HP 3458A repair.
Hi,
I have a 3458A that we sent to Agilent for calibration which it failed.
Before we sent it we calibrated it and it looked good to us. The infor. we
revived led us to believe that the cal memory may have caused the failure.
We ask that it be sent buck to us and paid half the cal charges (about
$800) insted of the $2660.64 they wanted to repair it. We were just going
to repalce the ram in try again.
When we got the meter back it came with befor and afer data Like before 10
volts read 9.9999957 and after it read 10.00009 so they did something or
the meter drifted that much.
The problem is 0.1 volt and 1.0 volts failed at 8 and 10 MHz but passed at
4 MHz.
4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED
8MHZ 0.1 volt reads 0.085712
Lower Limit is 0.0959
2
0
FAILED
10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED
4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED
8MHZ 1 volt reads 0.86389
Lower Limit is 0.95920
FAILED
10MHZ 1 volt reads 0.73514 Lower Limit is 0.84900 FAILED
The AC after readings are the same. I do not see how AC after could be that
identical even if they did not try to calibrate it. Did they just copy the
before data and call it after data?
My best guess is that if the 4 MHz is in and the higher frequencies are not
the meter requires some kind of mechanical adjustment to get the frequency
response withing spec or the AC board needs to be repaid.
Are they charging a standard repair charge to do a calibration? I do not
see changing the memory to fix this.
Where would you go from here if this was your meter?
--
John Phillips
John Phillips <john.phillips0@...> writes:
Hi,
I have a 3458A that we sent to Agilent for calibration which it failed.
Before we sent it we calibrated it and it looked good to us. The infor. we
revived led us to believe that the cal memory may have caused the failure.
We ask that it be sent buck to us and paid half the cal charges (about
$800) insted of the $2660.64 they wanted to repair it. We were just going
to repalce the ram in try again.
When we got the meter back it came with befor and afer data Like before 10
volts read 9.9999957 and after it read 10.00009 so they did something or
the meter drifted that much.
The problem is 0.1 volt and 1.0 volts failed at 8 and 10 MHz but passed at
4 MHz.
4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED
8MHZ 0.1 volt reads 0.085712
Lower Limit is 0.0959
2
0
FAILED
10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED
4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED
8MHZ 1 volt reads 0.86389
Lower Limit is 0.95920
FAILED
10MHZ 1 volt reads 0.73514 Lower Limit is 0.84900 FAILED
The AC after readings are the same. I do not see how AC after could be that
identical even if they did not try to calibrate it. Did they just copy the
before data and call it after data?
My best guess is that if the 4 MHz is in and the higher frequencies are not
the meter requires some kind of mechanical adjustment to get the frequency
response withing spec or the AC board needs to be repaid.
Are they charging a standard repair charge to do a calibration? I do not
see changing the memory to fix this.
Where would you go from here if this was your meter?
Tough call. I have a 3458A that has similar issues. I have delayed its
repair since I have a second one in better shape. It will not pass SCAL at 2
and 8 MHZ nor will it pass ACAL AC.
I have scoped a test input signal at the different SCAL frequencies, and it
does appear to drop well below what the RMS converter is expecting on the
higher frequencies. If you are having similar issues, it could be part of
the compensation circuits or attenuators on the AC board. It is hard to tell
if it is a hardware issue, or the cal memory is not setting the compensation
DAC's properly based on the input frequency.
Either way, I would think if you performed ACAL AC, that it would generate
some error like Flatness DAC Convergence.
BTW, what are the dates of your NVRAM? Have you received any Checksum errors
during the selftest?
As a last resort, if you do not need the capabilities of the AC range,
you may be able to get a limited calibration performed on the DC and Ohms
ranges.
The $2K+ Agilent repair should include a full calibration. The repair cost
is the difference, but still a big chunk of change.
John,
Can you give us more information? Serial number, Rev. number, CALNUM? How
much to invest will be determined by age and other condition.
It doesn't sound like a simple CALRAM issue but changing the CALRAM is
relatively easy. I removed all three DALLAS chips in mine and installed
sockets. The CALRAM can be read with a chip programmer and the data written
to a new DALLAS chip.
I would also call Gary Bierman at the Loveland Cal Lab and have a long talk
with him. He has a lot of insight into these meters and generally prefers
to do a component level repair rather than an assembly level repair. The
charge sounds like their standard repair charge, no matter what the problem
is, and includes a 'fresh calibration' along with a warranty, a year I
think, but Gary will be able to answer that question.
Also, once you get the meter calibrated by Agilent (and thus prove it is
functioning normally) it will be eligible for their 'repair agreement' which
is $178.68 per year. I would consider buying a 5 year agreement after the
repair.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of John Phillips
Sent: Tuesday, September 17, 2013 3:36 PM
To: Discussion of precise voltage measurement
Subject: [volt-nuts] HP 3458A repair.
Hi,
I have a 3458A that we sent to Agilent for calibration which it failed.
Before we sent it we calibrated it and it looked good to us. The infor. we
revived led us to believe that the cal memory may have caused the failure.
We ask that it be sent buck to us and paid half the cal charges (about
$800) insted of the $2660.64 they wanted to repair it. We were just going to
repalce the ram in try again.
When we got the meter back it came with befor and afer data Like before 10
volts read 9.9999957 and after it read 10.00009 so they did something or the
meter drifted that much.
The problem is 0.1 volt and 1.0 volts failed at 8 and 10 MHz but passed at
4 MHz.
4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED 8MHZ 0.1 volt
reads 0.085712 Lower Limit is 0.0959
2
0
FAILED
10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED
4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED 8MHZ 1 volt reads
0.86389 Lower Limit is 0.95920 FAILED 10MHZ 1 volt reads 0.73514 Lower Limit
is 0.84900 FAILED
The AC after readings are the same. I do not see how AC after could be that
identical even if they did not try to calibrate it. Did they just copy the
before data and call it after data?
My best guess is that if the 4 MHz is in and the higher frequencies are not
the meter requires some kind of mechanical adjustment to get the frequency
response withing spec or the AC board needs to be repaid.
Are they charging a standard repair charge to do a calibration? I do not see
changing the memory to fix this.
Where would you go from here if this was your meter?
--
John Phillips
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.
Tough call. I have a 3458A that has similar issues. I have delayed its
repair since I have a second one in better shape. It will not pass SCAL at 2
and 8 MHZ nor will it pass ACAL AC.
Be aware that you need very stable and very precise input signals
to pass the AC calibrations, any disturbance and the meter calls TILT!
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
The meter will be here in a few days. I did buy the ram. As far as the
meter age goes, unless it is a very old hardware revision, I would rather
have an old meter because it is more stable. That is until it brakes.
I do have before and after readings and the 4 readings are the only ones
that failed. The after readings are better than the before readings.
Because the 8 and 10 MHz failed we did not get a certificate but we do have
a good limited calibration up to 2 MHz. Just no official cal.
The cal we wanted was $1600. We will still have to pay that after the
repair.
From what I can tell they did not run SCAL or the before/after readings
would not have matched. Like they really did not run after readings or
there would have been some mismatch.
On Tue, Sep 17, 2013 at 6:50 PM, J. L. Trantham jltran@att.net wrote:
John,
Can you give us more information? Serial number, Rev. number, CALNUM? How
much to invest will be determined by age and other condition.
It doesn't sound like a simple CALRAM issue but changing the CALRAM is
relatively easy. I removed all three DALLAS chips in mine and installed
sockets. The CALRAM can be read with a chip programmer and the data
written
to a new DALLAS chip.
I would also call Gary Bierman at the Loveland Cal Lab and have a long talk
with him. He has a lot of insight into these meters and generally prefers
to do a component level repair rather than an assembly level repair. The
charge sounds like their standard repair charge, no matter what the problem
is, and includes a 'fresh calibration' along with a warranty, a year I
think, but Gary will be able to answer that question.
Also, once you get the meter calibrated by Agilent (and thus prove it is
functioning normally) it will be eligible for their 'repair agreement'
which
is $178.68 per year. I would consider buying a 5 year agreement after the
repair.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of John Phillips
Sent: Tuesday, September 17, 2013 3:36 PM
To: Discussion of precise voltage measurement
Subject: [volt-nuts] HP 3458A repair.
Hi,
I have a 3458A that we sent to Agilent for calibration which it failed.
Before we sent it we calibrated it and it looked good to us. The infor. we
revived led us to believe that the cal memory may have caused the failure.
We ask that it be sent buck to us and paid half the cal charges (about
$800) insted of the $2660.64 they wanted to repair it. We were just going
to
repalce the ram in try again.
When we got the meter back it came with befor and afer data Like before 10
volts read 9.9999957 and after it read 10.00009 so they did something or
the
meter drifted that much.
The problem is 0.1 volt and 1.0 volts failed at 8 and 10 MHz but passed at
4 MHz.
4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED 8MHZ 0.1 volt
reads 0.085712 Lower Limit is 0.0959
2
0
FAILED
10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED
4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED 8MHZ 1 volt reads
0.86389 Lower Limit is 0.95920 FAILED 10MHZ 1 volt reads 0.73514 Lower
Limit
is 0.84900 FAILED
The AC after readings are the same. I do not see how AC after could be that
identical even if they did not try to calibrate it. Did they just copy the
before data and call it after data?
My best guess is that if the 4 MHz is in and the higher frequencies are not
the meter requires some kind of mechanical adjustment to get the frequency
response withing spec or the AC board needs to be repaid.
Are they charging a standard repair charge to do a calibration? I do not
see
changing the memory to fix this.
Where would you go from here if this was your meter?
--
John Phillips
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.
--
John Phillips
I agree with your assessment of an 'old' meter being more desirable.
I would recommend a conversation with Gary Bierman if you have not already
done that.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of John Phillips
Sent: Wednesday, September 18, 2013 10:45 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3458A repair.
The meter will be here in a few days. I did buy the ram. As far as the meter
age goes, unless it is a very old hardware revision, I would rather have an
old meter because it is more stable. That is until it brakes.
I do have before and after readings and the 4 readings are the only ones
that failed. The after readings are better than the before readings.
Because the 8 and 10 MHz failed we did not get a certificate but we do have
a good limited calibration up to 2 MHz. Just no official cal.
The cal we wanted was $1600. We will still have to pay that after the
repair.
From what I can tell they did not run SCAL or the before/after readings
would not have matched. Like they really did not run after readings or there
would have been some mismatch.
On Tue, Sep 17, 2013 at 6:50 PM, J. L. Trantham jltran@att.net wrote:
John,
Can you give us more information? Serial number, Rev. number, CALNUM?
How much to invest will be determined by age and other condition.
It doesn't sound like a simple CALRAM issue but changing the CALRAM is
relatively easy. I removed all three DALLAS chips in mine and
installed sockets. The CALRAM can be read with a chip programmer and
the data written to a new DALLAS chip.
I would also call Gary Bierman at the Loveland Cal Lab and have a long
talk with him. He has a lot of insight into these meters and
generally prefers to do a component level repair rather than an
assembly level repair. The charge sounds like their standard repair
charge, no matter what the problem is, and includes a 'fresh
calibration' along with a warranty, a year I think, but Gary will be able
to answer that question.
Also, once you get the meter calibrated by Agilent (and thus prove it
is functioning normally) it will be eligible for their 'repair agreement'
which
is $178.68 per year. I would consider buying a 5 year agreement after
the repair.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com]
On Behalf Of John Phillips
Sent: Tuesday, September 17, 2013 3:36 PM
To: Discussion of precise voltage measurement
Subject: [volt-nuts] HP 3458A repair.
Hi,
I have a 3458A that we sent to Agilent for calibration which it failed.
Before we sent it we calibrated it and it looked good to us. The
infor. we revived led us to believe that the cal memory may have caused
the failure.
We ask that it be sent buck to us and paid half the cal charges
(about
$800) insted of the $2660.64 they wanted to repair it. We were just
going to repalce the ram in try again.
When we got the meter back it came with befor and afer data Like
before 10 volts read 9.9999957 and after it read 10.00009 so they did
something or the meter drifted that much.
The problem is 0.1 volt and 1.0 volts failed at 8 and 10 MHz but
passed at
4 MHz.
4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED 8MHZ 0.1
volt reads 0.085712 Lower Limit is 0.0959
2
0
FAILED
10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED
4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED 8MHZ 1 volt
reads
0.86389 Lower Limit is 0.95920 FAILED 10MHZ 1 volt reads 0.73514 Lower
Limit is 0.84900 FAILED
The AC after readings are the same. I do not see how AC after could be
that identical even if they did not try to calibrate it. Did they just
copy the before data and call it after data?
My best guess is that if the 4 MHz is in and the higher frequencies
are not the meter requires some kind of mechanical adjustment to get the
frequency
response withing spec or the AC board needs to be repaid.
Are they charging a standard repair charge to do a calibration? I do
not see changing the memory to fix this.
Where would you go from here if this was your meter?
--
John Phillips
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.
--
John Phillips
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.
I talked with Gary... it sounded more like a sales pitch like they replace
relays before they failed. The date code on the cal ram is 6 years past
replacement. The only problem seems to be the amplifier/attenuator
flatness. He said this could be caused by caps aging and changing value.
They tried calibrating the AC but it did not come withing spec so they did
not update the as left data... I think if they are going to send the as
left data it should be real as left or blank. This meter looks like a good
meter for what I will use it for so we will not use the AC above 2MHz as if
we ever did.
On Wed, Sep 18, 2013 at 9:17 AM, J. L. Trantham jltran@att.net wrote:
I agree with your assessment of an 'old' meter being more desirable.
I would recommend a conversation with Gary Bierman if you have not already
done that.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of John Phillips
Sent: Wednesday, September 18, 2013 10:45 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3458A repair.
The meter will be here in a few days. I did buy the ram. As far as the
meter
age goes, unless it is a very old hardware revision, I would rather have an
old meter because it is more stable. That is until it brakes.
I do have before and after readings and the 4 readings are the only ones
that failed. The after readings are better than the before readings.
Because the 8 and 10 MHz failed we did not get a certificate but we do have
a good limited calibration up to 2 MHz. Just no official cal.
The cal we wanted was $1600. We will still have to pay that after the
repair.
From what I can tell they did not run SCAL or the before/after readings
would not have matched. Like they really did not run after readings or
there
would have been some mismatch.
On Tue, Sep 17, 2013 at 6:50 PM, J. L. Trantham jltran@att.net wrote:
John,
Can you give us more information? Serial number, Rev. number, CALNUM?
How much to invest will be determined by age and other condition.
It doesn't sound like a simple CALRAM issue but changing the CALRAM is
relatively easy. I removed all three DALLAS chips in mine and
installed sockets. The CALRAM can be read with a chip programmer and
the data written to a new DALLAS chip.
I would also call Gary Bierman at the Loveland Cal Lab and have a long
talk with him. He has a lot of insight into these meters and
generally prefers to do a component level repair rather than an
assembly level repair. The charge sounds like their standard repair
charge, no matter what the problem is, and includes a 'fresh
calibration' along with a warranty, a year I think, but Gary will be able
to answer that question.
Also, once you get the meter calibrated by Agilent (and thus prove it
is functioning normally) it will be eligible for their 'repair agreement'
which
is $178.68 per year. I would consider buying a 5 year agreement after
the repair.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com]
On Behalf Of John Phillips
Sent: Tuesday, September 17, 2013 3:36 PM
To: Discussion of precise voltage measurement
Subject: [volt-nuts] HP 3458A repair.
Hi,
I have a 3458A that we sent to Agilent for calibration which it failed.
Before we sent it we calibrated it and it looked good to us. The
infor. we revived led us to believe that the cal memory may have caused
the failure.
We ask that it be sent buck to us and paid half the cal charges
(about
$800) insted of the $2660.64 they wanted to repair it. We were just
going to repalce the ram in try again.
When we got the meter back it came with befor and afer data Like
before 10 volts read 9.9999957 and after it read 10.00009 so they did
something or the meter drifted that much.
The problem is 0.1 volt and 1.0 volts failed at 8 and 10 MHz but
passed at
4 MHz.
4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED 8MHZ 0.1
volt reads 0.085712 Lower Limit is 0.0959
2
0
FAILED
10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED
4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED 8MHZ 1 volt
reads
0.86389 Lower Limit is 0.95920 FAILED 10MHZ 1 volt reads 0.73514 Lower
Limit is 0.84900 FAILED
The AC after readings are the same. I do not see how AC after could be
that identical even if they did not try to calibrate it. Did they just
copy the before data and call it after data?
My best guess is that if the 4 MHz is in and the higher frequencies
are not the meter requires some kind of mechanical adjustment to get the
frequency
response withing spec or the AC board needs to be repaid.
Are they charging a standard repair charge to do a calibration? I do
not see changing the memory to fix this.
Where would you go from here if this was your meter?
--
John Phillips
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.
--
John Phillips
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.
--
John Phillips
You have to remember he is employed by Agilent and he has considerable
energy invested in this meter. I'm not convinced he thinks moving
manufacturing to Malaysia was a smart move given the extreme performance
specs for this meter and the extreme performance specs required for the
parts that went into the meter.
It might be that he was giving you some hints about what to change to again
see if it would meet spec.
What 'standards' do you have that might address the scales in question? Do
you have another 'calibrated' meter that you might use as a 'transfer
standard'?
IIRC, they call for an HP 3325A as the source for the AC scales. I don't
have any 'thermal standards' but I did use an HP 3326A as the source and an
Ametek calibrated Solartron 7081 as the 'transfer standard' on the 3458A
that I calibrated but the two middle AC scales (can't recall right now as I
am OOT) did not meet spec in the 'as found' category but were able to be
calibrated by HP. All I got was the 'Agilent Cal' for about $500 or so. I
have since returned it to Agilent for 're-cal' just over a year later and it
was still 'in spec' 'as found'. I also got the 'Repair Agreement' after it
was calibrated. That way, if it fails in the next 5 years, it will be
repaired and calibrated 'no additional charge'.
So, if you have any insight from the conversation with Gary, you might try
changing the appropriate parts and see what you get.
I now have a Fluke 5100B and 5200A along with my 'in cal' 3458A and happy to
help in any way I can.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of John Phillips
Sent: Wednesday, September 18, 2013 3:51 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3458A repair.
I talked with Gary... it sounded more like a sales pitch like they replace
relays before they failed. The date code on the cal ram is 6 years past
replacement. The only problem seems to be the amplifier/attenuator
flatness. He said this could be caused by caps aging and changing value.
They tried calibrating the AC but it did not come withing spec so they did
not update the as left data... I think if they are going to send the as
left data it should be real as left or blank. This meter looks like a good
meter for what I will use it for so we will not use the AC above 2MHz as if
we ever did.
On Wed, Sep 18, 2013 at 9:17 AM, J. L. Trantham jltran@att.net wrote:
I agree with your assessment of an 'old' meter being more desirable.
I would recommend a conversation with Gary Bierman if you have not already
done that.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of John Phillips
Sent: Wednesday, September 18, 2013 10:45 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3458A repair.
The meter will be here in a few days. I did buy the ram. As far as the
meter
age goes, unless it is a very old hardware revision, I would rather have
an
old meter because it is more stable. That is until it brakes.
I do have before and after readings and the 4 readings are the only ones
that failed. The after readings are better than the before readings.
Because the 8 and 10 MHz failed we did not get a certificate but we do
have
a good limited calibration up to 2 MHz. Just no official cal.
The cal we wanted was $1600. We will still have to pay that after the
repair.
From what I can tell they did not run SCAL or the before/after readings
would not have matched. Like they really did not run after readings or
there
would have been some mismatch.
On Tue, Sep 17, 2013 at 6:50 PM, J. L. Trantham jltran@att.net wrote:
John,
Can you give us more information? Serial number, Rev. number, CALNUM?
How much to invest will be determined by age and other condition.
It doesn't sound like a simple CALRAM issue but changing the CALRAM is
relatively easy. I removed all three DALLAS chips in mine and
installed sockets. The CALRAM can be read with a chip programmer and
the data written to a new DALLAS chip.
I would also call Gary Bierman at the Loveland Cal Lab and have a long
talk with him. He has a lot of insight into these meters and
generally prefers to do a component level repair rather than an
assembly level repair. The charge sounds like their standard repair
charge, no matter what the problem is, and includes a 'fresh
calibration' along with a warranty, a year I think, but Gary will be
able
to answer that question.
Also, once you get the meter calibrated by Agilent (and thus prove it
is functioning normally) it will be eligible for their 'repair
agreement'
which
is $178.68 per year. I would consider buying a 5 year agreement after
the repair.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com]
On Behalf Of John Phillips
Sent: Tuesday, September 17, 2013 3:36 PM
To: Discussion of precise voltage measurement
Subject: [volt-nuts] HP 3458A repair.
Hi,
I have a 3458A that we sent to Agilent for calibration which it failed.
Before we sent it we calibrated it and it looked good to us. The
infor. we revived led us to believe that the cal memory may have caused
the failure.
We ask that it be sent buck to us and paid half the cal charges
(about
$800) insted of the $2660.64 they wanted to repair it. We were just
going to repalce the ram in try again.
When we got the meter back it came with befor and afer data Like
before 10 volts read 9.9999957 and after it read 10.00009 so they did
something or the meter drifted that much.
The problem is 0.1 volt and 1.0 volts failed at 8 and 10 MHz but
passed at
4 MHz.
4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED 8MHZ 0.1
volt reads 0.085712 Lower Limit is 0.0959
2
0
FAILED
10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED
4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED 8MHZ 1 volt
reads
0.86389 Lower Limit is 0.95920 FAILED 10MHZ 1 volt reads 0.73514 Lower
Limit is 0.84900 FAILED
The AC after readings are the same. I do not see how AC after could be
that identical even if they did not try to calibrate it. Did they just
copy the before data and call it after data?
My best guess is that if the 4 MHz is in and the higher frequencies
are not the meter requires some kind of mechanical adjustment to get the
frequency
response withing spec or the AC board needs to be repaid.
Are they charging a standard repair charge to do a calibration? I do
not see changing the memory to fix this.
Where would you go from here if this was your meter?
--
John Phillips
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
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and follow the instructions there.
--
John Phillips
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To unsubscribe, go to
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To unsubscribe, go to
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John Phillips
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To unsubscribe, go to
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and follow the instructions there.
Forgot to ask.
Do you have the CLIP?
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of John Phillips
Sent: Wednesday, September 18, 2013 3:51 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3458A repair.
I talked with Gary... it sounded more like a sales pitch like they replace
relays before they failed. The date code on the cal ram is 6 years past
replacement. The only problem seems to be the amplifier/attenuator
flatness. He said this could be caused by caps aging and changing value.
They tried calibrating the AC but it did not come withing spec so they did
not update the as left data... I think if they are going to send the as
left data it should be real as left or blank. This meter looks like a good
meter for what I will use it for so we will not use the AC above 2MHz as if
we ever did.
On Wed, Sep 18, 2013 at 9:17 AM, J. L. Trantham jltran@att.net wrote:
I agree with your assessment of an 'old' meter being more desirable.
I would recommend a conversation with Gary Bierman if you have not already
done that.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of John Phillips
Sent: Wednesday, September 18, 2013 10:45 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3458A repair.
The meter will be here in a few days. I did buy the ram. As far as the
meter
age goes, unless it is a very old hardware revision, I would rather have
an
old meter because it is more stable. That is until it brakes.
I do have before and after readings and the 4 readings are the only ones
that failed. The after readings are better than the before readings.
Because the 8 and 10 MHz failed we did not get a certificate but we do
have
a good limited calibration up to 2 MHz. Just no official cal.
The cal we wanted was $1600. We will still have to pay that after the
repair.
From what I can tell they did not run SCAL or the before/after readings
would not have matched. Like they really did not run after readings or
there
would have been some mismatch.
On Tue, Sep 17, 2013 at 6:50 PM, J. L. Trantham jltran@att.net wrote:
John,
Can you give us more information? Serial number, Rev. number, CALNUM?
How much to invest will be determined by age and other condition.
It doesn't sound like a simple CALRAM issue but changing the CALRAM is
relatively easy. I removed all three DALLAS chips in mine and
installed sockets. The CALRAM can be read with a chip programmer and
the data written to a new DALLAS chip.
I would also call Gary Bierman at the Loveland Cal Lab and have a long
talk with him. He has a lot of insight into these meters and
generally prefers to do a component level repair rather than an
assembly level repair. The charge sounds like their standard repair
charge, no matter what the problem is, and includes a 'fresh
calibration' along with a warranty, a year I think, but Gary will be
able
to answer that question.
Also, once you get the meter calibrated by Agilent (and thus prove it
is functioning normally) it will be eligible for their 'repair
agreement'
which
is $178.68 per year. I would consider buying a 5 year agreement after
the repair.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com]
On Behalf Of John Phillips
Sent: Tuesday, September 17, 2013 3:36 PM
To: Discussion of precise voltage measurement
Subject: [volt-nuts] HP 3458A repair.
Hi,
I have a 3458A that we sent to Agilent for calibration which it failed.
Before we sent it we calibrated it and it looked good to us. The
infor. we revived led us to believe that the cal memory may have caused
the failure.
We ask that it be sent buck to us and paid half the cal charges
(about
$800) insted of the $2660.64 they wanted to repair it. We were just
going to repalce the ram in try again.
When we got the meter back it came with befor and afer data Like
before 10 volts read 9.9999957 and after it read 10.00009 so they did
something or the meter drifted that much.
The problem is 0.1 volt and 1.0 volts failed at 8 and 10 MHz but
passed at
4 MHz.
4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED 8MHZ 0.1
volt reads 0.085712 Lower Limit is 0.0959
2
0
FAILED
10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED
4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED 8MHZ 1 volt
reads
0.86389 Lower Limit is 0.95920 FAILED 10MHZ 1 volt reads 0.73514 Lower
Limit is 0.84900 FAILED
The AC after readings are the same. I do not see how AC after could be
that identical even if they did not try to calibrate it. Did they just
copy the before data and call it after data?
My best guess is that if the 4 MHz is in and the higher frequencies
are not the meter requires some kind of mechanical adjustment to get the
frequency
response withing spec or the AC board needs to be repaid.
Are they charging a standard repair charge to do a calibration? I do
not see changing the memory to fix this.
Where would you go from here if this was your meter?
--
John Phillips
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.
--
John Phillips
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.
--
John Phillips
volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to
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and follow the instructions there.
Just the one from the Agilent site.
If I get one of these, I'll hit Dave up for a good copy.
Thanks,
Tom
----- Original Message -----
From: "J. L. Trantham" jltran@att.net
To: "'Discussion of precise voltage measurement'" volt-nuts@febo.com
Sent: Wednesday, September 18, 2013 10:54 PM
Subject: Re: [volt-nuts] HP 3458A repair.
Forgot to ask.
Do you have the CLIP?
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of John Phillips
Sent: Wednesday, September 18, 2013 3:51 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3458A repair.
I talked with Gary... it sounded more like a sales pitch like they replace
relays before they failed. The date code on the cal ram is 6 years past
replacement. The only problem seems to be the amplifier/attenuator
flatness. He said this could be caused by caps aging and changing value.
They tried calibrating the AC but it did not come withing spec so they did
not update the as left data... I think if they are going to send the as
left data it should be real as left or blank. This meter looks like a good
meter for what I will use it for so we will not use the AC above 2MHz as
if
we ever did.
On Wed, Sep 18, 2013 at 9:17 AM, J. L. Trantham jltran@att.net wrote:
I agree with your assessment of an 'old' meter being more desirable.
I would recommend a conversation with Gary Bierman if you have not
already
done that.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of John Phillips
Sent: Wednesday, September 18, 2013 10:45 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3458A repair.
The meter will be here in a few days. I did buy the ram. As far as the
meter
age goes, unless it is a very old hardware revision, I would rather have
an
old meter because it is more stable. That is until it brakes.
I do have before and after readings and the 4 readings are the only ones
that failed. The after readings are better than the before readings.
Because the 8 and 10 MHz failed we did not get a certificate but we do
have
a good limited calibration up to 2 MHz. Just no official cal.
The cal we wanted was $1600. We will still have to pay that after the
repair.
From what I can tell they did not run SCAL or the before/after readings
would not have matched. Like they really did not run after readings or
there
would have been some mismatch.
On Tue, Sep 17, 2013 at 6:50 PM, J. L. Trantham jltran@att.net wrote:
John,
Can you give us more information? Serial number, Rev. number, CALNUM?
How much to invest will be determined by age and other condition.
It doesn't sound like a simple CALRAM issue but changing the CALRAM is
relatively easy. I removed all three DALLAS chips in mine and
installed sockets. The CALRAM can be read with a chip programmer and
the data written to a new DALLAS chip.
I would also call Gary Bierman at the Loveland Cal Lab and have a long
talk with him. He has a lot of insight into these meters and
generally prefers to do a component level repair rather than an
assembly level repair. The charge sounds like their standard repair
charge, no matter what the problem is, and includes a 'fresh
calibration' along with a warranty, a year I think, but Gary will be
able
to answer that question.
Also, once you get the meter calibrated by Agilent (and thus prove it
is functioning normally) it will be eligible for their 'repair
agreement'
which
is $178.68 per year. I would consider buying a 5 year agreement after
the repair.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com]
On Behalf Of John Phillips
Sent: Tuesday, September 17, 2013 3:36 PM
To: Discussion of precise voltage measurement
Subject: [volt-nuts] HP 3458A repair.
Hi,
I have a 3458A that we sent to Agilent for calibration which it failed.
Before we sent it we calibrated it and it looked good to us. The
infor. we revived led us to believe that the cal memory may have caused
the failure.
We ask that it be sent buck to us and paid half the cal charges
(about
$800) insted of the $2660.64 they wanted to repair it. We were just
going to repalce the ram in try again.
When we got the meter back it came with befor and afer data Like
before 10 volts read 9.9999957 and after it read 10.00009 so they did
something or the meter drifted that much.
The problem is 0.1 volt and 1.0 volts failed at 8 and 10 MHz but
passed at
4 MHz.
4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED 8MHZ 0.1
volt reads 0.085712 Lower Limit is 0.0959
2
0
FAILED
10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED
4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED 8MHZ 1 volt
reads
0.86389 Lower Limit is 0.95920 FAILED 10MHZ 1 volt reads 0.73514 Lower
Limit is 0.84900 FAILED
The AC after readings are the same. I do not see how AC after could be
that identical even if they did not try to calibrate it. Did they just
copy the before data and call it after data?
My best guess is that if the 4 MHz is in and the higher frequencies
are not the meter requires some kind of mechanical adjustment to get
the
frequency
response withing spec or the AC board needs to be repaid.
Are they charging a standard repair charge to do a calibration? I do
not see changing the memory to fix this.
Where would you go from here if this was your meter?
--
John Phillips
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.
--
John Phillips
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.
--
John Phillips
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.