Re: 922 with "tilted" wave form.
On Mon, Apr 30, 2018 at 02:35 pm, Fabio Trevisan wrote:
Hello Mlynch,
What you describe looks like a "geometry" or Y-AXIS misadjustment.
If I understood correctly what's the equipment you have it's a T922
oscilloscope.
Looking at the Manual that is available on the TekWiki website (here:
), the adjustments are Y AXIS, R474 and
"GEOMETRY", R473, both are on the CRT & VERTICAL AMPLIFIER diagram, located on
the A1 INTERFACE BOARD.
Manual probably describes the correct procedure to adjust both of them, and
this is usually done in the very beginning of the calibration procedure,
meaning that most of the other calibrations are impacted to some extent by
these 2, as they change the shape of what's being shown on the screen.
Steps usually cover the following:
1. First of all, adjust the trace rotation (adjustment accessible from the
side of the scope), for a horizontal baseline (just sweep, no vertical
signal).
2. Then, using the X-Y mode, apply a signal to the Y channel enough to span
about 6 divisions height, leave the X-channel with no signal (set X input to
to GND). This will draw a vertical line on screen... Adjust now R474 so that
the vertical line, aligned to the central vertical graticule is perfectly
vertical.
3. Finally, change the scope back to normal mode, and apply a square wave to
one of the vertical channels, that is big enough to span 6 divisions
vertically, and set a sweep speed that you see about 20 cycles horizontally
accross the screen.
This setup will pretty much "fill" the screen with a square wave, from bottom
to top, left to right. Now you can adjust the geometry adjustment (R473) to
correct any "Pillow" or cushion distortions of the screen, so that the overall
shape of the displayed waveform is all "squared"...
4. The geometry adjustment, if it requires too big re-adjustment, will have
some side-effects to the Trace rotation and the Y-axis adjustment... Repeat
then Trace rotation and Y-Axis again, to make sure that the screen remains
aligned on the horizontal and vertical directions.
All that, above, assuming that - overall - the scope doesn't present other
misbehavior... However, the procedures above cannot assure you that everything
else is or will remain correct.
Since re-adjusting the Y axis and Geometry may have some impact on the size of
the waveforms displayed, by touching those adjustments, be aware that you may
need to readjust Vertical Gain and Horizontal gain... and this will require
that you have means to adjust those, or accept that they may become "off" by
some amount.
Rgrds,
Fabio
Fabio, FIXED! Followed your instructions and everything is exactly as it should be. The little scope performs well and has a beautiful bright trace. I am pleased with my $20 bargain. Even after buying the resistor array, I still only have $50 invested, The scope is worth twice that for parts. THANKS AGAIN!
|
Re: 922 with "tilted" wave form.
On Mon, Apr 30, 2018 at 06:46 pm, ykochcal wrote:
I would agree with the stuff below.
But would look closely at the screws around the CRT area, for ones that
don't have the right look, toand check to be sure you don't have a mini
magnet in the form of a screw that someone replaced that would be pulling
your picture.
John
John, Everything looks in order in that area. None of the screws look to be out of place on "non-Standard". But I will keep that in mind, since this may not be the last time I encounter this issue. I made the adjustments tonight and everything fell back into place. The Sine,Triangle and Square signals now reproduce. faithfully. Timing and amplitude measurements appear to be right on the money. Appreciate your advise.
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Fabio
Trevisan
Sent: Monday, April 30, 2018 2:36 PM
To: [email protected]
Subject: Re: [TekScopes] 922 with "tilted" wave form.
Hello Mlynch,
What you describe looks like a "geometry" or Y-AXIS misadjustment.
If I understood correctly what's the equipment you have it's a T922
oscilloscope.
Looking at the Manual that is available on the TekWiki website (here:
), the adjustments are Y AXIS, R474 and
"GEOMETRY", R473, both are on the CRT & VERTICAL AMPLIFIER diagram, located
on the A1 INTERFACE BOARD.
Manual probably describes the correct procedure to adjust both of them, and
this is usually done in the very beginning of the calibration procedure,
meaning that most of the other calibrations are impacted to some extent by
these 2, as they change the shape of what's being shown on the screen.
Steps usually cover the following:
1. First of all, adjust the trace rotation (adjustment accessible from the
side of the scope), for a horizontal baseline (just sweep, no vertical
signal).
2. Then, using the X-Y mode, apply a signal to the Y channel enough to span
about 6 divisions height, leave the X-channel with no signal (set X input to
to GND). This will draw a vertical line on screen... Adjust now R474 so that
the vertical line, aligned to the central vertical graticule is perfectly
vertical.
3. Finally, change the scope back to normal mode, and apply a square wave to
one of the vertical channels, that is big enough to span 6 divisions
vertically, and set a sweep speed that you see about 20 cycles horizontally
accross the screen.
This setup will pretty much "fill" the screen with a square wave, from
bottom to top, left to right. Now you can adjust the geometry adjustment
(R473) to correct any "Pillow" or cushion distortions of the screen, so that
the overall shape of the displayed waveform is all "squared"...
4. The geometry adjustment, if it requires too big re-adjustment, will have
some side-effects to the Trace rotation and the Y-axis adjustment... Repeat
then Trace rotation and Y-Axis again, to make sure that the screen remains
aligned on the horizontal and vertical directions.
All that, above, assuming that - overall - the scope doesn't present other
misbehavior... However, the procedures above cannot assure you that
everything else is or will remain correct.
Since re-adjusting the Y axis and Geometry may have some impact on the size
of the waveforms displayed, by touching those adjustments, be aware that you
may need to readjust Vertical Gain and Horizontal gain... and this will
require that you have means to adjust those, or accept that they may become
"off" by some amount.
Rgrds,
Fabio
|
To Jack, and the many others who have gently reminded me I need to recover the modest annual cost of hosting our data on 开云体育. Thank you. I think it is time to explain my inaction.
The short explanation is I have been avoiding it. I'm probably overthinking this but I just realized the TekScopes members can probably firure out solutions to every one of my concerns. Below are my concerns in no particular order. By writing them down here I am asking for your help. When the replies dwindle to a trickle I will distill down the best ideas and if necessary put them up for a vote.
The annual cost is ~$100. I paid for the first year to get us started without further delay because it appeared Yahoo would shut us down at any moment.
THIS IS GOING TO GENERATE A LOT OF MESSAGE TRAFFIC SO PLEASE ONLY REPLY AFTER READING ALL OF THE PRIOR POSTS AND REPLY ONLY IF YOU HAVE A CONTRIBUTION. I am concerned that there will be too much traffic so keep your replies short and to the point, and avoid unnecessary back and forth that might keep the thread going longer than necessary.
MY CONCERNS / QUESTIONS / ISSUES / RANDOM THOUGHTS:
* Any request for funds is going to result in more than $100 being sent to me. For example if we have 7,000 members and 10% are active at any given moment and they each sent in $1 that would be 7 years' worth of 开云体育 storage costs.
* Michael Dunn and I would both have control over the funds so in the event something happens to one of us the other could carry on alone.
* What do we do with the excess donations? Where should they be kept? Commercial banks charge too many fees. Perhaps a credit union is the answer. What about the Tektronix Credit Union? Can I apply if I was not an employee of Tek?
* Donating less than $1 is impractical.
* Fairness dictates that the cost be spread evenly so everybody contributed equally. This is also impractical.
* Everyone should have access to the donation list of who contributed and how much for total transparency. That way everyone can confirm their donation contributed to the total.
* There needs to be an automated way to accept and post the donations to the donation list because my wife and I do not have the time to do it. I have no idea how to do that part of this, but maybe somebody has the answer.
* I am hopeful whatever mechanism is chosen it accepts PayPal and checks. It is impractical to send a money order for $1. It is also not a good idea to send $1 in cash.
* How do foreign donations get handled? Maybe the automated system I alluded to above has the answer to that.
Dennis Tillman W7PF
toggle quoted message
Show quoted text
-----Original Message----- Jack Reynolds wrote on Monday, April 30, 2018 4:36 PM <snips> Hello all and especially Dennis,
I remember reading for a while before the switch to groups.io that there were going to be some modest
financial costs for the switch and for the maintenance of the groups.io
group which would be dealt with after the switchover. Dennis, would you be so kind as to update us on the who, where and how much, etc.?
Thanks,
Jack Reynolds -- Dennis Tillman W7PF TekScopes Moderator
|
Re: OT : How About A Group For "Other" ?
It seems I've created a monster. Well, not all monsters are bad.
"...there is a very active HP/Agilent/Keysight group on Yahoo. There's also a test equipment group (although it's not quite as active as some others)."
"...there are "funwithtubes" and "funwithtransistors" groups on Yahoo"
Yahoo and other such organizations are in business to make money, and they sell information to get money. I don't know the "scope" of what they do. I'm sure Google is selling my information due to using their email, so using their Usenet access is no big thing. Still, I get very little spam.
When I updated a browser in the past all the sudden I got a "Yahoo" search window up in the top part. I chose Google as my search engine, this was something I did not want nor need and I didn't ask for it nor was I asked to allow it. I don't know about you, but I don't like that. This site asked even just to EMAIL me. That I like.
"Maybe we should have a group for each Tektronix instrument of interest
where users from the main TekScopes group can post their albums. This would
give some organization to the images allowing for a browsing capability
based on the instrument."
"One group per instrument seems way too much detail and separation."
"Shouldn't be much more than a couple hundred groups."
A group just for image albums ? Well, I guess it is an option but I doubt the best option. I suggest that we somehow come to an agreement on a naming convention for image albums and stick to it. Without getting too longwinded, I faced a similar problem when I was downloading massive amounts of music on P2P. I used to rename each file with the artist first and it went into an alphabetical directory. Later I found it much better to make subdirectories for each artist and not even bother renaming all the files. So here, one way would be to name your album by the model of the scope. To avoid duplicate names it would maybe start with the model and then the initials of your username. something like that, as long as we all agree. This would also help if and when they do have a search utility of some sort, because how would a search find something pertaining to i.e. a Tek 11543 in a directory called "Problem in town" ? I see people using the filenames assigned by their camera, there is no way in hell those could ever be searchable without some form of heuristic analysis of the images themselves, and I think that is too much to ask.
If I were to start a group for everything but Tek copes, logically then the albums should be named with the brand first, then model. It is not hard to rename the images to be descriptive on your own PC, resize and then upload them. I have a small standalone program that does it but it is 32 bit so some people can't use it, but I am sure there is something out there.
"Nobody is stopping you from implementing your "great" idea.
Go ahead and punt."
I am leaning toward that. I think it would be a good idea.
"I kind of like the idea of a service/repair group specifically dedicated to
"Other.""
"Yes, such a group SHOULD allow "pot-smoking hippies" as members as long as
they have half a clue about electronics repairs, or at least wish to obtain
said half-a-clue."
"Let's develop this idea and then put it out
in the world if it looks good enough."
Of course I agree being the one who mentioned it. And people's recreational drug use is irrelevant . I like pot. I don't do it because of the insane prices, well once in a while. I don't do anything else but beer but I know people who can do coke or smack and still function at a very high level. On the other hand there are those who are totally straight and sober but just idiots. Luckily they seem rare in this business, well except in management. My Uncle worked for Big Blue for 100 years and told me some cool horror stories. When he couldn't get along with one of their "strawbosses" the strawboss got transferred. Problem solved. And, for the record I believe the government has no right to tell you what you can do to your own body. that's why prohibition was a constitutional amendment, because with the Constitution being enforced back then (somewhat) they couldn't just legislate it and let the President sign it. HA, the Kennedys would have them in court ! Speaking of the Constuitution :
"...started the group specifically as a protest against limits on free speech that were
arguably in violation of the First Amendment but were put in place by the people who either owned or controlled the speech venue..."
The first amendment does not apply. It only forbids the government from legislating against public speech, and not even completely. But in a private venue, you could get thrown out legally for using the word "green" if the person in charge decides.
Nothing wrong with the protest, that was his prerogative. I have no problem with it.
"Splitting it up will just deny the resulting groups
that mass, and they will fizzle out."
I think with proper guidelines that won't happen. Tektronix is/was in a class by itself. Lately I have heard that Rigol is actually better, but have no personal knowledge of it. The other group would specifically not include Tek scopes. What I don't know is whether other Tek equipment should be excluded.
"and learning from other's mistakes is so last century"
Last century was good for learning. From the first cars to the moon. Now people can't balance a checkbook and heaven forbid they need a square root. Last century I learned how to do them longhand so if the batteries all die maybe I can clean up doing that...
"I'll tell you this for nothing. If this group fragments in the ways that are being discussed..."
That is not my intent, what is is to do whatever possible to prevent it. There is good reason too, Tektronix engineering is not only better, but different. How many manufacturers use tunnel diodes ? (their tunnel diode triggering can actually lock in on noise ! I've done it) How many use one Zener to regulate a half dozen sources ? (I think their intent was that all the source come up in unison at power up) How many other scopes ever had a separate blanking electrode in the CRT ? I am sure there are many things I missed.
"If you want to segment this group
into sub-groups, take a look at
this site:
Again, in no way do I wish to segment this group. Tek Scopes still belongs here. There are archives here and eventually that will get straightened out so things can be found. that amfone.net has a structure I wouldn't want. I can't even say exactly what I don't like about it but it just seems off in some way.
"Splitting up in to 200 or so groups..."
"Lets wait for 开云体育 to get the search working."
I am not talking about 200 groups. One group for other test equipment. I think I have decided against brownwares altogether, most are junk and those few high end units could be tolerated because the wealth on knowledge here (and there I hope) would be a cut above. If that got out of hand, maybe a group for "Consumer" or something like that. But not 200.
"Pick a catalog and count the number of different products that are in it. Then go through all 70 years of catalogs and do the same thing."
I am talking about one group for all other test equipment, period. Only if one other brand, HP/Agilent/Keysight, B & K, Sencore or whatever becomes dominant in that group, then and only then should another group be considered.
"There were separate catalogs for Television products and military products and lots and lots of Mods."
If the topic is pertinent to test equipment for television products, military products, or mods to same, then it belongs.
"Dennis
Even if your off 2 or 3 orders of magnitude the elephant is too big to bar-b-que"
I only want an elephant ear sandwich. The problem is finding those big buns.
"The issue that I was addressing
has to do with the organization of the photos archive - which is
essentially non-existent."
Which is an important issue. If it would be possible for people to rename their albums and rearrange them here that would go a long way. but in the new group as well as in the future here I encourage people to name their albums and image in a descriptive way.
I see apparently there are 701 albums here. It would not take long to rename them, with cooperation. Since I see no option for a caption, the rest will have to be in the filename. We are not limited to the DOS 8+3 convention, so all we have to do is use that. Simple notices in text at the top of the pages where one creates an album and uploads images to it would go a long way. I believe people would comply voluntarily so there needs not be any forced routine built into the process. That could come later though once an actual search engine is established. Then, users could actually download their own images back, rename them and then create a whole new album or set of them that would work, and this would facilitate the function of a search anyway. eventually the old albums could be deleted to clean up the mess.
"There is only a two level structure - Albums > Photos. If
there was, for example, a three level or higher structure, e.g., 7000
Series Scopes > Albums > Photos, then that would resolve the browse photos
problem."
That would help greatly but I don't know how difficult it would be for the owners. And it still requires the cooperation of the members.
"One constraint to doing anything with albums is we don't want to do anything that would break the links to photos from old/existing messages."
Wow, that is a VERY valid point. Therefore I guess deleting the old albums would be out. but that doesn't stop the images from being copied into newer albums following new guideline. It is probably the only way to accomplish what we want without breaking things. Thanks for bringing that up. As such, in the creation of a new group I would include (and stress) such guidelines right in the beginning.
I think I am going to give it a whirl. You might want to wish me luck.
|
Re: OT : How About A Group For "Other" ?
One constraint to doing anything with albums is we don't want to do anything that would break the links to photos from old/existing messages.? So I don't see a way to rename albums or move photos around to new/other albums to effect a more effective structure.
But, a photo database? with links to the albums/photos could be organized in whatever level(s) structure is desired by the group. You could find your target through a database search or by browsing to to a link to the album/photo.
Hopefully, this is what the groups.io developers are working toward because it would be best if the solution was part of the group.io menu scheme.
Bob.
toggle quoted message
Show quoted text
On 4/30/2018 3:20 PM, JJ wrote: Dennis, it's amazing how many folks are misconstruing my intentions. I'm
not suggesting that we splinter the group - I think there is quite a bit of
power in having a single TekScopes group. The issue that I was addressing
has to do with the organization of the photos archive - which is
essentially non-existent. There appears to be no way to organize the images
because there isn't a hierarchical browse structure capability built into
the software. There is only a two level structure - Albums > Photos. If
there was, for example, a three level or higher structure, e.g., 7000
Series Scopes > Albums > Photos, then that would resolve the browse photos
problem.
My intention was to find a way around the present inadequacy of the
software to organize and browse images - being mindful to be able to easily
migrate those images into the main TekScope group in the event that the
hierarchical browse structure capability is provided in a future release of
the group's software.
There is a subgroup capability built into the software presently that could
allow a temporary solution. Like I said before, Tekscopes is still the main
group. The subgroups (e.g., 7000 Series Scopes) would only contain the
images (there may be a way to disable all the other options in the left
hand menu for subgroups). This in essence would be transparent to the user
- the link from the message would be made from TekScopes to the subgroup's
photo archive.
How the subgroup's are named and organized can be determined by those who
know a lot more about the subject matter than I do. There has to be a way
to create a browse capability for images - every subject matter on earth
can be categorized and grouped in a hierarchical structure.
We should also talk to the group's software people to request the
capability to have more than just two levels of hierarchy in the Photos
section (and Files section) along with an image metadata entry and search
capability. It may be fairly easy to add another level in the database if
it's a relational database - which I'm sure it is. They just need to add
another column and a table to the database.
If anyone really thinks that searching for images is a replacement for
browsing images in a hierarchical structure, I can't help you - you need to
spend more time on the Internet.
I'm sorry if my suggestion has offended anyone - it shouldn't have.
Best,
John
On Mon, Apr 30, 2018 at 5:22 PM, Dennis Tillman W7PF <dennis@...>
wrote:
Hi John,
As an former engineer I was taught to test my ideas with "back of the
envelope calculations" before taking them to my boss. That way you I would
get a sense of the scale of what I was going to propose. I did that just
now assuming the simplest version of your idea that I could think of and I
was surprised by what I found. I am probably totally wrong on the numbers I
came up with but even if I am off by an order of magnitude I don't see how
this can be done.
Pick a catalog and count the number of different products that are in it.
Then go through all 70 years of catalogs and do the same thing. Don't
forget the things that didn't appear in the catalogs like cal fixtures or
things that never went into production (I have several of those). There
were separate catalogs for Television products and military products and
lots and lots of Mods. Then eliminate the duplicates. That will give you
all the unique products Tek made or make now. My order of magnitude
estimate is Tek made / makes between 5 x 10^6 to 1 x 10^7 unique products.
That is 5,000,000 to 10,000,000 unique products.
If you could make 5 groups a minute it would take you 1,000,000 minutes to
make all the groups. That comes out to 700 24 hour days to make the groups.
Your persistence is admirable and you frustration with the way things are
now is clear. 开云体育 has a flaw, this is true, but they ae aware of it
and other groups beside ours have expressed the urgency to fix it. However,
we chose them because in all other respects (including their reputation)
they were the very best we found. I do not think there is anyone better.
Groups would be a temporary solution at best. The real solution is indexing
the album archives.
If you wish to make a real contribution find us a better site with all the
features we use that can host a group our size. Most important, but it was
invisible to you, the staff at 开云体育 did an incredible job on the
transition from Yahoo. This transition was something Michael and I were
dreading. It should have been a nightmare for us but they did everything
and we had to do virtually nothing.
In the meantime one way you can put some credibility behind your idea is
to find a group of comparable size that has done something like what you
are proposing and get some data on how they did it and how much work and
time was involved.
Dennis Tillman W7PF
-----Original Message----- JJ wrote on Monday, April 30, 2018 6:21 AM
Maybe we should have a group for each Tektronix instrument of interest
where users from the main TekScopes group can post their albums. This would
give some organization to the images allowing for a browsing capability
based on the instrument. Right now, you can't find anything.
Best,
John
--
Dennis Tillman W7PF
TekScopes Moderator
|
Re: Help with 24x5B processor board A5 and option 5 timer trigger
On Tue, 01 May 2018 00:40:52 +0000 (UTC), you wrote: On 04/30/2018 06:30 PM, machineguy59 via Groups.Io wrote:
the pitch on these pins is so tight that, in most cases, any trace passing between would be masked.? These are not.? I wonder why. When the solder mask gets too thin, it will come off. At that point, you just leave it out so that does not happen.
Then you cannot have too much solder or solder paste or it will blob short out between some copper. Adding a LOT of flux can help there, simply because it keeps the solder from oxidizing and forming strings between pins. If using solder wick to clean up the pins, flux very well, and it does help. More or less proven on 0.5 mm spacing pins with adequate pads, eutectic solder, and a rather thin tip on a metcal iron. Harvey
|
Re: 922 with "tilted" wave form.
I would agree with the stuff below.
But would look closely at the screws around the CRT area, for ones that
don't have the right look, toand check to be sure you don't have a mini
magnet in the form of a screw that someone replaced that would be pulling
your picture.
John
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Fabio Trevisan Sent: Monday, April 30, 2018 2:36 PM To: [email protected]Subject: Re: [TekScopes] 922 with "tilted" wave form. Hello Mlynch, What you describe looks like a "geometry" or Y-AXIS misadjustment. If I understood correctly what's the equipment you have it's a T922 oscilloscope. Looking at the Manual that is available on the TekWiki website (here: ), the adjustments are Y AXIS, R474 and "GEOMETRY", R473, both are on the CRT & VERTICAL AMPLIFIER diagram, located on the A1 INTERFACE BOARD. Manual probably describes the correct procedure to adjust both of them, and this is usually done in the very beginning of the calibration procedure, meaning that most of the other calibrations are impacted to some extent by these 2, as they change the shape of what's being shown on the screen. Steps usually cover the following: 1. First of all, adjust the trace rotation (adjustment accessible from the side of the scope), for a horizontal baseline (just sweep, no vertical signal). 2. Then, using the X-Y mode, apply a signal to the Y channel enough to span about 6 divisions height, leave the X-channel with no signal (set X input to to GND). This will draw a vertical line on screen... Adjust now R474 so that the vertical line, aligned to the central vertical graticule is perfectly vertical. 3. Finally, change the scope back to normal mode, and apply a square wave to one of the vertical channels, that is big enough to span 6 divisions vertically, and set a sweep speed that you see about 20 cycles horizontally accross the screen. This setup will pretty much "fill" the screen with a square wave, from bottom to top, left to right. Now you can adjust the geometry adjustment (R473) to correct any "Pillow" or cushion distortions of the screen, so that the overall shape of the displayed waveform is all "squared"... 4. The geometry adjustment, if it requires too big re-adjustment, will have some side-effects to the Trace rotation and the Y-axis adjustment... Repeat then Trace rotation and Y-Axis again, to make sure that the screen remains aligned on the horizontal and vertical directions. All that, above, assuming that - overall - the scope doesn't present other misbehavior... However, the procedures above cannot assure you that everything else is or will remain correct. Since re-adjusting the Y axis and Geometry may have some impact on the size of the waveforms displayed, by touching those adjustments, be aware that you may need to readjust Vertical Gain and Horizontal gain... and this will require that you have means to adjust those, or accept that they may become "off" by some amount. Rgrds, Fabio
|
My only contact was my mail order, since I grew up in Ohio. I bought from Poly Packs, BNF, Edlie, John Meshna and other mail order surplus stores.
I was close to Mendelson's, Dayton Surplus, and I made many trips to Fair radio back in the '70s and '80s.
toggle quoted message
Show quoted text
-----Original Message----- From: Brad Thompson <brad.thompson@...>
Hello, Michael--
I too was a long-time PolyPak customer, and I too found that
one could get some real bargains with some judicious inspection
of the Paks. Poly Pak was then located in Wakefield, MA, and
a stop on a Saturday surplus tour which typically included Meshna's
and the place in Newburyport with the pigeon-friendly loft.
The floor sweepings were educational, too-- I built a simple curve
tracer and pored through the "we bot thousands-- no time to test"
packs of top-hat silicon rectifiers and unmarked transistors.
Also located in Wakefield was Transitron-- a source of fodder for the Paks.
73--
Brad AA1IP Michael A. Terrell
|
Re: 922 with "tilted" wave form.
Other than this "Tilt" the scope presents no glaring issues. It works very well, considering that it is 40years old. There is no telling what the previous "repairman" did to the adjustments, after he tore the resistor array off the circuit board. Thank You for the detailed advice.
|
Re: 922 with "tilted" wave form.
Fabio,
I saw all of those adjustments but I did not make any changes to them. I
believe I can fix this thing with the aid of your precise instructions!
Thank you so much for the great detail that you have provided. I have the
manual and I will follow the procedure as close as possible.
Michael Lynch
11993 Wildcat Hollow Rd.
Dardanelle, AR 72834
479-477-1115 Cell Phone
479-229-0126 Land Line
mlynch002@...
mlynch003@...
|
Re: OT : How About A Group For "Other" ?
'Amen' on Jack's comments.
Who, where and how much?
tom jobe...
toggle quoted message
Show quoted text
On 4/30/2018 4:36 PM, Jack Reynolds wrote: Hello all and especially Dennis,
I do not really want to comment on the "Other Group", however your comments Dennis as shown below have reminded me of a pang of conscience which strikes me from time to time since the switch to groups.io. I do not believe it is related to eating spicy food! I remember reading for a while before the switch to groups.io that there were going to be some modest financial costs for the switch and for the maintenance of the groups.io group which would be dealt with after the switchover. After the switchover, I recall a flurry of messages where people were struggling to deal with communications within the "new" group. If there was some discussion as to how we as members could help to share the cost I must have overlooked it perhaps once again because of spicy food or maybe spirits consumption. Dennis, would you be so kind as to update us on the who, where and how much, etc.?
Thanks,
Jack Reynolds
However, we
chose them because in all other respects (including their reputation) they
were the very best we found. I do not think there is anyone better. Groups
would be a temporary solution at best. The real solution is indexing the album
archives.
If you wish to make a real contribution find us a better site with all the
features we use that can host a group our size. Most important, but it was
invisible to you, the staff at 开云体育 did an incredible job on the
transition from Yahoo. This transition was something Michael and I were
dreading. It should have been a nightmare for us but they did everything and
we had to do virtually nothing. Dennis Tillman W7PF
TekScopes Moderator
|
Re: Help with 24x5B processor board A5 and option 5 timer trigger
On 04/30/2018 06:30 PM, machineguy59 via Groups.Io wrote: the pitch on these pins is so tight that, in most cases, any trace passing between would be masked.? These are not.? I wonder why. When the solder mask gets too thin, it will come off. At that point, you just leave it out so that does not happen. Then you cannot have too much solder or solder paste or it will blob short out between some copper.
|
On 4/30/2018 6:13 PM, Michael A. Terrell wrote: They were called 'Blister Paks', and I bought a lot of useful parts from them over the years. Not everything was floor sweepings, so was leftovers from production lines. I bought things that I couldn't find anywhere else. There was no internet back then, and many distributors wanted a corporate account to sell you anything. I still have some long lever Microswitches that I bought from them, almost 50 years ago. I never found a bad one, and I used a lot of them repairing tape machines. I bough surplus GE recitifers by the pound. About a 3% defect rate, but what was 30 out of a little over 1000? I used those for myself, but I got things there that were too new or too scarce to find elsewhere.
Hello, Michael-- I too was a long-time PolyPak customer, and I too found that one could get some real bargains with some judicious inspection of the Paks. Poly Pak was then located in Wakefield, MA, and a stop on a Saturday surplus tour which typically included Meshna's and the place in Newburyport with the pigeon-friendly loft. The floor sweepings were educational, too-- I built a simple curve tracer and pored through the "we bot thousands-- no time to test" packs of top-hat silicon rectifiers and unmarked transistors. Also located in Wakefield was Transitron-- a source of fodder for the Paks. 73-- Brad AA1IP
|
I'm being lazy and not reading the manual, but if it's bright enough and the circuit doesn't care, you can get #2174 for pocket change at Mouser. That's 12V 40mA. Operating at 10V it should last a good long while. Dave Wise ________________________________________ From: [email protected] < [email protected]> on behalf of lop pol via Groups.Io <the_infinite_penguin@...> Sent: Monday, April 30, 2018 5:10 PM To: [email protected]Subject: Re: [TekScopes] 10V 40mA bulb(s) On Mon, Apr 30, 2018 at 04:50 pm, David DiGiacomo wrote:
On Mon, Apr 30, 2018 at 12:27 PM, lop pol via Groups.Io
<the_infinite_penguin@...> wrote:
One of my 453s needs a trigger lamp. (150-0046-00) Looks like its 10V and 40mA. I see nothing on the auction site. What are you guys doing to replace
those? Closest as I could find was 10V 60mA.
In case anyone is wondering, this is a #2107 lamp. There are a few of
them out there:
|
On Mon, Apr 30, 2018 at 04:50 pm, David DiGiacomo wrote:
On Mon, Apr 30, 2018 at 12:27 PM, lop pol via Groups.Io
<the_infinite_penguin@...> wrote:
One of my 453s needs a trigger lamp. (150-0046-00) Looks like its 10V and 40mA. I see nothing on the auction site. What are you guys doing to replace
those? Closest as I could find was 10V 60mA.
In case anyone is wondering, this is a #2107 lamp. There are a few of
them out there:
On Mon, Apr 30, 2018 at 04:50 pm, David DiGiacomo wrote:
On Mon, Apr 30, 2018 at 12:27 PM, lop pol via Groups.Io
<the_infinite_penguin@...> wrote:
One of my 453s needs a trigger lamp. (150-0046-00) Looks like its 10V and 40mA. I see nothing on the auction site. What are you guys doing to replace
those? Closest as I could find was 10V 60mA.
In case anyone is wondering, this is a #2107 lamp. There are a few of
them out there:
Thanks for that. Ordering now.
|
On Mon, Apr 30, 2018 at 12:27 PM, lop pol via Groups.Io <the_infinite_penguin@...> wrote: One of my 453s needs a trigger lamp. (150-0046-00) Looks like its 10V and 40mA. I see nothing on the auction site. What are you guys doing to replace those? Closest as I could find was 10V 60mA. In case anyone is wondering, this is a #2107 lamp. There are a few of them out there:
|
Re: OT : How About A Group For "Other" ?
Hello all and especially Dennis,
I do not really want to comment on the "Other Group", however your comments Dennis as shown below have reminded me of a pang of conscience which strikes me from time to time since the switch to groups.io. I do not believe it is related to eating spicy food! I remember reading for a while before the switch to groups.io that there were going to be some modest financial costs for the switch and for the maintenance of the groups.io group which would be dealt with after the switchover. After the switchover, I recall a flurry of messages where people were struggling to deal with communications within the "new" group. If there was some discussion as to how we as members could help to share the cost I must have overlooked it perhaps once again because of spicy food or maybe spirits consumption. Dennis, would you be so kind as to update us on the who, where and how much, etc.?
Thanks,
Jack Reynolds
However, we
toggle quoted message
Show quoted text
chose them because in all other respects (including their reputation) they
were the very best we found. I do not think there is anyone better. Groups
would be a temporary solution at best. The real solution is indexing the album
archives.
If you wish to make a real contribution find us a better site with all the
features we use that can host a group our size. Most important, but it was
invisible to you, the staff at 开云体育 did an incredible job on the
transition from Yahoo. This transition was something Michael and I were
dreading. It should have been a nightmare for us but they did everything and
we had to do virtually nothing. Dennis Tillman W7PF
TekScopes Moderator
|
Re: Help with 24x5B processor board A5 and option 5 timer trigger
It was the MUX (U2530)!!!? I think Chuck Harris was right when he said I probably cooked the MUX with my hot air wand since I didn't use a preheat system.? I feel like a newbie, lol.? On this second attempt I used my trusty soldering iron and some patience.? First time success at my second attempt.? I still want to try a preheat system as suggested by Chuck Harris.? But prudence says I should try it first on something less important.? Thanks for the help guys, especially Chuck Harris who gave me great advice.
toggle quoted message
Show quoted text
On ?Saturday?, ?April? ?28?, ?2018? ?08?:?40?:?59? ?PM? ?CDT, machineguy59 via Groups.Io <machineguy59@...> wrote: The original mask is unscathed.? But I am surprised that Tek did not cover the guard traces with mask.? They are just traces after all and covering them with mask would simplify repairs like this.? I understand the need for a good liquid flux, preferably no-clean which I clean after anyway.? But the pitch on these pins is so tight that, in most cases, any trace passing between would be masked.? These are not.? I wonder why. ? I don't usually make a big deal of soldering a simple part to a board, done it many times.? But I have never cooked a part with my heat wand before and it has me a bit skittish.? So, I am being extra careful (some might say obsessed) so I know the part isn't damaged.? Then if the MUX doesn't work I can confidently look elsewhere for the problem. Thanks again for your advice and help.? ? ? On ?Saturday?, ?April? ?28?, ?2018? ?07?:?35?:?35? ?PM? ?CDT, Chuck Harris <cfharris@...> wrote: My question would have to be: did you damage that solder mask the last time you worked on the MUX? If not, it should be fine the way it is. It is the flux that allows the solder to pull back into a blob.? Without a good flux, it forms oxide stringers that allow bridges.? Good flux, and everything works out nicely. I keep the board under preheat the entire time I am working on the topside.? When I am done, I just turn it off, and let the board cool down naturally.? I find that there are fewer stress problems that way. Let us know how you like working with the preheater.? You should see a remarkable difference. -Chuck Harris machineguy59 via Groups.Io wrote: ? I plan to replace the MUX (U2530) this weekend and wonder if I can put solder mask on the guard traces between signal pins?? I would use Circuit Works CW2500 epoxy which is good to 350 C.? I cant think of any downside and it would help avoid solder shorts.? The guard traces are very close to the signal pins and shorts mean rework with solder braid.? 14 pins at this pitch are sure to get one that needs touch up.?
I haven't decided yet whether I will do hand soldering or hot air.? I purchased a griddle at Walmart for $18.00 to act as a preheater and calibrated it with my IR temperature meter.? Its easy to hold the temperature around 170 C.? I will use a hand held fan to cool the board after soldering and before lifting it off the griddle so I don't temperature shock the board.? But I may loose my nerve and just hand solder the new part.? Either way, I think solder mask over the guard traces would help keep the solder from overflowing.?
|
Re: 7603 Z-Axis board transistor Q1152 running a little too hot?
Hello Al,
It seems that my calculations were, in the end, not that spot-on as I would expect.
I need to come back to my biasing transistors lessons from 40 years ago.
But I tend to reach to the same conclusion as you, especially in consideration of the other answers, confirming that this circuit operates rather hot and yours is operating normally.
The idea of adding a top hat to the TO-39 xsistors seems terrific (just be careful to avoid that the heat-sink touches other parts.
Regards,
Fabio
toggle quoted message
Show quoted text
On Sun, Apr 29, 2018 at 05:42 pm, Al Holt wrote:
On Fri, Apr 27, 2018 at 08:24 am, Fabio Trevisan wrote:
The 3K9 resistors at the emitter of the top transistors should have about
25V across them. Lift one of their leads and measure their resistance, to be
sure they're still at 3k9. If the resistors are within tolerance, and the
voltage is about 25V, then you know the collector current of the output
transistor pair is correct.
My measurements of the 3k9 resistors:
R1152 -- 3k95 Ohms & 26.83 Volts
R1132 -- 3k97 Ohms & 27.19 Volts
Measure the voltage at the collector of Q1136 and Q1156... they both should measure about 4V (relative to ground)...
My measurement were:
Q1136 -- 5.75 Volts
Q1156 -- 5.58 Volts
Finally, measure the voltage across the 120ohm resistors at the output... It will give you an idea of how much current is being drawn by the load circuitry
downstream. By no means this current can be more than the quiescent bias
current going through the output transistors, which is about 6mA. My wild
guess is that it shouldn't be any greater than half of it, or about 3mA,
because otherwise this would seriously upset the quiescent point of a Class A
amplifier.
My measurements were:
R1157: measured 122.3 Ohms, Voltage Drop: 6.2mV
R1137, measured 123.3 Ohms, Voltage Drop: 1.5mV
All told, I'd say the section is operating normally; the voltage drops across
the 120 Ohm resistors varies a lot from your hunch, but maybe that's a good
thing. For now I'll do a bit more cleaning up with larger 20k resistors and a
top-hat heatsink for Q1156 and try some more checks of the entire instrument.
Thanks again!
--Al
|
Re: OT : How About A Group For "Other" ?
Dennis, it's amazing how many folks are misconstruing my intentions. I'm not suggesting that we splinter the group - I think there is quite a bit of power in having a single TekScopes group. The issue that I was addressing has to do with the organization of the photos archive - which is essentially non-existent. There appears to be no way to organize the images because there isn't a hierarchical browse structure capability built into the software. There is only a two level structure - Albums > Photos. If there was, for example, a three level or higher structure, e.g., 7000 Series Scopes > Albums > Photos, then that would resolve the browse photos problem. My intention was to find a way around the present inadequacy of the software to organize and browse images - being mindful to be able to easily migrate those images into the main TekScope group in the event that the hierarchical browse structure capability is provided in a future release of the group's software. There is a subgroup capability built into the software presently that could allow a temporary solution. Like I said before, Tekscopes is still the main group. The subgroups (e.g., 7000 Series Scopes) would only contain the images (there may be a way to disable all the other options in the left hand menu for subgroups). This in essence would be transparent to the user - the link from the message would be made from TekScopes to the subgroup's photo archive. How the subgroup's are named and organized can be determined by those who know a lot more about the subject matter than I do. There has to be a way to create a browse capability for images - every subject matter on earth can be categorized and grouped in a hierarchical structure. We should also talk to the group's software people to request the capability to have more than just two levels of hierarchy in the Photos section (and Files section) along with an image metadata entry and search capability. It may be fairly easy to add another level in the database if it's a relational database - which I'm sure it is. They just need to add another column and a table to the database. If anyone really thinks that searching for images is a replacement for browsing images in a hierarchical structure, I can't help you - you need to spend more time on the Internet. I'm sorry if my suggestion has offended anyone - it shouldn't have. Best, John On Mon, Apr 30, 2018 at 5:22 PM, Dennis Tillman W7PF <dennis@...> wrote: Hi John,
As an former engineer I was taught to test my ideas with "back of the
envelope calculations" before taking them to my boss. That way you I would
get a sense of the scale of what I was going to propose. I did that just
now assuming the simplest version of your idea that I could think of and I
was surprised by what I found. I am probably totally wrong on the numbers I
came up with but even if I am off by an order of magnitude I don't see how
this can be done.
Pick a catalog and count the number of different products that are in it.
Then go through all 70 years of catalogs and do the same thing. Don't
forget the things that didn't appear in the catalogs like cal fixtures or
things that never went into production (I have several of those). There
were separate catalogs for Television products and military products and
lots and lots of Mods. Then eliminate the duplicates. That will give you
all the unique products Tek made or make now. My order of magnitude
estimate is Tek made / makes between 5 x 10^6 to 1 x 10^7 unique products.
That is 5,000,000 to 10,000,000 unique products.
If you could make 5 groups a minute it would take you 1,000,000 minutes to
make all the groups. That comes out to 700 24 hour days to make the groups.
Your persistence is admirable and you frustration with the way things are
now is clear. 开云体育 has a flaw, this is true, but they ae aware of it
and other groups beside ours have expressed the urgency to fix it. However,
we chose them because in all other respects (including their reputation)
they were the very best we found. I do not think there is anyone better.
Groups would be a temporary solution at best. The real solution is indexing
the album archives.
If you wish to make a real contribution find us a better site with all the
features we use that can host a group our size. Most important, but it was
invisible to you, the staff at 开云体育 did an incredible job on the
transition from Yahoo. This transition was something Michael and I were
dreading. It should have been a nightmare for us but they did everything
and we had to do virtually nothing.
In the meantime one way you can put some credibility behind your idea is
to find a group of comparable size that has done something like what you
are proposing and get some data on how they did it and how much work and
time was involved.
Dennis Tillman W7PF
-----Original Message----- JJ wrote on Monday, April 30, 2018 6:21 AM
Maybe we should have a group for each Tektronix instrument of interest
where users from the main TekScopes group can post their albums. This
would
give some organization to the images allowing for a browsing capability
based on the instrument. Right now, you can't find anything.
Best,
John
--
Dennis Tillman W7PF
TekScopes Moderator
|
Mlynch001
Jeff Urban
Michael A. Terrell
Fabio Trevisan