Empathy List Archives

BE

Bill Ezell

Tue, Feb 28, 2012 2:01 AM

I have several 7061's and 7081's. They're both excellent meters and tend
to hold calibration for a long time. My 7081 easily stays within a few
ppm/year. (checked against my Fluke-calibrated Datron 4910's)

In answer to a few of the questions recently asked:

The battery is only for backing up stored readings and settings. The
calibration values are in the eeprom, twice. So, unless it fails, you
won't lose the calibration factors. The purpose of the eeprom refresh is
just to do an read/erase/rewrite cycle. It was apparently a concern that
eeproms of that vintage wouldn't store values over long times (years)
reliably. I've not done a refresh on any of my 7061's and haven't had a
problem.

As for heat, the 7061's do run very hot, but that's how they were
designed. Not a good idea to put things on top of them without any
airspace, though. The hottest area in a properly working 7061 is a small
metal-shield box. It has some rather power-hungry IC's (74s series) in
it, and it gets too hot to touch. Every 7061 I've ever seen is like
that, so I assume it's operating as intended.

I wouldn't say the transformer runs hot in particular. If you're really
seeing that, it's possible you have leaky caps in the power supply,
although they'd have to leak a lot without exploding to raise the
current drain enough to overheat the transformer. More likely is that
it's a ventilation problem. Does your 7061 still have its feet to give
it some airspace at the bottom?

--
Bill Ezell

They said 'Windows or better'
so I used Linux.

I have several 7061's and 7081's. They're both excellent meters and tend to hold calibration for a long time. My 7081 easily stays within a few ppm/year. (checked against my Fluke-calibrated Datron 4910's) In answer to a few of the questions recently asked: The battery is only for backing up stored readings and settings. The calibration values are in the eeprom, twice. So, unless it fails, you won't lose the calibration factors. The purpose of the eeprom refresh is just to do an read/erase/rewrite cycle. It was apparently a concern that eeproms of that vintage wouldn't store values over long times (years) reliably. I've not done a refresh on any of my 7061's and haven't had a problem. As for heat, the 7061's do run very hot, but that's how they were designed. Not a good idea to put things on top of them without any airspace, though. The hottest area in a properly working 7061 is a small metal-shield box. It has some rather power-hungry IC's (74s series) in it, and it gets too hot to touch. Every 7061 I've ever seen is like that, so I assume it's operating as intended. I wouldn't say the transformer runs hot in particular. If you're really seeing that, it's possible you have leaky caps in the power supply, although they'd have to leak a lot without exploding to raise the current drain enough to overheat the transformer. More likely is that it's a ventilation problem. Does your 7061 still have its feet to give it some airspace at the bottom? -- Bill Ezell ---------- They said 'Windows or better' so I used Linux.

F

fabioeb@quipo.it

Tue, Feb 28, 2012 10:05 AM

Hello Bill, thank you for the answers.
This morning I swapped the original eeprom with a spare one,
I tried calibrate 0.1V to 100V, so the new constant is
stored during calibration and not hitting "refresh"?
This is confirmed by the fact that it retained the new
values even after power down without the "refresh" command.
So Fred's problem of losing costants should be due to faulty
eeprom? Also my instrument can have a faulty eeprom and have
lost costants during use?

A pair of things, easy to discover that can help somebody else
searching info like me:

cal key: I don't have the key and the switch is easily tampered
but I don't want to break it. Here are the connections on the
pin header connected to the cal switch:
cal off: connect Blue to Green, just put a jumper on the first
two pins on the header
cal on: connect Yellow to Green and Brown to Red two jumpers
on the pins 2-3 and 5-6
Ram memory: the capacitor makes it retain data also after power
down and without backup battery for some time, the voltage is as follow:
from 4.4V to 2V in 40s
to 1V in 1m 40s
to 0,5V in 2' 30s
the memory retains data also when it's only at 1V.

Fabio.

Bill Ezell wje@quackers.net ha scritto:

I have several 7061's and 7081's. They're both excellent meters and
tend to hold calibration for a long time. My 7081 easily stays
within a few ppm/year. (checked against my Fluke-calibrated Datron
4910's)

In answer to a few of the questions recently asked:

The battery is only for backing up stored readings and settings. The
calibration values are in the eeprom, twice. So, unless it fails,
you won't lose the calibration factors. The purpose of the eeprom
refresh is just to do an read/erase/rewrite cycle. It was apparently
a concern that eeproms of that vintage wouldn't store values over
long times (years) reliably. I've not done a refresh on any of my
7061's and haven't had a problem.

As for heat, the 7061's do run very hot, but that's how they were
designed. Not a good idea to put things on top of them without any
airspace, though. The hottest area in a properly working 7061 is a
small metal-shield box. It has some rather power-hungry IC's (74s
series) in it, and it gets too hot to touch. Every 7061 I've ever
seen is like that, so I assume it's operating as intended.

I wouldn't say the transformer runs hot in particular. If you're
really seeing that, it's possible you have leaky caps in the power
supply, although they'd have to leak a lot without exploding to
raise the current drain enough to overheat the transformer. More
likely is that it's a ventilation problem. Does your 7061 still have
its feet to give it some airspace at the bottom?

--
Bill Ezell

They said 'Windows or better'
so I used Linux.

volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.

This message was sent using IMP, the Internet Messaging Program.

Hello Bill, thank you for the answers. This morning I swapped the original eeprom with a spare one, I tried calibrate 0.1V to 100V, so the new constant is stored during calibration and not hitting "refresh"? This is confirmed by the fact that it retained the new values even after power down without the "refresh" command. So Fred's problem of losing costants should be due to faulty eeprom? Also my instrument can have a faulty eeprom and have lost costants during use? A pair of things, easy to discover that can help somebody else searching info like me: - cal key: I don't have the key and the switch is easily tampered but I don't want to break it. Here are the connections on the pin header connected to the cal switch: cal off: connect Blue to Green, just put a jumper on the first two pins on the header cal on: connect Yellow to Green and Brown to Red two jumpers on the pins 2-3 and 5-6 - Ram memory: the capacitor makes it retain data also after power down and without backup battery for some time, the voltage is as follow: from 4.4V to 2V in 40s to 1V in 1m 40s to 0,5V in 2' 30s the memory retains data also when it's only at 1V. Fabio. Bill Ezell <wje@quackers.net> ha scritto: > I have several 7061's and 7081's. They're both excellent meters and > tend to hold calibration for a long time. My 7081 easily stays > within a few ppm/year. (checked against my Fluke-calibrated Datron > 4910's) > > In answer to a few of the questions recently asked: > > The battery is only for backing up stored readings and settings. The > calibration values are in the eeprom, twice. So, unless it fails, > you won't lose the calibration factors. The purpose of the eeprom > refresh is just to do an read/erase/rewrite cycle. It was apparently > a concern that eeproms of that vintage wouldn't store values over > long times (years) reliably. I've not done a refresh on any of my > 7061's and haven't had a problem. > > As for heat, the 7061's do run very hot, but that's how they were > designed. Not a good idea to put things on top of them without any > airspace, though. The hottest area in a properly working 7061 is a > small metal-shield box. It has some rather power-hungry IC's (74s > series) in it, and it gets too hot to touch. Every 7061 I've ever > seen is like that, so I assume it's operating as intended. > > I wouldn't say the transformer runs hot in particular. If you're > really seeing that, it's possible you have leaky caps in the power > supply, although they'd have to leak a lot without exploding to > raise the current drain enough to overheat the transformer. More > likely is that it's a ventilation problem. Does your 7061 still have > its feet to give it some airspace at the bottom? > > -- > Bill Ezell > ---------- > They said 'Windows or better' > so I used Linux. > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

ME

Marvin E. Gozum

Tue, Feb 28, 2012 4:34 PM

Hi Bill, do you know what the 7061 power consumption is?

The 7061 user manual states < 40VA. Is that accurate?

The HP 3456a manual states 80VA, but I measured actual consumption a
watt meter, it draw 25W in operation. Also, no parts I worked on
were too hot too touch.

At 09:01 PM 2/27/2012, Bill Ezell wrote:

I have several 7061's and 7081's. They're both excellent meters and
tend to hold calibration for a long time. My 7081 easily stays
within a few ppm/year. (checked against my Fluke-calibrated Datron 4910's)

In answer to a few of the questions recently asked:

The battery is only for backing up stored readings and settings. The
calibration values are in the eeprom, twice. So, unless it fails,
you won't lose the calibration factors. The purpose of the eeprom
refresh is just to do an read/erase/rewrite cycle. It was apparently
a concern that eeproms of that vintage wouldn't store values over
long times (years) reliably. I've not done a refresh on any of my
7061's and haven't had a problem.

As for heat, the 7061's do run very hot, but that's how they were
designed. Not a good idea to put things on top of them without any
airspace, though. The hottest area in a properly working 7061 is a
small metal-shield box. It has some rather power-hungry IC's (74s
series) in it, and it gets too hot to touch. Every 7061 I've ever
seen is like that, so I assume it's operating as intended.

I wouldn't say the transformer runs hot in particular. If you're
really seeing that, it's possible you have leaky caps in the power
supply, although they'd have to leak a lot without exploding to
raise the current drain enough to overheat the transformer. More
likely is that it's a ventilation problem. Does your 7061 still have
its feet to give it some airspace at the bottom?

--
Bill Ezell

Sincerely,

Marv Gozum
Philadelphia, PA

Hi Bill, do you know what the 7061 power consumption is? The 7061 user manual states < 40VA. Is that accurate? The HP 3456a manual states 80VA, but I measured actual consumption a watt meter, it draw 25W in operation. Also, no parts I worked on were too hot too touch. At 09:01 PM 2/27/2012, Bill Ezell wrote: >I have several 7061's and 7081's. They're both excellent meters and >tend to hold calibration for a long time. My 7081 easily stays >within a few ppm/year. (checked against my Fluke-calibrated Datron 4910's) > >In answer to a few of the questions recently asked: > >The battery is only for backing up stored readings and settings. The >calibration values are in the eeprom, twice. So, unless it fails, >you won't lose the calibration factors. The purpose of the eeprom >refresh is just to do an read/erase/rewrite cycle. It was apparently >a concern that eeproms of that vintage wouldn't store values over >long times (years) reliably. I've not done a refresh on any of my >7061's and haven't had a problem. > >As for heat, the 7061's do run very hot, but that's how they were >designed. Not a good idea to put things on top of them without any >airspace, though. The hottest area in a properly working 7061 is a >small metal-shield box. It has some rather power-hungry IC's (74s >series) in it, and it gets too hot to touch. Every 7061 I've ever >seen is like that, so I assume it's operating as intended. > >I wouldn't say the transformer runs hot in particular. If you're >really seeing that, it's possible you have leaky caps in the power >supply, although they'd have to leak a lot without exploding to >raise the current drain enough to overheat the transformer. More >likely is that it's a ventilation problem. Does your 7061 still have >its feet to give it some airspace at the bottom? > >-- >Bill Ezell >---------- Sincerely, Marv Gozum Philadelphia, PA

FE

Fabio Eboli

Fri, Apr 6, 2012 2:26 PM

Hello, I recently repaired an old 7075,
the reference oven seem opened and leacky,
with what seems silicone getting out.
I measured the heater resistance and is of about 100ohm.
Is this normal?
Here some photos and more details about serial
interface

http://www.eevblog.com/forum/product-reviews-photos-and-discussion/solartron-7075-(or-will-i-be-able-to-reassemble-it-)/

I'm thinking to connect a micro to the
internal optoisolated interconnection to
bring out the readings, should be interesting
to log the glug signals stats.

Fabio.

This message was sent using IMP, the Internet Messaging Program.

Hello, I recently repaired an old 7075, the reference oven seem opened and leacky, with what seems silicone getting out. I measured the heater resistance and is of about 100ohm. Is this normal? Here some photos and more details about serial interface http://www.eevblog.com/forum/product-reviews-photos-and-discussion/solartron-7075-(or-will-i-be-able-to-reassemble-it-)/ I'm thinking to connect a micro to the internal optoisolated interconnection to bring out the readings, should be interesting to log the glug signals stats. Fabio. ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

CH

Chuck Harris

Fri, Apr 6, 2012 3:37 PM

Looks to me like the oven is simply a black plastic box,
that holds a 100 ohm resistor and a zener diode, that is
filled with silicone rubber.

-Chuck Harris

Fabio Eboli wrote:

Hello, I recently repaired an old 7075, the reference oven seem opened and
leacky, with what seems silicone getting out. I measured the heater resistance and
is of about 100ohm. Is this normal? Here some photos and more details about
serial interface

http://www.eevblog.com/forum/product-reviews-photos-and-discussion/solartron-7075-(or-will-i-be-able-to-reassemble-it-)/

I'm thinking to connect a micro to the internal optoisolated interconnection to
bring out the readings, should be interesting to log the glug signals stats.

Fabio.

---------------------------------------------------------------- This message was
sent using IMP, the Internet Messaging Program.

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Looks to me like the oven is simply a black plastic box, that holds a 100 ohm resistor and a zener diode, that is filled with silicone rubber. -Chuck Harris Fabio Eboli wrote: > Hello, I recently repaired an old 7075, the reference oven seem opened and > leacky, with what seems silicone getting out. I measured the heater resistance and > is of about 100ohm. Is this normal? Here some photos and more details about > serial interface > > http://www.eevblog.com/forum/product-reviews-photos-and-discussion/solartron-7075-(or-will-i-be-able-to-reassemble-it-)/ > > > > I'm thinking to connect a micro to the internal optoisolated interconnection to > bring out the readings, should be interesting to log the glug signals stats. > > Fabio. > > > > ---------------------------------------------------------------- This message was > sent using IMP, the Internet Messaging Program. > > > > _______________________________________________ volt-nuts mailing list -- > volt-nuts@febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the > instructions there.

FE

Fabio Eboli

Fri, Apr 6, 2012 4:56 PM

Chuck, from the damages, the instrument seem to have
been subject to acceleration ( e.g. a fall) or hard vibrations.
I'm curious if the 100 ohm value is correct or the
heater is damaged.

In this post, Mickle T. linked an image of the
diode oven:
http://www.radiokot.ru/forum/viewtopic.php?f=10&t=52829&start=60
This is the reference opened:
http://i011.radikal.ru/1202/04/76affad54e2c.jpg
So you imagined it correctly.
I'm also curious if the oven is a fixed resistance or a PTC,
I forgot to test for this when I had the multimeter opened.

Fabio.

Chuck Harris cfharris@erols.com ha scritto:

Looks to me like the oven is simply a black plastic box,
that holds a 100 ohm resistor and a zener diode, that is
filled with silicone rubber.

-Chuck Harris

Fabio Eboli wrote:

Hello, I recently repaired an old 7075, the reference oven seem opened and
leacky, with what seems silicone getting out. I measured the heater
resistance and
is of about 100ohm. Is this normal? Here some photos and more details about
serial interface

http://www.eevblog.com/forum/product-reviews-photos-and-discussion/solartron-7075-(or-will-i-be-able-to-reassemble-it-)/

I'm thinking to connect a micro to the internal optoisolated
interconnection to
bring out the readings, should be interesting to log the glug signals stats.

Fabio.

This message was
sent using IMP, the Internet Messaging Program.

_______________________________________________ volt-nuts mailing list --
volt-nuts@febo.com To unsubscribe, go to
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This message was sent using IMP, the Internet Messaging Program.

Chuck, from the damages, the instrument seem to have been subject to acceleration ( e.g. a fall) or hard vibrations. I'm curious if the 100 ohm value is correct or the heater is damaged. In this post, Mickle T. linked an image of the diode oven: http://www.radiokot.ru/forum/viewtopic.php?f=10&t=52829&start=60 This is the reference opened: http://i011.radikal.ru/1202/04/76affad54e2c.jpg So you imagined it correctly. I'm also curious if the oven is a fixed resistance or a PTC, I forgot to test for this when I had the multimeter opened. Fabio. Chuck Harris <cfharris@erols.com> ha scritto: > Looks to me like the oven is simply a black plastic box, > that holds a 100 ohm resistor and a zener diode, that is > filled with silicone rubber. > > -Chuck Harris > > Fabio Eboli wrote: >> Hello, I recently repaired an old 7075, the reference oven seem opened and >> leacky, with what seems silicone getting out. I measured the heater >> resistance and >> is of about 100ohm. Is this normal? Here some photos and more details about >> serial interface >> >> http://www.eevblog.com/forum/product-reviews-photos-and-discussion/solartron-7075-(or-will-i-be-able-to-reassemble-it-)/ >> >> >> >> I'm thinking to connect a micro to the internal optoisolated >> interconnection to >> bring out the readings, should be interesting to log the glug signals stats. >> >> Fabio. >> >> >> >> ---------------------------------------------------------------- >> This message was >> sent using IMP, the Internet Messaging Program. >> >> >> >> _______________________________________________ volt-nuts mailing list -- >> volt-nuts@febo.com To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the >> instructions there. > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

FE

Fabio Eboli

Sat, Apr 7, 2012 2:58 PM

For the record, and if anyone is interested,
the oven heater is a ptc, 100ohm at ambient temp.
and about 420ohm at working temp.
The temperature seem to be something around 80°C

here more details:
http://preview.tinyurl.com/cy764vt

Fabio.

Fabio Eboli FabioEb@quipo.it ha scritto:

Chuck, from the damages, the instrument seem to have
been subject to acceleration ( e.g. a fall) or hard vibrations.
I'm curious if the 100 ohm value is correct or the
heater is damaged.

In this post, Mickle T. linked an image of the
diode oven:
http://www.radiokot.ru/forum/viewtopic.php?f=10&t=52829&start=60
This is the reference opened:
http://i011.radikal.ru/1202/04/76affad54e2c.jpg
So you imagined it correctly.
I'm also curious if the oven is a fixed resistance or a PTC,
I forgot to test for this when I had the multimeter opened.

Fabio.

Chuck Harris cfharris@erols.com ha scritto:

Looks to me like the oven is simply a black plastic box,
that holds a 100 ohm resistor and a zener diode, that is
filled with silicone rubber.

-Chuck Harris

Fabio Eboli wrote:

Hello, I recently repaired an old 7075, the reference oven seem opened and
leacky, with what seems silicone getting out. I measured the
heater resistance and
is of about 100ohm. Is this normal? Here some photos and more details about
serial interface

http://www.eevblog.com/forum/product-reviews-photos-and-discussion/solartron-7075-(or-will-i-be-able-to-reassemble-it-)/

I'm thinking to connect a micro to the internal optoisolated
interconnection to
bring out the readings, should be interesting to log the glug
signals stats.

Fabio.

This message was
sent using IMP, the Internet Messaging Program.

_______________________________________________ volt-nuts mailing list --
volt-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the
instructions there.

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For the record, and if anyone is interested, the oven heater is a ptc, 100ohm at ambient temp. and about 420ohm at working temp. The temperature seem to be something around 80°C here more details: http://preview.tinyurl.com/cy764vt Fabio. Fabio Eboli <FabioEb@quipo.it> ha scritto: > Chuck, from the damages, the instrument seem to have > been subject to acceleration ( e.g. a fall) or hard vibrations. > I'm curious if the 100 ohm value is correct or the > heater is damaged. > > In this post, Mickle T. linked an image of the > diode oven: > http://www.radiokot.ru/forum/viewtopic.php?f=10&t=52829&start=60 > This is the reference opened: > http://i011.radikal.ru/1202/04/76affad54e2c.jpg > So you imagined it correctly. > I'm also curious if the oven is a fixed resistance or a PTC, > I forgot to test for this when I had the multimeter opened. > > Fabio. > > Chuck Harris <cfharris@erols.com> ha scritto: > >> Looks to me like the oven is simply a black plastic box, >> that holds a 100 ohm resistor and a zener diode, that is >> filled with silicone rubber. >> >> -Chuck Harris >> >> Fabio Eboli wrote: >>> Hello, I recently repaired an old 7075, the reference oven seem opened and >>> leacky, with what seems silicone getting out. I measured the >>> heater resistance and >>> is of about 100ohm. Is this normal? Here some photos and more details about >>> serial interface >>> >>> http://www.eevblog.com/forum/product-reviews-photos-and-discussion/solartron-7075-(or-will-i-be-able-to-reassemble-it-)/ >>> >>> >>> >>> I'm thinking to connect a micro to the internal optoisolated >>> interconnection to >>> bring out the readings, should be interesting to log the glug >>> signals stats. >>> >>> Fabio. >>> >>> >>> >>> ---------------------------------------------------------------- >>> This message was >>> sent using IMP, the Internet Messaging Program. >>> >>> >>> >>> _______________________________________________ volt-nuts mailing list -- >>> volt-nuts@febo.com To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the >>> instructions there. >> >> _______________________________________________ >> volt-nuts mailing list -- volt-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >> and follow the instructions there. >> > > > ---------------------------------------------------------------- > This message was sent using IMP, the Internet Messaging Program. > > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

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Re: [volt-nuts] Solartron 7061 help request (eeprom?) (Fred Schneider)

--
Bill Ezell

--
Bill Ezell

--
Bill Ezell