it to snap a shot! (It's not
clear how the film survived this treatment.)

Almost 30 years ago, while on a canoe trip, my Olympus XA got completely
immersed. I immediately bought another one, but I discovered -- several
years later -- that it still worked! And it still is working! It didn't rust
or corrode. Amazing. Structural plastics -- ya gotta love 'em.

* About 15 years ago, I took my HP 4M into work, because we were doing so
much printing there weren't enough printers to go around. (The company later
bought me a replacement toner cartridge.) As I was carrying it out of my
apartment, the paper tray came loose and crashed on the concrete steps,
breaking. This was around the time of a major California earthquake, and HP
had run an ad telling how another model of laser printer had fallen to the
floor without damage. I pointed out that HP couldn't very well use this fact
as an inducement to buy their products, then object when I asked for a
replacement tray that had been subjected to similar abuse. After some
haggling, I was sent a slightly used tray at no charge.

== 5 of 13 ==
Date: Sun, Apr 3 2011 7:34 am
From: "William Sommerwerck"

> On the other hand, a coffee percolator is not a young person's device,
> only people who drank their coffee before Mr. Coffee, Melita filters,
> and Starbucks would even think of using one. I'm sure there are a lot of
> older people out there who would buy one but have never quite grasped
> the concept of no metal in a micro. :-)

Actually, modern microwaves are more tolerant. You can put a metal tray in a
microwave, and nothing bad will happen.

The issue isn't metal, per se -- a metal plate reflects microwaves as the
cavity walls do -- but sharp spots at which the field intensity is so high
that you get corona discharge or arcing.

I once put a jar of Adam's peanut butter in the microwave to warm it -- and
you should have seen the arcing at the tiny -- really tiny -- bits of
aluminum that were left on the lip from the seal.

== 6 of 13 ==
Date: Sun, Apr 3 2011 9:25 am
From: Jeff Liebermann

On Sun, 3 Apr 2011 01:11:21 -0700 (PDT), Jeff Urban
<jurb6006@gmail.com> wrote:

>"The rounded corner distributes the inpact load over a larger
>area of the case than it would if it were more box shaped."
>
>You are an engineer somewhere ?

Yep. Wit out mah spellin chequer, I kin spel just like an engineer.
<http://www.linkedin.com/pub/jeff-liebermann/0/823/151>

>I am not being sarcastic, maybe you
>should be if you aren't. That's the way to think.

Thanks. The down side of being an engineer is the bad habit of
looking at any product and thinking that it could have been designed
better. For example, the doctor recommended I get some exercise. So,
I bought a bicycle, then another, etc, until I now have far too many
bicycles:
<http://802.11junk.com/jeffl/pics/bicycles/index.html>
Instead of riding them, I've been looking at the way they work, and
the way the components are designed. I've read some books on design,
researched patents, performed my own repairs, rebuilt a few bikes, and
pondered the logic behind the designs. Of course, I think I can do
better and have designed and built a few experimental components that
I might eventually sell. The problem is, I'm so busy analyzing the
bicycles, I don't have much time left to actually ride them. According
to the bicycle computah, I've only ridden about 100 miles in the last
3 months.

>Look at how some
>things, bigger things are built. You might scratch your head and say "
>What, did they think it was going to fall up ? ". Well that is exactly
>what they were thinking.

Yep. However, that's not exactly the way I do it. I think "What
problem were they trying to solve"? If you understand the motivation,
you usually understand the rational. That's often difficult when
dealing with industrial design and artistic concerns. The problem may
have been nothing more than product differentiation, or trying to look
sufficiently different than the rest of the pack. For example, the
rounded corners have many potential benefits besides surviving a drop
test. Rounded corners appeal more to women, while men prefer more
angular products. It's easier to mold parts with rounded angles, than
with angular corners. It may have been simply functional, so that the
iPhone doesn't rip one's pocket or purse liner. It might have been
human factors, where talking on a phone with a sharp edge digging into
one's palm, is not exactly ergonomic.

>I can design simple stuff, test fixtures and all that, apply a signal
>and watch the result through a current resistor, shit like that, but I
>am not an employable engineer, except by myself and a few others.

Welcome to the age of specialization. It's a dangerous place to be as
when your specialty is suddenly exported overseas, you're potentially
unemployable. I saw the problem early. Officially, I was an RF
engineer. However, I made the effort to get experience in many
adjacent fields, and bounced around the company doing almost
everything. Hint: avoid specialization.

>But
>I can think of it from their viewpoint.

You need to attend a few product brainstorming and subsequent design
review meetings to really understand how things work. Reverse
engineering is possible only if the motivations that inspired the
designs are logical. I've seen designs that were based on faulty
marketing, bad guesses as to user needs, managerial egos, and simple
stupidity. The designs that worked and sold were deemed brilliant.
Those that failed were deemed, ummm.... something else. For example,
the first incantation of the iPod player, was the Diamond Rio:
<http://en.wikipedia.org/wiki/Rio_PMP300>
which pre-dated the iPod by about 3 years. It was very similar to the
iPod, but instead was a flop. There were many problems, but the big
one as that Apple solved the legal issues prior to release, while
Diamond did not. Diamond spent the initial years fighting lawsuits,
while Apple had already made a deal with the recording industry. You
could not have determined any of this just looking at the product and
trying to reverse engineer the logic behind the design.

>All they care is get it on the
>shelves intact working and sellable.

Nope. I could easily design almost anything that will appear on the
shelf and be sellable. The trick is to make it profitable for
everyone involved. There's also litigation avoidance, bad press,
timing, reviews, distribution, warehousing, shipping, promotion, ad
infinitum that has to be dealt with. Those are often more difficult
and time consuming than the product design. I recall several product
launches that had to be delayed because of some obscure problem, such
as wrong wording on the legal disclaimers page/book or failure to
display some certification agency's logo with the proper font size.

I've worked on several products where the initial product design took
about 2 weeks. Prototypes and troubleshooting added another 3 weeks.
However, getting it into production, out the door, and into the hands
of paying customers, took an additional 30 weeks, little of which had
much to do with the initial design. In effect, the design was
"frozen" after 2 weeks.

>After that the minimum warranty
>possible, anything goes under US law. Got to watch it in Europe, their
>governments seem to work for the people there. We're working on that.
>But the US government works for us.

Not really. If you were ever to do your own product, you'll soon find
that the legal system heavily favors the plaintiff. In Europe, court
costs are paid by the loser, so there's a tremendous counter incentive
to solving problems by litigation. In the US, it's paid by both
parties, meaning that even if you prevail in court, you can easily
lose your potential profits or the company to the legal costs. Product
liability, tort reform, and patent law all currently favor the
"injured" party in the US.

>Think I'm fucking kidding ?

Yes, because engineers don't talk or write like that.

--
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

== 7 of 13 ==
Date: Sun, Apr 3 2011 9:40 am
From: Jeff Liebermann

On Sun, 3 Apr 2011 07:34:19 -0700, "William Sommerwerck"
<grizzledgeezer@comcast.net> wrote:

>Actually, modern microwaves are more tolerant. You can put a metal tray in a
>microwave, and nothing bad will happen.

Yep. Some come with metal racks:
<http://en.wikipedia.org/wiki/File:Microwave_metal_shelf.JPG>
As long as there is something inside the oven cavity that will ABSORB
the RF power, it's safe. Take away the absorber, such as with an
empty microwave oven, and the resultant standing waves will build up a
sufficiently large field to initiate arcing.

Of course, put anything, except food, in a microwave oven, and your
warranty is torched.

--
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

== 8 of 13 ==
Date: Sun, Apr 3 2011 9:48 am
From: "William Sommerwerck"

> As long as there is in the oven that will ABSORB
> the RF power, it's safe. Take away the absorber,
> such as with an empty microwave oven, and the
> resultant standing waves will build up a sufficiently
> large field to initiate arcing.

Even with something to absorb the energy, you can still get arcing from
sharp metal edges.

== 9 of 13 ==
Date: Sun, Apr 3 2011 4:15 pm
From: David Nebenzahl

On 4/3/2011 5:29 AM Geoffrey S. Mendelson spake thus:

> William Sommerwerck wrote:
>
>> That isn't quite so stupid as it sounds. Even though I had a good grasp of
>> electronics as a teenager, I didn't understand this.
>
> I can understand this, but anyone born after 1970 probably had their bottles
> heated in a microwave and have grown up with one. That makes it likely
> that they were taught as infants you never put metal into a microwave,
> and although there are some exceptions (they probably don't know them)

So--and this is completely out of left field, I know--what would happen
if a guy put a vacuum tube--say a biggish octal one, like a 5Y3 or a
6V6--into a microwave and nuked it?

I've nuked CDs and derived many seconds of amusement from that ...

--
The current state of literacy in our advanced civilization:

yo
wassup
nuttin
wan2 hang
k
where
here
k
l8tr
by

- from Usenet (what's *that*?)

== 10 of 13 ==
Date: Sun, Apr 3 2011 3:42 pm
From: "William Sommerwerck"

> So--and this is completely out of left field, I know -- what
> would happen if a guy put a vacuum tube -- say a biggish
> octal one, like a 5Y3 or a 6V6 -- into a microwave and
> nuked it?

You'd certainly get arcing from the pins. It's not obvious (to me) how the
tube's elements would react.

== 11 of 13 ==
Date: Sun, Apr 3 2011 5:43 pm
From: David Nebenzahl

On 4/3/2011 3:42 PM William Sommerwerck spake thus:

>> So--and this is completely out of left field, I know -- what
>> would happen if a guy put a vacuum tube -- say a biggish
>> octal one, like a 5Y3 or a 6V6 -- into a microwave and
>> nuked it?
>
> You'd certainly get arcing from the pins. It's not obvious (to me) how the
> tube's elements would react.

Ah, I forgot about the pins. OK, let's say we really have too much time
on our hands and want to continue the experiment, so we get something to
plug the tube into, say a pin straightener, with no exposed metal. What
then?

(What I'm hoping for, of course, is some kewl effect, like that purplish
glow you sometimes see emanating from the plates of overdriven tubes ...)

--
The current state of literacy in our advanced civilization:

yo
wassup
nuttin
wan2 hang
k
where
here
k
l8tr
by

- from Usenet (what's *that*?)

== 12 of 13 ==
Date: Sun, Apr 3 2011 4:52 pm
From: "Phil Allison"

"William Sommerwanker is a lying ASS"

>> Why is it that no maker ever gives advice on what to do
>> if your pocket digital wonder gets accidentally immersed
>> or suffers a spillage?
>
> It's common knowledge in the electronics industry...

** How would a bullshitting puke like you know anything of the sort ?

> that if the "soiled" item
> is thoroughly flushed in/with distilled water, then allowed to dry (or
> forcibly dried), it will often recover. If the manufacturer advises the
> consumer to do this, and the device remains dead, the manufacturer could
> find itself liable for a free replacement.

** Total BOLLOCKS.

..... Phil

== 13 of 13 ==
Date: Sun, Apr 3 2011 5:05 pm
From: "William Sommerwerck"

> What I'm hoping for, of course, is some kewl effect, like
> that purplish glow you sometimes see emanating from
> the plates of overdriven tubes...

Unfortunately, there's no gas in a "vacuum" tube to glow.

==============================================================================
TOPIC: LJ44-00092C
http://groups.google.com/group/sci.electronics.repair/t/aadca16cb07e5e34?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Apr 3 2011 3:05 am
From: "Arfa Daily"

"Eike Lantzsch, ZP6CGE" <eikelan@gmx.net> wrote in message
news:slrnipesl4.plr.eikelan@ID-77364.user.individual.net...
> eltron wrote:
>> Hello guys,
>> Please i need your assistance with this board [Samsung, LJ44-00092C].
>> There is a voltage shortage at VG out =15volt and D5v out =5.2v. The
>> current voltage i have here coming out from VG=15volt is 13volt and
>> D5v=5.2volt is 3volt. Every other dc outlets are outputing perfectly
>> fine. I have changed the voltage regulators 7815 for 15volt and
>> Lm2576t which is responsible for 5volt but yet i still get the same
>> 13volt and 3volt out. Can someone tell me what exactly is responsible
>> for this shortage? i'll really welcome your contributions.
>> Thanks guys hope to hear from you sooner.
>> eltron.
>
> I don't know the board.
> What is the input voltage for the regulators? I guess it's about 13V and
> 3V -
> so no regulation. Is it a switched PS? If switched is the chopper a
> push-pull arrangement or single ended? Is the transformer hot? Is there
> extreme ripple on the input voltages of the regulators? Is there a
> thermistor in series with the line input? Are both regulators on the
> same rectifier or do they have their own transformer winding, rectifier
> and capacitor? Last but not least: Do you operate a 230V PS on 120V?
> Not enough data to suggest a solution.
>
> Kind regards, Eike

I agree that the input voltages to those regulators are probably low, and
that the most likely cause, is a bad filter cap on a (shared ?) source rail.

Arfa

==============================================================================
TOPIC: Recommendation for electronics forums?
http://groups.google.com/group/sci.electronics.repair/t/a2a97ca7806d8277?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Apr 3 2011 3:42 am
From: Wiebe Cazemier

Michael A. Terrell wrote:

>
> Wiebe Cazemier wrote:
>>
>> Michael A. Terrell wrote:
>>
>> >> >> >>
>> >> >> >> > The subject of my current research is the ins and
>> >> >> >> > outs of op amps.
>> >> >> >>
>> >> >> >> A little pun, there?
>> >> >> >
>> >> >> > A bit bipolar, if you ask me...
>> >> >>
>> >> >> I dunno, but then again I may be biased.
>> >> >
>> >> >
>> >> > I figured that you were a little off center. :)
>> >> >
>> >> >
>> >>
>> >> Now that's unfair feedback :)
>> >
>> >
>> > Not if you're at unity gain... :)
>>
>> But then you'll run into oscillation
>
>
> Everyone needs to exercise. :)

To obtain a higher slew-rate?

==============================================================================
TOPIC: Need help finding/ordering part
http://groups.google.com/group/sci.electronics.repair/t/fc9a03cc9eeb828c?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Apr 3 2011 1:30 pm
From: tnom@mucks.net

I'm trying to repair a IR remote receiver. Have found what could be
the problem. Will replace two front end transistors.

The markings are a follows: TO 92 case, "KSP" top line, "10" second
line, "-238" bottom line, or perhaps KSP10-238 ?

Any ideas where I can find or order these? I have googled it and
can only find KSP10 No mention of -238 so I am not sure of how
to positively identify these two transistors.

Any help would be appreciated.

==============================================================================
TOPIC: Underwater Strobe Schematics (Sea & Sea YS-27DX)
http://groups.google.com/group/sci.electronics.repair/t/1b70462f9a3c462d?hl=en
==============================================================================

== 1 of 2 ==
Date: Sun, Apr 3 2011 2:08 pm
From: Chairman WAPSAC

I'm hoping someone can help here.

I have a dead Sea & Sea YS-27DX strobe. The strobe flooded and subsequently let out all the smoke making the circuit work!. I appreciate that the damage may in fact be catastrophic but I'll have a go at fixing it anyway!

The problem is I don't have any schematics. Sea & Sea won't respond to my requests for schematics (no surprise there then). So I'm wondering if anyone has a schematic for this unit?

Thanks,

Ian

== 2 of 2 ==
Date: Sun, Apr 3 2011 3:13 pm
From: "William Sommerwerck"

You might be able to fix it by (forgive me!) shotgunning the likely
components.

I assume the unit has been thoroughly flushed with distilled water and
dried, and that you have cleaned/checked all the switches. The transformer
should be to see if it's open or shorted.

The caps and the semiconductors would be a good place to start.

==============================================================================
TOPIC: DTV question [minor]
http://groups.google.com/group/sci.electronics.repair/t/d8b62bf63e76e1c5?hl=en
==============================================================================

== 1 of 2 ==
Date: Sun, Apr 3 2011 3:50 pm
From: David Nebenzahl

So one of my local TV stations seemingly stopped sending program
information data--you know, the text that says what's on, what's going
to be on, and explaining in more detail what's on. Landing on that
channel, display simply showed "- No program information -". (BTW, this
seems to be the default for all of the minor little public TV stations
around here, not including the big PBS stations which are diligent about
supplying this information.)

OK, no big deal, but slightly annoying, so I fired off an email to the
station, alerting them to this situation and asking them if this was due
to an omission at their end. (I confess I really don't know what that
information is called, or how it gets supplied at their end. All I know
is that it is somehow transmitted as part of the DTV datastream.)

Well, a day or two later, the program information started appearing for
that station. I figured it *might* have been on account of my email--big
slaps on the back for me as an Alert Citizen!--but since they hadn't
replied, I had no way of knowing.

Then a couple days after that I got a reply back. The station's
operations manager wrote and told me that they (the station) was
supplying that information, and therefore if I wasn't seeing it, it was
probably due to a problem at my end. He suggested doing a complete
rescan (not an "update scan") on my DTV box.

I wrote back, and he replied to that. Here's what he said, in part:

> Nothing changed on our end. However it is not unheard of for
> set-top-boxes to need to reload the PSIP tables for a channel once in a
> while. Forcing a rescan forces the tables to reload. Eventually they
> will usually reload on their own which is probably what happened in your
> case.

(I had done nothing to my DTV box this whole time.)

So does anyone know if this is correct? Now there's another station (one
of the big networks, not a local independent) that's missing its program
info. Is it possible that my DTV box would selectively omit this
information for just one or a few stations? Every other station shows
this info for me, with the exceptions noted above.

--
The current state of literacy in our advanced civilization:

yo
wassup
nuttin
wan2 hang
k
where
here
k
l8tr
by

- from Usenet (what's *that*?)

== 2 of 2 ==
Date: Sun, Apr 3 2011 3:10 pm
From: "William Sommerwerck"

> I wrote back, and he replied to that. Here's what he said, in part:

>> Nothing changed on our end. However it is not unheard of for
>> set-top-boxes to need to reload the PSIP tables for a channel once in a
>> while. Forcing a rescan forces the tables to reload. Eventually they
>> will usually reload on their own which is probably what happened in your
>> case.

> (I had done nothing to my DTV box this whole time.)

> So does anyone know if this is correct? Now there's another station (one
> of the big networks, not a local independent) that's missing its program
> info. Is it possible that my DTV box would selectively omit this
> information for just one or a few stations? Every other station shows
> this info for me, with the exceptions noted above.

It might be true. I note that the information supplied, and even the call
letters (!!!) of particular channels, can change from day to day on my
Vizio, even though I have done nothing.

==============================================================================
TOPIC: What causes this kind of failure in a CRT monitor?
http://groups.google.com/group/sci.electronics.repair/t/42b09cf82a8a222c?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Apr 3 2011 3:28 pm
From: nontelo@dico.no (Slater)

Hello, I have a Commodore 15KHz monitor that I tried to use as a TV
set by attaching it to my decoder through a SCART lead. It worked
perfectly for a while, then it started doing this:
http://www.youtube.com/watch?v=GaP2Bv5nCaQ
It hadn't been used for many months or maybe years.
What happened?

==============================================================================

You received this message because you are subscribed to the Google Groups "sci.electronics.repair"
group.

To post to this group, visit http://groups.google.com/group/sci.electronics.repair?hl=en

To unsubscribe from this group, send email to sci.electronics.repair+unsubscribe@googlegroups.com

To change the way you get mail from this group, visit:
http://groups.google.com/group/sci.electronics.repair/subscribe?hl=en

To report abuse, send email explaining the problem to abuse@googlegroups.com

==============================================================================
Google Groups: http://groups.google.com/?hl=en

Electronics

sci.electronics.repair - 25 new messages in 8 topics - digest

No Response to "sci.electronics.repair - 25 new messages in 8 topics - digest"

Post a Comment

Blog Roll

Blog Archive