Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
Hi Ron,
I wonder if we may know each other. I knew a Ron who would be about your age who ran an engineering organization in Cedar Rapids. At the time, I was a brash young engineering group manager in a different organization who thought he knew it all. Life has a way of humbling one.
Now I live in Southern California and fix up Tak scopes for fun and occasionally resell them. Still working, but probably not too much longer.
Regards,
Jeff
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You may address me as Ron, or Mac (for machineguy). I usually use Mac on the net and Ron in the "real world". >As a brief introduction, I am 78 years old, retired electronics engineer, now hobbyist, living in Iowa, USA.
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Sorry Raymond, again I missed you message of a few minutes ago!
BTW I sold my one and only 465 some time ago, so I can't help with doing measurements.
Albert
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On Mon, Jun 18, 2018 at 05:06 am, lop pol wrote:
Seeing that are both channels are essentially the same just seems weird to me.
The vertical output Amp and some other parts, like parts of the channel switch, are common. Raymond
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Re: Self Governance of TekScopes.
In the end, it is the moderator's responsibility to determine how he or she wished to have the list moderated. I this case, Dennis has laid out how he wishes the list to be moderated.
DaveD
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On 6/18/2018 5:52 AM, JJ wrote: I would think that it's the moderator's responsibility and no one else
(elders or otherwise) to filter the various threads. There are certain
topics that are completely off topic like politics and should be cutoff.
But, there are others that are technical and very informative which are
gleaned from years of experience that allow us to pick up information that
is very helpful. I welcome those. So, you need to have a jeweler's eye!
John Justin
On Mon, Jun 18, 2018 at 1:17 AM, Jeff Urban <JURB6006@...> wrote:
Bit odd you bring this up now when I just got through posting in a thread
about 2 sided boards, and that went into some other things. My experience,
someone else about car radios using the same manufacturing methods and all,
one with their own stereo unit the fixed by fixing a 2 sided board.
Now there's some thread drift forya, but it is still pertinent to the
subject. Of course WW2 is not. I have a group and I was thinking what I
would do. I would probably get in there and say "this one can slide, but
anymore of this political shit and we are talking action, I do not want it
here". And that it makes enemies easier than it makes friends.
But now there is the Fluke 3300 thread. That is not a Tek scope. I have
no problem with it, I think maybe they could have been spurred on to my
group but there are not enough members now to be sure to get anything good
back. If that is close enough to on topic fine. Good that you don't want to
stifle.
I think the thing here is that in moderating these, you can't just grind a
line into concrete. That's why we have human moderators. (and judges and
whatever)
You could send some to my group, which I made specifically for other test
equipment. But I don't want anyone forced. I don't want to force anyone to
do anything. Not the WW2 thing though.
Put it this way, I may respond in threads that go political, but I will
never start one. I have more respect than that.
|
On Mon, Jun 18, 2018 at 04:41 am, Raymond Domp Frank wrote:
On Mon, Jun 18, 2018 at 04:23 am, lop pol wrote:
I will start turning screws. I just wanted to get opinions on whether this
could possibly be a problem with a bad component prior to messing with the
calibration.
Before you start turning screws:
1. It is not uncommon for the variable caps to become open. I've had that
happen to some in the vertical (output) amplifier. I've seen both the rotor
not moving *and* the connection to the stator opening up. When screwing, check
those first by watching their influence.
2. Look at the flatness of the square wave at lower frequencies (1 kHz, 10 kHz
and up). I've seen an increase of the impedance in the differential circuits
out of the delay line causing huge distortions, not just slow edges, by
high-drifting low-value R's.
Now that I've become involved, I have to ask a stupid(?) question: You *are*
using the right i.e. fast edges of the PG506, are you? The left-hand BNC has a
fast *fall* time, the middle BNC has a fast *rise* time.
Raymond
Yes I'm using the correct output. The rise time reminded me of my 7a26 that had bad var capacitors, but that only affected one channel. Seeing that are both channels are essentially the same just seems weird to me.
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You have the proper fast rise generator to perform an adjustment. The risk in my opinion is that you destroy a stuck trimcap or trimpot.
You might first verify DC levels in the output amplifier stages and perhaps symmetry in the push-pull signals. Often some stages are common-base current driven which makes it more difficult to check signals.
Unlike some other manuals the 465 manuals do not tell which part of the curve is affected by each adjustment.
Which version output amplifier is in your 465, discrete or IC? It seems you use the pre-B250000 manual because of what you said about the 10X magnifier. The B250000-up manual clearly mentions the 10X mag. That manual also shows both versions output amplifier.
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Show quoted text
On Mon, Jun 18, 2018 at 04:23 am, lop pol wrote:
On Mon, Jun 18, 2018 at 12:34 am, Albert Otten wrote:
With curves like this
/g/TekScopes/photo/59361/1?p=Name,,,20,1,0,0 I wouldn't
even bother to calculate a rise time. Obviously the main problem is roll-off. I
would search the manual for Adjustments which influence that nanoseconds
part of the curve and try these first.
Ok. I will start turning screws. I just wanted to get opinions on whether this
could possibly be a problem with a bad component prior to messing with the
calibration. I would hate to have a bad transistor or capacitor causing the
bad rise time and start turning the adjustments and mess up something that was
actually already set correctly.
|
Re: Self Governance of TekScopes.
I would think that it's the moderator's responsibility and no one else
(elders or otherwise) to filter the various threads. There are certain
topics that are completely off topic like politics and should be cutoff.
But, there are others that are technical and very informative which are
gleaned from years of experience that allow us to pick up information that
is very helpful. I welcome those. So, you need to have a jeweler's eye!
John Justin
toggle quoted message
Show quoted text
On Mon, Jun 18, 2018 at 1:17 AM, Jeff Urban <JURB6006@...> wrote: Bit odd you bring this up now when I just got through posting in a thread
about 2 sided boards, and that went into some other things. My experience,
someone else about car radios using the same manufacturing methods and all,
one with their own stereo unit the fixed by fixing a 2 sided board.
Now there's some thread drift forya, but it is still pertinent to the
subject. Of course WW2 is not. I have a group and I was thinking what I
would do. I would probably get in there and say "this one can slide, but
anymore of this political shit and we are talking action, I do not want it
here". And that it makes enemies easier than it makes friends.
But now there is the Fluke 3300 thread. That is not a Tek scope. I have
no problem with it, I think maybe they could have been spurred on to my
group but there are not enough members now to be sure to get anything good
back. If that is close enough to on topic fine. Good that you don't want to
stifle.
I think the thing here is that in moderating these, you can't just grind a
line into concrete. That's why we have human moderators. (and judges and
whatever)
You could send some to my group, which I made specifically for other test
equipment. But I don't want anyone forced. I don't want to force anyone to
do anything. Not the WW2 thing though.
Put it this way, I may respond in threads that go political, but I will
never start one. I have more respect than that.
|
On Mon, Jun 18, 2018 at 04:23 am, lop pol wrote:
I will start turning screws. I just wanted to get opinions on whether this
could possibly be a problem with a bad component prior to messing with the
calibration.
Before you start turning screws: 1. It is not uncommon for the variable caps to become open. I've had that happen to some in the vertical (output) amplifier. I've seen both the rotor not moving *and* the connection to the stator opening up. When screwing, check those first by watching their influence. 2. Look at the flatness of the square wave at lower frequencies (1 kHz, 10 kHz and up). I've seen an increase of the impedance in the differential circuits out of the delay line causing huge distortions, not just slow edges, by high-drifting low-value R's. Now that I've become involved, I have to ask a stupid(?) question: You *are* using the right i.e. fast edges of the PG506, are you? The left-hand BNC has a fast *fall* time, the middle BNC has a fast *rise* time. Raymond
|
Is the bandwidth limit turned on ( maybe a fault with the switching? )
The BW limit switch is off. Turning it on increases the rise time and smoothed the trace like I would expect. Do you have any other scope with a higher bandwidth available? Some way to
verify the setup. Yes but i checked the setup with my 468 (100 mhz) and the rise time was the correct 3.5ns On Mon, Jun 18, 2018 at 12:34 am, Albert Otten wrote:
With curves like this
/g/TekScopes/photo/59361/1?p=Name,,,20,1,0,0 I wouldn't even
bother to calculate a rise time. Obviously the main problem is roll-off. I
would search the manual for Adjustments which influence that nanoseconds part
of the curve and try these first.
Ok. I will start turning screws. I just wanted to get opinions on whether this could possibly be a problem with a bad component prior to messing with the calibration. I would hate to have a bad transistor or capacitor causing the bad rise time and start turning the adjustments and mess up something that was actually already set correctly. So BW = 0.35/risetime in seconds or 0.35/0.000000006 = ~~60 MHz.
The 465 should go around 100 MHz bandwidth. Around 3.5 ns.
.
----- Original Message -----
From: "lop pol via Groups.Io" <the_infinite_penguin@...>
To: <[email protected]>
Sent: Monday, June 18, 2018 12:22 AM
Subject: Re: [TekScopes] 465 bad rise time
Time div is set to .05us but I have 10x mag on so that should be 5ns.
On Sun, Jun 17, 2018 at 09:10 pm, tmillermdems wrote:
Ok, it looked like a probe at first. What is the H sweep rate set to?
Can't
see it in the pictures.
Looks like 1 1/4 divisions on the horizontal 10-90% points.
Regards
----- Original Message -----
From: "lop pol via Groups.Io" <the_infinite_penguin@...>
To: <[email protected]>
Sent: Monday, June 18, 2018 12:02 AM
Subject: Re: [TekScopes] 465 bad rise time
Im using a 50ohm cable with a 50ohm through terminator.
/g/TekScopes/photo/59361/2?p=Name,,,20,1,0,0
On Sun, Jun 17, 2018 at 08:50 pm, tmillermdems wrote:
You are looking at the waveform with a scope probe that presents a 10
meg
ohm load to the pulse generator. What you need to do is use a 50 ohm
cable
to go from the generator to the scope input and include a 50 ohm through
termination right at the scope. A real simple solution would be to use a
BNC
T with the center loaded with a 49.9 ohm resistor. Or just look for a 50
ohm
through termination on ebay.
Regards
----- Original Message -----
From: "lop pol via Groups.Io" <the_infinite_penguin@...>
To: <[email protected]>
Sent: Sunday, June 17, 2018 9:47 PM
Subject: [TekScopes] 465 bad rise time
Hey guys. I have done a lot of work to this 465. I had initially planned
on
selling it to help me buy some plugins for my 7633. I decided I don't
want
to sell it and am keeping it. Today I checked its rise time with a pg506
fast rise. Both channel 1 and 2 closely resemble each other and they are
not
close to right. Before I start trying to calibrate this thing, does it
look
like there is some type of component issue left to fix? I am thinking
since
both channels are so alike there is something wrong besides just out of
calibration. Thanks guys.
here are some pictures
/g/TekScopes/photo/59361/0?p=Name,,,20,1,0,0
/g/TekScopes/photo/59361/1?p=Name,,,20,1,0,0
|
With curves like this /g/TekScopes/photo/59361/1?p=Name,,,20,1,0,0 I wouldn't even bother to calculate a rise time. Obviously the main problem is roll-off. I would search the manual for Adjustments which influence that nanoseconds part of the curve and try these first.
On Sun, Jun 17, 2018 at 09:59 pm, tmillermdems wrote:
So BW = 0.35/risetime in seconds or 0.35/0.000000006 = ~~60 MHz.
The 465 should go around 100 MHz bandwidth. Around 3.5 ns.
Is the bandwidth limit turned on ( maybe a fault with the switching? ).
Do you have any other scope with a higher bandwidth available? Some way to
verify the setup.
----- Original Message -----
From: "lop pol via Groups.Io" <the_infinite_penguin@...>
To: <[email protected]>
Sent: Monday, June 18, 2018 12:22 AM
Subject: Re: [TekScopes] 465 bad rise time
Time div is set to .05us but I have 10x mag on so that should be 5ns.
On Sun, Jun 17, 2018 at 09:10 pm, tmillermdems wrote:
Ok, it looked like a probe at first. What is the H sweep rate set to?
Can't
see it in the pictures.
Looks like 1 1/4 divisions on the horizontal 10-90% points.
Regards
----- Original Message -----
From: "lop pol via Groups.Io" <the_infinite_penguin@...>
To: <[email protected]>
Sent: Monday, June 18, 2018 12:02 AM
Subject: Re: [TekScopes] 465 bad rise time
Im using a 50ohm cable with a 50ohm through terminator.
/g/TekScopes/photo/59361/2?p=Name,,,20,1,0,0
On Sun, Jun 17, 2018 at 08:50 pm, tmillermdems wrote:
You are looking at the waveform with a scope probe that presents a 10
meg
ohm load to the pulse generator. What you need to do is use a 50 ohm
cable
to go from the generator to the scope input and include a 50 ohm through
termination right at the scope. A real simple solution would be to use a
BNC
T with the center loaded with a 49.9 ohm resistor. Or just look for a 50
ohm
through termination on ebay.
Regards
----- Original Message -----
From: "lop pol via Groups.Io" <the_infinite_penguin@...>
To: <[email protected]>
Sent: Sunday, June 17, 2018 9:47 PM
Subject: [TekScopes] 465 bad rise time
Hey guys. I have done a lot of work to this 465. I had initially planned
on
selling it to help me buy some plugins for my 7633. I decided I don't
want
to sell it and am keeping it. Today I checked its rise time with a pg506
fast rise. Both channel 1 and 2 closely resemble each other and they are
not
close to right. Before I start trying to calibrate this thing, does it
look
like there is some type of component issue left to fix? I am thinking
since
both channels are so alike there is something wrong besides just out of
calibration. Thanks guys.
here are some pictures
/g/TekScopes/photo/59361/0?p=Name,,,20,1,0,0
/g/TekScopes/photo/59361/1?p=Name,,,20,1,0,0
|
Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
Hey Ron
Nice to get to know you! Thanks for telling us your story.
I understand your dilemma with your wife - we all empathize, even if we won't admit it as candidly as you did ;-)
I had no intention to deprecate, even if if it came across that way, and if I offended you, please accept my apology.
My purpose here is to build an iron-clad 2465 BoM, which will offer ALL users (experienced or not) an optimal long-lasting solution which will not require subsequent intervention under the cover again in our lifetimes.
In short, bringing together ALL our combined knowledge to provide an expert community solution.
I would not be writing all this, if it was not for all your help, because 9 years ago, when I started out on this journey and overhauled my own 2465B, I had no idea where to start, or which parts to select. All I knew was audio and linear PSU's. Only by asking these questions on this forum, was I able to get the info I needed, to do this once-only-required overhaul.
Today, SMPS overhaul (especially in TV's) is a substantial part of my workload, and I have built up my knowledge base substantially, regarding which component types are suited best in which areas of the circuit. I normally go through a few hundred capacitors every month, in these repairs.
So, I bring that acquired knowledge back to the forum, as a form of gratitude.
9 years later, the 2465B is still operating flawlessly, except for 2 problems (unrelated to the overhaul) - U700 failure, and a diode failure.
Solved quickly and painlessly, with the help of the generous people here.
I expect to pass all my lab equipment onto my middle son, aged 17, who is the only one of my 4 children who shows any serious interest in my work. With the maintenance I do on my equipment, I expect it to last 30 years for him as well.
Regarding suppliers, when approaching a project like this, I have learnt to not skimp, and if I have to source the optimal BoM from more than one supplier, then the small additional shipping cost (from the 2nd supplier) is peanuts, when figuring in the 20-30-year lifetime of a job done perfectly, not requiring any redo's in the future.
I use both Mouser and Digikey, but for the 2465 kits, Mouser offers me the parts I want, and also cheaper than Digikey by a few $ for this particular selection. So that extra $1 which you may pay Mouser for shipping, you'll probably save on individual parts costs.
Ancel,
I have used Nichicon PJ in the past as well - I have no aversion to them at all - and I normally use Nichicon PW (a tighter-tolerance brother of PJ) as my #1 choice.
That preference was based entirely on the datasheet specs, I did no comparison testing at all.
Menahem
|
Re: Self Governance of TekScopes.
Bit odd you bring this up now when I just got through posting in a thread about 2 sided boards, and that went into some other things. My experience, someone else about car radios using the same manufacturing methods and all, one with their own stereo unit the fixed by fixing a 2 sided board.
Now there's some thread drift forya, but it is still pertinent to the subject. Of course WW2 is not. I have a group and I was thinking what I would do. I would probably get in there and say "this one can slide, but anymore of this political shit and we are talking action, I do not want it here". And that it makes enemies easier than it makes friends.
But now there is the Fluke 3300 thread. That is not a Tek scope. I have no problem with it, I think maybe they could have been spurred on to my group but there are not enough members now to be sure to get anything good back. If that is close enough to on topic fine. Good that you don't want to stifle.
I think the thing here is that in moderating these, you can't just grind a line into concrete. That's why we have human moderators. (and judges and whatever)
You could send some to my group, which I made specifically for other test equipment. But I don't want anyone forced. I don't want to force anyone to do anything. Not the WW2 thing though.
Put it this way, I may respond in threads that go political, but I will never start one. I have more respect than that.
|
So BW = 0.35/risetime in seconds or 0.35/0.000000006 = ~~60 MHz.
The 465 should go around 100 MHz bandwidth. Around 3.5 ns.
Is the bandwidth limit turned on ( maybe a fault with the switching? ).
Do you have any other scope with a higher bandwidth available? Some way to verify the setup.
toggle quoted message
Show quoted text
----- Original Message ----- From: "lop pol via Groups.Io" <the_infinite_penguin@...> To: < [email protected]> Sent: Monday, June 18, 2018 12:22 AM Subject: Re: [TekScopes] 465 bad rise time Time div is set to .05us but I have 10x mag on so that should be 5ns. On Sun, Jun 17, 2018 at 09:10 pm, tmillermdems wrote:
Ok, it looked like a probe at first. What is the H sweep rate set to? Can't
see it in the pictures.
Looks like 1 1/4 divisions on the horizontal 10-90% points.
Regards
----- Original Message -----
From: "lop pol via Groups.Io" <the_infinite_penguin@...>
To: <[email protected]>
Sent: Monday, June 18, 2018 12:02 AM
Subject: Re: [TekScopes] 465 bad rise time
Im using a 50ohm cable with a 50ohm through terminator.
/g/TekScopes/photo/59361/2?p=Name,,,20,1,0,0
On Sun, Jun 17, 2018 at 08:50 pm, tmillermdems wrote:
You are looking at the waveform with a scope probe that presents a 10 meg
ohm load to the pulse generator. What you need to do is use a 50 ohm cable
to go from the generator to the scope input and include a 50 ohm through
termination right at the scope. A real simple solution would be to use a
BNC
T with the center loaded with a 49.9 ohm resistor. Or just look for a 50
ohm
through termination on ebay.
Regards
----- Original Message -----
From: "lop pol via Groups.Io" <the_infinite_penguin@...>
To: <[email protected]>
Sent: Sunday, June 17, 2018 9:47 PM
Subject: [TekScopes] 465 bad rise time
Hey guys. I have done a lot of work to this 465. I had initially planned
on
selling it to help me buy some plugins for my 7633. I decided I don't want
to sell it and am keeping it. Today I checked its rise time with a pg506
fast rise. Both channel 1 and 2 closely resemble each other and they are
not
close to right. Before I start trying to calibrate this thing, does it
look
like there is some type of component issue left to fix? I am thinking
since
both channels are so alike there is something wrong besides just out of
calibration. Thanks guys.
here are some pictures
/g/TekScopes/photo/59361/0?p=Name,,,20,1,0,0
/g/TekScopes/photo/59361/1?p=Name,,,20,1,0,0
|
Re: Repairing plated through holes.
On Sat, Jun 16, 2018 at 05:04 pm, lop pol wrote:
I "pinned" my dolby board on my sansui 8080db using 24 gauge copper wire that
I tinned and put through all the holes.
You got a 9090DB ? Wow, well I guess you don't have to save money for a rainy day, those t hings go for some bucks. And for good reason. I may have been mistaken about the Marantz, I specifically remember it in a discussion and them mentioning the 9090DB. Think that was bad ? There was a VCR manufacturer that used a 2 sided board, but also printed resistors. And THEN they let the soldermask and silkscreening get into the holes after the components were there. I euthenised quite few of those worthless... nevermind But you talk Sansui with one of their top of the line products or close, they do it to save space. Everything impedes air, air is crucial when you can run a washing machine off the speaker wires. But those cheap VCRS, with their failure rate and all that, they were junk. Something like that Sansui needs to be pinned at what ? Maybe 35 years old ? There are other factors. Like in RPTVs, coolant. Let me tell you about 70 % ethylene glycol and 30 % glycerin - it is an excellent electrical insulator. When it is new. Now put about 300 mV per maybe 3 mm of it for about 14 months. It starts becoming conductive, and is then becomes corrosive. It turns the copper black as sure as capacitor shit, which is the other thing I have seen destroy boards, and of course it is worse on multilayer boards. And it soaks into the elcheapo PC board material, not FR-4 to say the least, and then if ever can solder on it again you have these bubbles that don't go away until you put a burn mark in the board. I have scraped pretty big sections away over this and rebuilt it with hand wiring. Hey, the money was good, what can I say ? And urine ? Cat or dog piss ? Even worse if you can believe it. At one time I thought that the mere presence of vias was a death knell but that is way worse. You can pin anything if you can't solder to it because the copper is black or green. In the 9090DB, they probably went because of thermal expansion. And I really am amazed that this is actually related to Tek scopes. But it is.
|
Time div is set to .05us but I have 10x mag on so that should be 5ns.
toggle quoted message
Show quoted text
On Sun, Jun 17, 2018 at 09:10 pm, tmillermdems wrote:
Ok, it looked like a probe at first. What is the H sweep rate set to? Can't
see it in the pictures.
Looks like 1 1/4 divisions on the horizontal 10-90% points.
Regards
----- Original Message -----
From: "lop pol via Groups.Io" <the_infinite_penguin@...>
To: <[email protected]>
Sent: Monday, June 18, 2018 12:02 AM
Subject: Re: [TekScopes] 465 bad rise time
Im using a 50ohm cable with a 50ohm through terminator.
/g/TekScopes/photo/59361/2?p=Name,,,20,1,0,0
On Sun, Jun 17, 2018 at 08:50 pm, tmillermdems wrote:
You are looking at the waveform with a scope probe that presents a 10 meg
ohm load to the pulse generator. What you need to do is use a 50 ohm cable
to go from the generator to the scope input and include a 50 ohm through
termination right at the scope. A real simple solution would be to use a
BNC
T with the center loaded with a 49.9 ohm resistor. Or just look for a 50
ohm
through termination on ebay.
Regards
----- Original Message -----
From: "lop pol via Groups.Io" <the_infinite_penguin@...>
To: <[email protected]>
Sent: Sunday, June 17, 2018 9:47 PM
Subject: [TekScopes] 465 bad rise time
Hey guys. I have done a lot of work to this 465. I had initially planned
on
selling it to help me buy some plugins for my 7633. I decided I don't want
to sell it and am keeping it. Today I checked its rise time with a pg506
fast rise. Both channel 1 and 2 closely resemble each other and they are
not
close to right. Before I start trying to calibrate this thing, does it
look
like there is some type of component issue left to fix? I am thinking
since
both channels are so alike there is something wrong besides just out of
calibration. Thanks guys.
here are some pictures
/g/TekScopes/photo/59361/0?p=Name,,,20,1,0,0
/g/TekScopes/photo/59361/1?p=Name,,,20,1,0,0
|
Ok, it looked like a probe at first. What is the H sweep rate set to? Can't see it in the pictures.
Looks like 1 1/4 divisions on the horizontal 10-90% points.
Regards
toggle quoted message
Show quoted text
----- Original Message ----- From: "lop pol via Groups.Io" <the_infinite_penguin@...> To: < [email protected]> Sent: Monday, June 18, 2018 12:02 AM Subject: Re: [TekScopes] 465 bad rise time Im using a 50ohm cable with a 50ohm through terminator. /g/TekScopes/photo/59361/2?p=Name,,,20,1,0,0 On Sun, Jun 17, 2018 at 08:50 pm, tmillermdems wrote:
You are looking at the waveform with a scope probe that presents a 10 meg
ohm load to the pulse generator. What you need to do is use a 50 ohm cable
to go from the generator to the scope input and include a 50 ohm through
termination right at the scope. A real simple solution would be to use a BNC
T with the center loaded with a 49.9 ohm resistor. Or just look for a 50 ohm
through termination on ebay.
Regards
----- Original Message -----
From: "lop pol via Groups.Io" <the_infinite_penguin@...>
To: <[email protected]>
Sent: Sunday, June 17, 2018 9:47 PM
Subject: [TekScopes] 465 bad rise time
Hey guys. I have done a lot of work to this 465. I had initially planned on
selling it to help me buy some plugins for my 7633. I decided I don't want
to sell it and am keeping it. Today I checked its rise time with a pg506
fast rise. Both channel 1 and 2 closely resemble each other and they are not
close to right. Before I start trying to calibrate this thing, does it look
like there is some type of component issue left to fix? I am thinking since
both channels are so alike there is something wrong besides just out of
calibration. Thanks guys.
here are some pictures
/g/TekScopes/photo/59361/0?p=Name,,,20,1,0,0
/g/TekScopes/photo/59361/1?p=Name,,,20,1,0,0
|
toggle quoted message
Show quoted text
On Sun, Jun 17, 2018 at 08:50 pm, tmillermdems wrote:
You are looking at the waveform with a scope probe that presents a 10 meg
ohm load to the pulse generator. What you need to do is use a 50 ohm cable
to go from the generator to the scope input and include a 50 ohm through
termination right at the scope. A real simple solution would be to use a BNC
T with the center loaded with a 49.9 ohm resistor. Or just look for a 50 ohm
through termination on ebay.
Regards
----- Original Message -----
From: "lop pol via Groups.Io" <the_infinite_penguin@...>
To: <[email protected]>
Sent: Sunday, June 17, 2018 9:47 PM
Subject: [TekScopes] 465 bad rise time
Hey guys. I have done a lot of work to this 465. I had initially planned on
selling it to help me buy some plugins for my 7633. I decided I don't want
to sell it and am keeping it. Today I checked its rise time with a pg506
fast rise. Both channel 1 and 2 closely resemble each other and they are not
close to right. Before I start trying to calibrate this thing, does it look
like there is some type of component issue left to fix? I am thinking since
both channels are so alike there is something wrong besides just out of
calibration. Thanks guys.
here are some pictures
/g/TekScopes/photo/59361/0?p=Name,,,20,1,0,0
/g/TekScopes/photo/59361/1?p=Name,,,20,1,0,0
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Clutter ? You gotta see this place. We moved out of 3 houses. Anyway, I got a couple pictures uploaded here you could look at. It's on AC so I didn't have all day, and my camera batteries are lunch to that thing, something I am going to do something about unless I get hit by a bus of some shit. So all I got are 2 pics, but they are alright. I can't seem to get this camera in the right color mode so I have to use software to get it to look right. But it's no big deal. I kinda like doing it and really, anyone out there who has pictures of poor quality, I will fix them. I got some decent software and know how to use it. If you have alot of them I want some beer or something, but one or two I'll just do. Almost for the fun of it but also for practice and get even more used to the software. It's old and I'll need to always have an older PC to rune it but I ain't giving it up. Not because Bill and Melinda want to feed every kid in Africa and vaccinate them while our vets die in the street out of poverty. I run XP. I will always run XP. (unless I could make 98SE work) If I can't get online with it I'll have something that does, but for everything else old Betsy here is great. Tell me to shut up once in a while OK ? Here are the pics : /g/TekScopes/photo/59366/0?p=Name,,,20,1,0,0 That is channel one on noise and two on the calibrate, it is in free run. Note the 3 meter P-6105 ! /g/TekScopes/photo/59366/1?p=Name,,,20,1,0,0 That is the collector of Q 1714, one of the choppers. the probe is not calibrated to that scope so it is not all that accurate, but I guess you can do it and I didn't even hook up the ground. I thought you could, but never actually tried it. I might leave it up and play around a bit. Waveforms in the horizontal, they are not likely to display well. But what about in chop or alternate, the vertical CRT plates ? that sounds i interesting. I very much doubt this could hurt the scope. It is not like plugging the speaker out to an input on an amp, unless you try to scope channel 1 with channel 1. Anyway, it depends on what comes up. I got a wiring job to do soon and I think I need at least a good box for this. I will never abandon it, but like frozen peas, it goes on the back burner. (that just popped up in my head as a sort of analogy) But it belongs there right now. Back burner. (actually I am out of ideas right now)
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You are looking at the waveform with a scope probe that presents a 10 meg ohm load to the pulse generator. What you need to do is use a 50 ohm cable to go from the generator to the scope input and include a 50 ohm through termination right at the scope. A real simple solution would be to use a BNC T with the center loaded with a 49.9 ohm resistor. Or just look for a 50 ohm through termination on ebay.
Regards
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----- Original Message ----- From: "lop pol via Groups.Io" <the_infinite_penguin@...> To: < [email protected]> Sent: Sunday, June 17, 2018 9:47 PM Subject: [TekScopes] 465 bad rise time Hey guys. I have done a lot of work to this 465. I had initially planned on selling it to help me buy some plugins for my 7633. I decided I don't want to sell it and am keeping it. Today I checked its rise time with a pg506 fast rise. Both channel 1 and 2 closely resemble each other and they are not close to right. Before I start trying to calibrate this thing, does it look like there is some type of component issue left to fix? I am thinking since both channels are so alike there is something wrong besides just out of calibration. Thanks guys. here are some pictures /g/TekScopes/photo/59361/0?p=Name,,,20,1,0,0 /g/TekScopes/photo/59361/1?p=Name,,,20,1,0,0
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Raymond Domp Frank
Jeff Urban