Empathy List Archives

RA

Robert Atkinson

Wed, Aug 1, 2012 6:14 PM

Hi All,
I recently picked up a 887A AC/DC differential voltmeter. Unfortunatly it had been dropped, has leaky batteries and is not in great condition. However on oprning the top cover I noticed that Q106, 107, 108 and 109 were missing from their sockets. Therse are the monostable and drivers for the 85Hz chopper. However thay were not inside the unit and the calibration seals were intact.......
I then noticed that PCB 3 which has the null detector lood shiney ans green. It appears that the mechanical null detector has been replaced by a new PCB with a solid state switch. It's marked 887A-4022 P/N812610 (C) 1987 and is obviously a genuine Fluke item. It has a TO8 IC marked [BB] HL805. Obviously a Burr Brown chip, But Ican find no info on the chip or the board.
Has anyone any information on this modification?

Robert G8RPI..

Hi All, I recently picked up a 887A AC/DC differential voltmeter. Unfortunatly it had been dropped, has leaky batteries and is not in great condition. However on oprning the top cover I noticed that Q106, 107, 108 and 109 were missing from their sockets. Therse are the monostable and drivers for the 85Hz chopper. However thay were not inside the unit and the calibration seals were intact....... I then noticed that PCB 3 which has the null detector lood shiney ans green. It appears that the mechanical null detector has been replaced by a new PCB with a solid state switch. It's marked 887A-4022 P/N812610 (C) 1987 and is obviously a genuine Fluke item. It has a TO8 IC marked [BB] HL805. Obviously a Burr Brown chip, But Ican find no info on the chip or the board. Has anyone any information on this modification? Robert G8RPI..

JL

J. L. Trantham

Wed, Aug 1, 2012 6:52 PM

Robert,

I have one of these meters that is missing the batteries. Can you tell me
what batteries it uses? There it BT1, BT2, and BT3 and they all may be
different.

Thanks,

Joe

-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of Robert Atkinson
Sent: Wednesday, August 01, 2012 1:15 PM
To: Discussionofprecisevoltagemeasurement
Subject: [volt-nuts] Fluke 887A replacement Null detector with solidstate
chopper

Hi All,
I recently picked up a 887A AC/DC differential voltmeter. Unfortunatly it
had been dropped, has leaky batteries and is not in great condition. However
on oprning the top cover I noticed that Q106, 107, 108 and 109 were missing
from their sockets. Therse are the monostable and drivers for the 85Hz
chopper. However thay were not inside the unit and the calibration seals
were intact.......
I then noticed that PCB 3 which has the null detector lood shiney ans green.
It appears that the mechanical null detector has been replaced by a new PCB
with a solid state switch. It's marked 887A-4022 P/N812610 (C) 1987 and is
obviously a genuine Fluke item. It has a TO8 IC marked [BB] HL805. Obviously
a Burr Brown chip, But Ican find no info on the chip or the board.
Has anyone any information on this modification?

Robert G8RPI..

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.

Robert, I have one of these meters that is missing the batteries. Can you tell me what batteries it uses? There it BT1, BT2, and BT3 and they all may be different. Thanks, Joe -----Original Message----- From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On Behalf Of Robert Atkinson Sent: Wednesday, August 01, 2012 1:15 PM To: Discussionofprecisevoltagemeasurement Subject: [volt-nuts] Fluke 887A replacement Null detector with solidstate chopper Hi All, I recently picked up a 887A AC/DC differential voltmeter. Unfortunatly it had been dropped, has leaky batteries and is not in great condition. However on oprning the top cover I noticed that Q106, 107, 108 and 109 were missing from their sockets. Therse are the monostable and drivers for the 85Hz chopper. However thay were not inside the unit and the calibration seals were intact....... I then noticed that PCB 3 which has the null detector lood shiney ans green. It appears that the mechanical null detector has been replaced by a new PCB with a solid state switch. It's marked 887A-4022 P/N812610 (C) 1987 and is obviously a genuine Fluke item. It has a TO8 IC marked [BB] HL805. Obviously a Burr Brown chip, But Ican find no info on the chip or the board. Has anyone any information on this modification? Robert G8RPI.. _______________________________________________ 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.

RA

Robert Atkinson

Wed, Aug 1, 2012 8:54 PM

Hi Joe,
They are all Ni-Cad. The two on the outside of the rear panel (BT1 &
BT3) each have 16 2/3AF 0.45mAh (17mm dia 28mm long) cells for 19.2V
total.. The pack on the inside of the rear panel BT2) was unmarked and
had 4 cells approx 22mm dia by 43mm long, i.e "sub C" or CS size. from
the age probably about 1.4Ah. The older units used two 9.6V DEAC coin
cell stacks for each of the 19.2V packs.

Hope this helps,
Robert G8RPI.

From: J. L. Trantham jltran@att.net
To: 'Robert Atkinson' robert8rpi@yahoo.co.uk; 'Discussion of precise voltage measurement' volt-nuts@febo.com
Sent: Wednesday, 1 August 2012, 19:52
Subject: RE: [volt-nuts] Fluke 887A replacement Null detector with solidstate chopper

Robert,

I have one of these meters that is missing the batteries. Can you tell me
what batteries it uses? There it BT1, BT2, and BT3 and they all may be
different.

Thanks,

Joe

-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of Robert Atkinson
Sent: Wednesday, August 01, 2012 1:15 PM
To: Discussionofprecisevoltagemeasurement
Subject: [volt-nuts] Fluke 887A replacement Null detector with solidstate
chopper

Hi All,
I recently picked up a 887A AC/DC differential voltmeter. Unfortunatly it
had been dropped, has leaky batteries and is not in great condition. However
on oprning the top cover I noticed that Q106, 107, 108 and 109 were missing
from their sockets. Therse are the monostable and drivers for the 85Hz
chopper. However thay were not inside the unit and the calibration seals
were intact.......
I then noticed that PCB 3 which has the null detector lood shiney ans green.
It appears that the mechanical null detector has been replaced by a new PCB
with a solid state switch. It's marked 887A-4022 P/N812610 (C) 1987 and is
obviously a genuine Fluke item. It has a TO8 IC marked [BB] HL805. Obviously
a Burr Brown chip, But Ican find no info on the chip or the board.
Has anyone any information on this modification?

Robert G8RPI..

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.

Hi Joe, They are all Ni-Cad. The two on the outside of the rear panel (BT1 & BT3) each have 16 2/3AF 0.45mAh (17mm dia 28mm long) cells for 19.2V total.. The pack on the inside of the rear panel BT2) was unmarked and had 4 cells approx 22mm dia by 43mm long, i.e "sub C" or CS size. from the age probably about 1.4Ah. The older units used two 9.6V DEAC coin cell stacks for each of the 19.2V packs. Hope this helps, Robert G8RPI. ________________________________ From: J. L. Trantham <jltran@att.net> To: 'Robert Atkinson' <robert8rpi@yahoo.co.uk>; 'Discussion of precise voltage measurement' <volt-nuts@febo.com> Sent: Wednesday, 1 August 2012, 19:52 Subject: RE: [volt-nuts] Fluke 887A replacement Null detector with solidstate chopper Robert, I have one of these meters that is missing the batteries. Can you tell me what batteries it uses? There it BT1, BT2, and BT3 and they all may be different. Thanks, Joe -----Original Message----- From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On Behalf Of Robert Atkinson Sent: Wednesday, August 01, 2012 1:15 PM To: Discussionofprecisevoltagemeasurement Subject: [volt-nuts] Fluke 887A replacement Null detector with solidstate chopper Hi All, I recently picked up a 887A AC/DC differential voltmeter. Unfortunatly it had been dropped, has leaky batteries and is not in great condition. However on oprning the top cover I noticed that Q106, 107, 108 and 109 were missing from their sockets. Therse are the monostable and drivers for the 85Hz chopper. However thay were not inside the unit and the calibration seals were intact....... I then noticed that PCB 3 which has the null detector lood shiney ans green. It appears that the mechanical null detector has been replaced by a new PCB with a solid state switch. It's marked 887A-4022 P/N812610 (C) 1987 and is obviously a genuine Fluke item. It has a TO8 IC marked [BB] HL805. Obviously a Burr Brown chip, But Ican find no info on the chip or the board. Has anyone any information on this modification? Robert G8RPI.. _______________________________________________ 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

Thu, Aug 2, 2012 3:59 AM

Robert,

Thanks. I'll do some research.

Joe

-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of Robert Atkinson
Sent: Wednesday, August 01, 2012 3:55 PM
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] Fluke 887A replacement Batteries

Hi Joe,
They are all Ni-Cad. The two on the outside of the rear panel (BT1 &
BT3) each have 16 2/3AF 0.45mAh (17mm dia 28mm long) cells for 19.2V
total.. The pack on the inside of the rear panel BT2) was unmarked and
had 4 cells approx 22mm dia by 43mm long, i.e "sub C" or CS size. from
the age probably about 1.4Ah. The older units used two 9.6V DEAC coin
cell stacks for each of the 19.2V packs.

Hope this helps,
Robert G8RPI.

From: J. L. Trantham jltran@att.net
To: 'Robert Atkinson' robert8rpi@yahoo.co.uk; 'Discussion of precise
voltage measurement' volt-nuts@febo.com
Sent: Wednesday, 1 August 2012, 19:52
Subject: RE: [volt-nuts] Fluke 887A replacement Null detector with
solidstate chopper

Robert,

I have one of these meters that is missing the batteries. Can you tell me
what batteries it uses? There it BT1, BT2, and BT3 and they all may be
different.

Thanks,

Joe

-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of Robert Atkinson
Sent: Wednesday, August 01, 2012 1:15 PM
To: Discussionofprecisevoltagemeasurement
Subject: [volt-nuts] Fluke 887A replacement Null detector with solidstate
chopper

Hi All,
I recently picked up a 887A AC/DC differential voltmeter. Unfortunatly it
had been dropped, has leaky batteries and is not in great condition. However
on oprning the top cover I noticed that Q106, 107, 108 and 109 were missing
from their sockets. Therse are the monostable and drivers for the 85Hz
chopper. However thay were not inside the unit and the calibration seals
were intact....... I then noticed that PCB 3 which has the null detector
lood shiney ans green. It appears that the mechanical null detector has been
replaced by a new PCB with a solid state switch. It's marked 887A-4022
P/N812610 (C) 1987 and is obviously a genuine Fluke item. It has a TO8 IC
marked [BB] HL805. Obviously a Burr Brown chip, But Ican find no info on the
chip or the board. Has anyone any information on this modification?

Robert G8RPI..

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.

Robert, Thanks. I'll do some research. Joe -----Original Message----- From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On Behalf Of Robert Atkinson Sent: Wednesday, August 01, 2012 3:55 PM To: 'Discussion of precise voltage measurement' Subject: Re: [volt-nuts] Fluke 887A replacement Batteries Hi Joe, They are all Ni-Cad. The two on the outside of the rear panel (BT1 & BT3) each have 16 2/3AF 0.45mAh (17mm dia 28mm long) cells for 19.2V total.. The pack on the inside of the rear panel BT2) was unmarked and had 4 cells approx 22mm dia by 43mm long, i.e "sub C" or CS size. from the age probably about 1.4Ah. The older units used two 9.6V DEAC coin cell stacks for each of the 19.2V packs. Hope this helps, Robert G8RPI. ________________________________ From: J. L. Trantham <jltran@att.net> To: 'Robert Atkinson' <robert8rpi@yahoo.co.uk>; 'Discussion of precise voltage measurement' <volt-nuts@febo.com> Sent: Wednesday, 1 August 2012, 19:52 Subject: RE: [volt-nuts] Fluke 887A replacement Null detector with solidstate chopper Robert, I have one of these meters that is missing the batteries. Can you tell me what batteries it uses? There it BT1, BT2, and BT3 and they all may be different. Thanks, Joe -----Original Message----- From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On Behalf Of Robert Atkinson Sent: Wednesday, August 01, 2012 1:15 PM To: Discussionofprecisevoltagemeasurement Subject: [volt-nuts] Fluke 887A replacement Null detector with solidstate chopper Hi All, I recently picked up a 887A AC/DC differential voltmeter. Unfortunatly it had been dropped, has leaky batteries and is not in great condition. However on oprning the top cover I noticed that Q106, 107, 108 and 109 were missing from their sockets. Therse are the monostable and drivers for the 85Hz chopper. However thay were not inside the unit and the calibration seals were intact....... I then noticed that PCB 3 which has the null detector lood shiney ans green. It appears that the mechanical null detector has been replaced by a new PCB with a solid state switch. It's marked 887A-4022 P/N812610 (C) 1987 and is obviously a genuine Fluke item. It has a TO8 IC marked [BB] HL805. Obviously a Burr Brown chip, But Ican find no info on the chip or the board. Has anyone any information on this modification? Robert G8RPI.. _______________________________________________ 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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Fluke 887A replacement Null detector with solidstate chopper