sci.electronics.repair@googlegroups.com

Today's topics:

* Valves badged Orange , rebadged what make? - 7 messages, 4 authors
http://groups.google.com/group/sci.electronics.repair/t/b405f7894dddeac4?hl=en
* hot sex - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/ca89be69d35f8006?hl=en
* Paradigm PS-12 subwoofer amp. repair tip. - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/76eb2c633056d04e?hl=en
* What kills a valve rectifier? - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/3452d3f8314c6ded?hl=en
* vcr repair emerson ev868 - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/f659f5c07e5f1eac?hl=en
* Wall Warts - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/de407a5056a54ee0?hl=en
* ghnvfg - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/8c2e6dae86d2dd78?hl=en

==============================================================================
TOPIC: Valves badged Orange , rebadged what make?
http://groups.google.com/group/sci.electronics.repair/t/b405f7894dddeac4?hl=en
==============================================================================

== 1 of 7 ==
Date: Fri, May 27 2011 12:53 am
From: "Phil Allison"

"Nutcase Kook"
>
> From pcb Enumber, the boards are made in Hong Kong, despite Union flag
> logo
> on the overlay and "Made in England" on the chassis. I will assume No-Name
> Chinese valves unless anyone knows any better

** Orange Amps do not use or recommend any particular brand of valve.

But you would be a fool to use anything less that the best EL84s and EL34s
you can get - cos those amps are sooooooo tough on output valves.

Svetlana and JJ are the ones to look at with EH down the list somewhat.

..... Phil

== 2 of 7 ==
Date: Fri, May 27 2011 4:27 am
From: "Gareth Magennis"

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:9493k8F5rjU1@mid.individual.net...
>
> "Nutcase Kook"
>>
>> From pcb Enumber, the boards are made in Hong Kong, despite Union flag
>> logo
>> on the overlay and "Made in England" on the chassis. I will assume
>> No-Name
>> Chinese valves unless anyone knows any better
>
>
> ** Orange Amps do not use or recommend any particular brand of valve.
>
> But you would be a fool to use anything less that the best EL84s and EL34s
> you can get - cos those amps are sooooooo tough on output valves.
>
> Svetlana and JJ are the ones to look at with EH down the list somewhat.
>
>
> ..... Phil
>

I've been buying and fitting JJ Tesla valves exclusively for the last 5
years or so. I bought a whole bunch straight from the factory (EL34, EL84,
6L6, ECC83 - not tried any JJ6550's, usually get Svetlanas as required).

I can't remember seeing any amps come back with a failed JJ Tube I fitted.
When I do see an amp back I recheck the bias current and they are always
still closely matched.
They are priced well towards the cheaper end of the quality tube market.

(Last Orange amp I had, a Rockverb 50, I replaced 4 x 6V6 with JJ's, haven't
seen it since)

Gareth.

== 3 of 7 ==
Date: Fri, May 27 2011 4:48 am
From: "N_Cook"

Gareth Magennis <sound.service@btconnect.com> wrote in message
news:VLKdnWhZzK4LF0LQnZ2dnUVZ8s-dnZ2d@bt.com...
>
> "Phil Allison" <phil_a@tpg.com.au> wrote in message
> news:9493k8F5rjU1@mid.individual.net...
> >
> > "Nutcase Kook"
> >>
> >> From pcb Enumber, the boards are made in Hong Kong, despite Union flag
> >> logo
> >> on the overlay and "Made in England" on the chassis. I will assume
> >> No-Name
> >> Chinese valves unless anyone knows any better
> >
> >
> > ** Orange Amps do not use or recommend any particular brand of valve.
> >
> > But you would be a fool to use anything less that the best EL84s and
EL34s
> > you can get - cos those amps are sooooooo tough on output valves.
> >
> > Svetlana and JJ are the ones to look at with EH down the list somewhat.
> >
> >
> > ..... Phil
> >
>
> I've been buying and fitting JJ Tesla valves exclusively for the last 5
> years or so. I bought a whole bunch straight from the factory (EL34,
EL84,
> 6L6, ECC83 - not tried any JJ6550's, usually get Svetlanas as required).
>
> I can't remember seeing any amps come back with a failed JJ Tube I fitted.
> When I do see an amp back I recheck the bias current and they are always
> still closely matched.
> They are priced well towards the cheaper end of the quality tube market.
>
>
> (Last Orange amp I had, a Rockverb 50, I replaced 4 x 6V6 with JJ's,
haven't
> seen it since)
>
>
> Gareth.
>
>

I take it from that , that the Orange amp reputation as valve-eaters is due
to whether Chinese or whatever Orange re-badged valves they use, for
reliability replace with good named brand ones at the first opportunity.

== 4 of 7 ==
Date: Fri, May 27 2011 5:01 am
From: "Gareth Magennis"

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:iro3b6$pao$1@dont-email.me...
> Gareth Magennis <sound.service@btconnect.com> wrote in message
> news:VLKdnWhZzK4LF0LQnZ2dnUVZ8s-dnZ2d@bt.com...
>>
>> "Phil Allison" <phil_a@tpg.com.au> wrote in message
>> news:9493k8F5rjU1@mid.individual.net...
>> >
>> > "Nutcase Kook"
>> >>
>> >> From pcb Enumber, the boards are made in Hong Kong, despite Union flag
>> >> logo
>> >> on the overlay and "Made in England" on the chassis. I will assume
>> >> No-Name
>> >> Chinese valves unless anyone knows any better
>> >
>> >
>> > ** Orange Amps do not use or recommend any particular brand of valve.
>> >
>> > But you would be a fool to use anything less that the best EL84s and
> EL34s
>> > you can get - cos those amps are sooooooo tough on output valves.
>> >
>> > Svetlana and JJ are the ones to look at with EH down the list somewhat.
>> >
>> >
>> > ..... Phil
>> >
>>
>> I've been buying and fitting JJ Tesla valves exclusively for the last 5
>> years or so. I bought a whole bunch straight from the factory (EL34,
> EL84,
>> 6L6, ECC83 - not tried any JJ6550's, usually get Svetlanas as required).
>>
>> I can't remember seeing any amps come back with a failed JJ Tube I
>> fitted.
>> When I do see an amp back I recheck the bias current and they are always
>> still closely matched.
>> They are priced well towards the cheaper end of the quality tube market.
>>
>>
>> (Last Orange amp I had, a Rockverb 50, I replaced 4 x 6V6 with JJ's,
> haven't
>> seen it since)
>>
>>
>> Gareth.
>>
>>
>
>
> I take it from that , that the Orange amp reputation as valve-eaters is
> due
> to whether Chinese or whatever Orange re-badged valves they use, for
> reliability replace with good named brand ones at the first opportunity.
>
>

Dunno about the Orange valve eaters, but cheap junk tubes break like any
other cheap junk.
I don't fit cheap junk cos I don't want the amps coming back, having failed
halfway though a gig, and being accused of fitting cheap junk!

Gareth.

== 5 of 7 ==
Date: Fri, May 27 2011 11:27 am
From: "Gareth Magennis"

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:9493k8F5rjU1@mid.individual.net...
>
> "Nutcase Kook"
>>
>> From pcb Enumber, the boards are made in Hong Kong, despite Union flag
>> logo
>> on the overlay and "Made in England" on the chassis. I will assume
>> No-Name
>> Chinese valves unless anyone knows any better
>
>
> ** Orange Amps do not use or recommend any particular brand of valve.
>
> But you would be a fool to use anything less that the best EL84s and EL34s
> you can get - cos those amps are sooooooo tough on output valves.
>
> Svetlana and JJ are the ones to look at with EH down the list somewhat.
>
>
> ..... Phil
>

Here's an interesting thing - I was told by Marshall that quite a few years
ago they tried using JJ Tesla EL34's on their production line. They say
that they had so many problems with returned amps that they reverted back to
their Svetlanas.
(These are the JJ tubes that have an additional small logo to current
production)

I suspect JJ sorted out what might have been a problem in the early days,
just a guess really as I have no data, unless of course there was some other
business type of dispute.

Gareth.

== 6 of 7 ==
Date: Fri, May 27 2011 3:00 pm
From: Meat Plow

On Fri, 27 May 2011 17:53:39 +1000, Phil Allison wrote:

> "Nutcase Kook"
>>
>> From pcb Enumber, the boards are made in Hong Kong, despite Union flag
>> logo
>> on the overlay and "Made in England" on the chassis. I will assume
>> No-Name Chinese valves unless anyone knows any better
>
>
> ** Orange Amps do not use or recommend any particular brand of valve.
>
> But you would be a fool to use anything less that the best EL84s and
> EL34s you can get - cos those amps are sooooooo tough on output
> valves.
>
> Svetlana and JJ are the ones to look at with EH down the list somewhat.
>
>
> ..... Phil

I've heard that EH stands up well. I'm not a Svetlana fan. Have had
limited success with JJs. Best for my concern would be some NOS Mullards
or RCA.

--
Live Fast Die Young, Leave A Pretty Corpse

== 7 of 7 ==
Date: Fri, May 27 2011 4:48 pm
From: "Gareth Magennis"

. Best for my concern would be some NOS Mullards
> or RCA.
>

Yeah well, we could all say that.

Doesn't help.

==============================================================================
TOPIC: hot sex
http://groups.google.com/group/sci.electronics.repair/t/ca89be69d35f8006?hl=en
==============================================================================

== 1 of 1 ==
Date: Fri, May 27 2011 7:29 am
From: SRAVANTHI LOVE

GOOD STUDY MATERIAL FOR KIDS
http://studymaterialforu.blogspot.com
UNIX INTERVIEW QUESTIONS
http://studymaterialforu.blogspot.com/2011/04/unix-interview-questions.html
JAVA INTERVIEW QUESTIONS
http://studymaterialforu.blogspot.com/2011/04/java-interview-questions.html
C ++ INTERVIEW QUESTIONS
http://studymaterialforu.blogspot.com/2011/04/c-interview-questions.html
CIVILS INTERCIEW QUESTIONS
http://studymaterialforu.blogspot.com/2011/04/civils-interview-questions-and-answers.html
DIGITAL LOGIC INTERCIEW QUESTIONS
http://studymaterialforu.blogspot.com/2011/04/digital-logic-design-interview.html
MICROPROCESSOR INTERVIEW QUESTIONS
http://studymaterialforu.blogspot.com/2011/04/microprocessor-interview-questions.html

==============================================================================
TOPIC: Paradigm PS-12 subwoofer amp. repair tip.
http://groups.google.com/group/sci.electronics.repair/t/76eb2c633056d04e?hl=en
==============================================================================

== 1 of 1 ==
Date: Fri, May 27 2011 12:43 pm
From: Chuck

Paradigm didn't supply schematics to these when I worked for a dealer
but a friend asked me to see if I could fix his. I wasn't very
optimistic but I said OK. There was a slight hum when it was turned
on but there was no output of the input signal. If the shield of the
rca cable was touched, the hum increased slightly. I thought the
input rca jacks looked familiar from a repair I did years ago where
there was no continuity from the shield to solder tab.. Some how the
plate the shield of the rca jacks connect to separates from the solder
tab. Without destroying the jack assy., it is impossible to see what
breaks. Running a wire from the shield plate to the connection
underneath the circuit board repaired the amp. Chuck

==============================================================================
TOPIC: What kills a valve rectifier?
http://groups.google.com/group/sci.electronics.repair/t/3452d3f8314c6ded?hl=en
==============================================================================

== 1 of 1 ==
Date: Fri, May 27 2011 2:57 pm
From: Meat Plow

On Fri, 27 May 2011 17:37:43 +1000, Phil Allison wrote:

> "Arfa Daily"
>>
>> The 5U4 appears to be able to handle more current, but at a lower max
>> plate voltage. Also, the heater requires substantially more current.
>> Might be an issue for the transformer supplying it ?
>
>
> ** Very unlikely to matter.
>
> Say the winding is rated at 5 volts and 2 amps to suit a 5AR4 and the
> copper wire is gauged to give about 10 % regulation factor. Then the
> heat loss in the 5 volt winding is 10% of the load power or about 1
> watt.
>
> If a 5U4 is subbed - the extra 1.1 amps will mean that 5.0 volts drops
> to 4.7 volts - well within specs for the valve.
>
> The extra heat in the winding amounts to 0.8 watts - which is trivial
> in a tranny designed to lose 15 to 30 watts as heat in normal operation.
>
>
> ..... Phil

Good to see the real Phil back for a little while.

--
Live Fast Die Young, Leave A Pretty Corpse

==============================================================================
TOPIC: vcr repair emerson ev868
http://groups.google.com/group/sci.electronics.repair/t/f659f5c07e5f1eac?hl=en
==============================================================================

== 1 of 2 ==
Date: Fri, May 27 2011 3:49 pm
From: nucleus

does anyone here have a schematic of a typical optical reader circuit
on a vcr?

problem is: emerson ev868 vcr powers up and responds to all buttons,
will load and eject tape but will not respond to remote control. vcr
does
send rf to tv.

remote does send IR, as determined with digital camera.

is it necessary to have an oscope to troubleshoot this problem?

optical eye on circuit board has been cleaned.

== 2 of 2 ==
Date: Fri, May 27 2011 4:46 pm
From: b

On May 28, 12:49 am, nucleus <rose122...@yahoo.com> wrote:
> does anyone here have a schematic of a typical optical reader circuit
> on a vcr?
>
> problem is: emerson ev868 vcr powers up and responds to all buttons,
> will load and eject tape but will not respond to remote control. vcr
> does
> send rf to tv.
>
> remote does send IR, as determined with digital camera.
>
> is it necessary to have an oscope to troubleshoot this problem?
>
> optical eye on circuit board has been cleaned.

There might have been a drift in the frequency of the resonator in the
handset - just because you get IR does not prove it's innocence!
. Also could be a duff cap or bad IR diode in the vcr. get a cheap
universal remote control and try that on the vcr.
-B

==============================================================================
TOPIC: Wall Warts
http://groups.google.com/group/sci.electronics.repair/t/de407a5056a54ee0?hl=en
==============================================================================

== 1 of 2 ==
Date: Fri, May 27 2011 5:37 pm
From: Jeff Liebermann

On Thu, 26 May 2011 12:51:48 -0500, Puddin' Man
<puddingDOTman@gmail.com> wrote:

>>>The + side measures 3 ohms.
>>
>>Ok. There may be a diode inside the base. Try reversing the leads on
>>the ohms-guesser and see if it acts like a diode.
>
>Measures infinite ohms when reversed.

It's a diode, with no series resistor. That presents a problem.
Without some form of current limiting, the voltage of the xformer will
need to be VERY carefully controlled to keep from overcharging the
battery. I will swear there's a resistor or charge controller
somewhere in the system, but I can't tell where from here.

>I'm 'fraid you'll have to elaborate on this last. And, what is "C" in
>.1C?

Sorry. C is the current rating of the battery in ampere-hours. A
typical NiCd pack, full of AA cells will have a rating of about 750
ma-hr. NiMH would be around 1200 to 2200 ma-hr. The maximum charge
current of the charger should be about 0.1 times this value (i.e. 10%)
or 75ma for the NiCd pack.

>>Of course, make sure you don't have a shorted
>>battery pack.
>
>So I gotta crack the battery pack open. And test each cell individually?
>How?

You don't need to destroy the battery pack in order to test it. First,
just measure the terminal voltage of the battery pack after it's been
sitting around for a day without being charged. Even if totally
discharged, it should have at least 1.1 volts per cell or about 7.7VDC
across the terminals. A fully charged NiCd will have about 1.45VDC
per cell or about 10.2VDC across the terminals.

Now, if you really want to test you battery packs, I have a West Mtn
Radio CBA-IIv1:
<http://www.westmountainradio.com/product_info.php?products_id=cba3>

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

== 2 of 2 ==
Date: Fri, May 27 2011 8:10 pm
From: Puddin' Man

On Fri, 27 May 2011 17:37:46 -0700, Jeff Liebermann <jeffl@cruzio.com> wrote:

>On Thu, 26 May 2011 12:51:48 -0500, Puddin' Man
><puddingDOTman@gmail.com> wrote:
>
>
>>>>The + side measures 3 ohms.
>>>
>>>Ok. There may be a diode inside the base. Try reversing the leads on
>>>the ohms-guesser and see if it acts like a diode.
>>
>>Measures infinite ohms when reversed.
>
>It's a diode, with no series resistor. That presents a problem.
>Without some form of current limiting, the voltage of the xformer will
>need to be VERY carefully controlled to keep from overcharging the
>battery. I will swear there's a resistor or charge controller
>somewhere in the system, but I can't tell where from here.

I dunno where it would be ...

>>I'm 'fraid you'll have to elaborate on this last. And, what is "C" in
>>.1C?
>
>Sorry. C is the current rating of the battery in ampere-hours. A
>typical NiCd pack, full of AA cells will have a rating of about 750
>ma-hr. NiMH would be around 1200 to 2200 ma-hr. The maximum charge
>current of the charger should be about 0.1 times this value (i.e. 10%)
>or 75ma for the NiCd pack.

Thanks.

>>>Of course, make sure you don't have a shorted
>>>battery pack.
>>
>>So I gotta crack the battery pack open. And test each cell individually?
>>How?
>
>You don't need to destroy the battery pack in order to test it.

Good! :-)

>First,
>just measure the terminal voltage of the battery pack after it's been
>sitting around for a day without being charged. Even if totally
>discharged, it should have at least 1.1 volts per cell or about 7.7VDC
>across the terminals. A fully charged NiCd will have about 1.45VDC
>per cell or about 10.2VDC across the terminals.

I measure just under 4vdc for the pack. Your opinion is
solicited.

>Now, if you really want to test you battery packs, I have a West Mtn
>Radio CBA-IIv1:
><http://www.westmountainradio.com/product_info.php?products_id=cba3>

Only $150-300. Lordy mercy!

I rambled thru my WW box again and found the following:

ATLINKS USA
Telephone power supply
Input: AC120V 60hz 4.4w
Output: DC 9v 200 mA
Class 2 transformer
UL etc

but when I measure, I get about 20vdc from my meter.
Any idea why the drastic difference from spec?

Thx,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

==============================================================================
TOPIC: ghnvfg
http://groups.google.com/group/sci.electronics.repair/t/8c2e6dae86d2dd78?hl=en
==============================================================================

== 1 of 1 ==
Date: Fri, May 27 2011 10:18 pm
From: hemaaruchamy hemalatha

http://123maza.com/65/Claws470/

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

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

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

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

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

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

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