sci.electronics.repair - 25 new messages in 11 topics - digest

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

sci.electronics.repair@googlegroups.com

Today's topics:

==============================================================================
TOPIC: Yamaha EMX5016 mixer amp from 2006
http://groups.google.com/group/sci.electronics.repair/t/bc288deddd9278ea?hl=en
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== 1 of 1 ==
Date: Sun, Jan 30 2011 1:00 am
From: "N_Cook"

N_Cook <diverse@tcp.co.uk> wrote in message
news:ii1n90$ii1$1@news.eternal-september.org...
> repair m on e-S and there is an inverter stuck in before the R ch o/p, not
> for the L
>
>
>
>

Is it just for evening up the ps?. If a momentary high draw from one PA on
+/ve rail dropping reservoir by 1V then also a matching 1V drop on the -ve
rail from the other ch, wheras usually that would be a 2V drop on + rail
only

==============================================================================
TOPIC: CRT Monitor Philips black screen when cold
http://groups.google.com/group/sci.electronics.repair/t/5e3cab73ac7d259c?hl=en
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== 1 of 1 ==
Date: Sun, Jan 30 2011 1:33 am
From: "Steinway"

"Sylvia Else" <sylvia@not.here.invalid> ha scritto nel messaggio
news:8qklutFigeU1@mid.individual.net...

>
> I'm confused, or perhaps just befuzzled. Aren't you the OP (original
> poster)?
>
> Sylvia.
>

Yes, I am the original poster, Steinway!

==============================================================================
TOPIC: DTV sound synch
http://groups.google.com/group/sci.electronics.repair/t/2896d12048fef530?hl=en
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== 1 of 1 ==
Date: Sun, Jan 30 2011 2:56 am
From: "Dave Plowman (News)"

In article
<ce9387ff-14b0-4e10-8673-144d7f67fe7f@d21g2000vbf.googlegroups.com>,
<stratus46@yahoo.com> wrote:
> > It's very unlikely you are seeing broadcast electronic video from the
> > 60s and 70s as good as it was then. It'll have been transferred a few
> > times as tape formats go out of use - and the transfer equipment
> > likely towards the end of its life. Plus the fact that even a single
> > generation of quad VTR caused noticeable degradation, and most of the
> > stuff which has been kept will be two or more generations.

> It IS unlikely but I work in Hollywood and am one of the few who still
> get (got?) to work on quads so it happens to be true. I was watching
> the original 2" quad tape played back on an Ampex AVR-1 just a few
> weeks ago. It was an NBC Danny Thomas special (low band color so there
> was some moire) from 1965 with Johnny Carson, Bill Cosby, Tim Conway
> and others.

I started work for the BBC at their main production centre in the early
'60s in the days when some drama and LE was still live. And therefore saw
the introduction of colour in the UK from the sharp end.

> You're also mistaken about how many generations you can go
> down before you have noticeable problems. Network on air tapes were a
> minimum of 3 generations down. Mind you, it's necessary to adjust
> things properly unlike the newest digital machines that are close to
> idiot proof but will tie you in knots with the myriad settings.

And you never noticed the degradation compared to live progs? With only
even one generation?

> You probably never saw a Super High Band Pilot quad tape where the
> time base reference was recorded analog along with the analog FM
> video. Zero velocity errors as the pilot was the sample clock and any
> timing errors on the video were also in the pilot so the error was
> nada. That came out in the '70s along with the first 1 inch decks
> which had the 'trick' video of slo-mo and still frames which were
> previously unavailable to local stations. Quad died fast after that
> but not until having a 20+ year run.

C-format degraded things too.

> I was just repairing Ampex AVR-3s this afternoon.
> G²

DigiBeta was the first tape based system I saw which in general didn't
degrade things noticeably.

--
*Why do overlook and oversee mean opposite things?

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

==============================================================================
TOPIC: Laptop not charging.
http://groups.google.com/group/sci.electronics.repair/t/3f52116e8141f1a4?hl=en
==============================================================================

== 1 of 6 ==
Date: Sun, Jan 30 2011 3:41 am
From: T i m

On Sun, 30 Jan 2011 06:22:59 +0000, Fred <nobody@home.com> wrote:

>T i m <news@spaced.me.uk> wrote in
>news:3jv7k654r4j25nunqb0dgnfsurhqkev45i@4ax.com:
>
>> Cheers, T i m
>>
>
>Get a competent technician to take the laptop apart and resolder all the
>connections between the power jack and the circuit board it is SUPPOSED
>to be soldered to.

We only have access to an aging ex BT trained Electronics Service Tech
here <g> and he carefully removed the old and replaced with new the
power socket. FWIW the original socket was showing no signs of damage
whatsoever and all 8 of it's pins were still nicely soldered to the
board.

>They get a hairline crack in the solder because
>that's the only thing holding the connector to the board.

Understood and board cracks were seen many a time on Plessy made
modules that made up the std 300 Baud BT PSTN modem sub modules back
in the day (Modulator unit, demodulator unit, filter unit, control
unit and PSU unit etc). GEC, STC and Marconi generally used fibreglass
boards so were much stronger so less prone to cracking.

> These cracks
>can be so thin you need a jeweler's loupe to see them, if you find them
>at all.

Understood and that's exactly what I was viewing them through (I used
am illuminated magnifier when I was de soldering and cleaning).
>
>Resoldering the connector to the board fixes the problem.

Not in this case though I'm afraid but also has for me on many
occasion (there were 5 different sockets in the last batch I ordered).
>
>The competent technician will, of course, load test her AC power supply
>before tearing into the computer, bending and pulling hard on the plug at
>the computer end to make sure the wires inside the plug and cable have
>not been broken, another common source of intermittent power,

Yup and done.

>say it was powering the computer so that's probably not the problem.

Not in this case I don't think and another (supposedly working) PUS
was substituted with no change in the symptoms).

>There is a switch telling the computer the power supply is plugged in on
>many models moved by the power supply plug and that switch's connections
>may be intermittent.

Again, looked for but none found (and if it were within the DC socket,
would have been replaced with the socket).

FWIW it is understood that there were two laptops on a sideboard and
laddos Mum picked up hers and thinking the were free of each other,
'pulled his laptop along a bit'. If that were true (and I have no
reason to think otherwise) I am inclined to thing the most likely
thing that could have happened would be the unusual temporary
disconnection of one of the connections causing a spike or some such
because the plug / socket combo were slightly loose (after two years
or very regular use and daily movement). But they were only slightly
loose (I use and have seen much worse myself) so I'm not sure.

We will see (hopefully).

Cheers, T i m

== 2 of 6 ==
Date: Sun, Jan 30 2011 3:50 am
From: T i m

On Sat, 29 Jan 2011 20:44:32 -0600, Ken <Ken@invalid.com> wrote:

>> http://www.deliran.net/refrence/Inspiron_1545/Inspiron_1545_eng/td_fan.htm
>>
>> You can just see the charger board under the system board top left.
>> Luckily it looks like you can get to the back of the socket and
>> 'device' with the thing mostly in one piece. Soo, if I measure a
>> voltage on one side of said device and not the other (with battery in
>> and charger in an on) /and/ it looks like it's wired in series with
>> the power socket it would most likely be a fuse?
>
> Is there any component designation?? Such as "F1" stamped on the
>board? Sometimes such a designation can tell you what the component is.

Understood but to be honest, whilst I was generally (subconsciously
even) looking out for anything untoward I wasn't looking for that
level of issue at the time (I was in 'let's change this socket and
hope the laptop still works afterwards').

> Is there any marking on the component? That also could tell you what
>it is. Are there any similar components elsewhere on the board? What
>is the resistance across other components of the same type compared to
>this one?

All good questions and when he's available next we will look at it
closer and with the DMM. ;-)

Cheers, T i m

== 3 of 6 ==
Date: Sun, Jan 30 2011 5:35 am
From: Adrian C

On 30/01/2011 00:59, T i m wrote:
>
> I'm not sure how I glean points there and whatever it is I'm not sure
> I could do so in Vietnamese (even with Google translate).
>
> Frustratingly close though ...
>
> Cheers, T i m
>

The first link from the google search is hidden until you register - no
points required though it takes you through to a 4shared server to
download it.

Anyway sod that, I've got it now - it's a 1MB file called 'Roberts-dr1.pdf'.

Is your email addy valid Tim?

--
Adrian C

== 4 of 6 ==
Date: Sun, Jan 30 2011 6:07 am
From: T i m

On Sun, 30 Jan 2011 13:35:03 +0000, Adrian C <email@here.invalid>
wrote:

>On 30/01/2011 00:59, T i m wrote:
>>
>> I'm not sure how I glean points there and whatever it is I'm not sure
>> I could do so in Vietnamese (even with Google translate).
>>
>> Frustratingly close though ...
>>
>> Cheers, T i m
>>
>
>The first link from the google search is hidden until you register - no
>points required though it takes you through to a 4shared server to
>download it.

Ah, ok.
>
>Anyway sod that, I've got it now - it's a 1MB file called 'Roberts-dr1.pdf'.

Good lad. ;-)
>
>Is your email addy valid Tim?

It is indeed. I owe you one.

Cheers, T i m

== 5 of 6 ==
Date: Sun, Jan 30 2011 7:33 am
From: Adrian C

On 30/01/2011 14:07, T i m wrote:

>> Is your email addy valid Tim?
>
> It is indeed. I owe you one.
>
> Cheers, T i m

Check your mail :)

--
Adrian C

== 6 of 6 ==
Date: Sun, Jan 30 2011 11:30 am
From: Baron

T i m Inscribed thus:

> Yesterday, thinking it /could/ be a socket and where the tiny inner /
> 3rd pin connects (thinking it might be a 'sense' wire and a socket was
> cheap etc) I changed it for him but again, no improvement.

That third wire the centre pin, is a one wire data interface ! The idea
is to prevent you from using a charger that is/was not supplied by the
manufacturer. Its quite possible that since the laptop works happily
from the charger, that the communications inside the laptop charging
circuits has been damaged. The charger board and the mainboard come as
a pair. A salvaged charger board will not work with a different
mainboard.

HTH

> Cheers, T i m

--
Best Regards:
Baron.

==============================================================================
TOPIC: possibly OT: players reject region 0 DVD
http://groups.google.com/group/sci.electronics.repair/t/b38242427b60f545?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Jan 30 2011 5:36 am
From: "William Sommerwerck"

> Now that you have the computer playing movies is a great time
> to dump all the DVD nonsense, learn how to download, decode
> and assemble the thousands and thousands of movies posted
> to alt.binaries.movies.divx, right here on usenet, every day. Does
> the big TV have a 3-row "computer" input to plug the old computer
> into?

The "big TV" is a 60" KURO, and I rarely play anything other than Blu-rays
on it. DVDs are largely reserved for my 36" flat-face CRT Sony IDTV in the
bedroom.

==============================================================================
TOPIC: Magnavox TB100 STB shuts off
http://groups.google.com/group/sci.electronics.repair/t/d1cceba0bc151243?hl=en
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== 1 of 1 ==
Date: Sun, Jan 30 2011 7:19 am
From: bob urz

Anyone successfully work on these cheap DTV converter boxes?
I got a Magnavox TB100. It powers up and displays the TV channel.
Then it shuts itself off in about 5 seconds. I did get into the setup
menu and the auto shut off is set to off so i assume its not that.
Have not been inside of it to check the caps yet. Are these POS
even fixable?

bob

==============================================================================
TOPIC: possible problem with Sony flat-face WEGA
http://groups.google.com/group/sci.electronics.repair/t/8fc4ce0a3ea9ba13?hl=en
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== 1 of 5 ==
Date: Sun, Jan 30 2011 7:21 am
From: "William Sommerwerck"

I'm posting this to see if anyone /knows/ the answer, or has a reasonable
suspicion. I do not want to initiate an interminable chain of speculation.

I own a 36" flat-face 400-series Sony WEGA IDTV and, yes, I have the service
manual. The set has gotten heavy use over the past decade; I often leave it
on when I go to bed. It wasn't cheap, and I'd like to get at least another
five years out of it. For a non-HD CRT set, it has an excellent picture,
especially with RGB signals from a DVD player.

When the set's turned on, the HV is apparently shut off, so that the CRT
heater has time to come to full temperature, to avoid stripping the cathode.
(This is speculation.) Though sound comes on almost immediately, it takes
about 10 seconds for the raster to appear.

Recently I've noticed "something new". For about two seconds after the
raster comes on, the black level is too light. You can see the image
"darkening" as the black level drops to its "correct" point. This occurs
only when the set is "cold"; cycling the power doesn't cause this.

I'm hoping someone will say "I've seen this. It's the ___________."
Troubleshooting this set won't be easy (if only because it's close to the
wall on a near-immovable stand). I don't want to tear into it until I'm
reasonably certain I can fix it on the first try.

Thanks in advance.

--
"We already know the answers -- we just haven't asked the right
questions." -- Edwin Land

== 2 of 5 ==
Date: Sun, Jan 30 2011 7:32 am
From: Jeffrey Angus

On 1/30/2011 9:21 AM, William Sommerwerck wrote:
> I own a 36" flat-face 400-series Sony WEGA IDTV and, yes, I have the service
> manual.

Is that the same set you kept trying to give away on
rec.antique.radio+phono?

Jeff

== 3 of 5 ==
Date: Sun, Jan 30 2011 8:26 am
From: "William Sommerwerck"

>> I own a 36" flat-face 400-series Sony WEGA IDTV
>> and, yes, I have the service manual.

> Is that the same set you kept trying to give away
> on rec.antique.radio+phono?

Are you kidding? That was an NAD MR-20A with a failing focus system.

It is a classic set, and worth restoring -- if you can find the parts needed
(most likely a no-longer-available HOT system). If someone wants it, it's
theirs for the cost of shipping.

== 4 of 5 ==
Date: Sun, Jan 30 2011 12:17 pm
From: Meat Plow

On Sun, 30 Jan 2011 07:21:36 -0800, William Sommerwerck wrote:

> I'm posting this to see if anyone /knows/ the answer, or has a
> reasonable suspicion. I do not want to initiate an interminable chain of
> speculation.
>
> I own a 36" flat-face 400-series Sony WEGA IDTV and, yes, I have the
> service manual. The set has gotten heavy use over the past decade; I
> often leave it on when I go to bed. It wasn't cheap, and I'd like to get
> at least another five years out of it. For a non-HD CRT set, it has an
> excellent picture, especially with RGB signals from a DVD player.
>
> When the set's turned on, the HV is apparently shut off, so that the CRT
> heater has time to come to full temperature, to avoid stripping the
> cathode. (This is speculation.) Though sound comes on almost
> immediately, it takes about 10 seconds for the raster to appear.
>
> Recently I've noticed "something new". For about two seconds after the
> raster comes on, the black level is too light. You can see the image
> "darkening" as the black level drops to its "correct" point. This occurs
> only when the set is "cold"; cycling the power doesn't cause this.
>
> I'm hoping someone will say "I've seen this. It's the ___________."
> Troubleshooting this set won't be easy (if only because it's close to
> the wall on a near-immovable stand). I don't want to tear into it until
> I'm reasonably certain I can fix it on the first try.
>
> Thanks in advance.

Wait until it is a problem that doesn't go away after 2 seconds.

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

== 5 of 5 ==
Date: Sun, Jan 30 2011 12:22 pm
From: "William Sommerwerck"

> Wait until it's a problem that doesn't go away after 2 seconds.

In other words, wait until an "intermittent" becomes permanent.

Definitely common sense -- but I'd rather make an end run around the
problem.

==============================================================================
TOPIC: surges slowly destroying
http://groups.google.com/group/sci.electronics.repair/t/97cd7b53147e2809?hl=en
==============================================================================

== 1 of 2 ==
Date: Sun, Jan 30 2011 7:37 am
From: mm

Question at ====> line:

http://www.squidoo.com/small-led-light-surge-protector

Small LED Light As Indicator In A Surge Protector
However, the most beneficial advancement of late is that small LED
bulbs are now utilized as indicator lights in the device that protects
equipment from power surges, the surge protector. Surges, otherwise
called voltage spikes or transient surges, are abrupt increases in
household voltage what happen when high-energy appliances or computers
are powered on. Such surges can take place in excess of 2,000 times
per year in homes, slowly destroying the components of a home

=====> Is this sentence true. Many times a year? And more
importantly, *slowly* destroying. Not ruined or "no damage"?

computer, a cell phone, and other fragile electronic equipment. Other
home appliances, furnaces, air conditioners, washers, dryers, and the
like, are also know to create surges which travel back through the
main breaker panel and out again through the home wiring.

== 2 of 2 ==
Date: Sun, Jan 30 2011 9:09 am
From: bud--

mm wrote:
> Question at ====> line:
>
> http://www.squidoo.com/small-led-light-surge-protector
>
> Small LED Light As Indicator In A Surge Protector
> However, the most beneficial advancement of late is that small LED
> bulbs are now utilized as indicator lights in the device that protects
> equipment from power surges, the surge protector. Surges, otherwise
> called voltage spikes or transient surges, are abrupt increases in
> household voltage what happen when high-energy appliances or computers
> are powered on. Such surges can take place in excess of 2,000 times
> per year in homes, slowly destroying the components of a home
>
> =====> Is this sentence true. Many times a year? And more
> importantly, *slowly* destroying. Not ruined or "no damage"?

Many times a year - sure. How big a surge counts? Do they count surges
that can do no damage? Yes.

Slowly deteriorating? Can happen. Mostly hype.

Manufacturers don't publish specs, but equipment is likely to have a
surge immunity of about 600 or 800V.

>
> computer, a cell phone, and other fragile electronic equipment. Other
> home appliances, furnaces, air conditioners, washers, dryers, and the
> like, are also know to create surges which travel back through the
> main breaker panel and out again through the home wiring.

Some devices, like motors when shut off, can create surges. Not likely
to damage anything. More hype.

Surges damage cell phones? I would ignore anything this source says.

An excellent source of information on surges for the general public is:
<http://www.nist.gov/public_affairs/practiceguides/surgesfnl.pdf>

For the more technically inclined a better source from the IEEE is:
<http://www.mikeholt.com/files/PDF/LightningGuide_FINALpublishedversion_May051.pdf>

--
bud--

==============================================================================
TOPIC: Is it possible to repair a whole house surge suppressor?
http://groups.google.com/group/sci.electronics.repair/t/ce6c11f1c7a190bf?hl=en
==============================================================================

== 1 of 5 ==
Date: Sun, Jan 30 2011 8:03 am
From: mm

Is it possible to repair a whole house surge suppressor?

At 100 to 200 dollars, I don't want to keep buying new ones.

I was going to install a whole house surge suppressor. When one of
them does its function, I think the MOV burns out, or some part does.

I haven't seen anything on the web about replacement modules for even
those units that might have them.

Will I be able to find, buy, and solder in replacement MOVs after the
first one burns out? (the green led goes out and the red led goes on)

I can't find any info about plug-in replacement parts, so if I can
repair any unit myself, I won't have to shop so thoroughly.

Items for sale, if interested:
I can install it myself. I'm considering, in ascending price order:
http://www.amazon.com/Intermatic-IG1240RC3-Type-2-Protection-Device/dp/B003NVLWN2/ref=pd_luc_sbs_00_01_t_lh
http://www.amazon.com/INTERMATIC-IG3240RC3-PANEL-SURGE-ARRESTOR/dp/B003A3MUJI/ref=pd_luc_sbs_00_02_t_lh
http://www.smarthome.com/4860/Leviton-51120-1-Whole-House-Surge-Suppressor-Surge-Protector/p.aspx

and less likely (plus two are required, one for each leg)
http://www.amazon.com/Square-D-SDSA1175CP-ARRESTER-LIGHTNG/dp/B002GUZ1NI

== 2 of 5 ==
Date: Sun, Jan 30 2011 8:39 am
From: "Geoffrey S. Mendelson"

mm wrote:
> Is it possible to repair a whole house surge suppressor?
>
> At 100 to 200 dollars, I don't want to keep buying new ones.

Stop buying junk. MOV surge protectors are really worthless junk. Here in
230v land, when they go, they often do so with a bang and sometimes catch
fire.

Look at TransTector ones. They use silicon avalance diodes which when compared
to MOVs are indestructable. They are more expensive but in the long run cheaper
as they don't fail like MOV ones.

You might also want to learn about how lightening works and how to avoid it.

Contrary to what people believe (yes Franklin got it wrong) lightening flows
from the GROUND UP. Once a path is opened from the ground, the polarity
reverses and the usual flash you see flows downward.

If you place grounded sharp pointed objects on top of buildings, you will
CREATE lightening.

If you place large "fuzzy" grounded objects on top of buildings, you will
dissipate any charges that build up and reduce the chance of lightening
strikes.

I got rid of a lightening problem by placing a large 2m ham band (144mHz)
antenna on my roof. It was a 12 foot beam with 10 vertical elements and
10 horizontal elements. At 144mHz it was an antenna, at DC (lightening)
it was just a big blob of aluminum connected to ground. So as charges
started to build up, they were dissipated.

When I moved, I took down the antenna, I wonder what my neighbors thought
when the lightening returned. :-(

Geoff.

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

== 3 of 5 ==
Date: Sun, Jan 30 2011 9:07 am
From: bud--

mm wrote:
> Is it possible to repair a whole house surge suppressor?
>
> At 100 to 200 dollars, I don't want to keep buying new ones.

It is an engineered device with internal protection matched to the MOVs.
I would never repair one.

>
>
> I was going to install a whole house surge suppressor. When one of
> them does its function, I think the MOV burns out, or some part does.

Surge hits to a MOV deteriorate it. With high ratings a suppressor will
last a very long time. The worst case surge on a service power line to
your house that has any reasonable chance of occurring is 10,000A.
Suppressors with much higher ratings are readily available.

For a house, the IEEE recommends ratings of 20,000 to 70,000A _per
wire_. For high lightning areas the recommendation is 40,000 to 120,000A
_per wire_.

>
> I haven't seen anything on the web about replacement modules for even
> those units that might have them.
>
> Will I be able to find, buy, and solder in replacement MOVs after the
> first one burns out? (the green led goes out and the red led goes on)
>
>
> I can't find any info about plug-in replacement parts, so if I can
> repair any unit myself, I won't have to shop so thoroughly.

Make sure your fire insurance covers the suppressor you engineered.

>
>
> Items for sale, if interested:
> I can install it myself. I'm considering, in ascending price order:
> http://www.amazon.com/Intermatic-IG1240RC3-Type-2-Protection-Device/dp/B003NVLWN2/ref=pd_luc_sbs_00_01_t_lh

This has minimal information and no ratings. Didn't look at the two below.

> http://www.amazon.com/INTERMATIC-IG3240RC3-PANEL-SURGE-ARRESTOR/dp/B003A3MUJI/ref=pd_luc_sbs_00_02_t_lh
> http://www.smarthome.com/4860/Leviton-51120-1-Whole-House-Surge-Suppressor-Surge-Protector/p.aspx
>
>
> and less likely (plus two are required, one for each leg)
> http://www.amazon.com/Square-D-SDSA1175CP-ARRESTER-LIGHTNG/dp/B002GUZ1NI

Also has minimal information and no ratings. If it only protects one
wire don't get it - get one made for a service protecting both wires. I
do like SquareD as a brand.

--
bud--

== 4 of 5 ==
Date: Sun, Jan 30 2011 9:38 am
From: bud--

Geoffrey S. Mendelson wrote:
> mm wrote:
>> Is it possible to repair a whole house surge suppressor?
>>
>> At 100 to 200 dollars, I don't want to keep buying new ones.
>
> Stop buying junk. MOV surge protectors are really worthless junk. Here in
> 230v land, when they go, they often do so with a bang and sometimes catch
> fire.

The IEEE (largest association of electrical and electronic engineers in
the US) says that ">90% of both hard-wired and plug-in protectors use
MOVs to perform the voltage-limiting function. In most AC protectors,
they are the only significant voltage limiters.".

MOVs work fine.

In the US, since 1998, UL has required suppressors have a thermal
disconnect to disconnect failing MOVS. I have seen no reason to believe
fires are a problem on UL listed suppressors made since 1998. Would
think that "230v land" would have similar requirements.

>
> Look at TransTector ones. They use silicon avalance diodes which when compared
> to MOVs are indestructable. They are more expensive but in the long run cheaper
> as they don't fail like MOV ones.

If you get high ratings, MOV based suppressors are not likely to fail.
It is one reason why some suppressors can have warranties on connected
equipment.

You can, of course, buy what you want.

>
> You might also want to learn about how lightening works and how to avoid it.
>
> Contrary to what people believe (yes Franklin got it wrong) lightening flows
> from the GROUND UP. Once a path is opened from the ground, the polarity
> reverses and the usual flash you see flows downward.

Polarity reverses?

The usual process is for charge do descend in steps - a stepped leader.
When the charge gets close enough to the earth the final link is a
stroke from the earth to end of the stepped leader.

>
> If you place grounded sharp pointed objects on top of buildings, you will
> CREATE lightening.

There is not a lot of research on what end on a lightning rod (now
called air terminals) is most effective. The best information I have
seen is that a 5/8" diameter rounded point is more effective, and the
difference is minimal. Rods protect by being the highest point. They are
a safe "point of attachment" for the lightning that will occur anyway.

>
> If you place large "fuzzy" grounded objects on top of buildings, you will
> dissipate any charges that build up and reduce the chance of lightening
> strikes.
>
> I got rid of a lightening problem by placing a large 2m ham band (144mHz)
> antenna on my roof. It was a 12 foot beam with 10 vertical elements and
> 10 horizontal elements. At 144mHz it was an antenna, at DC (lightening)
> it was just a big blob of aluminum connected to ground. So as charges
> started to build up, they were dissipated.

There are commercial lightning protection systems that claim to work by
dissipating charge. Everything I have seen is that they don't work. I
believe they lost a court case in the US.

>
> When I moved, I took down the antenna, I wonder what my neighbors thought
> when the lightening returned. :-(
>
> Geoff.
>

--
bud--

== 5 of 5 ==
Date: Sun, Jan 30 2011 9:49 am
From: "hrhofmann@att.net"

On Jan 30, 10:39 am, "Geoffrey S. Mendelson" <g...@mendelson.com>
wrote:
> mm wrote:
> > Is it possible to repair a whole house surge suppressor?
>
> > At 100 to 200 dollars, I don't want to keep buying new ones.
>
> Stop buying junk. MOV surge protectors are really worthless junk. Here in
> 230v land, when they go, they often do so with a bang and sometimes catch
> fire.
>
> Look at TransTector ones. They use silicon avalance diodes which when compared
> to MOVs are indestructable. They are more expensive but in the long run cheaper
> as they don't fail like MOV ones.
>
> You might also want to learn about how lightening works and how to avoid it.
>
> Contrary to what people believe (yes Franklin got it wrong) lightening flows
> from the GROUND UP. Once a path is opened from the ground, the polarity
> reverses and the usual flash you see flows downward.
>
> If you place grounded sharp pointed objects on top of buildings, you will
> CREATE lightening.
>
> If you place large "fuzzy" grounded objects on top of buildings, you will
> dissipate any charges that build up and reduce the chance of lightening
> strikes.
>
> I got rid of a lightening problem by placing a large 2m ham band (144mHz)
> antenna on my roof. It was a 12 foot beam with 10 vertical elements and
> 10 horizontal elements. At 144mHz it was an antenna, at DC (lightening)
> it was just a big blob of aluminum connected to ground. So as charges
> started to build up, they were dissipated.
>
> When I moved, I took down the antenna, I wonder what my neighbors thought
> when the lightening returned. :-(
>
> Geoff.
>
> --
> Geoffrey S. Mendelson N3OWJ/4X1GM
> Those who cannot remember the past are condemned to misquote it.

Geoff:

Lightening is what Michael Jackson did to his face. Lightning is that
big electrical discharge from the sky <G>

Bob Hofmann

==============================================================================
TOPIC: Pet hates ?
http://groups.google.com/group/sci.electronics.repair/t/e7925b5c2233e9ec?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Jan 30 2011 9:28 am
From: aemeijers

On 1/23/2011 3:02 AM, Smitty Two wrote:
> In article<4d3b9067$0$2378$822641b3@news.adtechcomputers.com>,
> David Nebenzahl<nobody@but.us.chickens> wrote:
>
>> On 1/21/2011 5:43 PM Arfa Daily spake thus:
>>
>>> He was in sunny Caffy-lornia ... Costa Mesa in Orange County, a few miles
>>> down the Interstate from LA
>>
>> OK, Arf, a small lesson in regional US dialects, free of charge:
>>
>> Nobody here in "Cal-ee-fonia", as our recently departed
>> Governator/Gropenator called it, calls them "interstates", even though
>> they are, in fact, interstate highways. Some folks back east may call
>> them that, though I'm not sure (I've heard them referred to as
>> "turnpikes" in some places). One wonders whether some LA residents even
>> know what an "interstate" is ...
>>
>> In any case, just in case you actually visit Caleefonia sometime in the
>> near future, you should also be aware of an important difference in
>> usage between SoCal (basically El-Lay and environs) and NoCal (San
>> Francisco and thereabouts). Down there, they don't use *any* noun for a
>> road (highway, interstate, etc.), but they do use articles with the road
>> number, as in "the 405", "the 101", etc.
>>
>> But beware: up here in the Beige Area, where we like to think we're so
>> much superior to our SoCal cousins, we never use the article, saying
>> instead "take 80 to get to Berkeley" or "take 101 to 280 to 17 to get
>> down to Santa Cruz". (One can easily spot newcomers to San Francisco who
>> refer to "the 80" or "the 101". That's just SO wrong!)
>
> I don't think Arfa is going to "blend" whether he uses your terminology
> or not, and I doubt that's his objective. But you wrote an awful lot of
> words without using "freeway," which is what we call the 101 here, and
> is the most common word for "interstate highway" throughout the midwest,
> as well. I'm not going to say unequivocally that it's widely used all
> over the U.S., because I don't know for sure, but I'd bet money on it.
>
> In cities with many freeways, they have to use more specific terms, but
> when there's only one, who needs a number?
>
> BTW, everyone I know in LA doesn't use numbers at all, but names that
> are meaningless to outsiders even if they have a map: "Ventura freeway,"
> "Hollywood freeway," "Pasadena freeway," etc.

Chicago, and to a lesser degree Detroit, are the same way. Must confuse
the crap out of visitors trying to understand traffic reports on the radio.

--
aem sends...

==============================================================================
TOPIC: Quest du jour- seeking T1.25 wire base blue tinted bulbs.
http://groups.google.com/group/sci.electronics.repair/t/a26e1506f0b6d44b?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Jan 30 2011 9:53 am
From: aemeijers

On 1/27/2011 3:12 PM, Harrison Lighting and Neon wrote:
> I am a lighting service person and we use DEKA brand transparent LIGHT BLUE
> #30
> glass stain. I have personally used this to dip antique x-mas lights and
> #47 dial bulbs with EXCELLENT results.......most any glass or hobby shop can
> get this.
> the small size bottle is 2/3 fluid ounce for about $4ea. this will do
> aprox 75 #40 lamps ( these were used as Christmas lights in the late
> 1940's)
> clean the lamps with alcohol, dip, stick the wire leads into a piece of
> Styrofoam at an angle so the paint drips down but not all over the
> leads....one dip will give very good results....if you really want to do it
> right bake these in a toaster oven at 200-300 degrees for aprox 15 minutes
> after they are dry to the touch. THIS WILL STINK a little,, so make sure
> the wife is away, but it wont damage the oven. or contact me by email and I
> can do a few for you if your not in a big hurry.
>
>
> Herb Harrison Oxnard Calif USA
>
>
>
>
> "aemeijers"<aemeijers@att.net> wrote in message
> news:PdSdnd-S09w2J93QnZ2dnUVZ_uidnZ2d@giganews.com...
>> Anybody know a source for T1 1/4 wire base bulbs (NOT LEDs) with blue
>> tint? Trying to replace the lights on the HVAC controls for a 2005
>> Caravan. Dealer claims they are unserviceable, and wants to sell me a
>> whole new pod for hundreds of dollars. I have already replaced them with
>> T1's (too small) after buying T1 3/4 that were too big (I feel like
>> Goldilocks), but the T1s are too short, and the blue condoms make them too
>> dim. I am aware of McMaster-Carr and Allied- that is where I wasted my
>> money on the first two tries, for the condoms and bulbs respectively.
>> Allied has clear bulbs in the right size (now that dummy me figured out
>> what the size is), but not the tinted ones.
>>
>> And yes, I already tried rec.autos.tech.
>>
>> --
>> aem sends...
>
>

I think we have a winner here. Local Hobby Lobby didn't have the exact
stuff specified, but they did have stained glass paint in daubing
bottles, that they claimed were from the same company, although it
didn't say so on the bottle. I tried it on a couple of the wrong-size
bulbs, and it seemed to work okay. I have ordered t1.25s from Allied,
and first warm (or at least above-freezing) day, I'll open it up and
give it another try. Bulbs should be here Monday or Tues, so I'll
pre-paint enough of them and leave them stuck in the foam block sitting
in a sunny window for several days, for maximum hardness (short of over
baking. After 4 years of non-use, I'm scared to open my oven.)

--
aem sends...

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

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9 Response to sci.electronics.repair - 25 new messages in 11 topics - digest

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March 23, 2015 at 2:37 AM

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May 1, 2015 at 12:53 AM

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