sci.electronics.repair@googlegroups.com

Today's topics:

* Toroidal mains Tx inrush limiter - retrofit - 3 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/da7ba841cd54d76f?hl=en
* Recommendation for electronics forums? - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/a2a97ca7806d8277?hl=en
* AVO 8 Mk 4 ... - 17 messages, 10 authors
http://groups.google.com/group/sci.electronics.repair/t/a0ca6d125e6a7e97?hl=en
* Speaker Crossover Wiring : Solve the Puzzle - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/9ce83c1fb5063b0f?hl=en
* LJ44-00092C - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/aadca16cb07e5e34?hl=en
* Compaq Presario 1230 Laptop Accessing BIOS Setup - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/82c722abeb2ce43e?hl=en
* לימוד תופים בסטודיו קצב הקשב - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/e3c480e79f4e43b9?hl=en

==============================================================================
TOPIC: Toroidal mains Tx inrush limiter - retrofit
http://groups.google.com/group/sci.electronics.repair/t/da7ba841cd54d76f?hl=en
==============================================================================

== 1 of 3 ==
Date: Sat, Apr 2 2011 12:33 am
From: "N_Cook"

Mike Tomlinson <mike@jasper.org.uk> wrote in message
news:GZ$5xNEjVclNFwGu@jasper.org.uk...
> In article <in4d0o$4dq$1@dont-email.me>, N_Cook <diverse@tcp.co.uk>
> writes
>
> >This green thermistor limiter 10 deg C over ambient with no throughput
and
> >20 deg C over with 0.4 amp mains with amp driving load.
>
> Bit warmer than I would be comfortable with.
>
> --
> Mike Tomlinson

Odd you say that. The next amp I looked at, this time mixer amp but also
300W and toroid Tx. Owner bought knowing 2 of the 8 channels were duff and
used as such for some years. He now needs all 8 ch .
Before he owned it , it must have been dropped and broke the awkward
size/shape mains switch. So someone spade jumpered the leads and covered
with heatshrink, leaving un-blanked off hole in chassis. Under his
heatshrink and touching the ordinary mains wire sleeving is an inrush
thermistor. Black , with 0.8mm leads, marked SG 130, 3.2R cold, 0.8R 20 sec
of soldering iron barrel. Presumably originally fixed to the sw and
unsupported other lead other than cable tie further down the cable loom.
Hopefully originally there was some woven glass sleeving over the thermistor

data for SG130 RTI Surge Guard, 0.07 ohms at 7 amps max , 2.5R at 25 deg C
27 joules rating for a 15 x 6.3 mm black (body radiator?) lump and .8mm
leads for anyone who can convert to temperature (not on the RTI datasheet)

== 2 of 3 ==
Date: Sat, Apr 2 2011 1:07 am
From: "N_Cook"

It looks as though you use the de-rating curve
http://www.rtie.com/ntc/surggard.htm
So for 7 amp NTC running outside of short duration peaks say an average 1/3
of 7 amps of mains 240V for driven amp and less than rated mains fuse then
125 degrees would be the operational maximum of the thermistor.
Would be nice to know a rule of thumb formula for real life "black body"
radiator/convector temperature and power consumption whether disc
thermistors or rod
resistors

== 3 of 3 ==
Date: Sat, Apr 2 2011 5:57 am
From: "N_Cook"

Testing this SG 130 on a 12V SLA and headlamp, stabilised at 2.8 amp, .91V
over it and 102 deg C (ambient 18 deg C), no woven glass sleeve covering

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

== 1 of 1 ==
Date: Sat, Apr 2 2011 1:26 am
From: Wiebe Cazemier

Michael A. Terrell wrote:

>> >> >>
>> >> >> > The subject of my current research is the ins and
>> >> >> > outs of op amps.
>> >> >>
>> >> >> A little pun, there?
>> >> >
>> >> > A bit bipolar, if you ask me...
>> >>
>> >> I dunno, but then again I may be biased.
>> >
>> >
>> > I figured that you were a little off center. :)
>> >
>> >
>>
>> Now that's unfair feedback :)
>
>
> Not if you're at unity gain... :)

But then you'll run into oscillation

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

== 1 of 17 ==
Date: Sat, Apr 2 2011 2:26 am
From: Harry Bloomfield

Dave Plowman (News) used his keyboard to write :
> In article <Cqmlp.4035$KZ7.856@newsfe08.ams2>,
> Arfa Daily <arfa.daily@ntlworld.com> wrote:
>> Anybody got a copy of the schematic that's in the back of the user guide
>> that they can scan for me, please ? I've searched all my files and
>> drawers high and low, and can't find my book anywhere ... I thought
>> that the 'net would be awash with copies of the schematic, but it seems
>> only for the Mk 2, which is totally different to the MK 4.
>
> Have you tried AVO direct? They still make the Model 8, IIRC.

They stopped making it about, oh - two or three years ago. I think too
expensive, too complex to make were the reasons quoted.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

== 2 of 17 ==
Date: Sat, Apr 2 2011 2:35 am
From: John Williamson

Harry Bloomfield wrote:
> Dave Plowman (News) used his keyboard to write :
>> In article <Cqmlp.4035$KZ7.856@newsfe08.ams2>,
>> Arfa Daily <arfa.daily@ntlworld.com> wrote:
>>> Anybody got a copy of the schematic that's in the back of the user guide
>>> that they can scan for me, please ? I've searched all my files and
>>> drawers high and low, and can't find my book anywhere ... I thought
>>> that the 'net would be awash with copies of the schematic, but it seems
>>> only for the Mk 2, which is totally different to the MK 4.
>>
>> Have you tried AVO direct? They still make the Model 8, IIRC.
>
> They stopped making it about, oh - two or three years ago. I think too
> expensive, too complex to make were the reasons quoted.
>
The last one came off the line in November 2008. This gave rise to
simultaneous nostalgia and relief that reference quality meters now
weighed less than a sack of coal. ;-)

--
Tciao for Now!

John.

== 3 of 17 ==
Date: Sat, Apr 2 2011 2:40 am
From: "Arfa Daily"

"Ian Field" <gangprobing.alien@ntlworld.com> wrote in message
news:c1rlp.2624$Pi.960@newsfe22.ams2...
>
> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
> news:5Rqlp.4508$o81.2161@newsfe28.ams2...
>>
>>
>> "Robin" <see@sig.sep> wrote in message
>> news:97olp.1305$bT6.318@newsfe05.ams2...
>>> Arfa Daily wrote:
>>>> Anybody got a copy of the schematic that's in the back of the user
>>>> guide that they can scan for me, please ? I've searched all my files
>>>> and drawers high and low, and can't find my book anywhere ... I
>>>> thought that the 'net would be awash with copies of the schematic,
>>>> but it seems only for the Mk 2, which is totally different to the MK
>>>> 4.
>>>> TIA
>>>>
>>> Is it the circuit diagram at
>>> http://www.radiomuseum.org/r/avo_universal_avometer_8_mk_i.html ?
>>> (Registration necessary for download. I have not done it as mine's a Mk
>>> II.)
>>> --
>>> Robin
>>> PM may be sent to rbw0{at}hotmail{dot}com
>>>
>>
>> Hi Robin, thanks for that. It would appear to be the correct one. Looks
>> as though you need to pay to become a member, so I will hold off for now
>> until all the feelers that I have out, run dry. It's really annoying
>> because I have owned the meter from new when I was an apprentice, and I
>> have the book, which has the schematic in it, carefully filed away
>> somewhere, but I'm buggered if I can now find it. It is in a box file,
>> but said boxfile is not where I know it should be. Even more annoying is
>> that I have damaged the meter by my own stupidity, so now have the need
>> to fix it ... :-(
>
> There may be an outside chance its turned up on
> alt.binaries.e-book.technical at some time or other.
>
> Whether I'd have downloaded it is another matter, and it would take a
> while to search my archives.
>
> You could try a REQ: on that group while I try to remember where I put all
> the unsorted stuff.
>

Thanks Ian. Be appreciated if you were able to have a quick look. Wouldn't
have been a problem back in our old TeleMag days. John would have flung an
ad in "Help Wanted" for me ... :-)

Arfa

== 4 of 17 ==
Date: Sat, Apr 2 2011 2:45 am
From: "Arfa Daily"

"Meat Plow" <mhywattt@yahoo.com> wrote in message
news:pan.2011.04.01.21.02.25@lmao.lol.lol...
> On Fri, 01 Apr 2011 21:46:53 +0100, Arfa Daily wrote:
>
>> "Robin" <see@sig.sep> wrote in message
>> news:97olp.1305$bT6.318@newsfe05.ams2...
>>> Arfa Daily wrote:
>>>> Anybody got a copy of the schematic that's in the back of the user
>>>> guide that they can scan for me, please ? I've searched all my files
>>>> and drawers high and low, and can't find my book anywhere ... I
>>>> thought that the 'net would be awash with copies of the schematic, but
>>>> it seems only for the Mk 2, which is totally different to the MK 4.
>>>> TIA
>>>>
>>> Is it the circuit diagram at
>>> http://www.radiomuseum.org/r/avo_universal_avometer_8_mk_i.html ?
>>> (Registration necessary for download. I have not done it as mine's a
>>> Mk II.)
>>> --
>>> Robin
>>> PM may be sent to rbw0{at}hotmail{dot}com
>>>
>>>
>> Hi Robin, thanks for that. It would appear to be the correct one. Looks
>> as though you need to pay to become a member, so I will hold off for now
>> until all the feelers that I have out, run dry. It's really annoying
>> because I have owned the meter from new when I was an apprentice, and I
>> have the book, which has the schematic in it, carefully filed away
>> somewhere, but I'm buggered if I can now find it. It is in a box file,
>> but said boxfile is not where I know it should be. Even more annoying is
>> that I have damaged the meter by my own stupidity, so now have the need
>> to fix it ... :-(
>>
>> Arfa
>
> That's too bad. I have some old gear I used as an apprentice that have a
> high value in the nostalgia department. An old EICO 232 VTVM, B&K 1801
> freq. counter, Beckman Tech 310 DVM, Amprobe Amp Clamp and some other
> things that I can't think of right now.
>
>
>

Yes, Meat. It's very frustrating. I cut my 'professional' teeth with that
meter, and it has served me faithfully over the years without serious
mishap. It is still in weekly use, but not quite the daily use that it once
was. For some types of repair, the swinging needle of a quality instrument
like this, is so much more appropriate than a digital type ...

Arfa
> --

== 5 of 17 ==
Date: Sat, Apr 2 2011 2:59 am
From: The Natural Philosopher

Arfa Daily wrote:
>
>
> "Meat Plow" <mhywattt@yahoo.com> wrote in message
> news:pan.2011.04.01.21.02.25@lmao.lol.lol...
>> On Fri, 01 Apr 2011 21:46:53 +0100, Arfa Daily wrote:
>>
>>> "Robin" <see@sig.sep> wrote in message
>>> news:97olp.1305$bT6.318@newsfe05.ams2...
>>>> Arfa Daily wrote:
>>>>> Anybody got a copy of the schematic that's in the back of the user
>>>>> guide that they can scan for me, please ? I've searched all my files
>>>>> and drawers high and low, and can't find my book anywhere ... I
>>>>> thought that the 'net would be awash with copies of the schematic, but
>>>>> it seems only for the Mk 2, which is totally different to the MK 4.
>>>>> TIA
>>>>>
>>>> Is it the circuit diagram at
>>>> http://www.radiomuseum.org/r/avo_universal_avometer_8_mk_i.html ?
>>>> (Registration necessary for download. I have not done it as mine's a
>>>> Mk II.)
>>>> --
>>>> Robin
>>>> PM may be sent to rbw0{at}hotmail{dot}com
>>>>
>>>>
>>> Hi Robin, thanks for that. It would appear to be the correct one. Looks
>>> as though you need to pay to become a member, so I will hold off for now
>>> until all the feelers that I have out, run dry. It's really annoying
>>> because I have owned the meter from new when I was an apprentice, and I
>>> have the book, which has the schematic in it, carefully filed away
>>> somewhere, but I'm buggered if I can now find it. It is in a box file,
>>> but said boxfile is not where I know it should be. Even more annoying is
>>> that I have damaged the meter by my own stupidity, so now have the need
>>> to fix it ... :-(
>>>
>>> Arfa
>>
>> That's too bad. I have some old gear I used as an apprentice that have a
>> high value in the nostalgia department. An old EICO 232 VTVM, B&K 1801
>> freq. counter, Beckman Tech 310 DVM, Amprobe Amp Clamp and some other
>> things that I can't think of right now.
>>
>>
>>
>
> Yes, Meat. It's very frustrating. I cut my 'professional' teeth with
> that meter, and it has served me faithfully over the years without
> serious mishap. It is still in weekly use, but not quite the daily use
> that it once was. For some types of repair, the swinging needle of a
> quality instrument like this, is so much more appropriate than a digital
> type ...
>

Its a well known fact that the human eye can gain a rough ideas of
what's going on much faster with an analogue display, as it takes longer
to read a digital display, although in the end that is more accurate.

I have never felt the need for a DVM or DAM..99.99% of voltage and
current readings are of the 'is it within 20% of where it should be'
flavour.

The fact is an LCD meter is CHEAPER than a quality moving needle display.

Not better.

> Arfa
>> --
>
>

== 6 of 17 ==
Date: Sat, Apr 2 2011 3:24 am
From: "Dave Plowman (News)"

In article <mn.12727db4d00bbc3b.106911@NOSPAM.tiscali.co.uk>,
Harry Bloomfield <harry.m1byt@NOSPAM.tiscali.co.uk> wrote:
> > Have you tried AVO direct? They still make the Model 8, IIRC.

> They stopped making it about, oh - two or three years ago. I think too
> expensive, too complex to make were the reasons quoted.

They were certainly very expensive last time I saw them for sale - about
700 quid? So most probably just bought for a museum or display purposes.

--
*Could it be that "I do " is the longest sentence? *

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

== 7 of 17 ==
Date: Sat, Apr 2 2011 3:27 am
From: Geo

Not MK4 but MK3 is here:-
http://www.richardsradios.co.uk/avo8.html

MK4 on ebay but high priced (IMO):-
http://cgi.ebay.co.uk/Avo8-Mk4-Manual-Circuit-/270727895670#ht_500wt_1156

== 8 of 17 ==
Date: Sat, Apr 2 2011 3:41 am
From: Ian Jackson

In message <5Rqlp.4508$o81.2161@newsfe28.ams2>, Arfa Daily
<arfa.daily@ntlworld.com> writes
>
>
>"Robin" <see@sig.sep> wrote in message
>news:97olp.1305$bT6.318@newsfe05.ams2...
>> Arfa Daily wrote:
>>> Anybody got a copy of the schematic that's in the back of the user
>>> guide that they can scan for me, please ? I've searched all my files
>>> and drawers high and low, and can't find my book anywhere ... I
>>> thought that the 'net would be awash with copies of the schematic,
>>> but it seems only for the Mk 2, which is totally different to the MK
>>> 4.
>>> TIA
>>>
>> Is it the circuit diagram at
>>http://www.radiomuseum.org/r/avo_universal_avometer_8_mk_i.html ?
>>(Registration necessary for download. I have not done it as mine's a
>>Mk II.)
>> -- Robin
>> PM may be sent to rbw0{at}hotmail{dot}com
>>
>
>Hi Robin, thanks for that. It would appear to be the correct one. Looks
>as though you need to pay to become a member, so I will hold off for
>now until all the feelers that I have out, run dry. It's really
>annoying because I have owned the meter from new when I was an
>apprentice, and I have the book, which has the schematic in it,
>carefully filed away somewhere, but I'm buggered if I can now find it.
>It is in a box file, but said boxfile is not where I know it should be.
>Even more annoying is that I have damaged the meter by my own
>stupidity, so now have the need to fix it ... :-(
>

http://www.vintage-radio.net/forum/showthread.php?t=756
---->
http://www.g1jbg.co.uk/service.htm
Any good?
--
Ian

== 9 of 17 ==
Date: Sat, Apr 2 2011 5:56 am
From: "Ian Field"

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:HaClp.2679$Pi.398@newsfe22.ams2...
>
>
> "Ian Field" <gangprobing.alien@ntlworld.com> wrote in message
> news:c1rlp.2624$Pi.960@newsfe22.ams2...
>>
>> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
>> news:5Rqlp.4508$o81.2161@newsfe28.ams2...
>>>
>>>
>>> "Robin" <see@sig.sep> wrote in message
>>> news:97olp.1305$bT6.318@newsfe05.ams2...
>>>> Arfa Daily wrote:
>>>>> Anybody got a copy of the schematic that's in the back of the user
>>>>> guide that they can scan for me, please ? I've searched all my files
>>>>> and drawers high and low, and can't find my book anywhere ... I
>>>>> thought that the 'net would be awash with copies of the schematic,
>>>>> but it seems only for the Mk 2, which is totally different to the MK
>>>>> 4.
>>>>> TIA
>>>>>
>>>> Is it the circuit diagram at
>>>> http://www.radiomuseum.org/r/avo_universal_avometer_8_mk_i.html ?
>>>> (Registration necessary for download. I have not done it as mine's a
>>>> Mk II.)
>>>> --
>>>> Robin
>>>> PM may be sent to rbw0{at}hotmail{dot}com
>>>>
>>>
>>> Hi Robin, thanks for that. It would appear to be the correct one. Looks
>>> as though you need to pay to become a member, so I will hold off for now
>>> until all the feelers that I have out, run dry. It's really annoying
>>> because I have owned the meter from new when I was an apprentice, and I
>>> have the book, which has the schematic in it, carefully filed away
>>> somewhere, but I'm buggered if I can now find it. It is in a box file,
>>> but said boxfile is not where I know it should be. Even more annoying is
>>> that I have damaged the meter by my own stupidity, so now have the need
>>> to fix it ... :-(
>>
>> There may be an outside chance its turned up on
>> alt.binaries.e-book.technical at some time or other.
>>
>> Whether I'd have downloaded it is another matter, and it would take a
>> while to search my archives.
>>
>> You could try a REQ: on that group while I try to remember where I put
>> all the unsorted stuff.
>>
>
> Thanks Ian. Be appreciated if you were able to have a quick look. Wouldn't
> have been a problem back in our old TeleMag days. John would have flung an
> ad in "Help Wanted" for me ... :-)

All I found is the AVO 8 MKII user manual with schematic and a document
claiming to be the AVO 8 service manual, its a collection of pages in
typewriter font describing servicing proceedures - no illustrations.

If you want them name a binaries I can upload to.

Have you tried BAMA? - I haven't been there since they changed their website
to stop people like me leeching the whole lot - they've undoubtedly added
new stuff since then.

== 10 of 17 ==
Date: Sat, Apr 2 2011 7:15 am
From: "Arfa Daily"

"Ian Field" <gangprobing.alien@ntlworld.com> wrote in message
news:I2Flp.7637$5t2.6791@newsfe06.ams2...
>
> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
> news:HaClp.2679$Pi.398@newsfe22.ams2...
>>
>>
>> "Ian Field" <gangprobing.alien@ntlworld.com> wrote in message
>> news:c1rlp.2624$Pi.960@newsfe22.ams2...
>>>
>>> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
>>> news:5Rqlp.4508$o81.2161@newsfe28.ams2...
>>>>
>>>>
>>>> "Robin" <see@sig.sep> wrote in message
>>>> news:97olp.1305$bT6.318@newsfe05.ams2...
>>>>> Arfa Daily wrote:
>>>>>> Anybody got a copy of the schematic that's in the back of the user
>>>>>> guide that they can scan for me, please ? I've searched all my files
>>>>>> and drawers high and low, and can't find my book anywhere ... I
>>>>>> thought that the 'net would be awash with copies of the schematic,
>>>>>> but it seems only for the Mk 2, which is totally different to the MK
>>>>>> 4.
>>>>>> TIA
>>>>>>
>>>>> Is it the circuit diagram at
>>>>> http://www.radiomuseum.org/r/avo_universal_avometer_8_mk_i.html ?
>>>>> (Registration necessary for download. I have not done it as mine's a
>>>>> Mk II.)
>>>>> --
>>>>> Robin
>>>>> PM may be sent to rbw0{at}hotmail{dot}com
>>>>>
>>>>
>>>> Hi Robin, thanks for that. It would appear to be the correct one. Looks
>>>> as though you need to pay to become a member, so I will hold off for
>>>> now until all the feelers that I have out, run dry. It's really
>>>> annoying because I have owned the meter from new when I was an
>>>> apprentice, and I have the book, which has the schematic in it,
>>>> carefully filed away somewhere, but I'm buggered if I can now find it.
>>>> It is in a box file, but said boxfile is not where I know it should be.
>>>> Even more annoying is that I have damaged the meter by my own
>>>> stupidity, so now have the need to fix it ... :-(
>>>
>>> There may be an outside chance its turned up on
>>> alt.binaries.e-book.technical at some time or other.
>>>
>>> Whether I'd have downloaded it is another matter, and it would take a
>>> while to search my archives.
>>>
>>> You could try a REQ: on that group while I try to remember where I put
>>> all the unsorted stuff.
>>>
>>
>> Thanks Ian. Be appreciated if you were able to have a quick look.
>> Wouldn't have been a problem back in our old TeleMag days. John would
>> have flung an ad in "Help Wanted" for me ... :-)
>
>
> All I found is the AVO 8 MKII user manual with schematic and a document
> claiming to be the AVO 8 service manual, its a collection of pages in
> typewriter font describing servicing proceedures - no illustrations.
>
> If you want them name a binaries I can upload to.
>
> Have you tried BAMA? - I haven't been there since they changed their
> website to stop people like me leeching the whole lot - they've
> undoubtedly added new stuff since then.
>
A friend of mine has access to Model 8 I, II, III, V, VI, and VII , but no
IV. Curious ... Interestingly, I have now found my book, which I was
absolutely certain was issued to me with the meter, and it's for a
Mk III , which is entirely different. Hmmm ...

I just went and looked at a BAMA mirror site, and lo ! I have found a file
that says it's for the Mk IV. I've downloaded it, but now need to find some
software to open it. It says that it is .DJVU format ??

Arfa

== 11 of 17 ==
Date: Sat, Apr 2 2011 7:22 am
From: "Arfa Daily"

"Ian Jackson" <ianREMOVETHISjackson@g3ohx.demon.co.uk> wrote in message
news:CZnwdpQd1vlNFw2E@g3ohx.demon.co.uk...
> In message <5Rqlp.4508$o81.2161@newsfe28.ams2>, Arfa Daily
> <arfa.daily@ntlworld.com> writes
>>
>>
>>"Robin" <see@sig.sep> wrote in message
>>news:97olp.1305$bT6.318@newsfe05.ams2...
>>> Arfa Daily wrote:
>>>> Anybody got a copy of the schematic that's in the back of the user
>>>> guide that they can scan for me, please ? I've searched all my files
>>>> and drawers high and low, and can't find my book anywhere ... I
>>>> thought that the 'net would be awash with copies of the schematic,
>>>> but it seems only for the Mk 2, which is totally different to the MK
>>>> 4.
>>>> TIA
>>>>
>>> Is it the circuit diagram at
>>> http://www.radiomuseum.org/r/avo_universal_avometer_8_mk_i.html ?
>>> (Registration necessary for download. I have not done it as mine's a Mk
>>> II.)
>>> -- Robin
>>> PM may be sent to rbw0{at}hotmail{dot}com
>>>
>>
>>Hi Robin, thanks for that. It would appear to be the correct one. Looks as
>>though you need to pay to become a member, so I will hold off for now
>>until all the feelers that I have out, run dry. It's really annoying
>>because I have owned the meter from new when I was an apprentice, and I
>>have the book, which has the schematic in it, carefully filed away
>>somewhere, but I'm buggered if I can now find it. It is in a box file, but
>>said boxfile is not where I know it should be. Even more annoying is that
>>I have damaged the meter by my own stupidity, so now have the need to fix
>>it ... :-(
>>
>
> http://www.vintage-radio.net/forum/showthread.php?t=756
> ---->
> http://www.g1jbg.co.uk/service.htm
> Any good?
> --
> Ian

Yep. Been to all those places Ian. Thanks anyway

Arfa

== 12 of 17 ==
Date: Sat, Apr 2 2011 7:57 am
From: "Arfa Daily"

"Geo" <hw9j-s5hw@dea.spamcon.org> wrote in message
news:mfudp6pnu6aleqg8i7j4172g5dp71tde23@4ax.com...
>
> Not MK4 but MK3 is here:-
> http://www.richardsradios.co.uk/avo8.html
>
> MK4 on ebay but high priced (IMO):-
> http://cgi.ebay.co.uk/Avo8-Mk4-Manual-Circuit-/270727895670#ht_500wt_1156
>
>

Thanks Geo. The Mk 3 is quite different from the 4. I guess that the high
price on eBay is commanded by the fact that it seems to be a lot rarer than
I thought it was ...

Arfa

== 13 of 17 ==
Date: Sat, Apr 2 2011 8:10 am
From: "N_Cook"

Dave Plowman (News) <dave@davenoise.co.uk> wrote in message
news:51bd92dcdcdave@davenoise.co.uk...
> In article <mn.12727db4d00bbc3b.106911@NOSPAM.tiscali.co.uk>,
> Harry Bloomfield <harry.m1byt@NOSPAM.tiscali.co.uk> wrote:
> > > Have you tried AVO direct? They still make the Model 8, IIRC.
>
> > They stopped making it about, oh - two or three years ago. I think too
> > expensive, too complex to make were the reasons quoted.
>
> They were certainly very expensive last time I saw them for sale - about
> 700 quid? So most probably just bought for a museum or display purposes.
>
> --
> *Could it be that "I do " is the longest sentence? *
>
> Dave Plowman dave@davenoise.co.uk London SW
> To e-mail, change noise into sound.

Perhaps like Fluke 75 actually specified by name and model in a particular
statutary regulation . So if you use anything other than a Fluke 75 it may
be an illegal act

== 14 of 17 ==
Date: Sat, Apr 2 2011 8:12 am
From: "Arfa Daily"

Result ! It's fixed ! Looking at all the schematics for the other marks,
they all seemed to use a fairly straightforward AC voltage measuring scheme,
employing two diodes in bridge with two resistors, for the rectification. In
view of the fact that I'd twatted it with a high pulse voltage, I figured
that the most likely bet was those diodes. When I found them, they were
white glass ones type HG5808, so a fairly bog-standard germanium type.
Casting around in the parts drawers, I found a packet of brand new OA91s, so
I bunged a couple in, and voila ! - my good old AVO is now reading the right
thing again on AC volts

Arfa

== 15 of 17 ==
Date: Sat, Apr 2 2011 8:21 am
From: "Robin"

> I just went and looked at a BAMA mirror site, and lo ! I have found a
> file that says it's for the Mk IV. I've downloaded it, but now need
> to find some software to open it. It says that it is .DJVU format ??
>
The site has links to viewers: see eg
http://bama.edebris.com/manuals/avo FWIW I use Irfan. And you will
need then the djvu plug-in (from the same site). But I am sorry to have
to tell you that if you have downloaded mk4elect.djvu it is the manual
for the Avo Electronic Testmeter Mark 4. (I know 'cos I got some of my
manuals from BAMA and looked there yesterday when you first asked: I am
*really* looking for excuses not to get back to crawling around in the
loft!)

--
Robin
PM may be sent to rbw0{at}hotmail{dot}com

== 16 of 17 ==
Date: Sat, Apr 2 2011 8:36 am
From: The Natural Philosopher

N_Cook wrote:
> So if you use anything other than a Fluke 75 it may
> be an illegal act
>
...As the actress said the the bishop, stirring her tea...
>
>

== 17 of 17 ==
Date: Sat, Apr 2 2011 9:04 am
From: Ian Jackson

In message <YMGlp.2602$9h6.1532@newsfe02.ams2>, Arfa Daily
<arfa.daily@ntlworld.com> writes
>
>
>"Ian Jackson" <ianREMOVETHISjackson@g3ohx.demon.co.uk> wrote in message
news:CZnwdpQd1vlNFw2E@g3ohx.demon.co.uk...
>>

>>
>> http://www.vintage-radio.net/forum/showthread.php?t=756
>> ---->
>> http://www.g1jbg.co.uk/service.htm
>> Any good?
>> -- Ian
>
>Yep. Been to all those places Ian. Thanks anyway
>
Ah! The Mk 4 is an AVO Multiminor - not an Avo 8. Sorry!
--
Ian

==============================================================================
TOPIC: Speaker Crossover Wiring : Solve the Puzzle
http://groups.google.com/group/sci.electronics.repair/t/9ce83c1fb5063b0f?hl=en
==============================================================================

== 1 of 1 ==
Date: Sat, Apr 2 2011 3:09 am
From: "Arfa Daily"

"Chris F." <zappyman@hotmail.com> wrote in message
news:4d961d4e$0$3983$9a566e8b@news.aliant.net...
> I should note that L1 and L2 both measure about 1 ohm.
>
> "Chris F." <zappyman@hotmail.com> wrote in message
> news:4d961cda$0$3982$9a566e8b@news.aliant.net...
>> Someone brought me an old Wharfedale model W-90 monitor speaker, a
>> massive old beast with two highs, two midranges, and two 15" woofers. The
>> problem was that the crossover circuits are damaged; two 50 ohm
>> potentiometers were burned up, and someone had attempted to bypass them,
>> getting the wiring mixed up in the process. I've drawn up a diagram of
>> the components, numbering each component lead rather than show how they
>> were hooked up. You can view the diagram here:
>>
>> http://s282.photobucket.com/albums/kk275/packrat79/?action=view&current=WharfedaleSpeaker.jpg
>>
>> I'm hoping that someone can figure out the arrangement, and rather than
>> have to draw up a schematic for me, you can just point out which numbers
>> to connect.
>> Some notes:
>> -the connections between the high and midrange speakers appear to be
>> original, though I cannot be certain
>> -the woofers are presently connected in series (each measures 4 ohms)
>> -values of the other components are as follows:
>> C1 - 25 uF 50VDC
>> C2 - 12 uF 25VAC (much larger than C1)
>> L1, L2 - values unknown, but both look identical
>> VR1, VR2 - 50 ohms, 5 watts wirewound
>>
>> I played around for a while and was able to achieve a decent sound with
>> the following configuration: 1-3-8-13, 2-18-24, 22-23, 4-5, 7-17, 9-10,
>> 11-19, 14-21. This doesn't seem right though, since only two leads of
>> each pot are used, and L2 isn't used at all....
>> Any help with this would be appreciated.
>>
>>

The 'L' elements of crossovers are often in parallel with the speakers
rather than series, and may be combined with a 'C'. There are, however, many
different configurations of crossovers, so it's virtually impossible to
guide you with any certainty. As to the pots, they could have been for
level, or phase adjustment. My money would be on level, in which case only
two legs being in use - i.e. with the pots connected as variable resistors,
one in series with the two tweeters in parallel, and one with the two mids
in parallel - would be the expected configuration.

If you put "passive three way crossover designs" into Google, you will get
an information overload on them, that you might be able to pick the bones
out of to decide on what your design originally was or needs to be.

Arfa

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

== 1 of 1 ==
Date: Sat, Apr 2 2011 3:52 am
From: eltron

Hello guys,
Please i need your assistance with this board [Samsung, LJ44-00092C].
There is a voltage shortage at VG out =15volt and D5v out =5.2v. The
current voltage i have here coming out from VG=15volt is 13volt and
D5v=5.2volt is 3volt. Every other dc outlets are outputing perfectly
fine. I have changed the voltage regulators 7815 for 15volt and
Lm2576t which is responsible for 5volt but yet i still get the same
13volt and 3volt out. Can someone tell me what exactly is responsible
for this shortage? i'll really welcome your contributions.
Thanks guys hope to hear from you sooner.
eltron.

==============================================================================
TOPIC: Compaq Presario 1230 Laptop Accessing BIOS Setup
http://groups.google.com/group/sci.electronics.repair/t/82c722abeb2ce43e?hl=en
==============================================================================

== 1 of 1 ==
Date: Sat, Apr 2 2011 6:13 am
From: jaugustine@verizon.net

Hi,

It was too good to be true. The next time I turned it on, I have the
same problem. I decided to put it with my other "dead" laptops for
parts. I paid $25.00 for it in 2009, and I got my money's worth.

Once again, thanks to everyone, John

PS, I will not check here for more responses.

On Fri, 01 Apr 2011 13:06:12 -0500, in microsoft.public.win98.gen_discussion
you wrote:

>Hi,
>
> Laptop is "Working"!
>
> I have system information regarding all my old computers so I decided to
>look for one that has a Phoenix BIOS made around the same time as this 1230.
>I found one in my Fujitsu laptop. I have the OM for the Fujitsu, so I looked
>for information regarding BIOS setup. On that page I saw, if I press Esc key
>during boot up (Fujitsu), I will be presented with an option to boot from a
>different drive.
>
> I decided to try that on the 1230, but I was not presented with this
>option (pick a drive). Instead, I saw a message that stated "configuration
>was restored" (not exact words). Not only that, my floppy drive is
>"working"!
>
> I don't know if pressing Esc key restored parameters, but I made a note
>of that should this event happen again. That's not all. Now I can press
>F10 during power up and get into BIOS settings without a pass word!
>Note: I searched the SM (.PDF) for "Esc" (whole word), but no information
>was found.
>
> Of course I changed the boot sequence to CD drive first.
>
> Again, Thanks to everyone, John
>
>
>On Thu, 31 Mar 2011 08:43:39 -0500, in sci.electronics.repair you wrote:
>
>>Hi,
>>
>> I service TVs, etc. Once in a while, I service my own computers, one of
>>which is a Compaq Presario 1230 laptop with Windows 98se I bought second hand
>>a few years ago. You may consider this obsolete, but to me, it is very
>>useful.
>>
>> Recently, during power up, I saw "Error, O2BO: Diskette drive A error".
>>I removed the floppy drive, but I got the same error, which could be
>>it's controller?
>>
>> I inserted a bootable CD rom hoping that the boot sequence might start at
>>the CD rom, but it didn't. It must be A: drive first. Note: The HDD is fine
>>because I removed it and checked it on anther PC.
>>
>> If I can change the boot sequence, I can do without the floppy drive,
>>but to get into the settings by pressing F10, I have to enter a password.
>>I don't have the phone number of the person I bought it from who lives
>>out of town.
>>
>> I removed the RTC/CMOS battery (soldered in) and waited 24 hours
>>hoping that it may "clear" the password requirement, but it did not.
>>Maybe I should wait longer?
>>
>> Pressing F10 presents a screen that says, "Phoenix BIOS Setup Utility"
>>followed by a prompt for a password. I tried some by guessing, but it
>>didn't work. I hope the password isn't stored in the BIOS.
>>
>> Do you know a technique to bypass the password requirement so
>>I can change the boot sequence?
>>
>> Thank You in Advance, John
>>
>>PS, Remove "ine" from my email address
>>

==============================================================================
TOPIC: לימוד תופים בסטודיו קצב הקשב
http://groups.google.com/group/sci.electronics.repair/t/e3c480e79f4e43b9?hl=en
==============================================================================

== 1 of 1 ==
Date: Sat, Apr 2 2011 7:49 am
From: dave b

לימוד תופים בסטודיו קצב הקשב

קצב הקשב - סטודיו ללימוד תופים
לימודי תיפוף למתחילים החל מגיל 7. שעורים דינמיים
ואישיים בנושאי תאוריה וקצב, קריאת תווים, קואורדינציה, ליווי שירים,
היבטים של נגינה בהרכב,
תרגילי יסוד, תרגילי מערכת, ישיבה ויציבה, בדגש על התקדמות התלמיד וטעמיו
המוזיקליים, בתקשורת טובה והמון סבלנות.
הלימוד מתבצע בסטודיו במושב גאליה, על שתי מערכות תופים, למורה ולתלמיד.
ניתן לבצע שיעורים גם בבית התלמיד.

מומלץ לסובלים מהפרעות קשב וריכוז:
- שיפור הקשבה החוצה אל הסביבה, ופנימה, בצורה פרקטית ולא רוחנית בלבד.
- העצמת ערך עצמי ובטחון עצמי.
- עידוד וחיזוק התמודדות עם אתגרים.
- שיפור מידת הסבלנות ואורך הרוח בהתמודדות מול קושי.
- תיעול וכיוון אנרגיות שליליות, כעסים ותסכולים, אל עשייה יצירתית,
חיובית והתפתחותית.

טלפון לתאום: 052-5390913
קישור לפייסבוק שלנו:
http://www.facebook.com/pages/qzb-hqsb/183017275042273?v=info

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

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