sci.electronics.repair - 26 new messages in 8 topics - digest

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Today's topics:

==============================================================================
TOPIC: Magnifying glass for smd components
http://groups.google.com/group/sci.electronics.repair/t/152fab9f5593225c?hl=en
==============================================================================

== 1 of 8 ==
Date: Sat, Jan 15 2011 12:40 am
From: "N_Cook"

Jack00 <SPal508596@aol.com> wrote in message
news:cb4d689d-d0b4-42ae-a5dc-1b288aa86ce4@a10g2000vby.googlegroups.com...
> Does anyone know a magnifying glass that can be used for surface
> mounted components as they are too small to see with a standard
> magnifying glass. And also which amplification ie 2x 5x 10x 20x
>
> Cheers

I usually use one of these
http://www.growhubhydroponics.com/images/Pocket_Microscope.jpg
with the transparent bit slid off. It has x30 and a goodly amount of
"headroom" between SMD and the lens.
If SMD lies right next to a large/deep lump on the pcb then a kids
microscope barrel with a large notch ground into the objective end, actually
ground into the plastic lens,
originally used for viewing VCR heads.

== 2 of 8 ==
Date: Sat, Jan 15 2011 9:52 am
From: Baron

D Yuniskis Inscribed thus:

> On 1/14/2011 4:22 PM, Jack00 wrote:
>> Does anyone know a magnifying glass that can be used for surface
>> mounted components as they are too small to see with a standard
>> magnifying glass. And also which amplification ie 2x 5x 10x 20x
>
> Depends on how fried your eyes are! :>
>
> I use:
> - 1.5, 2.0 and 3.0 diopter "illuminated reading glasses"
> (depending on how close I need to work) for quick jobs
> - a pair of prescription eyeglasses with a *pair* of
> magnifying glasses that flip down on a ~3" arm for
> a bit more involved work -- this has the advantage that
> I can look up and read something in a book/monitor
> without being forced to try to read *through* the
> magnified image (but I have never encountered another
> pair of these glasses so you'd have to resort to
> something like a loupe that clips onto your existing
> eyeglasses -- the problem is that most of those clip
> on very *close* to your lenses)
> - 0.7X to 30X (variable) stereoscope for more "involved"
> work (e.g., inspecting *all* of the joints on a board)
>
> I have found that adequate *light* is more important than
> magnification (but that may just be the age of my eyes)

I can certainly empathise with that last paragraph. Good lighting is
very important. Particularly where identifying colors is required.

--
Best Regards:
Baron.

== 3 of 8 ==
Date: Sat, Jan 15 2011 10:21 am
From: Spehro Pefhany

On Sat, 15 Jan 2011 17:52:51 +0000, the renowned Baron
<baron.nospam@linuxmaniac.nospam.net> wrote:

>D Yuniskis Inscribed thus:
>
>> On 1/14/2011 4:22 PM, Jack00 wrote:
>>> Does anyone know a magnifying glass that can be used for surface
>>> mounted components as they are too small to see with a standard
>>> magnifying glass. And also which amplification ie 2x 5x 10x 20x
>>
>> Depends on how fried your eyes are! :>
>>
>> I use:
>> - 1.5, 2.0 and 3.0 diopter "illuminated reading glasses"
>> (depending on how close I need to work) for quick jobs
>> - a pair of prescription eyeglasses with a *pair* of
>> magnifying glasses that flip down on a ~3" arm for
>> a bit more involved work -- this has the advantage that
>> I can look up and read something in a book/monitor
>> without being forced to try to read *through* the
>> magnified image (but I have never encountered another
>> pair of these glasses so you'd have to resort to
>> something like a loupe that clips onto your existing
>> eyeglasses -- the problem is that most of those clip
>> on very *close* to your lenses)
>> - 0.7X to 30X (variable) stereoscope for more "involved"
>> work (e.g., inspecting *all* of the joints on a board)
>>
>> I have found that adequate *light* is more important than
>> magnification (but that may just be the age of my eyes)
>
>I can certainly empathise with that last paragraph. Good lighting is
>very important. Particularly where identifying colors is required.

I like to see >1000 lux general illumination, and more for task
lighting.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

== 4 of 8 ==
Date: Sat, Jan 15 2011 11:14 am
From: D Yuniskis

On 1/15/2011 10:52 AM, Baron wrote:
> D Yuniskis Inscribed thus:
>> I have found that adequate *light* is more important than
>> magnification (but that may just be the age of my eyes)
>
> I can certainly empathise with that last paragraph. Good lighting is
> very important. Particularly where identifying colors is required.

I find that I need more than "good" :-/

I used to be able to read the markings on DIPs at arm's length
"with a glance". Now, I need to rock them back and forth to get
the light to reflect off them at the right angle before things
are visible (at times, I swear they have changed to BLACK INK!! :< )

Ditto for color codes. Seems like the colors have crept closer together
in the spectrum :-/

== 5 of 8 ==
Date: Sat, Jan 15 2011 1:08 pm
From: Jeff Liebermann

On Fri, 14 Jan 2011 15:22:26 -0800 (PST), Jack00 <SPal508596@aol.com>
wrote:

>Does anyone know a magnifying glass that can be used for surface
>mounted components as they are too small to see with a standard
>magnifying glass. And also which amplification ie 2x 5x 10x 20x

There are plenty of optical instruments, microsocopes, and magnifiers
that can be used. For portable use, I have a small 10x pocket
magnifier I bought somewhere. Overchoice:
<http://www.pocketmagnifying.com>

However, that's not what I use on the bench. I butchered a USB camera
and what's left of a childrens microscope into a nifty magnifying
system. The LCD monitor displays the image and the computah can
capture the image if necessary. I suggest you just play with whatever
lenses you can scrounge and a USB camera and see what you can do.

What I use in my office is rather disgusting. I have a Luxo
magnifying lamp on the bench. The circular fluorescent light provides
really nice lighting. I put on a pair of 3 diopeter commodity
eyeglasses and shove my face up against the glass lens. I don't know
what magnification that offers, but it's good enough for all but the
smallest components. If I want more power, I have an Olympus BH
microscope.

Incidentally, I have a small camera ty-wrapped to my soldering iron.
The depth of field sucks, but it's amazingly useful once I retrained
myself to look at the screen and not at the work.

You can buy such USB microscope cameras on eBay or various web sites.
Just search for "USB microscope". Most of them are 100x to 400x but
there are a few with lower power or with zoom. For example, 10x to
200x:
<http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=110499624122>

--
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 8 ==
Date: Sat, Jan 15 2011 1:26 pm
From: D Yuniskis

On 1/15/2011 2:08 PM, Jeff Liebermann wrote:
> However, that's not what I use on the bench. I butchered a USB camera
> and what's left of a childrens microscope into a nifty magnifying
> system. The LCD monitor displays the image and the computah can
> capture the image if necessary. I suggest you just play with whatever
> lenses you can scrounge and a USB camera and see what you can do.

I have a USB camera mounted on a gooseneck (manual focus) that
I can position over (one of) the stereoscope's eyepiece. Or,
use "unaided" to just examine boards/components. I can;t recall
who makes it -- it was from a "science" classroom intended to
let students examine bugs, minerals, anything under a microscope,
etc. I.e., *designed* for this sort of purpose (instead of as
a "web cam")

== 7 of 8 ==
Date: Sat, Jan 15 2011 1:23 pm
From: Baron

D Yuniskis Inscribed thus:

> On 1/15/2011 10:52 AM, Baron wrote:
>> D Yuniskis Inscribed thus:
>>> I have found that adequate *light* is more important than
>>> magnification (but that may just be the age of my eyes)
>>
>> I can certainly empathise with that last paragraph. Good lighting is
>> very important. Particularly where identifying colors is required.
>
> I find that I need more than "good" :-/
>
> I used to be able to read the markings on DIPs at arm's length
> "with a glance". Now, I need to rock them back and forth to get
> the light to reflect off them at the right angle before things
> are visible (at times, I swear they have changed to BLACK INK!! :< )
>
> Ditto for color codes. Seems like the colors have crept closer
> together in the spectrum :-/

Yes colours have definitely become harder to read. I've used the "PTFE"
tape trick on IC's and SMD parts a number of times to read the
markings.

--
Best Regards:
Baron.

== 8 of 8 ==
Date: Sat, Jan 15 2011 1:27 pm
From: Baron

D Yuniskis Inscribed thus:

> On 1/15/2011 2:08 PM, Jeff Liebermann wrote:
>> However, that's not what I use on the bench. I butchered a USB
>> camera and what's left of a childrens microscope into a nifty
>> magnifying
>> system. The LCD monitor displays the image and the computah can
>> capture the image if necessary. I suggest you just play with
>> whatever lenses you can scrounge and a USB camera and see what you
>> can do.
>
> I have a USB camera mounted on a gooseneck (manual focus) that
> I can position over (one of) the stereoscope's eyepiece. Or,
> use "unaided" to just examine boards/components. I can;t recall
> who makes it -- it was from a "science" classroom intended to
> let students examine bugs, minerals, anything under a microscope,
> etc. I.e., *designed* for this sort of purpose (instead of as
> a "web cam")

Veho ! Maybe !

--
Best Regards:
Baron.

==============================================================================
TOPIC: IEC 705-88 Microwave Oven power measurement???what is it?
http://groups.google.com/group/sci.electronics.repair/t/ea891b75f315fec8?hl=en
==============================================================================

== 1 of 4 ==
Date: Sat, Jan 15 2011 4:27 am
From: mike

Phil Allison wrote:
> "mike"
>> IEC 705-88 Microwave Oven power measurement???what is it?
>>
>
> ** Very secret & very mysterious .....
>
>
>> What is the IEC 705-88 procedure for measuring microwave
>> oven power output?
>>
>> I've googled myself silly. Only thing I found is one
>> Amazon book excerpt. Starts describing the procedure,
>> but deletes two pages out of the middle...please insert
>> $200 to read the entire article...thankyouverymuch.
>>
>> I AM NOT ASKING HOW TO MEASURE MICROWAVE OVEN POWER OUTPUT.
>> I AM NOT ASKING HOW TO MEASURE MICROWAVE OVEN POWER OUTPUT
>> I AM NOT ASKING HOW TO MEASURE MICROWAVE OVEN POWER OUTPUT
>> I AM NOT ASKING HOW TO MEASURE MICROWAVE OVEN POWER OUTPUT
>> I AM NOT ASKING HOW TO MEASURE MICROWAVE OVEN POWER OUTPUT
>>
>> Maybe if I write it 5 times, the message will get through.
>>
>> I know how to measure it with a thermometer and a stopwatch.
>>
>> What I'm asking is...
>> When I go to the store and look at the numbers written
>> on the box that state the power output per iec705,
>> what do THEY mean...and how does that relate to what I'm
>> gonna find when I use my stopwatch and thermometer.
>
>
> ** All references on the net suggest that the IEC method uses a " formula "
> to compute the effective microwave power level on the basis of a specified
> test.
>
> The dish of water and a thermometer method is fairly obviously not
> recise - there is the heat stored in the dish itself and lost when water
> vapour that is formed during the test.
>
> PLUS heat energy is lost due to radiation and conduction from the dish as it
> rises above ambient.
>
> Seems the IEC method compensates for all these factors and you wind up with
> a figure that is about 10 to 15 % more than the imprecise method.
>
>
Thanks, the 15% number is what I was after.
Still would be nice to be able to know the procedure. Only reason
to keep stuff secret is that it's somehow misleading and can't stand
scrutiny.
Oh well, what's new...
>
>
>
>
>
>
>
>
>
>

== 2 of 4 ==
Date: Sat, Jan 15 2011 4:40 am
From: Jeffrey Angus

On 1/15/2011 6:27 AM, mike wrote:
> Thanks, the 15% number is what I was after.
> Still would be nice to be able to know the procedure. Only reason
> to keep stuff secret is that it's somehow misleading and can't stand
> scrutiny.
> Oh well, what's new...

Sort of like Campbell Hausfield being able to claim
that an air compressor motor that draws 15 amps is
5 HP.

Or my favorite, watts as measured in "music power."

Jeff

== 3 of 4 ==
Date: Sat, Jan 15 2011 4:59 am
From: "Phil Allison"

"mike"
> Phil Allison wrote:
>
>> Seems the IEC method compensates for all these factors and you wind up
>> with a figure that is about 10 to 15 % more than the imprecise method.
>>
>>
> Thanks, the 15% number is what I was after.
> Still would be nice to be able to know the procedure. Only reason
> to keep stuff secret is that it's somehow misleading and can't stand
> scrutiny.

** It ain't actually secret - it's just well protected by copyright.

So you 'as to pay to know.

Keeps out the riff-raff who are merely curious ....

.... Phil

== 4 of 4 ==
Date: Sat, Jan 15 2011 5:09 am
From: "Michael A. Terrell"

Jeffrey Angus wrote:
>
> On 1/15/2011 6:27 AM, mike wrote:
> > Thanks, the 15% number is what I was after.
> > Still would be nice to be able to know the procedure. Only reason
> > to keep stuff secret is that it's somehow misleading and can't stand
> > scrutiny.
> > Oh well, what's new...
>
> Sort of like Campbell Hausfield being able to claim
> that an air compressor motor that draws 15 amps is
> 5 HP.
>
> Or my favorite, watts as measured in "music power."
>
> Jeff

Or computer speakers rated '1500 WATTS!!!', yet they are powered by a
9 volt 500 mA wall wart.

--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.

==============================================================================
TOPIC: PC PSU Component Value (TH1)
http://groups.google.com/group/sci.electronics.repair/t/8484746dd62b9840?hl=en
==============================================================================

== 1 of 1 ==
Date: Sat, Jan 15 2011 5:23 am
From: "Michael Kennedy"

"Bob Villa" <pheeh.zero@gmail.com> wrote in message
news:5536bca2-513d-4008-9290-a7d6ca63a209@k3g2000yqc.googlegroups.com...
On Jan 13, 5:52 am, Bob Villa <pheeh.z...@gmail.com> wrote:
> Would anyone know the value or an equivalent for "TH1" on a CoolMax
> PSU? (CA-400)
> TIA
> bob_v

Can you give some sort of description of the componenet?

By the way, are you really Bob Vila?

Mike

==============================================================================
TOPIC: Jeantech JN120-450-AP, ATX PSU.
http://groups.google.com/group/sci.electronics.repair/t/889cc20861c3f086?hl=en
==============================================================================

== 1 of 3 ==
Date: Sat, Jan 15 2011 8:16 am
From: "Ian Field"

A relative donated this, said it was sparking when switched on.

On opening the case I found a group of electrolytics behind the bunch of
output wires had vented.

Does anyone know of a specific component failure that causes the regulation
to go haywire?

There's brown glue on the sub-panel on the primary side, this was a common
cause of problems with CRT monitors.

Any help appreciated.

Thanks.

== 2 of 3 ==
Date: Sat, Jan 15 2011 9:43 am
From: "Wild_Bill"

Quite a few people will repair computer PSUs, but new replacements are
readily available and not very expensive.
Almost any new PSU will be much more reliable than a repaired used one.

The actual value of a used, failed, then repaired PSU is very low.. both
monitarily and from a reliability perspective, IMO.

I'll generally save the wire leads and the AC cord receptacle, screws, and
little else.

The capacitors may have failed because they were very low quality parts..
I'd expect that the other parts would be of approximately the same quality.

--
Cheers,
WB
.............

"Ian Field" <gangprobing.alien@ntlworld.com> wrote in message
news:bLjYo.63373$B77.46395@newsfe29.ams2...
>A relative donated this, said it was sparking when switched on.
>
> On opening the case I found a group of electrolytics behind the bunch of
> output wires had vented.
>
> Does anyone know of a specific component failure that causes the
> regulation to go haywire?
>
> There's brown glue on the sub-panel on the primary side, this was a common
> cause of problems with CRT monitors.
>
> Any help appreciated.
>
> Thanks.
>

== 3 of 3 ==
Date: Sat, Jan 15 2011 11:30 am
From: PlainBill47@yawho.com

On Sat, 15 Jan 2011 16:16:01 -0000, "Ian Field"
<gangprobing.alien@ntlworld.com> wrote:

>A relative donated this, said it was sparking when switched on.
>
>On opening the case I found a group of electrolytics behind the bunch of
>output wires had vented.
>
>Does anyone know of a specific component failure that causes the regulation
>to go haywire?
>
>There's brown glue on the sub-panel on the primary side, this was a common
>cause of problems with CRT monitors.
>
>Any help appreciated.
>
>Thanks.
>
Vented electrolytics are a likely cause of poor requlation. The caps
didn't vent because the output voltage was too high, they vented
because they were poorly manufactured.

One intelligent approach would be to replace every cap on the
secondary side with name brand low ESR caps of the original voltage
and capacity. Also replace any small (<100 µF) caps on the primary
side, as well as any high voltage electrolytics on the primary side
that look in any way suspicious. My preferred capacitor for use in
teh secondary of a SMPS is Panasonic FM or FC series. Rubycon,
Nichicon, United Chemicon also make high quality caps.

Another equally valid approach is to buy a new good quality power
supply. Not only are the cheap power supplies built with crap caps,
the fans are garbage also.

PlainBill

==============================================================================
TOPIC: OT--Actual electronics repair question
http://groups.google.com/group/sci.electronics.repair/t/1c7563aead5e20a6?hl=en
==============================================================================

== 1 of 5 ==
Date: Sat, Jan 15 2011 9:43 am
From: Baron

Jeff Liebermann Inscribed thus:

> On Thu, 13 Jan 2011 21:37:02 +0000 (UTC), Meat Plow
> <mhywatt@yahoo.com> wrote:
>
>>No, tapping on it will not induce micro-phonics but will often lessen
>>the howl.
>
> Well, if it were "grounding", then banging on the case would have no
> effect (unless there were some screws loose).
>
> Incidentally, I tried my VX-5 turn on/off times. It took about 1
> second to turn on, and the same to turn off. Pushing the button to
> turn off was *NOT* instantaneous. I had to hold it for 1 sec. It's
> been like that since new, so there's been no deterioration. At this
> point, I don't know if it's a firmware issue, settings issue, or dirty
> keyboard. Save, reset and reload seems the easiest to do first.
>
>>Once the radio is on, the howl goes away, maybe after 10 minutes.
>
> Something is getting warm perhaps?
>
>>We have it here due to severe thunderstorms with large hail, damaging
>>winds, localized flooding, micro-bursts and tornadoes.
>
> That's why I like California. Other than earthquakes and government,
> we don't have much in the way to disasters here.
>
>>... I had just purchased a Dodge 4x4 in the spring. I was
>>out chasing a storm around and got pelted by some golf ball sized
>>hail. That ended my chasing days. I don't have a beater that I care
>>about looking like someone took a hammer to it.
>
> Ouch. I've never even seen a tornado, so I have no idea what it might
> be like. Raining golf balls sounds like no fun. Yes, Skywarn has its
> place in your part of the country.
>

This thing doesn't have a backup battery does it ?
If so have you replaced it !

--
Best Regards:
Baron.

== 2 of 5 ==
Date: Sat, Jan 15 2011 12:33 pm
From: Jeff Liebermann

On Fri, 14 Jan 2011 16:27:32 -0800, David Nebenzahl
<nobody@but.us.chickens> wrote:

>On 1/14/2011 12:58 PM Jeff Liebermann spake thus:
>
>> That's why I like California. Other than earthquakes and government,
>> we don't have much in the way to disasters here.
>
>Hmm, tell that to all those folks who live "up the hill" from you off 17
>whose houses perennially slip-slide away in the rainy season ...

Oh, you mean like my house?
<http://802.11junk.com/jeffl/pics/home/slides/BL-house1.html>
My guess(tm) is I'm on a 45 degree slope. However, I'm not worried
about sliding down the hill. I've gone through some effort to divert
water around the house and check for hydraulic and geological hazards.
What worries me is having one of the huge trees land on my house or
getting caught in a forest fire.

>But yeah, I guess apart from that, a few houses falling into the ocean
>each year, and those houses that got blown up/burned up in San Bruno,
>we're relatively disaster-free here.

Little lightning, no tornados, no hurricanes, minimal flooding, etc.
Yeah, I like it here (except for the government disasters).

--
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

== 3 of 5 ==
Date: Sat, Jan 15 2011 12:54 pm
From: Meat Plow

On Sat, 15 Jan 2011 17:43:05 +0000, Baron wrote:

> Jeff Liebermann Inscribed thus:
>
>> On Thu, 13 Jan 2011 21:37:02 +0000 (UTC), Meat Plow <mhywatt@yahoo.com>
>> wrote:
>>
>>>No, tapping on it will not induce micro-phonics but will often lessen
>>>the howl.
>>
>> Well, if it were "grounding", then banging on the case would have no
>> effect (unless there were some screws loose).
>>
>> Incidentally, I tried my VX-5 turn on/off times. It took about 1
>> second to turn on, and the same to turn off. Pushing the button to
>> turn off was *NOT* instantaneous. I had to hold it for 1 sec. It's
>> been like that since new, so there's been no deterioration. At this
>> point, I don't know if it's a firmware issue, settings issue, or dirty
>> keyboard. Save, reset and reload seems the easiest to do first.
>>
>>>Once the radio is on, the howl goes away, maybe after 10 minutes.
>>
>> Something is getting warm perhaps?
>>
>>>We have it here due to severe thunderstorms with large hail, damaging
>>>winds, localized flooding, micro-bursts and tornadoes.
>>
>> That's why I like California. Other than earthquakes and government,
>> we don't have much in the way to disasters here.
>>
>>>... I had just purchased a Dodge 4x4 in the spring. I was out chasing a
>>>storm around and got pelted by some golf ball sized hail. That ended my
>>>chasing days. I don't have a beater that I care about looking like
>>>someone took a hammer to it.
>>
>> Ouch. I've never even seen a tornado, so I have no idea what it might
>> be like. Raining golf balls sounds like no fun. Yes, Skywarn has its
>> place in your part of the country.
>>
>>
> This thing doesn't have a backup battery does it ? If so have you
> replaced it !

I think it stores in erasable prom but can't be sure. I had it open once
and don't recall seeing anything big enough to be a supercap or battery.
It's really miniaturized.

--
Live Fast, Die Young and Leave a Pretty Corpse

== 4 of 5 ==
Date: Sat, Jan 15 2011 1:13 pm
From: Baron

Meat Plow Inscribed thus:

> On Sat, 15 Jan 2011 17:43:05 +0000, Baron wrote:
>
>> Jeff Liebermann Inscribed thus:
>>
>>> On Thu, 13 Jan 2011 21:37:02 +0000 (UTC), Meat Plow
>>> <mhywatt@yahoo.com> wrote:
>>>
>>>>No, tapping on it will not induce micro-phonics but will often
>>>>lessen the howl.
>>>
>>> Well, if it were "grounding", then banging on the case would have no
>>> effect (unless there were some screws loose).
>>>
>>> Incidentally, I tried my VX-5 turn on/off times. It took about 1
>>> second to turn on, and the same to turn off. Pushing the button to
>>> turn off was *NOT* instantaneous. I had to hold it for 1 sec. It's
>>> been like that since new, so there's been no deterioration. At this
>>> point, I don't know if it's a firmware issue, settings issue, or
>>> dirty
>>> keyboard. Save, reset and reload seems the easiest to do first.
>>>
>>>>Once the radio is on, the howl goes away, maybe after 10 minutes.
>>>
>>> Something is getting warm perhaps?
>>>
>>>>We have it here due to severe thunderstorms with large hail,
>>>>damaging winds, localized flooding, micro-bursts and tornadoes.
>>>
>>> That's why I like California. Other than earthquakes and
>>> government, we don't have much in the way to disasters here.
>>>
>>>>... I had just purchased a Dodge 4x4 in the spring. I was out
>>>>chasing a storm around and got pelted by some golf ball sized hail.
>>>>That ended my chasing days. I don't have a beater that I care about
>>>>looking like someone took a hammer to it.
>>>
>>> Ouch. I've never even seen a tornado, so I have no idea what it
>>> might
>>> be like. Raining golf balls sounds like no fun. Yes, Skywarn has
>>> its place in your part of the country.
>>>
>>>
>> This thing doesn't have a backup battery does it ? If so have you
>> replaced it !
>
> I think it stores in erasable prom but can't be sure. I had it open
> once and don't recall seeing anything big enough to be a supercap or
> battery. It's really miniaturized.
>

A friend of mine had a HT, Icom I think, with a 2021 battery in it. It
went bananas changing channels when you pressed TX. Turned out that
the battery was the problem. Now I don't know whether it was low
voltage or corrosion because it was repaired by the supplier.

Sadly he's now silent key, so I can't go and ask him. Come to think
about it my FT290 has a battery in it... I'll have to check that !

--
Best Regards:
Baron.

== 5 of 5 ==
Date: Sat, Jan 15 2011 1:25 pm
From: Jeff Liebermann

On Sat, 15 Jan 2011 20:54:48 +0000 (UTC), Meat Plow
<mhywatt@yahoo.com> wrote:

>I think it stores in erasable prom but can't be sure. I had it open once
>and don't recall seeing anything big enough to be a supercap or battery.
>It's really miniaturized.

I'm too lazy to dig out the schematic, but I guess(tm) it's NVRAM of
some sort. I don't see a coin cell inside. Some inside photos:
<http://www.mods.dk/picture.php?brandid=7&model=vx-5r>
Registration required to see them full size.

Note the big white circle that is silk screen to the PCB. That's
where the speaker magnet is positioned. I suspect that if you place
some foam tape to put some pressure on the PCB, it might reduce the
microphonics.

Also, two reasons it's only on 440Mhz. It might be a seperate VCO
oscillator for each band, and the LO multiplier ratio is higher for
440 than for the other bands.

Incidentally, I sorta blundered across this BNC to SMA adapter made
specifically for various Yaesu handhelds. Looks better than the
easily broken adapters I've been using.
<http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350298285336>
There a bunch of others with similar design available.

--
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: AA-sized conductor (fake battery) wanted
http://groups.google.com/group/sci.electronics.repair/t/33083a4b1e46ccc0?hl=en
==============================================================================

== 1 of 3 ==
Date: Sat, Jan 15 2011 9:46 am
From: Baron

D Yuniskis Inscribed thus:

> On 1/14/2011 6:26 AM, baron wrote:
>> D Yuniskis Inscribed thus:
>>
>>> On 1/13/2011 1:46 PM, Baron wrote:
>>>> D Yuniskis Inscribed thus:
>>>>
>>>>> On 1/13/2011 4:24 AM, baron wrote:
>>>>>> Eldor Inscribed thus:
>>>>>>
>>>>>>> Hello all NG
>>>>>>>
>>>>>>> I am looking for a fake AA battery, i.e. a conductor of the same
>>>>>>> size, so that I can put it in an AA battery holder and have a
>>>>>>> lower voltage (N-1 x 1.5V) . Actually I want multiple of them so
>>>>>>> that I can make a "configurable voltage" battery.
>>>>>>>
>>>>>>> I have looked around but I can't find it. Does anybody know any?
>>>>>>>
>>>>>>> Alternatively I could look for a battery which can be charged at
>>>>>>> various voltage levels, but it needs to hold a significant
>>>>>>> charge at any voltage level. I don't think it exists.
>>>>>>>
>>>>>>> Thanks for any help
>>>>>>
>>>>>> Whats wrong with a piece of rolled up cardboard ?
>>>>>
>>>>> Cardboard isn't a very good conductor at low voltages :>
>>>>
>>>> Sorry ! My brain fart :-(
>>>> I meant to write "Whats wrong with a piece of alloy foil wrapped
>>>> over rolled up cardboard ?"
>>>
>>> Wrapping the foil might be tricky -- especially if it
>>> *is* "foil" -- since you want a durable and reliable
>>> contact surface yet can't really tolerate lumps, bumps,
>>> etc. "Shrink-wrap-aluminum"! Now *that* would be
>>> an idea! :> (not "shrink-WRAPPED-aluminum")
>>
>> I've actually used rolled up cardboard and wrapped aluminium cooking
>> foil round it, folding the ends over to make contact surfaces. It
>> works quite well. I imagine that its current carrying capacity would
>> be quite low.
>>
>>> The ideal would be to turn a length of copper dowel to
>>> the correct profile and then encase in shrink wrap.
>>> But, I suspect the OP doesn't have access to a lathe
>>> (though many people *have* lathes so "asking around"
>>> could be an option -- note that the profile is probably
>>> published as a standard someplace so it's just a matter
>>> of getting someone to give you 3 minutes of time on a
>>> lathe).
>>
>> Actually a hacksaw and a short length of 0.5" or 13.0mm bar/rod cut
>> to 2" or 51mm long would do !
>
> My comment was intended more as "tongue-in-cheek" (I have a
> friend that I *never* ask for things like this as he *would*
> turn something on a lathe for me and I often end up embarassed
> at the "excessive quality" of his solution! :> )

Us mechanical engineer types take great pride in our hobbies ! :-)

> Some batteries (against which the "dummy" may mate) require
> the little "nub" on the + end to ensure contact. Likewise,
> some battery holders "guard" the + terminal with a bit of
> raised plastic to protect against a battery installed backwards.
> (i.e., a "flat surface" -- like the - terminal -- won't connect)

Ah ! In that case you would need to turn it to produce the pip on one
end.

--
Best Regards:
Baron.

== 2 of 3 ==
Date: Sat, Jan 15 2011 11:25 am
From: D Yuniskis

On 1/15/2011 10:46 AM, Baron wrote:
>> My comment was intended more as "tongue-in-cheek" (I have a
>> friend that I *never* ask for things like this as he *would*
>> turn something on a lathe for me and I often end up embarassed
>> at the "excessive quality" of his solution! :> )
>
> Us mechanical engineer types take great pride in our hobbies ! :-)

Well, *he's* the mechanical type: lathe, end mill, surface grinder,
shadow graph, coil winder, etc.

Of course, another friend has a sinker EDM and a couple of wire EDM
machines... a bit too expensive to qualify as "toys" :-/

>> Some batteries (against which the "dummy" may mate) require
>> the little "nub" on the + end to ensure contact. Likewise,
>> some battery holders "guard" the + terminal with a bit of
>> raised plastic to protect against a battery installed backwards.
>> (i.e., a "flat surface" -- like the - terminal -- won't connect)
>
> Ah ! In that case you would need to turn it to produce the pip on one
> end.

Yes, that was why I suggested the lathe instead of just cutting drill
rod, etc.

Though, with copper, I think you could *almost* use a file as "cutting
tool" and a large electric (hand) drill to spin the work. Wouldn't have
much control over the dimension of the pip but I suspect you could
fashion a functional one in a few minutes. Heck, even putting a
slight taper on the one end would work!

== 3 of 3 ==
Date: Sat, Jan 15 2011 1:20 pm
From: Baron

D Yuniskis Inscribed thus:

> On 1/15/2011 10:46 AM, Baron wrote:
>>> My comment was intended more as "tongue-in-cheek" (I have a
>>> friend that I *never* ask for things like this as he *would*
>>> turn something on a lathe for me and I often end up embarassed
>>> at the "excessive quality" of his solution! :> )
>>
>> Us mechanical engineer types take great pride in our hobbies ! :-)
>
> Well, *he's* the mechanical type: lathe, end mill, surface grinder,
> shadow graph, coil winder, etc.
>
> Of course, another friend has a sinker EDM and a couple of wire EDM
> machines... a bit too expensive to qualify as "toys" :-/
>

Ooo ! I feel the green eyed monster coming on. :-)

>>> Some batteries (against which the "dummy" may mate) require
>>> the little "nub" on the + end to ensure contact. Likewise,
>>> some battery holders "guard" the + terminal with a bit of
>>> raised plastic to protect against a battery installed backwards.
>>> (i.e., a "flat surface" -- like the - terminal -- won't connect)
>>
>> Ah ! In that case you would need to turn it to produce the pip on one
>> end.
>
> Yes, that was why I suggested the lathe instead of just cutting drill
> rod, etc.

I wasn't aware of that limitation. Though my son just pointed out the
battery holder in the Wii was shaped so you couldn't put the battery in
backwards.

> Though, with copper, I think you could *almost* use a file as "cutting
> tool" and a large electric (hand) drill to spin the work. Wouldn't
> have much control over the dimension of the pip but I suspect you
> could fashion a functional one in a few minutes. Heck, even putting a
> slight taper on the one end would work!

Very true ! A trick I've used to clean up the end of damaged bolts.

--
Best Regards:
Baron.

==============================================================================
TOPIC: Nightmare Samsung PTV
http://groups.google.com/group/sci.electronics.repair/t/53c2c1c21b44407f?hl=en
==============================================================================

== 1 of 1 ==
Date: Sat, Jan 15 2011 11:26 am
From: "Chris F."

I think I have this straightened out... I hope. After installing the two new
convergence IC's, I was surprised to see the exact same symptom. I pulled
the convergence processor board, which I had newly replaced, and saw a
burned zener diode. I replaced it with one from the old module, and
everything seemed back to normal. But to be certain, I reset the convergence
to factory default and started over. I also attached ammeters to the +25
and -25 supplies going to the convergence output board, to monitor the
current as I made the adjustments. Once the convergence adjustments were
done, the current draw was about 600mA on each supply, at 23V. The IC's were
still quite hot, and I realized that this was due to poor design: both were
bolted to a single, thin heatsink which mounts to the steel frame. Very
little heat was getting transferred to the steel frame, even though
everything was mounted properly. So what I did was remove the module from
the steel frame, and bolted a much larger heatsink to the existing one, and
mounted everything to the side of the cabinet. The IC's run much cooler now,
and hopefully this will prevent them from failing again.
I've learned a few things from this, the most important being to never
gamble money on a Samsung. Once this TV is sold I hope I never see it again.

"Chris F." <zappyman@hotmail.com> wrote in message
news:4d276e28$0$5583$9a566e8b@news.aliant.net...
> This Samsung HCN4767W projection set is really making a nuisance of
> itself. It had a blown convergence IC when I acquired it, so I replaced
> them both. It ran for a few days in the shop (about 6-8 hours a day), then
> blew one of the same IC's again. I replaced them again, and also replaced
> the convergence processor board. Again, it seemed to work fine for a few
> days, but now the bloody IC's have blown again. The supply voltage to the
> IC's is a solid 25V (pos. and neg.), well within the 50V max. supply
> voltage the IC's are rated for. Both IC's are properly heatsinked, though
> they seem to run quite hot - I assumed this was just normal. I've also
> gone through the convergence board and power supply looking for caps up in
> ESR, but found none.
> The replacement IC's were supposed to be OEM, but I have to wonder just
> how compatible they really are. It's the only explanation I can think of.
> I'm tired of wasting time and money on this piece of junk. Unless I can
> be certain any further replacement parts will work, I'm going to scrap it
> and take my losses, which would be close to $300 as of right now. I will
> also vow to never gamble on a Samsung again - they're nothing but trouble.
> Any advice would be appreciated
>

==============================================================================
TOPIC: Wanted: Sony Digital8 Camcorder Power Board
http://groups.google.com/group/sci.electronics.repair/t/dda3ce8bdc07d825?hl=en
==============================================================================

== 1 of 1 ==
Date: Sat, Jan 15 2011 11:32 am
From: "Chris F."

I need a power board for my old camcorder, a Sony DCR-TRV110. The board #
is 1-672-457. The camera stopped working after I connected an aftermarket AC
adapter, which was intended for this camera but was obviously defective(a
subject for another post someday I have more time). I'm hoping the power
board is all that's damaged.
If anyone has this board or a non-working camera of the same model please
let me know.

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