Does anybody have an old large panel meter (case inside dia of 3"). The
meter can (should) be broken as all I need is the outside case. I need
a bezel for a 3" CRT and a case from a broken panel meter with a 3"
(inside) diameter would work fine.

On Jan 14, 6:22*am, Kenneth Scharf wrote:
Does anybody have an old large panel meter (case inside dia of 3"). *The
meter can (should) be broken as all I need is the outside case. *I need
a bezel for a 3" CRT and a case from a broken panel meter with a 3"
(inside) diameter would work fine.

I'll look this evening, or tomorrow. Do you want metal or plastic?
Where are you located? I am in Oregon.

Paul, KD7HB

wrote:
On Jan 14, 6:22 am, Kenneth Scharf wrote:
Does anybody have an old large panel meter (case inside dia of 3"). The
meter can (should) be broken as all I need is the outside case. I need
a bezel for a 3" CRT and a case from a broken panel meter with a 3"
(inside) diameter would work fine.

I'll look this evening, or tomorrow. Do you want metal or plastic?
Where are you located? I am in Oregon.

Paul, KD7HB
I'm in south Florida (FTL area). I think plastic might work out better,
but if it's non-magnetic metal (brass, aluminum, etc) that should be OK
too. The ID needs to be at least 3" so the CRT will fit. Most 3"
meters are a bit smaller than that, I know they made larger ones, but
not a popular size. I don't need the movement so if that's toast so
much the better, rather than destroy a good meter. Of course if it has
a useless range like 200A DC who cares?

On Jan 15, 12:26*pm, Kenneth Scharf wrote:
wrote:
On Jan 14, 6:22 am, Kenneth Scharf wrote:
Does anybody have an old large panel meter (case inside dia of 3"). *The
meter can (should) be broken as all I need is the outside case. *I need
a bezel for a 3" CRT and a case from a broken panel meter with a 3"
(inside) diameter would work fine.

I'll look this evening, or tomorrow. Do you want metal or plastic?
Where are you located? I am in Oregon.

Paul, KD7HB

I'm in south Florida (FTL area). *I think plastic might work out better,
but if it's non-magnetic metal (brass, aluminum, etc) that should be OK
too. *The ID needs to be at least 3" so the CRT will fit. *Most 3"
meters are a bit smaller than that, I know they made larger ones, but
not a popular size. *I don't need the movement so if that's toast so
much the better, rather than destroy a good meter. *Of course if it has
a useless range like 200A DC who cares?

Well, we are in luck, maybe. I have a meter here that is 3.000 inside
the removable back plate. However, below that, the case ID is reduced
to 2.910 inches, making a ledge for the back to rest on. The whole
case, front and back, is a single molding. The lower 40% of the meter
face is part of the molding. If you need the entire front of the scope
to be viewable, the case will need to be chucked in a lathe and the
front turned off. The window part of the case is glass cemented to the
case.

This meter came from an old German made wave solder machine that
registered the chain speed in meters per minute. It has internal
circuitry. The size is certainly Metric.

I can send pictures if you would like. I can also try to turn off the
face in a lathe, but it would be much better if you supervised the
operation so you get what you want.

I may have more meters at work, but probably none that come this close
to the size you need. Will look for the box on Monday, but I think
they are all smaller.

If this works for you, just pay for postage.

Paul, KD7HB

wrote:
On Jan 15, 12:26 pm, Kenneth Scharf wrote:

wrote:

On Jan 14, 6:22 am, Kenneth Scharf wrote:

Does anybody have an old large panel meter (case inside dia of 3"). The
meter can (should) be broken as all I need is the outside case. I need
a bezel for a 3" CRT and a case from a broken panel meter with a 3"
(inside) diameter would work fine.

I'll look this evening, or tomorrow. Do you want metal or plastic?
Where are you located? I am in Oregon.

Paul, KD7HB

I'm in south Florida (FTL area). I think plastic might work out better,
but if it's non-magnetic metal (brass, aluminum, etc) that should be OK
too. The ID needs to be at least 3" so the CRT will fit. Most 3"
meters are a bit smaller than that, I know they made larger ones, but
not a popular size. I don't need the movement so if that's toast so
much the better, rather than destroy a good meter. Of course if it has
a useless range like 200A DC who cares?


Well, we are in luck, maybe. I have a meter here that is 3.000 inside
the removable back plate. However, below that, the case ID is reduced
to 2.910 inches, making a ledge for the back to rest on. The whole
case, front and back, is a single molding. The lower 40% of the meter
face is part of the molding. If you need the entire front of the scope
to be viewable, the case will need to be chucked in a lathe and the
front turned off. The window part of the case is glass cemented to the
case.

This meter came from an old German made wave solder machine that
registered the chain speed in meters per minute. It has internal
circuitry. The size is certainly Metric.

I can send pictures if you would like. I can also try to turn off the
face in a lathe, but it would be much better if you supervised the
operation so you get what you want.

I may have more meters at work, but probably none that come this close
to the size you need. Will look for the box on Monday, but I think
they are all smaller.

If this works for you, just pay for postage.

Paul, KD7HB

How about a 3 inch bezel and a 3 inch crt with socket. I have one in my
junk box.

Bill K7NOM (near Sacramento CA)

On Jan 16, 5:00*pm, Bill Janssen wrote:
wrote:
On Jan 15, 12:26 pm, Kenneth Scharf wrote:

wrote:

On Jan 14, 6:22 am, Kenneth Scharf wrote:

Does anybody have an old large panel meter (case inside dia of 3"). *The
meter can (should) be broken as all I need is the outside case. *I need
a bezel for a 3" CRT and a case from a broken panel meter with a 3"
(inside) diameter would work fine.

I'll look this evening, or tomorrow. Do you want metal or plastic?
Where are you located? I am in Oregon.

Paul, KD7HB

I'm in south Florida (FTL area). *I think plastic might work out better,
but if it's non-magnetic metal (brass, aluminum, etc) that should be OK
too. *The ID needs to be at least 3" so the CRT will fit. *Most 3"
meters are a bit smaller than that, I know they made larger ones, but
not a popular size. *I don't need the movement so if that's toast so
much the better, rather than destroy a good meter. *Of course if it has
a useless range like 200A DC who cares?

Well, we are in luck, maybe. I have a meter here that is 3.000 inside
the removable back plate. However, below that, the case ID is reduced
to 2.910 inches, making a ledge for the back to rest on. The whole
case, front and back, is a single molding. The lower 40% of the meter
face is part of the molding. If you need the entire front of the scope
to be viewable, the case will need to be chucked in a lathe and the
front turned off. The window part of the case is glass cemented to the
case.

This meter came from an old German made wave solder machine that
registered the chain speed in meters per minute. It has internal
circuitry. The size is certainly Metric.

I can send pictures if you would like. I can also try to turn off the
face in a lathe, but it would be much better if you supervised the
operation so you get what you want.

I may have more meters at work, but probably none that come this close
to the size you need. Will look for the box on Monday, but I think
they are all smaller.

If this works for you, just pay for postage.

Paul, KD7HB

How about a 3 inch bezel and a 3 inch crt with socket. *I have one in my
junk box.

Bill K7NOM (near Sacramento CA)

I was thinking about offering him my old military surplus 3" scope but
thought he might have more fun with a meter housing. The scope was an
Air Force MARS issue and I used it for RTTY tuning. Boy, was that a
long time ago!

Paul, KD7HB

Bill Janssen wrote:
wrote:
On Jan 15, 12:26 pm, Kenneth Scharf wrote:

wrote:

On Jan 14, 6:22 am, Kenneth Scharf wrote:

Does anybody have an old large panel meter (case inside dia of
3"). The
meter can (should) be broken as all I need is the outside case. I
need
a bezel for a 3" CRT and a case from a broken panel meter with a 3"
(inside) diameter would work fine.

I'll look this evening, or tomorrow. Do you want metal or plastic?
Where are you located? I am in Oregon.
Paul, KD7HB

I'm in south Florida (FTL area). I think plastic might work out better,
but if it's non-magnetic metal (brass, aluminum, etc) that should be OK
too. The ID needs to be at least 3" so the CRT will fit. Most 3"
meters are a bit smaller than that, I know they made larger ones, but
not a popular size. I don't need the movement so if that's toast so
much the better, rather than destroy a good meter. Of course if it has
a useless range like 200A DC who cares?


Well, we are in luck, maybe. I have a meter here that is 3.000 inside
the removable back plate. However, below that, the case ID is reduced
to 2.910 inches, making a ledge for the back to rest on. The whole
case, front and back, is a single molding. The lower 40% of the meter
face is part of the molding. If you need the entire front of the scope
to be viewable, the case will need to be chucked in a lathe and the
front turned off. The window part of the case is glass cemented to the
case.

This meter came from an old German made wave solder machine that
registered the chain speed in meters per minute. It has internal
circuitry. The size is certainly Metric.

I can send pictures if you would like. I can also try to turn off the
face in a lathe, but it would be much better if you supervised the
operation so you get what you want.

I may have more meters at work, but probably none that come this close
to the size you need. Will look for the box on Monday, but I think
they are all smaller.

If this works for you, just pay for postage.

Paul, KD7HB

How about a 3 inch bezel and a 3 inch crt with socket. I have one in my
junk box.

Bill K7NOM (near Sacramento CA)
Hey if someone has an actual CRT bezel for a 3" tube that would be nice!
Is it a Millen or something war surplus? I don't need the tube,
actually I have a VERY nice 3ADP1 by Dumont. It's a weird bottle, the
front is not a cone shape but rather a cylinder that goes straight back
for about 3" before it tapers all at once to a smaller cylinder holding
the electron gun. The deflection plates and the second anode connect to
pins sticking out of the tube neck. It has a standard 12 pin crt base
(12 pin "octal"). It's a PDA type with the third anode connector in the
usual place on the tube bulb. VERY high deflection sensitivity and
probably good to over 100 MHZ. If anybody has ever seen the cover of
the November/December 1975 73 magazine you know what I'm building!

I also have a 3ACP1 and a Millen shield that fits it, but the 3ADP1 is a
better tube and I don't have a way to mount it (no shield I've ever seen
that mounts to the panel will fit this tube!).

On Jan 17, 1:43*pm, Kenneth Scharf wrote:
Bill Janssen wrote:
wrote:
On Jan 15, 12:26 pm, Kenneth Scharf wrote:

wrote:

On Jan 14, 6:22 am, Kenneth Scharf wrote:

Does anybody have an old large panel meter (case inside dia of
3"). *The
meter can (should) be broken as all I need is the outside case. *I
need
a bezel for a 3" CRT and a case from a broken panel meter with a 3"
(inside) diameter would work fine.

I'll look this evening, or tomorrow. Do you want metal or plastic?
Where are you located? I am in Oregon.
* * * Paul, KD7HB

I'm in south Florida (FTL area). *I think plastic might work out better,
but if it's non-magnetic metal (brass, aluminum, etc) that should be OK
too. *The ID needs to be at least 3" so the CRT will fit. *Most 3"
meters are a bit smaller than that, I know they made larger ones, but
not a popular size. *I don't need the movement so if that's toast so
much the better, rather than destroy a good meter. *Of course if it has
a useless range like 200A DC who cares?

Well, we are in luck, maybe. I have a meter here that is 3.000 inside
the removable back plate. However, below that, the case ID is reduced
to 2.910 inches, making a ledge for the back to rest on. The whole
case, front and back, is a single molding. The lower 40% of the meter
face is part of the molding. If you need the entire front of the scope
to be viewable, the case will need to be chucked in a lathe and the
front turned off. The window part of the case is glass cemented to the
case.

This meter came from an old German made wave solder machine that
registered the chain speed in meters per minute. It has internal
circuitry. The size is certainly Metric.

I can send pictures if you would like. I can also try to turn off the
face in a lathe, but it would be much better if you supervised the
operation so you get what you want.

I may have more meters at work, but probably none that come this close
to the size you need. Will look for the box on Monday, but I think
they are all smaller.

If this works for you, just pay for postage.

Paul, KD7HB

How about a 3 inch bezel and a 3 inch crt with socket. *I have one in my
junk box.

Bill K7NOM (near Sacramento CA)

Hey if someone has an actual CRT bezel for a 3" tube that would be nice!
Is it a Millen or something war surplus? *I don't need the tube,
actually I have a VERY nice 3ADP1 by Dumont. *It's a weird bottle, the
front is not a cone shape but rather a cylinder that goes straight back
for about 3" before it tapers all at once to a smaller cylinder holding
the electron gun. *The deflection plates and the second anode connect to
pins sticking out of the tube neck. *It has a standard 12 pin crt base
(12 pin "octal"). *It's a PDA type with the third anode connector in the
usual place on the tube bulb. *VERY high deflection sensitivity and
probably good to over 100 MHZ. *If anybody has ever seen the cover of
the November/December 1975 73 magazine you know what I'm building!

I also have a 3ACP1 and a Millen shield that fits it, but the 3ADP1 is a
better tube and I don't have a way to mount it (no shield I've ever seen
that mounts to the panel will fit this tube!).

I pulled up a PDF of the specs on the 3ADP1 and see the dia. is 3" +_
1/16, so unless you have measured the tube diameter to be exactly 3",
the meter housing will not work. The ID could be bored to 3",but not
any more. Besides, the tube may not be an exact cylinder and that is
probably why they have the +_ 1/16.

If you are familiar with the OS-8 surplus scope,that is what I have
gathering dust. It has a pull-out light shield as part of the front
bezel.

I am sure I have seen the 73 magazine issue, but that was back in
1975! Memory is not able to access a picture of the front cover.

You are welcome to the OS-8, if that will help.

73, Paul KD7HB

On Mon, 18 Jan 2010, wrote:

I am sure I have seen the 73 magazine issue, but that was back in
1975! Memory is not able to access a picture of the front cover.

It was the last small issue, the second part was in the first larger
size issue. It was a combined issue so they could get the larger
format out before the competition, all the magazines switched over
at the same time. The scope was on the cover, it kind of looked like a
Tektronix 453? (it's wider than it is high), and if I recall properly, it
had a built in battery so you could run it away from the power line. It
was an impressive project, yet it was also limited, no really high
frequency response.

John W. Campbell's solution about 15 years before in "CQ" was to do away
with amplifiers and run the scope tube off a relatively low voltage, which
gave them better sensitivity. Feed the signal right into the plates,
you'd get a dim trace but great frequency response. He got the idea from
Bell Labs.

Michael VE2BVW

Michael Black wrote:
On Mon, 18 Jan 2010, wrote:

I am sure I have seen the 73 magazine issue, but that was back in
1975! Memory is not able to access a picture of the front cover.

It was the last small issue, the second part was in the first larger
size issue. It was a combined issue so they could get the larger format
out before the competition, all the magazines switched over
at the same time. The scope was on the cover, it kind of looked like a
Tektronix 453? (it's wider than it is high), and if I recall properly, it
had a built in battery so you could run it away from the power line. It
was an impressive project, yet it was also limited, no really high
frequency response.

John W. Campbell's solution about 15 years before in "CQ" was to do away
with amplifiers and run the scope tube off a relatively low voltage, which
gave them better sensitivity. Feed the signal right into the plates,
you'd get a dim trace but great frequency response. He got the idea
from Bell Labs.

Michael VE2BVW

That's the scope. It did look like a tek 465/475 series that gotten
shrunk down a bit (3" vs 5" tube). Actually the frequency response
could have been as high as 50MHz with that circuit. As described the
scope used transistors with an ft of 50MHz which got the scope to about
15-20MHz top end. The op amp used in the vertical preamp was good to
about 90MHz. I corresponded with the author on some details and was
told that he had later substituted transistors with higher ft (100MHz)
and got 45MHz out of the vertical chain with some tweaking. He
suspected it would go a bit higher by hand picking transistors / op
amps. I have some 140MHz transistors I can use and have a bunch of op
amps so I can hand pick those for best response. The 3ADP1 should in
theory go higher in frequency than the 3ACP1 (and I have two of each).

I suppose that today most would consider a 50MHz scope as not being
really HF, but that's about high enough for most work with 8 bit
microcontrollers and HF radio gear. BTW, this scope DOES run at low
voltage, +/- 600 volts on a PDA tube designed for +/- 2000. The author
suggested a mod for dual trace and I even considered this, but running
the tube at low voltage to get the deflection sensitivity and bandwidth
would make a dual trace option too dim to see well.

Today the way to build a scope is with fast A/D converters and software.
Digital scopes react to oversampling in a different way than analog
scopes though. Instead of rounding off square waves and showing reduced
amplitude they build false waveforms due to aliasing errors. (they lie).

I suppose I'm guilty of the worlds worst case of procrastination on a
project with this one!