# Capacitance Meter Recommendation

N

#### Nomen Nescio

Jan 1, 1970
0
I'm just starting the process of bringing back from the dead a very old
1950's RCA color television. The CTC-7 chassis is very ugly looking, with
over 75 paper capacitors. There are also two Sprague can-type
electrolytics, 3 caps in each can. Will have to make something to replace.
Powering on is out of the question until I can replace numerous components.

I want to buy a capacitance meter to check both the caps that I'm replacing
and the replacement parts I will install. I've been looking at a BK
Precision 810c Capacitance Meter. Or maybe I'll buy a Fluke 177. But then
I read this from a post in 2002:

"don't expect the Capacitance measurements (of a DMM) to equal that of even
the cheapest C meter. Even on the "expensive" meters." Paul Grohe,
sci.electronics.basics

My concern is that the capacitor checker function built into a
multi-purpose DMM isn't as good as a stand-alone capacitance meter. Is
there any truth to this statement?

J

#### John Bachman

Jan 1, 1970
0
I'm just starting the process of bringing back from the dead a very old
1950's RCA color television. The CTC-7 chassis is very ugly looking, with
over 75 paper capacitors. There are also two Sprague can-type
electrolytics, 3 caps in each can. Will have to make something to replace.
Powering on is out of the question until I can replace numerous components.

I want to buy a capacitance meter to check both the caps that I'm replacing
and the replacement parts I will install. I've been looking at a BK
Precision 810c Capacitance Meter. Or maybe I'll buy a Fluke 177. But then
I read this from a post in 2002:

"don't expect the Capacitance measurements (of a DMM) to equal that of even
the cheapest C meter. Even on the "expensive" meters." Paul Grohe,
sci.electronics.basics

My concern is that the capacitor checker function built into a
multi-purpose DMM isn't as good as a stand-alone capacitance meter. Is
there any truth to this statement?

Nearly everyone who is into restoring old radios or TV's (myself
included) replace all of the paper caps with polypropylenes or mylars
and all of the electrolytics with new ones. If one of them is still
good, it is likely to fail soon, so why not just replace them all?

Do that and you do not need a meter as the new caps are surely good.

But, if you really want a cap meter I can offer the ESR60 which
measures ESR and value at US$149.00. See www.anatekcorp.com/testequipment/atlasesr60.htm for details. John The Electronic Repair Center at www.anatekcorp.com T #### Tom MacIntyre Jan 1, 1970 0 I'm just starting the process of bringing back from the dead a very old 1950's RCA color television. The CTC-7 chassis is very ugly looking, with over 75 paper capacitors. There are also two Sprague can-type electrolytics, 3 caps in each can. Will have to make something to replace. Powering on is out of the question until I can replace numerous components. I want to buy a capacitance meter to check both the caps that I'm replacing and the replacement parts I will install. I've been looking at a BK Precision 810c Capacitance Meter. Or maybe I'll buy a Fluke 177. But then I read this from a post in 2002: "don't expect the Capacitance measurements (of a DMM) to equal that of even the cheapest C meter. Even on the "expensive" meters." Paul Grohe, sci.electronics.basics My concern is that the capacitor checker function built into a multi-purpose DMM isn't as good as a stand-alone capacitance meter. Is there any truth to this statement? If you want to verify electrolytic capacitors, you have to be able to check the ESR. Tom N #### Nomen Nescio Jan 1, 1970 0 Nearly everyone who is into restoring old radios or TV's (myself included) replace all of the paper caps with polypropylenes or mylars and all of the electrolytics with new ones. If one of them is still good, it is likely to fail soon, so why not just replace them all? There are only three electrolytics in the entire set, one has already been replaced. The remaining caps are paper, mica, and ceramic. From my reading up on caps, it's the paper ones that need replacement. Over the years some of the paper caps have been replaced with orange drops. So I don't have to do all of them. Still, it's a literal bird's nest of wires on the underside of the chassis. Seems like back in the 1950's, the way a TV was designed (or maybe it was just RCA) such that one component wouldn't short out another, was to simply bend the leads so that nothing touches. Frightening! The TV may also have transformer problems, although the flyback looks very clean, with no signs of arcing. At one time I was very good at troubleshooting an AN/SPS-10 surface search radar, so I'm confident I'll be able to get this thing showing a color peacock once again. My main focus will be to get the power supply area cleaned up. After that I'll work on the deflection circuits. Only when I can get some kind of raster will I then turn to the video and color areas. I've read about the ESR meters, just never used one before. And don't quite understand how it could work with a cap in circuit, as other components would effect the values of the component under test (like an inductor in parallel with the capacitor). N #### Nomen Nescio Jan 1, 1970 0 But, if you really want a cap meter I can offer the ESR60 which measures ESR and value at US$149.00. See
www.anatekcorp.com/testequipment/atlasesr60.htm for details.

According to the specifications for your meter, the minimum Capacitance
measurement range is 1uF. How would this meter work for paper capacitors,
when all of the fixed paper capacitors in my set are all under 1uF, with
the smallest being .0018uF and the largest being .47uF. Just doesn't seem
the appropriate product for my application.

H

#### [email protected]

Jan 1, 1970
0
Why not tuen on the set and see what happens. The vacuum tube color
sets, which I worked on in the 50's to go thru college, were very
forgiving of temporary overloads, etc. If you are familiear with
tubes, you understand there is much more margin than with transistors
as far as temporary overloads are concerned.

H. R.(Bob) Hofmann

J

#### John Bachman

Jan 1, 1970
0
There are only three electrolytics in the entire set, one has already been
replaced. The remaining caps are paper, mica, and ceramic. From my
reading up on caps, it's the paper ones that need replacement. Over the
years some of the paper caps have been replaced with orange drops. So I
don't have to do all of them. Still, it's a literal bird's nest of wires
on the underside of the chassis. Seems like back in the 1950's, the way a
TV was designed (or maybe it was just RCA) such that one component wouldn't
short out another, was to simply bend the leads so that nothing touches.
Frightening! The TV may also have transformer problems, although the
flyback looks very clean, with no signs of arcing.

I've read about the ESR meters, just never used one before. And don't
quite understand how it could work with a cap in circuit, as other
components would effect the values of the component under test (like an
inductor in parallel with the capacitor).

First we have to establish that we are talking about two very
different applications: old TV/radio restoration and ESR.

When your TV was designed no one worried much about ESR, it just was
not an important characteristic of capacitors, electrolytic and
otherwise. So ESR measurement is not a big deal in those situations.
I only mentioned it thinking that you might have other applications in
which ESR measurement would be useful.

You are correct in that ESR is affected by other components in the
circuit. Most ESR measurements are made on electrolytic filter
capacitors, not frequency sensitive circuits. In those case, the ESR
can be measured in-circuit as long as the meter does not forward bias
any semiconductors in the circuit. Not a problem with 50's TVs

John

J

#### John Bachman

Jan 1, 1970
0
According to the specifications for your meter, the minimum Capacitance
measurement range is 1uF. How would this meter work for paper capacitors,
when all of the fixed paper capacitors in my set are all under 1uF, with
the smallest being .0018uF and the largest being .47uF. Just doesn't seem
the appropriate product for my application.

See my post to your other question.

Yes, the ESR60 will not measure the value of the paper capacitors you
are dealing with.

John

N

#### Nomen Nescio

Jan 1, 1970
0
Why not tuen on the set and see what happens. The vacuum tube color
sets, which I worked on in the 50's to go thru college, were very
forgiving of temporary overloads, etc. If you are familiear with
tubes, you understand there is much more margin than with transistors
as far as temporary overloads are concerned.

Believe me, this set ain't in power-on condition. I was told that the set
was broken, hadn't been turned on in years, sat in an unheated garage for
years, and the power cord was snipped off. Upon a visual inspection, the
horizontal output tube was up to air (getter all white), and the chassis
was only partially bolted in place, bolts finger tight, another bolt
rolling around loose inside, along with several tube shields. The main
power transformer has leaked a dark brown goo down on the chassis (the
chassis sits vertically on its side), with the video board all gunked up.
The CRT board took a nice hit, cracking the neck socket. Fortunately the
wires to the socket are all intact, and the vacuum is still there. Believe
me, there have been many hands in this set, with many modifications from
the schematic I've obtained. The CRT is a 21FBP22, replacing the original
21CYP22. The old man who used to own it must have been in love with the
thing, because it appears the CRT has been exchanged twice from when it was
purchased in 1957. Looks like around the mid 1970's the repair shop told
the guy to give it a decent burial, because that's when the repair tags
end. They probably didn't want to work on it anymore.

So anyway, I'm going to give this my best shot. Have a whole bunch of caps
on order. Once I get the power supply cleaned up, I may attempt to fire it
up (only talking figuratively here and see if I can get raster....

D

#### Dolemite

Jan 1, 1970
0
Dont know much about TVs,but how good would a 1950s TV picture look
compared to say, a new HDTV? just wondering wouldnt it be a lot more worth
repairing a broken HDTV or plasma TV? were TVs built a lot better in the
50s?

K

#### Ken Weitzel

Jan 1, 1970
0
Dolemite said:
Dont know much about TVs,but how good would a 1950s TV picture look
compared to say, a new HDTV? just wondering wouldnt it be a lot more worth
repairing a broken HDTV or plasma TV? were TVs built a lot better in the
50s?

Hi...

Memories, my (must be young) friend, memories

about those boiling hot shields on the if's And trying
to find the key to put hot tubes back in the tuner. And
squeezing wax paper caps gently with a pair of long nose to
test them.

And cleaning tuner contacts... and fine tuning the fine
tuning... and real solid wood cabinets that weighed tons...
and antennas on the roof... more and more keeps flooding back

Memories, wonderful memories

Take care.

Ken

Q

#### quietguy

Jan 1, 1970
0
Surely you would replace all those caps as a matter of course, as well as the
high value resisters

David

J

#### Jamie

Jan 1, 1970
0
Nomen said:
I'm just starting the process of bringing back from the dead a very old
1950's RCA color television. The CTC-7 chassis is very ugly looking, with
over 75 paper capacitors. There are also two Sprague can-type
electrolytics, 3 caps in each can. Will have to make something to replace.
Powering on is out of the question until I can replace numerous components.

I want to buy a capacitance meter to check both the caps that I'm replacing
and the replacement parts I will install. I've been looking at a BK
Precision 810c Capacitance Meter. Or maybe I'll buy a Fluke 177. But then
I read this from a post in 2002:

"don't expect the Capacitance measurements (of a DMM) to equal that of even
the cheapest C meter. Even on the "expensive" meters." Paul Grohe,
sci.electronics.basics

My concern is that the capacitor checker function built into a
multi-purpose DMM isn't as good as a stand-alone capacitance meter. Is
there any truth to this statement?
you will also need a variable HV supply to check for leakage, more like
a HI-POT unit.

J

#### Jamie

Jan 1, 1970
0
Nomen said:
Believe me, this set ain't in power-on condition. I was told that the set
was broken, hadn't been turned on in years, sat in an unheated garage for
years, and the power cord was snipped off. Upon a visual inspection, the
horizontal output tube was up to air (getter all white), and the chassis
was only partially bolted in place, bolts finger tight, another bolt
rolling around loose inside, along with several tube shields. The main
power transformer has leaked a dark brown goo down on the chassis (the
chassis sits vertically on its side), with the video board all gunked up.
The CRT board took a nice hit, cracking the neck socket. Fortunately the
wires to the socket are all intact, and the vacuum is still there. Believe
me, there have been many hands in this set, with many modifications from
the schematic I've obtained. The CRT is a 21FBP22, replacing the original
21CYP22. The old man who used to own it must have been in love with the
thing, because it appears the CRT has been exchanged twice from when it was
purchased in 1957. Looks like around the mid 1970's the repair shop told
the guy to give it a decent burial, because that's when the repair tags
end. They probably didn't want to work on it anymore.

So anyway, I'm going to give this my best shot. Have a whole bunch of caps
on order. Once I get the power supply cleaned up, I may attempt to fire it
up (only talking figuratively here and see if I can get raster....
you may find that the flyback is out in left field.
good luck in locating another.
it was a common problem of having bad flyback transformers
for various reasons.
one of the common problems was losing the horizontal drive, the tube
would heat up thus popping it self during its melt down and heating the
heck out of the flyback melting the wax while in process.

N

#### Nomen Nescio

Jan 1, 1970
0
Dont know much about TVs,but how good would a 1950s TV picture look
compared to say, a new HDTV? just wondering wouldnt it be a lot more worth
repairing a broken HDTV or plasma TV? were TVs built a lot better in the
50s?

Well sure, if I wanted a new color TV, I could easily go over to Best Buy
and get a new Sony Wega 16:9. But that's not that point. A 1950's color
TV is a rare and beautiful thing indeed:

http://www.novia.net/~ereitan/Gallery/Gallery_Index.html

People throughout the country and world restore all sorts of old
technologies. Here's one I found the other day. So fascinating:

http://www.automaticwasher.org/

J

#### John Bachman

Jan 1, 1970
0
Dont know much about TVs,but how good would a 1950s TV picture look
compared to say, a new HDTV? just wondering wouldnt it be a lot more worth
repairing a broken HDTV or plasma TV? were TVs built a lot better in the
50s?
"Jamie" <[email protected]> wrote in message

Slide over to rec.antiques.radio+phono and see how many people are
into restoration of old electronics. It might give you a different
perspective.

John

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