sci.electronics.repair - 22 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: What is this strange encoder motor?
http://groups.google.com/group/sci.electronics.repair/t/c033e5f3d5b31265?hl=en
==============================================================================

== 1 of 2 ==
Date: Tues, Aug 3 2010 2:10 pm
From: Ignoramus30076

On 2010-08-03, Jon Elson <jmelson@wustl.edu> wrote:
> Ignoramus18921 wrote:
>
>> Tim, how much angular accuracy could I get from this resolver, in
>> pulses per revolution?
>>
> The AD2S1200 converter chip I use in my converter board gives 4096
> quadrature counts/rev, with an index pulse.

Sounds like a luxury item.

I already bought this converter from you. Things seemingly are going
well.

Igor

== 2 of 2 ==
Date: Wed, Aug 4 2010 1:54 am
From: Clifford Heath

Tim Wescott wrote:
> I would bore the hole for the threads

And the easiest way to help get the hole concentric is
to fix the drill bit and rotate the shaft in a lathe.
Since you probably can't chuck the motor's armature, is
is possible you could drill the hole using the motor's
own power to rotate the shaft?

==============================================================================
TOPIC: Videorecorder problem - see pics
http://groups.google.com/group/sci.electronics.repair/t/6e566ea01f711ec0?hl=en
==============================================================================

== 1 of 3 ==
Date: Tues, Aug 3 2010 2:23 pm
From: Adrian C

On 03/08/2010 14:41, Meat Plow wrote:
I started out in the VTR
> repair world back when it took two people to life a U-Matic deck on the
> workbench.

Resuscitate? Kiss of life?

--
Adrian C

== 2 of 3 ==
Date: Tues, Aug 3 2010 2:40 pm
From: Meat Plow

On Tue, 03 Aug 2010 22:23:07 +0100, Adrian C wrote:

> On 03/08/2010 14:41, Meat Plow wrote:
> I started out in the VTR
>> repair world back when it took two people to life a U-Matic deck on the
>> workbench.
>
> Resuscitate? Kiss of life?

LOL

--
This is a test sig

== 3 of 3 ==
Date: Tues, Aug 3 2010 2:42 pm
From: Meat Plow

On Tue, 03 Aug 2010 22:23:07 +0100, Adrian C wrote:

> On 03/08/2010 14:41, Meat Plow wrote:
> I started out in the VTR
>> repair world back when it took two people to life a U-Matic deck on the
>> workbench.
>
> Resuscitate? Kiss of life?

Life...just saw that. Not a typo the t and e keys aren't together. More
life a Freudian slip.

--
This is a test sig

==============================================================================
TOPIC: 125 VAC motor won't start
http://groups.google.com/group/sci.electronics.repair/t/a1adec446eb7f728?hl=en
==============================================================================

== 1 of 3 ==
Date: Tues, Aug 3 2010 4:30 pm
From: a453

I searched but found no reference to my motor.. it's a bit old.... the
old capacitor is all rusty and unreadable so with some approximation on
"similar " motors I trend to install a new 220v 108-130 MFD
capacitor.... the motor ran fine for a bit and then the capacitor
"popped"... I guess I burned it....

SHould I try use a capacitor with a higher or lower MFD number (the
motor runs on ordinary houseol 115-120volt power) thanks

== 2 of 3 ==
Date: Tues, Aug 3 2010 7:20 pm
From: "hr(bob) hofmann@att.net"

On Aug 3, 6:30 pm, a453 <a...@a453.nospam.nospam.com> wrote:
> I searched but found no reference to my motor.. it's a bit old.... the
> old capacitor is all rusty and unreadable so with some approximation on
> "similar " motors I trend to install a new 220v 108-130 MFD
> capacitor.... the motor ran fine for a bit and then the capacitor
> "popped"... I guess I burned it....
>
> SHould I try use a capacitor with a higher or lower MFD number (the
> motor runs on ordinary houseol 115-120volt power) thanks

TRy a higher voltage capacitor.

== 3 of 3 ==
Date: Tues, Aug 3 2010 10:22 pm
From: "Jack Myers"

a453 <a453@a453.nospam.nospam.com> wrote:

> I searched but found no reference to my motor.. it's a bit old.... the
> old capacitor is all rusty and unreadable so with some approximation on
> "similar " motors I trend to install a new 220v 108-130 MFD
> capacitor.... the motor ran fine for a bit and then the capacitor
> "popped"... I guess I burned it....

> SHould I try use a capacitor with a higher or lower MFD number (the
> motor runs on ordinary houseol 115-120volt power) thanks

A motor starting capacitor is designed to carry AC (alternating current)
when an alternating voltage is applied. Did you perchance substitute a
capacitor rated for 220v DC? That would almost certainly pop.

--
Jack Myers / Westminster, California, USA

Our policy is, when in doubt, do the right thing.
-- Roy L. Ash, ex-president, Litton Industries

==============================================================================
TOPIC: STA5141 , TO5 transistor from 1974
http://groups.google.com/group/sci.electronics.repair/t/afb089d26be1db16?hl=en
==============================================================================

== 1 of 2 ==
Date: Tues, Aug 3 2010 1:59 am
From: "Arfa Daily"

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:i38jil$uni$1@news.eternal-september.org...
> N_Cook <diverse@tcp.co.uk> wrote in message
> news:i38htv$pbu$1@news.eternal-september.org...
>> In the pa of HH HA100 amp from 1974, probably ok but cannot find any info
> on
>> it, just maybe STA6141, a bit indistinct
>>
>>
>
> Logo on this and the other contemporaneous TO5 of 2N3440 and 2N5415 is
> indistinct that at first sight looks like curvey M but is STT or SIT or
> STI
> with shaded and sloping capital letters melded together
>
>

Wasn't STT one of Thomson's before they became Thomson Microelectronics, or
some such ?

Arfa

== 2 of 2 ==
Date: Wed, Aug 4 2010 12:28 am
From: "N_Cook"

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:Jw26o.18757$MQ3.15750@hurricane...
>
>
> "N_Cook" <diverse@tcp.co.uk> wrote in message
> news:i38jil$uni$1@news.eternal-september.org...
> > N_Cook <diverse@tcp.co.uk> wrote in message
> > news:i38htv$pbu$1@news.eternal-september.org...
> >> In the pa of HH HA100 amp from 1974, probably ok but cannot find any
info
> > on
> >> it, just maybe STA6141, a bit indistinct
> >>
> >>
> >
> > Logo on this and the other contemporaneous TO5 of 2N3440 and 2N5415 is
> > indistinct that at first sight looks like curvey M but is STT or SIT or
> > STI
> > with shaded and sloping capital letters melded together
> >
> >
>
> Wasn't STT one of Thomson's before they became Thomson Microelectronics,
or
> some such ?
>
> Arfa
>

I cannot be sure it is STT logo, I would not say it was STC , no C at the
end. There was an STC STA9... range. Anyway for anyone meeting one in
earnest it is TO3, NPN, "D" pinning EBC and probably 300V rating like the
others in that area

==============================================================================
TOPIC: SMT rework
http://groups.google.com/group/sci.electronics.repair/t/cab4440230d769af?hl=en
==============================================================================

== 1 of 3 ==
Date: Tues, Aug 3 2010 8:25 am
From: "Arfa Daily"

"Herman" <ripe@bellsouth.net> wrote in message
news:i393ul$gdd$1@news.albasani.net...
>
> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
> news:FBh5o.37277$gM.26872@hurricane...
>>
>>
>> "Herman" <ripe@bellsouth.net> wrote in message
>> news:i32fmn$iu8$1@news.albasani.net...
>>> I am looking to buy a hot air SMT rework station. Only for occasional
>>> use. I like the idea of the vacuum pencil and the hot tweezers. What
>>> would be the recommended tips for general use for ICs and resistors etc.
>>> I do not need to do the PLLC size chips. Price $300 max or so.
>>>
>>
>> I have recently purchased a hot air rework station. It has hot air
>> handpiece with fully controllable airflow and temperature. Digital
>> readout for temp. Also has conventional iron with stand, again fully
>> controllable temp and digital readout. Comes with 5 round hot air
>> nozzles. Square ones for QFPs etc purchased from other sources fit, I
>> understand from a friend who also has one. Also 5 tips for the soldering
>> iron, spare element for the hot air and spare element for the soldering
>> iron. I paid 55UKP for it, so work that out in USD - about $80 maybe.
>> Company I got it from is in China and called dragondirectmall. Very
>> efficient and helpful service. Once it had been collected from them by
>> DHL, arrived at my door less than 24 Hrs later. On their eBay site, they
>> have a video showing a station being built, and you can see that for the
>> money, it is incredible value.
>>
>> Go to eBay and put in "KADA 852D" then look for the one that says "buy
>> now for £55". They have USD prices as well, as far as I recall. Very
>> satisfied with mine, so far.
>>
>> Arfa
>
> I was looking at that one. What do you think about the vacuum pencil and
> the hot tweezers? Seems like a good idea for resistors and diodes. Do
> the tips supplied work for small ICs? I have never used one of these
> stations.
>

I've never bothered with vacuum pencils and hot tweezers. I guess it depends
how much you are going to be doing with it. I work with surface mount on a
daily basis, but it's actually pretty reliable stuff, in general. When I
need to get a resistor off a board, I just heat both ends alternately with a
standard iron, and then 'flick' it off the pads. If I have one that is in an
awkward place to do that, I use one of the shaped bits that I have for my
Antex station. These are just 'standard' tips in that they fit any Antex 25
watt iron, but have a sort of 'forked' tip, the prongs being the right
distance apart to heat both ends simultaneously, of standard profile sm
components. There are also tips in the same range that have an I.C. spacing
to the forks, and are the length of an IC. Good for your standard sized 8 /
14 / 24 etc pinned sm ICs. I have a full set of these specially shaped tips
that I use when needed with my Antex temp controlled station. Not cheap, but
a good investment. As for picking the devices up, I just use needle tipped
stainless steel tweezers.

The smallest nozzle supplied for the hot air handpiece is a couple of mm
diameter. It easily allows removal of ICs as long as they are not too big.
The process involves going round and round the pin rows until it's hot
enough for the solder on all pins to stay molten long enough to flick the IC
off the board. Obviously, if it's a very big QFP package, then that's not so
easy to do, and a shaped nozzle to heat all four sides at once, is more
appropriate.

That said, when I got my KADA hot air station, I spent a while getting a
'feel' for it, and I removed all sizes of QFP ICs from and old mother board,
and just to prove that you could, I even removed two BGAs that were probably
4cm square each.

I guess it's horses for courses, but for general use, so far, I can
thoroughly recommend my KADA as being a good value for money tool, and
actually, of remarkable quality and functionality, for the price.

Arfa

== 2 of 3 ==
Date: Tues, Aug 3 2010 8:32 pm
From: stratus46@yahoo.com

On Aug 3, 6:01 am, "Herman" <r...@bellsouth.net> wrote:
<snip>
> I was looking at that one. What do you think about the vacuum
pencil and
> the hot tweezers? Seems like a good idea for resistors and diodes.
Do the
> tips supplied work for small ICs? I have never used one of these
stations.

A couple weeks back we had to transplant a pair of 100 pin QFP chips
on an old Sony broadcast VTR. To remove them we used an Ungar hot air
gun like you'd use for heat shrink. To replace them we used a Metcal
STTC-126 tip and over-soldered and cleaned up with solder wick
followed by flux removal. These were not high density pins but I have
used this technique on 0.5 mm pin spacing. Personally I find a Metcal
soldering iron a far more useful tool.

G²

== 3 of 3 ==
Date: Tues, Aug 3 2010 8:44 pm
From: Jim Yanik

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in
news:Kw26o.18759$MQ3.15154@hurricane:

>
>
> "Herman" <ripe@bellsouth.net> wrote in message
> news:i393ul$gdd$1@news.albasani.net...
>>
>> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
>> news:FBh5o.37277$gM.26872@hurricane...
>>>
>>>
>>> "Herman" <ripe@bellsouth.net> wrote in message
>>> news:i32fmn$iu8$1@news.albasani.net...
>>>> I am looking to buy a hot air SMT rework station. Only for
>>>> occasional use. I like the idea of the vacuum pencil and the hot
>>>> tweezers. What would be the recommended tips for general use for
>>>> ICs and resistors etc. I do not need to do the PLLC size chips.
>>>> Price $300 max or so.
>>>>
>>>
>>> I have recently purchased a hot air rework station. It has hot air
>>> handpiece with fully controllable airflow and temperature. Digital
>>> readout for temp. Also has conventional iron with stand, again fully
>>> controllable temp and digital readout. Comes with 5 round hot air
>>> nozzles. Square ones for QFPs etc purchased from other sources fit,
>>> I understand from a friend who also has one. Also 5 tips for the
>>> soldering iron, spare element for the hot air and spare element for
>>> the soldering iron. I paid 55UKP for it, so work that out in USD -
>>> about $80 maybe. Company I got it from is in China and called
>>> dragondirectmall. Very efficient and helpful service. Once it had
>>> been collected from them by DHL, arrived at my door less than 24 Hrs
>>> later. On their eBay site, they have a video showing a station being
>>> built, and you can see that for the money, it is incredible value.
>>>
>>> Go to eBay and put in "KADA 852D" then look for the one that says
>>> "buy now for £55". They have USD prices as well, as far as I recall.
>>> Very satisfied with mine, so far.
>>>
>>> Arfa
>>
>> I was looking at that one. What do you think about the vacuum pencil
>> and the hot tweezers? Seems like a good idea for resistors and
>> diodes. Do the tips supplied work for small ICs? I have never used
>> one of these stations.
>>
>
> I've never bothered with vacuum pencils and hot tweezers. I guess it
> depends how much you are going to be doing with it. I work with
> surface mount on a daily basis, but it's actually pretty reliable
> stuff, in general. When I need to get a resistor off a board, I just
> heat both ends alternately with a standard iron, and then 'flick' it
> off the pads. If I have one that is in an awkward place to do that, I
> use one of the shaped bits that I have for my Antex station. These are
> just 'standard' tips in that they fit any Antex 25 watt iron, but have
> a sort of 'forked' tip, the prongs being the right distance apart to
> heat both ends simultaneously, of standard profile sm components.
> There are also tips in the same range that have an I.C. spacing to the
> forks, and are the length of an IC. Good for your standard sized 8 /
> 14 / 24 etc pinned sm ICs. I have a full set of these specially shaped
> tips that I use when needed with my Antex temp controlled station. Not
> cheap, but a good investment. As for picking the devices up, I just
> use needle tipped stainless steel tweezers.
>
> The smallest nozzle supplied for the hot air handpiece is a couple of
> mm diameter. It easily allows removal of ICs as long as they are not
> too big. The process involves going round and round the pin rows until
> it's hot enough for the solder on all pins to stay molten long enough
> to flick the IC off the board. Obviously, if it's a very big QFP
> package, then that's not so easy to do, and a shaped nozzle to heat
> all four sides at once, is more appropriate.
>
> That said, when I got my KADA hot air station, I spent a while getting
> a 'feel' for it, and I removed all sizes of QFP ICs from and old
> mother board, and just to prove that you could, I even removed two
> BGAs that were probably 4cm square each.
>
> I guess it's horses for courses, but for general use, so far, I can
> thoroughly recommend my KADA as being a good value for money tool, and
> actually, of remarkable quality and functionality, for the price.
>
> Arfa
>
>

I've used the Pace thermo-tweeze system,at Tektronix.It's nice,but the tips
for the many types of ICs gets costly.

do you use a hot plate [or other pre-heat] for pre-heat of the workpiece?

--
Jim Yanik
jyanik
at
localnet
dot com

==============================================================================
TOPIC: hissing sound coming from behind woofer on one side AR11
http://groups.google.com/group/sci.electronics.repair/t/3a9cce9766f809ce?hl=en
==============================================================================

== 1 of 3 ==
Date: Mon, Aug 2 2010 5:18 pm
From: "Arfa Daily"

"Meat Plow" <mhywatt@yahoo.com> wrote in message
news:pan.2010.08.02.16.02.36@hahahahahahahah.nutz...
> On Mon, 02 Aug 2010 09:21:24 -0500, Chuck wrote:
>
>> On Tue, 20 Jul 2010 12:30:48 -0700 (PDT), Amanda Ripanykhazov
>> <dmanzaluni@googlemail.com> wrote:
>>
>>>Anyone know what this means? This hissing sound isnt constant, it is
>>>irregular: It isnt related to the music or any movement of the cone or
>>>any signal put through it, though it doesnt happen when no sound is put
>>>through the speaker.
>>>
>>>Frankly it sounds more mechancial than electronic (as if there is
>>>something behind there!) but as I say, it isnt related to whatever is
>>>coming through the speaker though it does increase and decrease with
>>>adjustment of the volume control. Andit is louder than most signals put
>>>through the woofer itself??
>>>
>>>Is it indicative of some pot in the crossover needing cleaning or is
>>>there something else going on please? (I have seen reference to people
>>>improving the sound of AR11s by bypassing the tone controls in the
>>>speaker completely). This speaker is quite elderly and I would imagine
>>>that if it does use mechanical pots, they must be fairly dirty by now
>>
>>
>> I once lived in an old mansion that had been converted into an apartment
>> building where one of my KLH 32 speakers was mounted by the main
>> electrical entrance for the building. There sometimes was a soft noise
>> from the tweeter without the amplifier being on. Later on we discovered
>> that the owner of the building had replaced one of the cartridge fuses
>> in series with the hot 120 AC in with a piece of copper pipe that was
>> arcing at the fuse clips. I know this sounds apocryphal but I spent 32
>> years in the consumer audio field as a technician, and service and store
>> manager so you can be reasonably sure, in this case, that I'm not a
>> troll . Chuck
>
> An old friend used to live within a hundred feet of a radio station. He
> swears that on one occasion he could hear programming coming from a
> filling in one of his molars.

This is quite common. The BBC used to operated a long wave transmitter in
the county where I live. It was 200kW during the daylight hours, and 470kW
at night. There were always reports in the local newspaper of people
experiencing oddball reception events, and picking up radio 'in your head'
was a regular one. Apparently, it happens more when fillings are new, and
the oxide layers or what have you, are still building. Supposedly, the
filling acts as a simple diode detector, and if the field strength is high
enough, actually 'rattles' mechanically. The vibration from this passes out
of the tooth and up the jawbone into the skull, where it is picked up
directly by the ears. I have also seen the phenomenon explained as the
detected audio voltage passing out of the tooth, and directly stimulating
nerves that are part of the hearing centre. I suppose that's possible, but
it sounds less likely to me, than the first explanation.

Another few favourites for 'ghost' reception near this transmitter, were
electric cookers, stereo systems that were turned off, and mattress springs
!!

Arfa

== 2 of 3 ==
Date: Tues, Aug 3 2010 5:37 pm
From: Meat Plow

On Tue, 03 Aug 2010 01:18:22 +0100, Arfa Daily wrote:

> "Meat Plow" <mhywatt@yahoo.com> wrote in message
> news:pan.2010.08.02.16.02.36@hahahahahahahah.nutz...
>> On Mon, 02 Aug 2010 09:21:24 -0500, Chuck wrote:
>>
>>> On Tue, 20 Jul 2010 12:30:48 -0700 (PDT), Amanda Ripanykhazov
>>> <dmanzaluni@googlemail.com> wrote:
>>>
>>>>Anyone know what this means? This hissing sound isnt constant, it is
>>>>irregular: It isnt related to the music or any movement of the cone
>>>>or any signal put through it, though it doesnt happen when no sound is
>>>>put through the speaker.
>>>>
>>>>Frankly it sounds more mechancial than electronic (as if there is
>>>>something behind there!) but as I say, it isnt related to whatever is
>>>>coming through the speaker though it does increase and decrease with
>>>>adjustment of the volume control. Andit is louder than most signals
>>>>put through the woofer itself??
>>>>
>>>>Is it indicative of some pot in the crossover needing cleaning or is
>>>>there something else going on please? (I have seen reference to people
>>>>improving the sound of AR11s by bypassing the tone controls in the
>>>>speaker completely). This speaker is quite elderly and I would
>>>>imagine that if it does use mechanical pots, they must be fairly dirty
>>>>by now
>>>
>>>
>>> I once lived in an old mansion that had been converted into an
>>> apartment building where one of my KLH 32 speakers was mounted by the
>>> main electrical entrance for the building. There sometimes was a soft
>>> noise from the tweeter without the amplifier being on. Later on we
>>> discovered that the owner of the building had replaced one of the
>>> cartridge fuses in series with the hot 120 AC in with a piece of
>>> copper pipe that was arcing at the fuse clips. I know this sounds
>>> apocryphal but I spent 32 years in the consumer audio field as a
>>> technician, and service and store manager so you can be reasonably
>>> sure, in this case, that I'm not a troll . Chuck
>>
>> An old friend used to live within a hundred feet of a radio station. He
>> swears that on one occasion he could hear programming coming from a
>> filling in one of his molars.
>
> This is quite common. The BBC used to operated a long wave transmitter
> in the county where I live. It was 200kW during the daylight hours, and
> 470kW at night. There were always reports in the local newspaper of
> people experiencing oddball reception events, and picking up radio 'in
> your head' was a regular one. Apparently, it happens more when fillings
> are new, and the oxide layers or what have you, are still building.
> Supposedly, the filling acts as a simple diode detector, and if the
> field strength is high enough, actually 'rattles' mechanically. The
> vibration from this passes out of the tooth and up the jawbone into the
> skull, where it is picked up directly by the ears. I have also seen the
> phenomenon explained as the detected audio voltage passing out of the
> tooth, and directly stimulating nerves that are part of the hearing
> centre. I suppose that's possible, but it sounds less likely to me, than
> the first explanation.
>
> Another few favourites for 'ghost' reception near this transmitter, were
> electric cookers, stereo systems that were turned off, and mattress
> springs !!
>
> Arfa

So Amanda may live near a 500kw transmitter that plays wildlife sounds.
That would explain the snake hissing behind her speaker.

--
This is a test sig

== 3 of 3 ==
Date: Tues, Aug 3 2010 8:34 pm
From: "Michael A. Terrell"

Arfa Daily wrote:
>
> "Meat Plow" <mhywatt@yahoo.com> wrote in message
> news:pan.2010.08.02.16.02.36@hahahahahahahah.nutz...
> > On Mon, 02 Aug 2010 09:21:24 -0500, Chuck wrote:
> >
> >> On Tue, 20 Jul 2010 12:30:48 -0700 (PDT), Amanda Ripanykhazov
> >> <dmanzaluni@googlemail.com> wrote:
> >>
> >>>Anyone know what this means? This hissing sound isnt constant, it is
> >>>irregular: It isnt related to the music or any movement of the cone or
> >>>any signal put through it, though it doesnt happen when no sound is put
> >>>through the speaker.
> >>>
> >>>Frankly it sounds more mechancial than electronic (as if there is
> >>>something behind there!) but as I say, it isnt related to whatever is
> >>>coming through the speaker though it does increase and decrease with
> >>>adjustment of the volume control. Andit is louder than most signals put
> >>>through the woofer itself??
> >>>
> >>>Is it indicative of some pot in the crossover needing cleaning or is
> >>>there something else going on please? (I have seen reference to people
> >>>improving the sound of AR11s by bypassing the tone controls in the
> >>>speaker completely). This speaker is quite elderly and I would imagine
> >>>that if it does use mechanical pots, they must be fairly dirty by now
> >>
> >>
> >> I once lived in an old mansion that had been converted into an apartment
> >> building where one of my KLH 32 speakers was mounted by the main
> >> electrical entrance for the building. There sometimes was a soft noise
> >> from the tweeter without the amplifier being on. Later on we discovered
> >> that the owner of the building had replaced one of the cartridge fuses
> >> in series with the hot 120 AC in with a piece of copper pipe that was
> >> arcing at the fuse clips. I know this sounds apocryphal but I spent 32
> >> years in the consumer audio field as a technician, and service and store
> >> manager so you can be reasonably sure, in this case, that I'm not a
> >> troll . Chuck
> >
> > An old friend used to live within a hundred feet of a radio station. He
> > swears that on one occasion he could hear programming coming from a
> > filling in one of his molars.
>
> This is quite common. The BBC used to operated a long wave transmitter in
> the county where I live. It was 200kW during the daylight hours, and 470kW
> at night. There were always reports in the local newspaper of people
> experiencing oddball reception events, and picking up radio 'in your head'
> was a regular one. Apparently, it happens more when fillings are new, and
> the oxide layers or what have you, are still building. Supposedly, the
> filling acts as a simple diode detector, and if the field strength is high
> enough, actually 'rattles' mechanically. The vibration from this passes out
> of the tooth and up the jawbone into the skull, where it is picked up
> directly by the ears. I have also seen the phenomenon explained as the
> detected audio voltage passing out of the tooth, and directly stimulating
> nerves that are part of the hearing centre. I suppose that's possible, but
> it sounds less likely to me, than the first explanation.
>
> Another few favourites for 'ghost' reception near this transmitter, were
> electric cookers, stereo systems that were turned off, and mattress springs
> !!

WLW in Cincinnati, Ohio used to run 500 KW on 700 KHz under an
experimental license. Local farmers reported talking and singing fence
wire or a few miles from their tower.

http://hawkins.pair.com/wlw.shtml has some photos and a description,
along with a simplified schematic of the beast. It also has one of the
few remaining Blaw-Knox diamond towers.

WSM in Nashville has another Blaw-Knox tower. http://www.wsmonline.com

==============================================================================
TOPIC: Prada Watch cheapsale <free shipping paypal payment> (http://
http://groups.google.com/group/sci.electronics.repair/t/3eda51630ad33367?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Aug 3 2010 6:44 pm
From: su。

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==============================================================================
TOPIC: Glass fibre basket retainer for 5881/6L6
http://groups.google.com/group/sci.electronics.repair/t/16c10415e29b4168?hl=en
==============================================================================

== 1 of 2 ==
Date: Tues, Aug 3 2010 7:29 pm
From: "hr(bob) hofmann@att.net"

On Jul 31, 11:03 am, "N_Cook" <dive...@tcp.co.uk> wrote:
> Meat Plow <mhyw...@yahoo.com> wrote in message
>
> news:pan.2010.07.31.15.03.11@hahahahahahahah.nutz...
>
>
>
>
>
> > On Sat, 31 Jul 2010 14:20:52 +0100, N_Cook wrote:
>
> > > Meat Plow <mhyw...@yahoo.com> wrote in message
> > >news:pan.2010.07.31.13.02.48@hahahahahahahah.nutz...
> > >> On Sat, 31 Jul 2010 11:07:31 +0100, N_Cook wrote:
>
> > >> > Owner has managed to get away with dragons teeth retaining clips
> > >> > digging into the glass envelope of his replacement type with no
> > >> > bakelite base . How to fabricate something approximating those woven
> > >> > glass mesh baskets that go over the envelope and then a pair of
> > >> > springs down to the chassis or any other ideas other than replacing
> > >> > with based envelope types ?
>
> > >> > Incidently the first thing I did was undo the screws of the dragons
> > >> > teeth in hope of relieving some of the teeth force before removing
> > >> > the valves , but was that the correct approach?
>
> > >> Make something like Marshall used. Metal cap and springs.
>
> > > I don't fancy making a pierced metal dome shape, that has to avoid the
> > > fragile central area of the glass dome. So far I'm thinking of a length
> > > of high temp glass sleeving knotted into a ring, slightly smaller than
> > > envelope circumference, with a balancing "knot" on the other side. Then
> > > silicone sleeving or springs and glass sleeving down to a pair of solder
> > > tags as anchors. Nasty dragons teeth chips in the bottles but they
> > > survived
>
> > I think making an approximation of the Marshall device is your best bet.
> > They seem to not harm the glass in any I've worked on. And putting those
> > kind of 5881's in a jaw clamp is just plain idiotic. Especially if the
> > tubes hang.
>
> Another awkwardness of the Marshall ones is the tension points must be a
> good inch below the bottle tops and part wrap around to avoid sliding off.
> Yes underslung 2002 German Engl E320 50W combo.
> First time I've come across one of these , to do anything you have to take
> the whole amp to bits. Surprisingly 2 plain washers were split, probably
> from using a windy-drill to torque up. Even the maker's ECC83 retainers are
> an awkward bodge-up, not even fully screening.- Hide quoted text -
>
> - Show quoted text -

For those of us on the west side of the big pond, are you talking
about shields or about mounting clips to hold the tubes in place when
they are mounted other than pins down??

== 2 of 2 ==
Date: Wed, Aug 4 2010 12:33 am
From: "N_Cook"

hr(bob) hofmann@att.net <hrhofmann@att.net> wrote in message
news:8a5f11bb-2bf9-4e45-af3b-99679e34f885@q35g2000yqn.googlegroups.com...
On Jul 31, 11:03 am, "N_Cook" <dive...@tcp.co.uk> wrote:
> Meat Plow <mhyw...@yahoo.com> wrote in message
>
> news:pan.2010.07.31.15.03.11@hahahahahahahah.nutz...
>
>
>
>
>
> > On Sat, 31 Jul 2010 14:20:52 +0100, N_Cook wrote:
>
> > > Meat Plow <mhyw...@yahoo.com> wrote in message
> > >news:pan.2010.07.31.13.02.48@hahahahahahahah.nutz...
> > >> On Sat, 31 Jul 2010 11:07:31 +0100, N_Cook wrote:
>
> > >> > Owner has managed to get away with dragons teeth retaining clips
> > >> > digging into the glass envelope of his replacement type with no
> > >> > bakelite base . How to fabricate something approximating those
woven
> > >> > glass mesh baskets that go over the envelope and then a pair of
> > >> > springs down to the chassis or any other ideas other than replacing
> > >> > with based envelope types ?
>
> > >> > Incidently the first thing I did was undo the screws of the dragons
> > >> > teeth in hope of relieving some of the teeth force before removing
> > >> > the valves , but was that the correct approach?
>
> > >> Make something like Marshall used. Metal cap and springs.
>
> > > I don't fancy making a pierced metal dome shape, that has to avoid the
> > > fragile central area of the glass dome. So far I'm thinking of a
length
> > > of high temp glass sleeving knotted into a ring, slightly smaller than
> > > envelope circumference, with a balancing "knot" on the other side.
Then
> > > silicone sleeving or springs and glass sleeving down to a pair of
solder
> > > tags as anchors. Nasty dragons teeth chips in the bottles but they
> > > survived
>
> > I think making an approximation of the Marshall device is your best bet.
> > They seem to not harm the glass in any I've worked on. And putting those
> > kind of 5881's in a jaw clamp is just plain idiotic. Especially if the
> > tubes hang.
>
> Another awkwardness of the Marshall ones is the tension points must be a
> good inch below the bottle tops and part wrap around to avoid sliding off.
> Yes underslung 2002 German Engl E320 50W combo.
> First time I've come across one of these , to do anything you have to take
> the whole amp to bits. Surprisingly 2 plain washers were split, probably
> from using a windy-drill to torque up. Even the maker's ECC83 retainers
are
> an awkward bodge-up, not even fully screening.- Hide quoted text -
>
> - Show quoted text -

For those of us on the west side of the big pond, are you talking
about shields or about mounting clips to hold the tubes in place when
they are mounted other than pins down??

Not shields , these are output devices. We would call them retainers , just
to keep the valve in its socket , especially when upside down like here. Of
course shields also retain usually, dual function

==============================================================================
TOPIC: +++ NFL Jerseys On Sale at www.ajerseys.com
http://groups.google.com/group/sci.electronics.repair/t/25ecafc563d2ba82?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Aug 3 2010 8:18 pm
From: nana

NFL Jerseys On Sale at www.ajerseys.com

The National Football League (NFL) is the highest level of
professional American football. It was formed by eleven teams in 1920
as the American Professional Football Association, with the league
changing its name to the National Football League in 1922. The league
currently consists of thirty-two teams from the United States. The
league is divided evenly into two conferences — the American Football
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average attendance per game, with 68,509 fans per game in the latest
regular season.

==============================================================================
TOPIC: Supper Cooling Radion GPU in HP Pavilion tx2350ea Laptop - How to ?
http://groups.google.com/group/sci.electronics.repair/t/dd36c5466aa61918?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Aug 3 2010 10:02 pm
From: isw

In article <pan.2010.08.04.17.13.53.631152@mailinator.com>,
Gnack Nol <mchozfcesujcfc@mailinator.com> wrote:

> On Tue, 03 Aug 2010 13:45:42 +0000, Meat Plow wrote:
>
> > On Tue, 03 Aug 2010 13:41:42 +0100, mbegz wrote:
> >
> >> Hi all,
> >>
> >> I have this Laptop which has given up the ghost immediately two days
> >> after its warranty expiring. To cut the long story short, I have
> >> ordered another mobo. The original heat sink method for GPU on this
> >> mobo is thermal pad which I think is very inefficient, causing lots of
> >> laptop failure and HP has, I believe withdrawn this laptop from the
> >> market.
> >>
> >> There is a gap of about 1mm between the GPU and heat sink, and the
> >> surface of the heat sink is not flat for the obvious reason that it is
> >> meant for thermal pad.
> >>
> >> What alternative I have for cooling the GPU more effeciently ? Is it
> >> possible to fill the gap with some thermal compound which would not run
> >> or blead. Or reduce the gap with a copper shim and use thermal paste on
> >> either side. Resurfacing the original heat sink surface is not an
> >> option.
> >>
> >> Appreciate your thoughts on it.
> >
> > Direct contact with an even thin film of past is always the best.
> > Whatever you can do to approximate that would be the best solution. I
> > find it hard to believe there was a 1mm gap between the sink and the top
> > of the cpu, that's insanity.
>
> Well it's just the tip of the iceburg. This has been industry practice for
> at least 5 years now. They use a boron impregnated rubber pad to ease
> their quick assembly builds and make careful surfacing of the heatsink
> assembly unnecessary also it's street labor friendly for the building.

It's not unusual for Theta cs (thermal resistance, case to sink) to be
lower with a good silicone pad than with that "goo".

Isaac

==============================================================================
TOPIC: ===Christian Louboutin - www.vipchristianlouboutin.com
http://groups.google.com/group/sci.electronics.repair/t/37be626e9fe8b9f3?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Aug 3 2010 11:50 pm
From: ckedsdfs

Christian Louboutin - www.vipchristianlouboutin.com

Christian Louboutin was founded in 1992,France but it rapidly became
a
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Victoria Beckham. Once the red outsole appeared you will easily find
out that is Christian Louboutin. Ladies are crazy about it. If you
are
engaged in the vogue or you want keep the same pace with the trend.
Christian Louboutin could be your best choice

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

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