Empathy List Archives

BG

Bill Gold

Tue, Sep 13, 2011 7:08 AM

Joe:

Your experience with the electrolytics in your 335A matches what I have found in four 332Bs and one 335A.  Except for the null meter in the 335A the boards are exactly the same.  I found that the best way to insure everything was OK was to check every electrolytic cap on every board in the instrument.  And like you I found that most of the bad ones were "open" with no measurable capacitance.  And the majority were the 50uf/50v caps.  Just a poor choice of manufacturer and I am sure that Fluke didn't realize what they had done at the time.

I also found that the feedback string rotary switches, the seven rotary switches that set up the voltage for the range selected, were all unreliable as far as constant contact resistance each time they are set to a different digit.  So what you will probably find is that when you rotate the most significant digit switch, i.e. 0 to 10 volts on the 10 volt range, you will have a slightly different voltage every time, if you have a meter with enough digits to show this.  Also this makes it difficult to adjust the first three sets of decade resistors because you will have varying contact resistance every time you change the switch settings.  The 0 to 10 volt switch is selecting 100k resistors so the contact resistance effect is minimal.  I could see this on a 6 1/2 digit meter (HP 3456A).  But where you are going to see this problem manifest the problem the worst is the lower digit switches where the resistors in the string are the smallest.  Here any unstable contact resistance is going to be worse because it is a larger part of the resistance being switched.  I believe these are 0.1 ohms each on the 1 uv switch.  While this switch is only 1 uv per step and is insignificant in the overall accuracy of the instrument, it does affect the zero setting of each range.  The cal procedure wants each range to be set to +/- 2 uv on each range ( 10v, 100v, 1000v ).  While the 1 uv switch on the 10 volt range will affect the zero very little, the same switch becomes the 100 uv switch when the range is set to the 1000 volt range.  Now the smallest change in contact resistance will affect the zero on the 1000 volt range and you will not be able to keep the zero anywhere near ideal.  Again this may not be important to you if you are simply trying to cal a 8050 meter.

My solution was to remove the feedback string board from the instrument, clean all of the switches, and then apply a thin film of Caig Labs DeOxit and then a thin film of Presevit.  Be careful as you may also have another problem depending upon when your instrument was manufactured.  The insulator standoffs for this board can simply crumble because the standoff material has degenerated over time.  I had to manufacture new standoffs for my 335A.  Also the range switch which selects the 10 v, 100v and 1000v range can also suffer from the same contact problems.  This is much more difficult to service, but I used the same chemicals on this one also, with fairly good results.

Good luck

Bill

Joe: Your experience with the electrolytics in your 335A matches what I have found in four 332Bs and one 335A. Except for the null meter in the 335A the boards are exactly the same. I found that the best way to insure everything was OK was to check every electrolytic cap on every board in the instrument. And like you I found that most of the bad ones were "open" with no measurable capacitance. And the majority were the 50uf/50v caps. Just a poor choice of manufacturer and I am sure that Fluke didn't realize what they had done at the time. I also found that the feedback string rotary switches, the seven rotary switches that set up the voltage for the range selected, were all unreliable as far as constant contact resistance each time they are set to a different digit. So what you will probably find is that when you rotate the most significant digit switch, i.e. 0 to 10 volts on the 10 volt range, you will have a slightly different voltage every time, if you have a meter with enough digits to show this. Also this makes it difficult to adjust the first three sets of decade resistors because you will have varying contact resistance every time you change the switch settings. The 0 to 10 volt switch is selecting 100k resistors so the contact resistance effect is minimal. I could see this on a 6 1/2 digit meter (HP 3456A). But where you are going to see this problem manifest the problem the worst is the lower digit switches where the resistors in the string are the smallest. Here any unstable contact resistance is going to be worse because it is a larger part of the resistance being switched. I believe these are 0.1 ohms each on the 1 uv switch. While this switch is only 1 uv per step and is insignificant in the overall accuracy of the instrument, it does affect the zero setting of each range. The cal procedure wants each range to be set to +/- 2 uv on each range ( 10v, 100v, 1000v ). While the 1 uv switch on the 10 volt range will affect the zero very little, the same switch becomes the 100 uv switch when the range is set to the 1000 volt range. Now the smallest change in contact resistance will affect the zero on the 1000 volt range and you will not be able to keep the zero anywhere near ideal. Again this may not be important to you if you are simply trying to cal a 8050 meter. My solution was to remove the feedback string board from the instrument, clean all of the switches, and then apply a thin film of Caig Labs DeOxit and then a thin film of Presevit. Be careful as you may also have another problem depending upon when your instrument was manufactured. The insulator standoffs for this board can simply crumble because the standoff material has degenerated over time. I had to manufacture new standoffs for my 335A. Also the range switch which selects the 10 v, 100v and 1000v range can also suffer from the same contact problems. This is much more difficult to service, but I used the same chemicals on this one also, with fairly good results. Good luck Bill

FS

Fred Schneider

Tue, Sep 13, 2011 7:56 AM

My 332 also had some bad caps.
The problem you describe about the switches is helpfull. This is exact my problem. I adjusted everything according the book ( but was wise enough not to alter the dividers or so) and the 0-10 and 10-100 range give a difference in the order you write. Now winter comes and it is more easy to keep temperature stable, and now I have a 7,5 digit meter and the 845 AB is perfect again I will do a recalibration of the 332 and clean the switches,

The standoff material problem I have with my 720 Kelvin Varley devider. Almost al standoffs and the center thing on the end of the switch rod that interfaces between the switch deck and the rod where disintergrated. I made new one from teflon but i have still a poblrm in one switch. It sometimes has a to high resistance like you descibe for the 335. I will see if I can get the lubricant and cleaner you mentioned over here ( is it is allowed to sell here, we have very strickt rules about that. It must often have ( expensive) permission ( after testing) to be allowed to sell for this rather small local market. This results in strange things like for instance enviorment friendly weed poison, only problem is the weeds are not killed too)

I use methanol and amonia for switches.

Fred

Op 13 sep. 2011 om 09:08 heeft "Bill Gold" wpgold3637@att.net het volgende geschreven:

Joe:

Your experience with the electrolytics in your 335A matches what I have found in four 332Bs and one 335A.  Except for the null meter in the 335A the boards are exactly the same.  I found that the best way to insure everything was OK was to check every electrolytic cap on every board in the instrument.  And like you I found that most of the bad ones were "open" with no measurable capacitance.  And the majority were the 50uf/50v caps.  Just a poor choice of manufacturer and I am sure that Fluke didn't realize what they had done at the time.

I also found that the feedback string rotary switches, the seven rotary switches that set up the voltage for the range selected, were all unreliable as far as constant contact resistance each time they are set to a different digit.  So what you will probably find is that when you rotate the most significant digit switch, i.e. 0 to 10 volts on the 10 volt range, you will have a slightly different voltage every time, if you have a meter with enough digits to show this.  Also this makes it difficult to adjust the first three sets of decade resistors because you will have varying contact resistance every time you change the switch settings.  The 0 to 10 volt switch is selecting 100k resistors so the contact resistance effect is minimal.  I could see this on a 6 1/2 digit meter (HP 3456A).  But where you are going to see this problem manifest the problem the worst is the lower digit switches where the resistors in the string are the smallest.  Here any unstable contact resistance is going to be worse because it is a larger part of the resistance being switched.  I believe these are 0.1 ohms each on the 1 uv switch.  While this switch is only 1 uv per step and is insignificant in the overall accuracy of the instrument, it does affect the zero setting of each range.  The cal procedure wants each range to be set to +/- 2 uv on each range ( 10v, 100v, 1000v ).  While the 1 uv switch on the 10 volt range will affect the zero very little, the same switch becomes the 100 uv switch when the range is set to the 1000 volt range.  Now the smallest change in contact resistance will affect the zero on the 1000 volt range and you will not be able to keep the zero anywhere near ideal.  Again this may not be important to you if you are simply trying to cal a 8050 meter.

My solution was to remove the feedback string board from the instrument, clean all of the switches, and then apply a thin film of Caig Labs DeOxit and then a thin film of Presevit.  Be careful as you may also have another problem depending upon when your instrument was manufactured.  The insulator standoffs for this board can simply crumble because the standoff material has degenerated over time.  I had to manufacture new standoffs for my 335A.  Also the range switch which selects the 10 v, 100v and 1000v range can also suffer from the same contact problems.  This is much more difficult to service, but I used the same chemicals on this one also, with fairly good results.

Good luck

Bill

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.

My 332 also had some bad caps. The problem you describe about the switches is helpfull. This is exact my problem. I adjusted everything according the book ( but was wise enough not to alter the dividers or so) and the 0-10 and 10-100 range give a difference in the order you write. Now winter comes and it is more easy to keep temperature stable, and now I have a 7,5 digit meter and the 845 AB is perfect again I will do a recalibration of the 332 and clean the switches, The standoff material problem I have with my 720 Kelvin Varley devider. Almost al standoffs and the center thing on the end of the switch rod that interfaces between the switch deck and the rod where disintergrated. I made new one from teflon but i have still a poblrm in one switch. It sometimes has a to high resistance like you descibe for the 335. I will see if I can get the lubricant and cleaner you mentioned over here ( is it is allowed to sell here, we have very strickt rules about that. It must often have ( expensive) permission ( after testing) to be allowed to sell for this rather small local market. This results in strange things like for instance enviorment friendly weed poison, only problem is the weeds are not killed too) I use methanol and amonia for switches. Fred Op 13 sep. 2011 om 09:08 heeft "Bill Gold" <wpgold3637@att.net> het volgende geschreven: > Joe: > > Your experience with the electrolytics in your 335A matches what I have found in four 332Bs and one 335A. Except for the null meter in the 335A the boards are exactly the same. I found that the best way to insure everything was OK was to check every electrolytic cap on every board in the instrument. And like you I found that most of the bad ones were "open" with no measurable capacitance. And the majority were the 50uf/50v caps. Just a poor choice of manufacturer and I am sure that Fluke didn't realize what they had done at the time. > > I also found that the feedback string rotary switches, the seven rotary switches that set up the voltage for the range selected, were all unreliable as far as constant contact resistance each time they are set to a different digit. So what you will probably find is that when you rotate the most significant digit switch, i.e. 0 to 10 volts on the 10 volt range, you will have a slightly different voltage every time, if you have a meter with enough digits to show this. Also this makes it difficult to adjust the first three sets of decade resistors because you will have varying contact resistance every time you change the switch settings. The 0 to 10 volt switch is selecting 100k resistors so the contact resistance effect is minimal. I could see this on a 6 1/2 digit meter (HP 3456A). But where you are going to see this problem manifest the problem the worst is the lower digit switches where the resistors in the string are the smallest. Here any unstable contact resistance is going to be worse because it is a larger part of the resistance being switched. I believe these are 0.1 ohms each on the 1 uv switch. While this switch is only 1 uv per step and is insignificant in the overall accuracy of the instrument, it does affect the zero setting of each range. The cal procedure wants each range to be set to +/- 2 uv on each range ( 10v, 100v, 1000v ). While the 1 uv switch on the 10 volt range will affect the zero very little, the same switch becomes the 100 uv switch when the range is set to the 1000 volt range. Now the smallest change in contact resistance will affect the zero on the 1000 volt range and you will not be able to keep the zero anywhere near ideal. Again this may not be important to you if you are simply trying to cal a 8050 meter. > > My solution was to remove the feedback string board from the instrument, clean all of the switches, and then apply a thin film of Caig Labs DeOxit and then a thin film of Presevit. Be careful as you may also have another problem depending upon when your instrument was manufactured. The insulator standoffs for this board can simply crumble because the standoff material has degenerated over time. I had to manufacture new standoffs for my 335A. Also the range switch which selects the 10 v, 100v and 1000v range can also suffer from the same contact problems. This is much more difficult to service, but I used the same chemicals on this one also, with fairly good results. > > Good luck > > Bill > _______________________________________________ > 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.

G

gbusg

Tue, Sep 13, 2011 8:10 AM

I had similar, severe repeatability problems with the rotary switches in a
very old (blue front panel) Fluke 335A.

By comparison I later acquired a much newer (late serial number with beige
front panel) 335D having much more stable and repeatable output as related
to its rotary switch settings.

Joe and Bill, did you happen to notice the date codes on the capacitors (and
other parts) in your old 335As? (I no longer have my 335A, but I suspect it
was made in the 1970 timeframe? By contrast, IIRC, my 335D was made in the
1990 timeframe.)

Greg

----- Original Message -----
From: "Bill Gold" wpgold3637@att.net
To: volt-nuts@febo.com
Sent: Tuesday, September 13, 2011 1:08 AM
Subject: Re: [volt-nuts] Fluke 335A

Joe:

Your experience with the electrolytics in your 335A matches what I have

found in four 332Bs and one 335A. Except for the null meter in the 335A the
boards are exactly the same. I found that the best way to insure everything
was OK was to check every electrolytic cap on every board in the instrument.
And like you I found that most of the bad ones were "open" with no
measurable capacitance. And the majority were the 50uf/50v caps. Just a
poor choice of manufacturer and I am sure that Fluke didn't realize what
they had done at the time.

I also found that the feedback string rotary switches, the seven rotary

switches that set up the voltage for the range selected, were all unreliable
as far as constant contact resistance each time they are set to a different
digit. So what you will probably find is that when you rotate the most
significant digit switch, i.e. 0 to 10 volts on the 10 volt range, you will
have a slightly different voltage every time, if you have a meter with
enough digits to show this. Also this makes it difficult to adjust the
first three sets of decade resistors because you will have varying contact
resistance every time you change the switch settings. The 0 to 10 volt
switch is selecting 100k resistors so the contact resistance effect is
minimal. I could see this on a 6 1/2 digit meter (HP 3456A). But where you
are going to see this problem manifest the problem the worst is the lower
digit switches where the resistors in the string are the smallest. Here any
unstable contact resistance is going to be worse because it is a larger part
of the resistance being switched. I believe these are 0.1 ohms each on the
1 uv switch. While this switch is only 1 uv per step and is insignificant
in the overall accuracy of the instrument, it does affect the zero setting
of each range. The cal procedure wants each range to be set to +/- 2 uv on
each range ( 10v, 100v, 1000v ). While the 1 uv switch on the 10 volt range
will affect the zero very little, the same switch becomes the 100 uv switch
when the range is set to the 1000 volt range. Now the smallest change in
contact resistance will affect the zero on the 1000 volt range and you will
not be able to keep the zero anywhere near ideal. Again this may not be
important to you if you are simply trying to cal a 8050 meter.

My solution was to remove the feedback string board from the instrument,

clean all of the switches, and then apply a thin film of Caig Labs DeOxit
and then a thin film of Presevit. Be careful as you may also have another
problem depending upon when your instrument was manufactured. The insulator
standoffs for this board can simply crumble because the standoff material
has degenerated over time. I had to manufacture new standoffs for my 335A.
Also the range switch which selects the 10 v, 100v and 1000v range can also
suffer from the same contact problems. This is much more difficult to
service, but I used the same chemicals on this one also, with fairly good
results.

Good luck

Bill

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 had similar, severe repeatability problems with the rotary switches in a very old (blue front panel) Fluke 335A. By comparison I later acquired a much newer (late serial number with beige front panel) 335D having much more stable and repeatable output as related to its rotary switch settings. Joe and Bill, did you happen to notice the date codes on the capacitors (and other parts) in your old 335As? (I no longer have my 335A, but I suspect it was made in the 1970 timeframe? By contrast, IIRC, my 335D was made in the 1990 timeframe.) Greg ----- Original Message ----- From: "Bill Gold" <wpgold3637@att.net> To: <volt-nuts@febo.com> Sent: Tuesday, September 13, 2011 1:08 AM Subject: Re: [volt-nuts] Fluke 335A Joe: Your experience with the electrolytics in your 335A matches what I have found in four 332Bs and one 335A. Except for the null meter in the 335A the boards are exactly the same. I found that the best way to insure everything was OK was to check every electrolytic cap on every board in the instrument. And like you I found that most of the bad ones were "open" with no measurable capacitance. And the majority were the 50uf/50v caps. Just a poor choice of manufacturer and I am sure that Fluke didn't realize what they had done at the time. I also found that the feedback string rotary switches, the seven rotary switches that set up the voltage for the range selected, were all unreliable as far as constant contact resistance each time they are set to a different digit. So what you will probably find is that when you rotate the most significant digit switch, i.e. 0 to 10 volts on the 10 volt range, you will have a slightly different voltage every time, if you have a meter with enough digits to show this. Also this makes it difficult to adjust the first three sets of decade resistors because you will have varying contact resistance every time you change the switch settings. The 0 to 10 volt switch is selecting 100k resistors so the contact resistance effect is minimal. I could see this on a 6 1/2 digit meter (HP 3456A). But where you are going to see this problem manifest the problem the worst is the lower digit switches where the resistors in the string are the smallest. Here any unstable contact resistance is going to be worse because it is a larger part of the resistance being switched. I believe these are 0.1 ohms each on the 1 uv switch. While this switch is only 1 uv per step and is insignificant in the overall accuracy of the instrument, it does affect the zero setting of each range. The cal procedure wants each range to be set to +/- 2 uv on each range ( 10v, 100v, 1000v ). While the 1 uv switch on the 10 volt range will affect the zero very little, the same switch becomes the 100 uv switch when the range is set to the 1000 volt range. Now the smallest change in contact resistance will affect the zero on the 1000 volt range and you will not be able to keep the zero anywhere near ideal. Again this may not be important to you if you are simply trying to cal a 8050 meter. My solution was to remove the feedback string board from the instrument, clean all of the switches, and then apply a thin film of Caig Labs DeOxit and then a thin film of Presevit. Be careful as you may also have another problem depending upon when your instrument was manufactured. The insulator standoffs for this board can simply crumble because the standoff material has degenerated over time. I had to manufacture new standoffs for my 335A. Also the range switch which selects the 10 v, 100v and 1000v range can also suffer from the same contact problems. This is much more difficult to service, but I used the same chemicals on this one also, with fairly good results. Good luck Bill _______________________________________________ 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.

JL

John Lofgren

Tue, Sep 13, 2011 1:47 PM

What other service have any of you performed on the 335A?

I have a beige unit, S/N 2710010, that was working for about a year and then developed a problem where the voltage won't stay stable. After power-on with the metr in the TVM mode you could wath the meter slowly swing up and down the scale at varying rates, but never settling on a stable value. I've put it on the shelf for about the last 6 years and haven't been back to it, since.

The troubleshooting flow chart leads me to the chopper oscillator section. I've read through the procedure but haven't gone into the unit to attemp the alignment. I am curious about the part of the procedure cautioning the user about going too far one way or the other in the adjustment and causing instrument damage. Any comments or tips?

I'll also check the electrolytics while I'm in there. Probably do that before the chopper aligment.

-John

-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On Behalf Of gbusg
Sent: Tuesday, September 13, 2011 3:11 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Fluke 335A

I had similar, severe repeatability problems with the rotary switches in a
very old (blue front panel) Fluke 335A.

By comparison I later acquired a much newer (late serial number with beige
front panel) 335D having much more stable and repeatable output as related
to its rotary switch settings.

Joe and Bill, did you happen to notice the date codes on the capacitors (and
other parts) in your old 335As? (I no longer have my 335A, but I suspect it
was made in the 1970 timeframe? By contrast, IIRC, my 335D was made in the
1990 timeframe.)

Greg

What other service have any of you performed on the 335A? I have a beige unit, S/N 2710010, that was working for about a year and then developed a problem where the voltage won't stay stable. After power-on with the metr in the TVM mode you could wath the meter slowly swing up and down the scale at varying rates, but never settling on a stable value. I've put it on the shelf for about the last 6 years and haven't been back to it, since. The troubleshooting flow chart leads me to the chopper oscillator section. I've read through the procedure but haven't gone into the unit to attemp the alignment. I am curious about the part of the procedure cautioning the user about going too far one way or the other in the adjustment and causing instrument damage. Any comments or tips? I'll also check the electrolytics while I'm in there. Probably do that before the chopper aligment. -John -----Original Message----- From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On Behalf Of gbusg Sent: Tuesday, September 13, 2011 3:11 AM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] Fluke 335A I had similar, severe repeatability problems with the rotary switches in a very old (blue front panel) Fluke 335A. By comparison I later acquired a much newer (late serial number with beige front panel) 335D having much more stable and repeatable output as related to its rotary switch settings. Joe and Bill, did you happen to notice the date codes on the capacitors (and other parts) in your old 335As? (I no longer have my 335A, but I suspect it was made in the 1970 timeframe? By contrast, IIRC, my 335D was made in the 1990 timeframe.) Greg

JL

J. L. Trantham

Wed, Sep 14, 2011 1:05 AM

All the capacitors that were dead were marked:

'GI 85 C' with the 'degree' symbol after the '85'
The respective capacitance and voltage value
'2407432'

I did not look at the markings of the 'surviving' capacitors or other
elements.

It is SN 25513 with a light grey/beige and black face.

Joe

----- Original Message -----
From: "gbusg" gbusg@comcast.net
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Tuesday, September 13, 2011 3:10 AM
Subject: Re: [volt-nuts] Fluke 335A

.

Joe and Bill, did you happen to notice the date codes on the capacitors
(and
other parts) in your old 335As?

All the capacitors that were dead were marked: 'GI 85 C' with the 'degree' symbol after the '85' The respective capacitance and voltage value '2407432' I did not look at the markings of the 'surviving' capacitors or other elements. It is SN 25513 with a light grey/beige and black face. Joe ----- Original Message ----- From: "gbusg" <gbusg@comcast.net> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com> Sent: Tuesday, September 13, 2011 3:10 AM Subject: Re: [volt-nuts] Fluke 335A . > > Joe and Bill, did you happen to notice the date codes on the capacitors > (and > other parts) in your old 335As?

G

gbusg

Wed, Sep 14, 2011 1:20 AM

I'm not sure how to decode those numbers.

Maybe it was the 32nd week of 1974?

Do any of you know if there's a way to estimate dates according to Fluke
serial numbers?

Greg

----- Original Message -----
From: "J. L. Trantham" jltran@att.net
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Tuesday, September 13, 2011 7:05 PM
Subject: Re: [volt-nuts] Fluke 335A

All the capacitors that were dead were marked:

'GI 85 C' with the 'degree' symbol after the '85'
The respective capacitance and voltage value
'2407432'

I did not look at the markings of the 'surviving' capacitors or other
elements.

It is SN 25513 with a light grey/beige and black face.

Joe

----- Original Message -----
From: "gbusg" gbusg@comcast.net
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Tuesday, September 13, 2011 3:10 AM
Subject: Re: [volt-nuts] Fluke 335A

.

Joe and Bill, did you happen to notice the date codes on the capacitors
(and
other parts) in your old 335As?

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'm not sure how to decode those numbers. Maybe it was the 32nd week of 1974? Do any of you know if there's a way to estimate dates according to Fluke serial numbers? Greg ----- Original Message ----- From: "J. L. Trantham" <jltran@att.net> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com> Sent: Tuesday, September 13, 2011 7:05 PM Subject: Re: [volt-nuts] Fluke 335A All the capacitors that were dead were marked: 'GI 85 C' with the 'degree' symbol after the '85' The respective capacitance and voltage value '2407432' I did not look at the markings of the 'surviving' capacitors or other elements. It is SN 25513 with a light grey/beige and black face. Joe ----- Original Message ----- From: "gbusg" <gbusg@comcast.net> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com> Sent: Tuesday, September 13, 2011 3:10 AM Subject: Re: [volt-nuts] Fluke 335A . > > Joe and Bill, did you happen to notice the date codes on the capacitors > (and > other parts) in your old 335As? _______________________________________________ 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.

JL

J. L. Trantham

Wed, Sep 14, 2011 2:00 AM

Greg,

I am totally 'clueless' when it comes to date of manufacture of Fluke
instruments.

Joe

----- Original Message -----
From: "gbusg" gbusg@comcast.net
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Tuesday, September 13, 2011 8:20 PM
Subject: Re: [volt-nuts] Fluke 335A

I'm not sure how to decode those numbers.

Maybe it was the 32nd week of 1974?

Do any of you know if there's a way to estimate dates according to Fluke
serial numbers?

Greg

----- Original Message -----
From: "J. L. Trantham" jltran@att.net
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Tuesday, September 13, 2011 7:05 PM
Subject: Re: [volt-nuts] Fluke 335A

All the capacitors that were dead were marked:

'GI 85 C' with the 'degree' symbol after the '85'
The respective capacitance and voltage value
'2407432'

I did not look at the markings of the 'surviving' capacitors or other
elements.

It is SN 25513 with a light grey/beige and black face.

Joe

----- Original Message -----
From: "gbusg" gbusg@comcast.net
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Tuesday, September 13, 2011 3:10 AM
Subject: Re: [volt-nuts] Fluke 335A

.

Joe and Bill, did you happen to notice the date codes on the capacitors
(and
other parts) in your old 335As?

volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to
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Greg, I am totally 'clueless' when it comes to date of manufacture of Fluke instruments. Joe ----- Original Message ----- From: "gbusg" <gbusg@comcast.net> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com> Sent: Tuesday, September 13, 2011 8:20 PM Subject: Re: [volt-nuts] Fluke 335A > I'm not sure how to decode those numbers. > > Maybe it was the 32nd week of 1974? > > Do any of you know if there's a way to estimate dates according to Fluke > serial numbers? > > Greg > > > ----- Original Message ----- > From: "J. L. Trantham" <jltran@att.net> > To: "Discussion of precise voltage measurement" <volt-nuts@febo.com> > Sent: Tuesday, September 13, 2011 7:05 PM > Subject: Re: [volt-nuts] Fluke 335A > > > All the capacitors that were dead were marked: > > 'GI 85 C' with the 'degree' symbol after the '85' > The respective capacitance and voltage value > '2407432' > > I did not look at the markings of the 'surviving' capacitors or other > elements. > > It is SN 25513 with a light grey/beige and black face. > > Joe > > ----- Original Message ----- > From: "gbusg" <gbusg@comcast.net> > To: "Discussion of precise voltage measurement" <volt-nuts@febo.com> > Sent: Tuesday, September 13, 2011 3:10 AM > Subject: Re: [volt-nuts] Fluke 335A > > > . >> >> Joe and Bill, did you happen to notice the date codes on the capacitors >> (and >> other parts) in your old 335As? > > > _______________________________________________ > 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.

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Re: [volt-nuts] Fluke 335A