I've had a Triplett 930PL for over 40 years and it's always performed
well. In recent years, I've not needed it for resistance
measurements, so I removed the batteries. Just today I found that the
voltage readings are terribly off. Imagine my surprise when working
on a outdoor irrigation timer when I measured the input voltage at
205V (should be 115-120) and the transformer output at 32V (should be
24). I tried a few other measurements using a bettery charger and the
readings are always significantly off. I have not even opened the
case yet because I don't know what to look for (if anything). Is
there a specific repairable/replaceable component that I should be
inspecting? TIA.

On Thu, 28 May 2009 17:02:50 GMT, (Michael Todd)
wrote:

I've had a Triplett 930PL for over 40 years and it's always performed
well. In recent years, I've not needed it for resistance
measurements, so I removed the batteries. Just today I found that the
voltage readings are terribly off. Imagine my surprise when working
on a outdoor irrigation timer when I measured the input voltage at
205V (should be 115-120) and the transformer output at 32V (should be
24). I tried a few other measurements using a bettery charger and the
readings are always significantly off. I have not even opened the
case yet because I don't know what to look for (if anything). Is
there a specific repairable/replaceable component that I should be
inspecting? TIA.

Here's some more info:

I opened the case and visually inspected the replaceable parts. There
are two resistors that seem like they may be faulty. One especially
is bulging at one end. The manual states only the resistance value of
these resistors as 2.5 ohms and 25.12 ohms. It does not say what type
they are or any other specification value. Any ideas on the type,
power, % etc.? It looks like a pretty easy replacement using the
existing leads, but I need to identify what parts to order.

On Thu, 28 May 2009 22:17:54 GMT (Richard Cranium)
wrote in Message id: :

On Thu, 28 May 2009 17:02:50 GMT, (Michael Todd)
wrote:

I've had a Triplett 930PL for over 40 years and it's always performed
well. In recent years, I've not needed it for resistance
measurements, so I removed the batteries. Just today I found that the
voltage readings are terribly off. Imagine my surprise when working
on a outdoor irrigation timer when I measured the input voltage at
205V (should be 115-120) and the transformer output at 32V (should be
24). I tried a few other measurements using a bettery charger and the
readings are always significantly off. I have not even opened the
case yet because I don't know what to look for (if anything). Is
there a specific repairable/replaceable component that I should be
inspecting? TIA.

Here's some more info:

I opened the case and visually inspected the replaceable parts. There
are two resistors that seem like they may be faulty. One especially
is bulging at one end. The manual states only the resistance value of
these resistors as 2.5 ohms and 25.12 ohms. It does not say what type
they are or any other specification value. Any ideas on the type,
power, % etc.? It looks like a pretty easy replacement using the
existing leads, but I need to identify what parts to order.

A bulging resistor? That's a new one... Can you take pictures of the
parts?

"Michael Todd" wrote in message
...
I've had a Triplett 930PL for over 40 years and it's always performed
well. In recent years, I've not needed it for resistance
measurements, so I removed the batteries. Just today I found that the
voltage readings are terribly off. Imagine my surprise when working
on a outdoor irrigation timer when I measured the input voltage at
205V (should be 115-120) and the transformer output at 32V (should be
24). I tried a few other measurements using a bettery charger and the
readings are always significantly off. I have not even opened the
case yet because I don't know what to look for (if anything). Is
there a specific repairable/replaceable component that I should be
inspecting? TIA.



Some old meters require the battery to bias the AC rectifier. The original
AVO 7 is this way. Pretty standard type VOM, but the AC voltage readings are
wrong if no 1.5 volt battery is in place.


Mark Z.

On Fri, 29 May 2009 05:27:44 -0400, JW wrote:

On Thu, 28 May 2009 22:17:54 GMT (Richard Cranium)
wrote in Message id: :

On Thu, 28 May 2009 17:02:50 GMT, (Michael Todd)
wrote:

I've had a Triplett 930PL for over 40 years and it's always performed
well. In recent years, I've not needed it for resistance
measurements, so I removed the batteries. Just today I found that the
voltage readings are terribly off. Imagine my surprise when working
on a outdoor irrigation timer when I measured the input voltage at
205V (should be 115-120) and the transformer output at 32V (should be
24). I tried a few other measurements using a bettery charger and the
readings are always significantly off. I have not even opened the
case yet because I don't know what to look for (if anything). Is
there a specific repairable/replaceable component that I should be
inspecting? TIA.

Here's some more info:

I opened the case and visually inspected the replaceable parts. There
are two resistors that seem like they may be faulty. One especially
is bulging at one end. The manual states only the resistance value of
these resistors as 2.5 ohms and 25.12 ohms. It does not say what type
they are or any other specification value. Any ideas on the type,
power, % etc.? It looks like a pretty easy replacement using the
existing leads, but I need to identify what parts to order.

A bulging resistor? That's a new one... Can you take pictures of the
parts?

Well ... maybe 'bulge' was a poor word choice. However, there does
appear to be damage at one end of a resistor. Not sure if a binary
will be allowed here, but I shrunk a picture down to 56K to show the
damaged part.

On Fri, 29 May 2009 07:30:05 -0500, "Mark Zacharias"
wrote:

"Michael Todd" wrote in message
.. .
I've had a Triplett 930PL for over 40 years and it's always performed
well. In recent years, I've not needed it for resistance
measurements, so I removed the batteries. Just today I found that the
voltage readings are terribly off. Imagine my surprise when working
on a outdoor irrigation timer when I measured the input voltage at
205V (should be 115-120) and the transformer output at 32V (should be
24). I tried a few other measurements using a bettery charger and the
readings are always significantly off. I have not even opened the
case yet because I don't know what to look for (if anything). Is
there a specific repairable/replaceable component that I should be
inspecting? TIA.



Some old meters require the battery to bias the AC rectifier. The original
AVO 7 is this way. Pretty standard type VOM, but the AC voltage readings are
wrong if no 1.5 volt battery is in place.


Mark Z.

I don't think that's the case here as the meter has been working fine
without the batteries for quite a while now. I'm pretty sure there is
a damaged resistor and am trying to post a photo here of same.

On Fri, 29 May 2009 05:27:44 -0400, JW wrote:

Here's a shot of the full meter back.

On Fri, 29 May 2009 13:22:22 GMT (Richard Cranium)
wrote in Message id: :

[picture]

Looks a bit burnt, I'd say. As a guess, it's probably about 2-3 watts.
Since it's likely to be fairly important as far as accuracy of the meter
is concerned, the closer the better. Perhaps .1% if you can find them. For
the wattage go with the highest that will fit in the meter (within reason,
of course)

"Richard Cranium" wrote in message
.. .
On Fri, 29 May 2009 05:27:44 -0400, JW wrote:

On Thu, 28 May 2009 22:17:54 GMT (Richard Cranium)
wrote in Message id: :

On Thu, 28 May 2009 17:02:50 GMT, (Michael Todd)
wrote:

I've had a Triplett 930PL for over 40 years and it's always performed
well. In recent years, I've not needed it for resistance
measurements, so I removed the batteries. Just today I found that the
voltage readings are terribly off. Imagine my surprise when working
on a outdoor irrigation timer when I measured the input voltage at
205V (should be 115-120) and the transformer output at 32V (should be
24). I tried a few other measurements using a bettery charger and the
readings are always significantly off. I have not even opened the
case yet because I don't know what to look for (if anything). Is
there a specific repairable/replaceable component that I should be
inspecting? TIA.

Here's some more info:

I opened the case and visually inspected the replaceable parts. There
are two resistors that seem like they may be faulty. One especially
is bulging at one end. The manual states only the resistance value of
these resistors as 2.5 ohms and 25.12 ohms. It does not say what type
they are or any other specification value. Any ideas on the type,
power, % etc.? It looks like a pretty easy replacement using the
existing leads, but I need to identify what parts to order.

A bulging resistor? That's a new one... Can you take pictures of the
parts?

Well ... maybe 'bulge' was a poor word choice. However, there does
appear to be damage at one end of a resistor. Not sure if a binary
will be allowed here, but I shrunk a picture down to 56K to show the
damaged part.

Richard, the resistors that you've mentioned are in the DC Current circuit;
not even involved in the AC Voltmeter circuit.
It's to be expected that a 40 year-old multimeter will have some
inaccuracies due to inevitable changes in component values. If you don't
have a good digital multimeter to measure the resistors, maybe you could
borrow one from a friend or neighbor. The resistors (R1 through R6) and the
rectifier in the AC Voltage circuit should be under scrutiny, especially the
rectifier. Check the values of the resistors. If they are pretty close
(they are 1% resistors), then the rectifier is the most likely suspect, and
it might be difficult to find a direct replacement.
I don't see the picture that you posted (this isn't a binaries group), but
if you'll repost the image to a binaries group such as
alt.binaries.schematics.electronic, I'm sure more people can see it. I used
to work in a calibration lab that serviced Simpson, Triplett and Weston
meters and multimeters. I don't remember specifically what the rectifier
looks like, but it's possible that I might have one or two in my junque box
that I can send if the resistors prove to be OK.

Cheers!!

--
HAM AND EGGS -- A day's work for a chicken, a lifetime commitment for a pig.

Dave M

On Fri, 29 May 2009 11:11:53 -0400, "Dave M"
wrote:

"Richard Cranium" wrote in message
. ..
On Fri, 29 May 2009 05:27:44 -0400, JW wrote:

On Thu, 28 May 2009 22:17:54 GMT (Richard Cranium)
wrote in Message id: :

On Thu, 28 May 2009 17:02:50 GMT, (Michael Todd)
wrote:

I've had a Triplett 930PL for over 40 years and it's always performed
well. In recent years, I've not needed it for resistance
measurements, so I removed the batteries. Just today I found that the
voltage readings are terribly off. Imagine my surprise when working
on a outdoor irrigation timer when I measured the input voltage at
205V (should be 115-120) and the transformer output at 32V (should be
24). I tried a few other measurements using a bettery charger and the
readings are always significantly off. I have not even opened the
case yet because I don't know what to look for (if anything). Is
there a specific repairable/replaceable component that I should be
inspecting? TIA.

Here's some more info:

I opened the case and visually inspected the replaceable parts. There
are two resistors that seem like they may be faulty. One especially
is bulging at one end. The manual states only the resistance value of
these resistors as 2.5 ohms and 25.12 ohms. It does not say what type
they are or any other specification value. Any ideas on the type,
power, % etc.? It looks like a pretty easy replacement using the
existing leads, but I need to identify what parts to order.

A bulging resistor? That's a new one... Can you take pictures of the
parts?

Well ... maybe 'bulge' was a poor word choice. However, there does
appear to be damage at one end of a resistor. Not sure if a binary
will be allowed here, but I shrunk a picture down to 56K to show the
damaged part.

Richard, the resistors that you've mentioned are in the DC Current circuit;
not even involved in the AC Voltmeter circuit.
It's to be expected that a 40 year-old multimeter will have some
inaccuracies due to inevitable changes in component values. If you don't
have a good digital multimeter to measure the resistors, maybe you could
borrow one from a friend or neighbor. The resistors (R1 through R6) and the
rectifier in the AC Voltage circuit should be under scrutiny, especially the
rectifier. Check the values of the resistors. If they are pretty close
(they are 1% resistors), then the rectifier is the most likely suspect, and
it might be difficult to find a direct replacement.
I don't see the picture that you posted (this isn't a binaries group), but
if you'll repost the image to a binaries group such as
alt.binaries.schematics.electronic, I'm sure more people can see it. I used
to work in a calibration lab that serviced Simpson, Triplett and Weston
meters and multimeters. I don't remember specifically what the rectifier
looks like, but it's possible that I might have one or two in my junque box
that I can send if the resistors prove to be OK.

Cheers!!

--
HAM AND EGGS -- A day's work for a chicken, a lifetime commitment for a pig.

Dave M


Hi Dave:

Unfortunately, BellSouth, in their infinite wisdom, is blocking the
binary groups. Upon inspecting the meter, it's very clear that one
resistor is damaged. What I initially described as a bulge seems to
be a burned section at one end of the resistior. In the manual it's
designated as R8 with a value of 2.5 ohms. The Triplett part number
is listed as 15-2869. I thought itwould be relatively easy to locate
such a replacement but that doesn't seem to be the case (plus I'm a
1960's vintage ME, not an EE). I looked up resistors in a Digi-Key
catalog and the first time a 2.5 ohm value appears is as a RS Series
Silicone Coated Wirewound (3 Watts; 1%). I then opened an Allied
catalog and quickly recognized that I'm over my head in that I need a
more complete description of the type of component I should be looking
for.

Along the lines you suggested what circuit is the resistor
associated with, I looked at the schematic and R8 is part of the DC MA
circuit. Resistors R1 through R6 all look OK. I'll try to borrow a
multimeter in the next few days to check them more thoroughly and
report back here.

Richard Cranium wrote:
[a photo]

Well, the photo made it to my server okay, & it's nice & clear. It looks
to me like your resistor is a wirewound job, & the bulge is just a weld
or something on the former, & unrelated to the problem you're having. I
suspect that when you test it with a DMM, it'll turn out to be fine.

I think you'll need to look elsewhere for the cause of your problem.
As another poster suggested, I think it's just drifted out of
calibration with age. You know you can pick up a basic DMM these days
for under $25, right?


--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

"Richard Cranium" wrote in message
.. .
On Fri, 29 May 2009 11:11:53 -0400, "Dave M"
wrote:

"Richard Cranium" wrote in message
...
On Fri, 29 May 2009 05:27:44 -0400, JW wrote:

On Thu, 28 May 2009 22:17:54 GMT (Richard Cranium)
wrote in Message id: :

On Thu, 28 May 2009 17:02:50 GMT, (Michael Todd)
wrote:

I've had a Triplett 930PL for over 40 years and it's always performed
well. In recent years, I've not needed it for resistance
measurements, so I removed the batteries. Just today I found that the
voltage readings are terribly off. Imagine my surprise when working
on a outdoor irrigation timer when I measured the input voltage at
205V (should be 115-120) and the transformer output at 32V (should be
24). I tried a few other measurements using a bettery charger and the
readings are always significantly off. I have not even opened the
case yet because I don't know what to look for (if anything). Is
there a specific repairable/replaceable component that I should be
inspecting? TIA.

Here's some more info:

I opened the case and visually inspected the replaceable parts. There
are two resistors that seem like they may be faulty. One especially
is bulging at one end. The manual states only the resistance value of
these resistors as 2.5 ohms and 25.12 ohms. It does not say what type
they are or any other specification value. Any ideas on the type,
power, % etc.? It looks like a pretty easy replacement using the
existing leads, but I need to identify what parts to order.

A bulging resistor? That's a new one... Can you take pictures of the
parts?

Well ... maybe 'bulge' was a poor word choice. However, there does
appear to be damage at one end of a resistor. Not sure if a binary
will be allowed here, but I shrunk a picture down to 56K to show the
damaged part.

Richard, the resistors that you've mentioned are in the DC Current
circuit;
not even involved in the AC Voltmeter circuit.
It's to be expected that a 40 year-old multimeter will have some
inaccuracies due to inevitable changes in component values. If you don't
have a good digital multimeter to measure the resistors, maybe you could
borrow one from a friend or neighbor. The resistors (R1 through R6) and
the
rectifier in the AC Voltage circuit should be under scrutiny, especially
the
rectifier. Check the values of the resistors. If they are pretty close
(they are 1% resistors), then the rectifier is the most likely suspect,
and
it might be difficult to find a direct replacement.
I don't see the picture that you posted (this isn't a binaries group), but
if you'll repost the image to a binaries group such as
alt.binaries.schematics.electronic, I'm sure more people can see it. I
used
to work in a calibration lab that serviced Simpson, Triplett and Weston
meters and multimeters. I don't remember specifically what the rectifier
looks like, but it's possible that I might have one or two in my junque
box
that I can send if the resistors prove to be OK.

Cheers!!

--
HAM AND EGGS -- A day's work for a chicken, a lifetime commitment for a
pig.

Dave M


Hi Dave:

Unfortunately, BellSouth, in their infinite wisdom, is blocking the
binary groups. Upon inspecting the meter, it's very clear that one
resistor is damaged. What I initially described as a bulge seems to
be a burned section at one end of the resistior. In the manual it's
designated as R8 with a value of 2.5 ohms. The Triplett part number
is listed as 15-2869. I thought itwould be relatively easy to locate
such a replacement but that doesn't seem to be the case (plus I'm a
1960's vintage ME, not an EE). I looked up resistors in a Digi-Key
catalog and the first time a 2.5 ohm value appears is as a RS Series
Silicone Coated Wirewound (3 Watts; 1%). I then opened an Allied
catalog and quickly recognized that I'm over my head in that I need a
more complete description of the type of component I should be looking
for.

Along the lines you suggested what circuit is the resistor
associated with, I looked at the schematic and R8 is part of the DC MA
circuit. Resistors R1 through R6 all look OK. I'll try to borrow a
multimeter in the next few days to check them more thoroughly and
report back here.

Richard, the resistors in the DC Current ranges are 1% units at 1 watt or
greater. The current shunts in multimerters are usually wirewound, so the
resistor you found at Digikey will work fine. R8 is the current shunt for
the 100ma range.
Those part numbers in the manual are Triplett part numbers, and are
meaningful only to Triplett (now owned and known as Jewell Instruments,
LLC). If you need anything non-standard for your meter, you might try to
find a service shop or cal lab that services Triplett instruments. They are
likely to have those parts. Also, you could email Triplett at
and ask for a quote on the parts.
The 630 is quite old, and some parts might not be available.

Cheers
--
HAM AND EGGS -- A day's work for a chicken, a lifetime commitment for a pig.

Dave M

Richard Cranium wrote:

On Fri, 29 May 2009 11:11:53 -0400, "Dave M"
wrote:

"Richard Cranium" wrote in message
. ..
On Fri, 29 May 2009 05:27:44 -0400, JW wrote:

On Thu, 28 May 2009 22:17:54 GMT (Richard Cranium)
wrote in Message id: :

On Thu, 28 May 2009 17:02:50 GMT, (Michael Todd)
wrote:

I've had a Triplett 930PL for over 40 years and it's always performed
well. In recent years, I've not needed it for resistance
measurements, so I removed the batteries. Just today I found that the
voltage readings are terribly off. Imagine my surprise when working
on a outdoor irrigation timer when I measured the input voltage at
205V (should be 115-120) and the transformer output at 32V (should be
24). I tried a few other measurements using a bettery charger and the
readings are always significantly off. I have not even opened the
case yet because I don't know what to look for (if anything). Is
there a specific repairable/replaceable component that I should be
inspecting? TIA.

Here's some more info:

I opened the case and visually inspected the replaceable parts. There
are two resistors that seem like they may be faulty. One especially
is bulging at one end. The manual states only the resistance value of
these resistors as 2.5 ohms and 25.12 ohms. It does not say what type
they are or any other specification value. Any ideas on the type,
power, % etc.? It looks like a pretty easy replacement using the
existing leads, but I need to identify what parts to order.

A bulging resistor? That's a new one... Can you take pictures of the
parts?

Well ... maybe 'bulge' was a poor word choice. However, there does
appear to be damage at one end of a resistor. Not sure if a binary
will be allowed here, but I shrunk a picture down to 56K to show the
damaged part.

Richard, the resistors that you've mentioned are in the DC Current circuit;
not even involved in the AC Voltmeter circuit.
It's to be expected that a 40 year-old multimeter will have some
inaccuracies due to inevitable changes in component values. If you don't
have a good digital multimeter to measure the resistors, maybe you could
borrow one from a friend or neighbor. The resistors (R1 through R6) and the
rectifier in the AC Voltage circuit should be under scrutiny, especially the
rectifier. Check the values of the resistors. If they are pretty close
(they are 1% resistors), then the rectifier is the most likely suspect, and
it might be difficult to find a direct replacement.
I don't see the picture that you posted (this isn't a binaries group), but
if you'll repost the image to a binaries group such as
alt.binaries.schematics.electronic, I'm sure more people can see it. I used
to work in a calibration lab that serviced Simpson, Triplett and Weston
meters and multimeters. I don't remember specifically what the rectifier
looks like, but it's possible that I might have one or two in my junque box
that I can send if the resistors prove to be OK.

Cheers!!

--
HAM AND EGGS -- A day's work for a chicken, a lifetime commitment for a pig.

Dave M


Hi Dave:

Unfortunately, BellSouth, in their infinite wisdom, is blocking the
binary groups. Upon inspecting the meter, it's very clear that one
resistor is damaged. What I initially described as a bulge seems to
be a burned section at one end of the resistior. In the manual it's
designated as R8 with a value of 2.5 ohms. The Triplett part number
is listed as 15-2869. I thought itwould be relatively easy to locate
such a replacement but that doesn't seem to be the case (plus I'm a
1960's vintage ME, not an EE). I looked up resistors in a Digi-Key
catalog and the first time a 2.5 ohm value appears is as a RS Series
Silicone Coated Wirewound (3 Watts; 1%). I then opened an Allied
catalog and quickly recognized that I'm over my head in that I need a
more complete description of the type of component I should be looking
for.

Along the lines you suggested what circuit is the resistor
associated with, I looked at the schematic and R8 is part of the DC MA
circuit. Resistors R1 through R6 all look OK. I'll try to borrow a
multimeter in the next few days to check them more thoroughly and
report back here.


Create a free account at http://www.flikr.com, and make the images
public.


--
You can't have a sense of humor, if you have no sense!