Date   

Re: CRT static charge

 

Dave,

You might also be noticing it now because of a change in humidity. Higher humidity air is better at bleeding off the static charge from the face of the tube than low humidity air, so you are more likely that get that crackling noise in the winter than in the summer.

This is an effect that was very well known in the days of CRT TVs, and I remember it as one of the distinctive auditory experiences of using TVs back then (that and the sound of the flyback transformer). I just tried one of my Tek scopes, and I didn't get any crackling on power up, nor do I feel any static field holding the back of my hand near the tube face, but it may not be very dry yet here in Maryland, and the implosion shield may block some of the static field that I would otherwise be able to detect by hairs standing up on the back of my hand.

-- Jeff Dutky


Re: CRT static charge

Dave Peterson
 

OMG, that's so funny. I totally forgot about that. As soon as my eyes landed on that bit about old TVs my brain jumped back to 1970 and the crackle that accompanied twisting the power/volume knob on the TV flooded back into my mind. Thanks for that old memory! Oh yeah! CRTs! It's been a long while. Perhaps that's part of the nostalgia and joy of old oscilloscopes.
Dave

On Monday, December 7, 2020, 10:44:27 AM PST, Eric <ericsp@gmail.com> wrote:

IMHO that is very normal and a product of the accelerating voltage in the CRT. If it was arcing out of the tube there would be no vacuum left in the tube and  the tube would be bad. All my 7000 series scopes do it and the old tube TV’s used to do it. I used to check the high voltage section of a tv by just running the back of my hand over the the tube about and inch off the face, no dissemble needed. If the hairs on my arm stood up the HV section of the TV was good.

Eric
-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Dave Peterson via groups.io
Sent: Monday, December 7, 2020 1:36 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] CRT static charge

Thanks Raymond. I figured when dealing with voltages with a "k" suffix it's probably wise to be safer than sorry-er.

Dave
    On Monday, December 7, 2020, 10:32:23 AM PST, Raymond Domp Frank <hewpatek@gmail.com> wrote:

On Mon, Dec  7, 2020 at 07:29 PM, Dave Peterson wrote:


Is this normal?

Could it be an indication of anything untoward?
Short answer to your two questions: Yes, it is, and No, it isn't.

Raymond


Re: SUCCESS! The "sick" 475A is now the "fixed" 475A!

Dave Peterson
 

Yes, intermittent transient problems are the worst.

I figure any recovered parts scope comes with 0 assumptions. When it at first did nothing I wasn't the slightest bit surprised. I was more surprised that it did work - and is working pretty darn well. My primary guess is that the "Regulating Range Selector" - the jumper in the main fuse holder? - was the culprit. That removing and reinstalling it broke whatever surface corrosion was interfering. The power switch had already been cycled a few times (without power) during the disassembly/reassembly process. Should it be taken back out and and cleaned? Sure, along with every other contact surface in the scope? I'm not that patient and thorough, yet.

It's doing a lot of off-nominal things that can't be of any surprise: pots being "jumpy", etc. I have to wonder how long this thing has been sitting on a shelf in the most non-ideal conditions. There have been a lot of water spots on internal metal parts. I think mostly likely condensation. The boards have appeared rather pristine, though it also appears to have had some boards and shields removed. Obvious solder work on the wires and BNCs necessary to disassemble/reassemble. I suspect several attempts to fix it have been made before.

Things are cleaning up as I use it - position pots are settling down with use, BNCs are being noisy and intermittent, but getting better. Small oxidation and corrosion on contacts has to be expected. I'll get into cleaning methodologies as I get into the calibration and determine what is and isn't working.

Just part of the fun!
Dave


Re: SUCCESS! The "sick" 475A is now the "fixed" 475A!

 

Jim Ford wrote:

I'd be wary of problems that go away by themselves.
Well, if the problem had simply stopped without my touching anything, I would agree with you (and then some: a problem that goes away by itself is likely to return with friends). In my case I suspect that one lead of the cap had been bent down and was making contact with a neighboring signal trace, shorting out the cap. I straightened the leads after desoldering it while measuring it on my multimeter, so when I reinstalled the cap I did so with straightened leads that couldn't touch the circuit board in the wrong places. I still find it amusing that I didn't replace any parts and still managed to fix the problem, but some problems on the 475 are like that: cleaning drum switch contacts, and cleaning and reseating socketed components are the two examples that leap to mind. Removing heavy dust build-up could also improve the performance of a really dirty scope, but you might expect that if the dust were causing significant overheating then some components might also be permanently damaged.

-- Jeff Dutky


Re: CRT static charge

Eric
 

IMHO that is very normal and a product of the accelerating voltage in the CRT. If it was arcing out of the tube there would be no vacuum left in the tube and the tube would be bad. All my 7000 series scopes do it and the old tube TV’s used to do it. I used to check the high voltage section of a tv by just running the back of my hand over the the tube about and inch off the face, no dissemble needed. If the hairs on my arm stood up the HV section of the TV was good.

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Dave Peterson via groups.io
Sent: Monday, December 7, 2020 1:36 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] CRT static charge

Thanks Raymond. I figured when dealing with voltages with a "k" suffix it's probably wise to be safer than sorry-er.

Dave
On Monday, December 7, 2020, 10:32:23 AM PST, Raymond Domp Frank <hewpatek@gmail.com> wrote:

On Mon, Dec 7, 2020 at 07:29 PM, Dave Peterson wrote:


Is this normal?

Could it be an indication of anything untoward?
Short answer to your two questions: Yes, it is, and No, it isn't.

Raymond


Re: I give up.

Mlynch001
 

I have had a very strange situation, not the fault of PayPal, but people should be aware when using a Business Debit or Credit card for any purchase. I recently had a charge on my business card from an online backup company. They had my card on file, for Automatic renewal. I did not want to renew, and did not give them my “new” expiration. Thinking this would prevent them from charging me. Regardless, they ran the charge through by “guessing” my expiration date (wrong) and, even though they got the expiration wrong, the charge went through. I had to fight with the company for a refund. I found out that this is a quirk in Arkansas law that allows a business credit or debit card to be charged, as long as they have the card # correct, even when they provide the “wrong” expiration. This may be isolated to Arkansas, but needless to say, I no longer store or save my business card online with any company, including PayPal.

--
Michael Lynch
Dardanelle, AR


Re: Calibrating a PG506 w/o Sampling System

Jim Ford
 

Yeah, I believe that about the 7T11/7S11 pair, Chuck; I have a 7S12 and a 7S11, with a couple of S-4 sampling heads and S-51 and S-53 for triggering. PITA to get them to display anything on the 7904! At some point, I will look for an 11800 series scope like the one I had at work a few decades ago. I don't remember any issues with triggering back then. And the SD-24 sampling head got top marks for pulse fidelity from PicoSecond Pulse Labs (sold to Tek in 2014, IIRC) back then. Just got to run the purchase by the finance committee (my wife)! She can't say anything about the space it takes up; I have that covered with a 19-inch rack next to my bench....

Jim Ford

------ Original Message ------
From: "Chuck Harris" <cfharris@erols.com>
To: TekScopes@groups.io
Sent: 12/7/2020 9:32:49 AM
Subject: Re: [TekScopes] Calibrating a PG506 w/o Sampling System

I do the PG506 calibration on a tek 11801C. It reveals
all.

But, using a 7104 will only make things worse, best not
done. As Raymond says, a PG506 adjusted to a pretty
waveform on a 7104 looks like something you could spear
fish with on a 11801C.

The 7T11/7S11 pair is supposed to be adequate with the
proper sampling head, but I have never been able to get
such a pair to work reliably. It kind of drifts into
a measurement, and drifts out. I never found the problem
to be worth investigating. If someone wanted to, I am
sure that my 7T11/7S11 pair could be had for a reasonable
price... whatever that is these days.

-Chuck Harris

Raymond Domp Frank wrote:
On Mon, Dec 7, 2020 at 05:17 PM, Jean-Paul wrote:


From transient CAL of 2467B, I can say its a tricky and iterative process, and
the correct gens and fixtures are essential.

You may get by with a 1 GHz digital scope but not the Chinese, HP, TEK or
Lecroy.
First of all: Unless the edge settings have been changed, it's probably not necessary to adjust them because your work hasn't influenced them. I certainly wouldn't touch them without the right equipment.
OTOH, the transient response calibration of a PG506 is a very simple adjustment, *if* you have the right equipment and perform the procedure correctly: One capacitor for the positive edge (C1000) and one for the negative edge (C940); optimize overshoot for both. That's it. Capacitor refs. are for SM "Late Model": S/N B040000 up.
However, since you're adjusting a rise/fall time <= 1 ns (that's spec, in practice usually 700 ps or better), your 'scope (as a rule of thumb) needs to have a rise time of at most 20% of that: 200 ps. That means a BW for a 'scope with Gaussian behavior of at least 1750 MHz, about 1400 MHz with many digital 'scopes.
So, using a 1 GHz BW digital 'scope won't crack it: The edge may look fine on it but probably will have serious overshoot, which you won't see on your (too slow) 'scope.
In practice, I'd consider 2.5 - 3 GHz to be the minimum BW required, taking into account that actual rise/fall time of most units is about 700 ps.

Raymond









Re: CRT static charge

Dave Peterson
 

Thanks Raymond. I figured when dealing with voltages with a "k" suffix it's probably wise to be safer than sorry-er.

Dave

On Monday, December 7, 2020, 10:32:23 AM PST, Raymond Domp Frank <hewpatek@gmail.com> wrote:

On Mon, Dec  7, 2020 at 07:29 PM, Dave Peterson wrote:


Is this normal?

Could it be an indication of anything untoward?
Short answer to your two questions: Yes, it is, and No, it isn't.

Raymond


Re: CRT static charge

 

On Mon, Dec 7, 2020 at 07:29 PM, Dave Peterson wrote:


Is this normal?

Could it be an indication of anything untoward?
Short answer to your two questions: Yes, it is, and No, it isn't.

Raymond


CRT static charge

Dave Peterson
 

Something interesting noted on restored parts scope: when powered up the CRT seems to create a static charge crackling noise.

That is, my perception is that the sound is coming from the face of the CRT. This scope currently has a clear shield on it. My existing 465 with a blue shield does not crackle when started. Every component of the face of the scope has been freshly cleaned, so is presumably very dry and free of any oils from handling. The screen shield wiped with a glasses cloth you get from the optometrist to get rid of the static cling. Otherwise lots of dust would obviously accumulate. So presumably the shield has been discharged. The scope is properly grounded, including the ground plug on the face of the scope.

It sounds like fresh laundry being separated, but much quieter. It barely audible, but it's there.

Is this normal? I don't ever recall it from my previous experiences, but it's so innocuous sounding that I'm sure it wouldn't arouse much suspicion otherwise. I'm just very attentive to every sound, and very wary of anything with a scope of completely unknown origin and state. Could it be an indication of anything untoward? Haven't gone through a calibration yet. Getting ready to do so.

Dave


Re: FS: Tek P6102 probe

 

On Mon, Dec 7, 2020 at 06:43 PM, Oz-in-DFW wrote:


Tek's "Discontinued Probes Guide" has an entry for the P6102A (what I'm offering is **not** an A, Just a P6102)
Your pic says P6012 so I guess that's what it is .....

/Håkan


Re: I give up.

stevenhorii
 

I’ve been fortunate (so far) with PayPal. They even refunded a purchase
amount even before I asked for it. It was a mistake on the part of the
seller - apparently he did something that resulted in him getting paid
twice. PayPal must have noticed and investigated because they refunded one
of the payments (identical amounts). I contacted the seller and he said it
was a mistake (I believed him - he has a solid feedback record and
delivered my item well-packed and on-time) and though he didn’t angrily
blame eBay, he did say that he thought it was something to do with what
seemed to be a time delay in eBay responding to him, so he clicked the
payment button again.

I actually have a similar situation cooking now. We’ll see how PayPal
responds. A Web site I purchased a journal article from ended the
transaction because my “response took more than 30 minutes”. My time to
send the payment from PayPal was about 30 seconds. The payment went
through, but I needed the article for a lecture I was preparing, so I just
logged in again and bought it with a credit card. PayPal sent me the usual
notice of payment, so the publisher got paid twice. My next step is to
contact them about it.

Steve H.

On Mon, Dec 7, 2020 at 12:15 Tom Gardner <tggzzz@gmail.com> wrote:

Regrettably it isn't that simple; the banking and e-money laws are a mess
and
almost all people have zero chance of understanding them and their
ramifications.

Today's report is...

Some PayPal customers have found it difficult to get reimbursed when
they’ve run
into problems – particularly victims of fraud.
...
Here, we look at how PayPal is failing to protect and reimburse victims of
fraud, and what it can do about it.
...

https://www.which.co.uk/news/2020/12/how-paypal-fails-fraud-victims/
(Which? used to be far more sensibly named "Consumer Association". It is
generally respected in the UK)


On 07/12/20 14:19, cheater cheater wrote:
Yeah no, asking me if I can deny "major data thefts" happen "almost
daily"
and then transferring that to whether you'll lose money on PayPal is just
high level crackpottery, and if you think this is a valid way of looking
at
the world, then you should have a long hard look in the mirror. It
doesn't
matter how long you've been "doing computers", obviously you're not in
any
way capable of talking about computer security. Some sort of nebulous
"potential problems" with nebulous "companies involved in e-commerce" are
just paranoid thoughts, you can't even answer such a question with a yes
or
no, you've constructed it to give yourself worry.

On Fri, Dec 4, 2020 at 6:16 PM - <rrrr6789@gmail.com> wrote:

Maybe you haven't been reading the messages but Dennis has already
been
paid and that's all taken care of. But I have to admit that I hadn't
considered a wire transfer INTO PayPal. I've never heard of that being
done
and there's nothing about it on their website and I don't even know if
it's
possible. I don't think that it is but perhaps.

I was talking about the potential problems of PayPal and other
companies involved in E-commerce. And you can't deny that those are
real.
All you have to do is to read any newspaper or watch any TV news to know
that major data thefts are happening almost daily. And your 20 years is
nothing, that was when Windows 98 was still new. I beta tested Windows
1.1! I started programming in 1969 in APL on an IBM 1130 and had been
tinkering with computer hardware for two years before that. I was the
person that installed *the* first computers for the Gallup poll in New
Jersey (another IBM 1130 with added core memory) , Virginia Military
Institute and Washington and Lee university and a host of others back in
the mid-1970s.






FS: Tek P6102 probe

Oz-in-DFW
 

FS: Tek P6102 probe. New old stock in original sealed bag. $25 + actual shipping. Paypal OK.

Hi Res pics are here: https://ozindfw.net/Tek_P6102/ I'm afraid they are not great because it's in a heat sealed bag and I had no luck adjusting lighting.

I didn't find anything useful on this model on TekWiki.

Tek's "Discontinued Probes Guide" has an entry for the P6102A (what I'm offering is **not** an A, Just a P6102) It says: Type Opt.: P6102A, Cable Length Meter: 2, Cable Length Feet: 6.6, Atten: 10, B/W at -3 dB (MHz): 60, Input Impedance Resist (MO): 10, Input Impedance Cap (pF): 13, Max V (DC + pk AC): 500, Comp Range Min (pF): 15, Comp Range Max (pF): 35, R/O: Yes, ID: Yes, Tip/Head Style: 5 mm (Min.)

Buyer pays actual shipping. I will (of course) provide tracking info.

I will ship internationally as long as you cover all costs/fees/taxes/duties/mordida/soborno and accept international mailing risk.

--
Oz (in DFW) N1OZ


Re: Calibrating a PG506 w/o Sampling System

Chuck Harris <cfharris@...>
 

I do the PG506 calibration on a tek 11801C. It reveals
all.

But, using a 7104 will only make things worse, best not
done. As Raymond says, a PG506 adjusted to a pretty
waveform on a 7104 looks like something you could spear
fish with on a 11801C.

The 7T11/7S11 pair is supposed to be adequate with the
proper sampling head, but I have never been able to get
such a pair to work reliably. It kind of drifts into
a measurement, and drifts out. I never found the problem
to be worth investigating. If someone wanted to, I am
sure that my 7T11/7S11 pair could be had for a reasonable
price... whatever that is these days.

-Chuck Harris

Raymond Domp Frank wrote:

On Mon, Dec 7, 2020 at 05:17 PM, Jean-Paul wrote:


From transient CAL of 2467B, I can say its a tricky and iterative process, and
the correct gens and fixtures are essential.

You may get by with a 1 GHz digital scope but not the Chinese, HP, TEK or
Lecroy.
First of all: Unless the edge settings have been changed, it's probably not necessary to adjust them because your work hasn't influenced them. I certainly wouldn't touch them without the right equipment.
OTOH, the transient response calibration of a PG506 is a very simple adjustment, *if* you have the right equipment and perform the procedure correctly: One capacitor for the positive edge (C1000) and one for the negative edge (C940); optimize overshoot for both. That's it. Capacitor refs. are for SM "Late Model": S/N B040000 up.
However, since you're adjusting a rise/fall time <= 1 ns (that's spec, in practice usually 700 ps or better), your 'scope (as a rule of thumb) needs to have a rise time of at most 20% of that: 200 ps. That means a BW for a 'scope with Gaussian behavior of at least 1750 MHz, about 1400 MHz with many digital 'scopes.
So, using a 1 GHz BW digital 'scope won't crack it: The edge may look fine on it but probably will have serious overshoot, which you won't see on your (too slow) 'scope.
In practice, I'd consider 2.5 - 3 GHz to be the minimum BW required, taking into account that actual rise/fall time of most units is about 700 ps.

Raymond






Re: AM503 latch

Jaap Rusticus
 

Hello David, I have a pull tab for you, Just send me a picture of what you need and your address by PM and I can send it to you.
Jaap from Netherlands


Re: I give up.

Colin Herbert
 

"Which" was a magazine produced by the Consumers' Association. It appears that the CA, which is a charity, sits at the top of the Which? Group.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Tom Gardner
Sent: 07 December 2020 17:15
To: TekScopes@groups.io
Subject: Re: [TekScopes] I give up.

Regrettably it isn't that simple; the banking and e-money laws are a mess and
almost all people have zero chance of understanding them and their ramifications.

Today's report is...

Some PayPal customers have found it difficult to get reimbursed when they’ve run
into problems – particularly victims of fraud.
...
Here, we look at how PayPal is failing to protect and reimburse victims of
fraud, and what it can do about it.
...

https://www.which.co.uk/news/2020/12/how-paypal-fails-fraud-victims/
(Which? used to be far more sensibly named "Consumer Association". It is
generally respected in the UK)


On 07/12/20 14:19, cheater cheater wrote:
Yeah no, asking me if I can deny "major data thefts" happen "almost daily"
and then transferring that to whether you'll lose money on PayPal is just
high level crackpottery, and if you think this is a valid way of looking at
the world, then you should have a long hard look in the mirror. It doesn't
matter how long you've been "doing computers", obviously you're not in any
way capable of talking about computer security. Some sort of nebulous
"potential problems" with nebulous "companies involved in e-commerce" are
just paranoid thoughts, you can't even answer such a question with a yes or
no, you've constructed it to give yourself worry.

On Fri, Dec 4, 2020 at 6:16 PM - <rrrr6789@gmail.com> wrote:

Maybe you haven't been reading the messages but Dennis has already been
paid and that's all taken care of. But I have to admit that I hadn't
considered a wire transfer INTO PayPal. I've never heard of that being done
and there's nothing about it on their website and I don't even know if it's
possible. I don't think that it is but perhaps.

I was talking about the potential problems of PayPal and other
companies involved in E-commerce. And you can't deny that those are real.
All you have to do is to read any newspaper or watch any TV news to know
that major data thefts are happening almost daily. And your 20 years is
nothing, that was when Windows 98 was still new. I beta tested Windows
1.1! I started programming in 1969 in APL on an IBM 1130 and had been
tinkering with computer hardware for two years before that. I was the
person that installed *the* first computers for the Gallup poll in New
Jersey (another IBM 1130 with added core memory) , Virginia Military
Institute and Washington and Lee university and a host of others back in
the mid-1970s.


Re: I give up.

Tom Gardner
 

Regrettably it isn't that simple; the banking and e-money laws are a mess and almost all people have zero chance of understanding them and their ramifications.

Today's report is...

Some PayPal customers have found it difficult to get reimbursed when they’ve run into problems – particularly victims of fraud.
...
Here, we look at how PayPal is failing to protect and reimburse victims of fraud, and what it can do about it.
...

https://www.which.co.uk/news/2020/12/how-paypal-fails-fraud-victims/
(Which? used to be far more sensibly named "Consumer Association". It is generally respected in the UK)

On 07/12/20 14:19, cheater cheater wrote:
Yeah no, asking me if I can deny "major data thefts" happen "almost daily"
and then transferring that to whether you'll lose money on PayPal is just
high level crackpottery, and if you think this is a valid way of looking at
the world, then you should have a long hard look in the mirror. It doesn't
matter how long you've been "doing computers", obviously you're not in any
way capable of talking about computer security. Some sort of nebulous
"potential problems" with nebulous "companies involved in e-commerce" are
just paranoid thoughts, you can't even answer such a question with a yes or
no, you've constructed it to give yourself worry.

On Fri, Dec 4, 2020 at 6:16 PM - <rrrr6789@gmail.com> wrote:

Maybe you haven't been reading the messages but Dennis has already been
paid and that's all taken care of. But I have to admit that I hadn't
considered a wire transfer INTO PayPal. I've never heard of that being done
and there's nothing about it on their website and I don't even know if it's
possible. I don't think that it is but perhaps.

I was talking about the potential problems of PayPal and other
companies involved in E-commerce. And you can't deny that those are real.
All you have to do is to read any newspaper or watch any TV news to know
that major data thefts are happening almost daily. And your 20 years is
nothing, that was when Windows 98 was still new. I beta tested Windows
1.1! I started programming in 1969 in APL on an IBM 1130 and had been
tinkering with computer hardware for two years before that. I was the
person that installed *the* first computers for the Gallup poll in New
Jersey (another IBM 1130 with added core memory) , Virginia Military
Institute and Washington and Lee university and a host of others back in
the mid-1970s.


Re: SUCCESS! The "sick" 475A is now the "fixed" 475A!

Jim Ford
 

I'd be wary of problems that go away by themselves.  They often come back by themselves as well.  Just an FYI.    Jim Ford Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Jeff Dutky <jeff.dutky@gmail.com> Date: 12/6/20 10:36 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] SUCCESS! The "sick" 475A is now the "fixed" 475A! Dave,That's quite similar to my experience with the first fault on the 475A: I had bad voltage on the +110 V rail, so I started testing components in the circuit for that rail. I found what seemed to be a shorted ceramic disc capacitor, so I unsoldered it to be certain. When I tested it out of circuit it tested fine, so I soldered it back in place. Just for giggles I powered it back on and the +110 V rail was fixed!Sometimes just taking something apart and putting it (carefully) back together does the trick. It doesn't always work, and it feels like it shouldn't, but it can.It does feel good to get something like this fixed up. Part of it is, I think, that these are such well crafted objects that it feels good to make them whole, but there's also a fair amount of pride in skill and determination.Congrats, and wishes for further success!-- Jeff Dutky


Re: Calibrating a PG506 w/o Sampling System

 

On Mon, Dec 7, 2020 at 05:17 PM, Jean-Paul wrote:


From transient CAL of 2467B, I can say its a tricky and iterative process, and
the correct gens and fixtures are essential.

You may get by with a 1 GHz digital scope but not the Chinese, HP, TEK or
Lecroy.
First of all: Unless the edge settings have been changed, it's probably not necessary to adjust them because your work hasn't influenced them. I certainly wouldn't touch them without the right equipment.
OTOH, the transient response calibration of a PG506 is a very simple adjustment, *if* you have the right equipment and perform the procedure correctly: One capacitor for the positive edge (C1000) and one for the negative edge (C940); optimize overshoot for both. That's it. Capacitor refs. are for SM "Late Model": S/N B040000 up.
However, since you're adjusting a rise/fall time <= 1 ns (that's spec, in practice usually 700 ps or better), your 'scope (as a rule of thumb) needs to have a rise time of at most 20% of that: 200 ps. That means a BW for a 'scope with Gaussian behavior of at least 1750 MHz, about 1400 MHz with many digital 'scopes.
So, using a 1 GHz BW digital 'scope won't crack it: The edge may look fine on it but probably will have serious overshoot, which you won't see on your (too slow) 'scope.
In practice, I'd consider 2.5 - 3 GHz to be the minimum BW required, taking into account that actual rise/fall time of most units is about 700 ps.

Raymond


Re: Can capacitors

n4buq
 

Hi David,

I haven't been to that mall yet, but I keep meaning to just to see what the P.R. Mallory Factory Outlet store might have in it. I can just imagine the rows and rows of can capacitors there - all on sale!

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "David Kuhn" <Daveyk021@gmail.com>
To: TekScopes@groups.io
Sent: Monday, December 7, 2020 10:41:25 AM
Subject: Re: [TekScopes] Can capacitors

" They demolished the building a few years ago and there's a
shopping/eating mall there now."

And Barry, that mall isn't lasting as long as the capacitor MFG did - lol.

On Sat, Dec 5, 2020 at 11:28 AM n4buq <n4buq@knology.net> wrote:

Mallory Capacitor Company had a manufacturing facility here in Huntsville,
Alabama. I don't know the exact dates of operation, but it was an active
facility through the 1960s and probably well into or past the 1970s. The
building was on the main drag and I must've passed it thousands of times.
I always wondered what it looked like on the inside. The mother of one of
my friends who lived across the street from me when I was very young worked
there but I don't know what she did. They demolished the building a few
years ago and there's a shopping/eating mall there now.

Good times...

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "ken chalfant" <kpchalfant@msn.com>
To: HP-Agilent-Keysight-equipment@groups.io, TekScopes@groups.io
Sent: Saturday, December 5, 2020 2:17:12 AM
Subject: [TekScopes] Can capacitors

Greetings,

From time to time I see that someone is working to repair or restore an
instrument with the old multi capacitor metal can components and that
appears to be a never ending struggle.

The other night I reconnected with an old friend with whom I had not
spoken
in a couple of years.

He has always had an interest in restoring old audio equipment. As we
visited he mentioned a company that still builds Mallory style metal can
capacitors. My friend said they even use the old, original equipment.

I was very surprised and actually found that a little hard to believe,
but it
turns out to be true.

While I do not know about configurations, minimum quantities or pricing
it
appears this company makes those old style metal can multi-unit
capacitors.

www.cemfg.com <http://www.cemfg.com/>

I have no financial interest - or really - any other interest in this -
just
hoping it helps some of our group.

Regards,

Ken

















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