Date   

Re: 2465 Fan Collet Thingy

 

Hi Li,

would it be possible to add a guidance hole for the insert? Like some 2mm diameter and 5mm deep...

It seems crucial the hole is drilled in the very middle of the piece for the fan not to wobble around. Without guidance that seems rather difficult to obtain.

cheers
Martin


FS: Tek 11301A with 4 Chan & Diff Comparator Plug-ins

Bill Perkins
 

I have a Tek 11301A mainframe ser. no. B010135, an 11A34 4-chan plug-in ser. no. B010219 and an 11A33 diff comparator plug-in ser. no. B020129 for sale.

Everything had been sitting unused and owed to me for the last three years and finally arrived in beautifully packed, excellent condition from Toronto last week.

I bought an Artek Op manual copy for it, have spent a couple of hours with it and everything seems to work as expected. All controls respond, the touch screen areas all respond, everything drawn on the screen is sharp and clear with no trace of screen burn.

Cosmetically the mainframe is excellent, not a mark of the front or rear panels or controls and only a small-ish dig on the blue vinyl (?) covering on the removable top cover. The 4-chan plugin is unmarked while the diff comparator took a hit and has a chunk cracked out of its plastic front panel overlay, otherwise it's fine.

The cal' stickers are intact on both plug-ins although no cal' date is to be seen, leading me to think they might be the factory originals.

The keep alive batteries measure 3V as they should and it holds its settings thru a restart.

The shipping container is excellent, with at least 2" of fitted foam on all six sides. It rode 3,000 miles to Calgary from Toronto by UPS Ground and arrived unmarked and in such condition that it's reusable for reshipment.

$US550.00 all-up but shipping costs which are on the buyer's dime.

I also have a little cute little HP 3476A Digital Multimeter for $US50.00, a Wavetek 182A 4MHz Function Gen for $US75.00, and two of the 182A's exact predecessor from 'ED Engineering Co. Ltd.' in Japan, their model FG-1881, for $US75.00 for both. One is fine, the other produces no output.

Wavetek 182A Op_Serv is here:

https://www.pearl-hifi.com/06_Lit_Archive/15_Mfrs_Publications/38_Wavetek/Wavetek_182A.pdf


Hit me off-list pls.

Best,
Bill Perkins
PEARL, Inc.
3020a Erlton St. SW
Calgary, AB
T2S 2Y6

+ 403 244 4434 Office fwds to cell' on 4th ring
+ 587 578 4434 Cell' and text

https://www.pearl-hifi.com


Re: 475 With a bowed display. . . .Ideas?

Michael W. Lynch
 

I am going to post some pictures of the phenomenon later today. I am also going to follow up on all the suggestion or ideas presented in the preceding conversations. I have plenty to check off the list for now.

If the Astigmatism, Geometry and Y Axis Align voltages and component values check out, then I will proceed with a CRT substitution. That will definitely help to isolate the issue to either the CRT or the Instrument circuitry.

I wish that I was better at using the proper terms to describe what I am seeing. I feel like I lead people astray when I use the wrong terms or otherwise poor wording to describe the issue. For example, my using the term "loading" when this was not a case of low voltage due to an overload in the circuit.



Thanks again for all the help!

--
Michael Lynch
Dardanelle, AR


Re: 7834 Missing Trace

Colin Herbert
 

To remove a plug-in with a broken pull-tab:

If you can grasp some of the pull-tab with long-nosed pliers, do so once you have put something to act as a pull-handle onto one of the BNCs (it doesn't matter which, but don't obscure the pull-tab too much and don't use a BNC Tee-piece; they simply pull apart. Something like a Normalizer is perfect). Pull the plug-in forward gently without pulling the whole scope off the bench and then give the pull-tab a pull with the long-nosed pliers while keeping pulling gently at the plug-in. You might hear a click as the retainer disengages and the plug-in start to move out. Once you have got the plug-in out of the scope, don't put it back into that or any other scope until you have sourced a spare pull-tab or disabled the retaining ability of the broken one, otherwise you are back at square one.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of sdferg7@...
Sent: 08 August 2020 17:08
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7834 Missing Trace

The trace only gets fuzzy when I have the calibrator signal plugged in, and only the top half. The issue still comes and goes, usually after I change a setting, e.g. the vertical channel. With no signal the only time the trace flickers from moving up and down is when it goes through the trigger.

Unfortunately the scope only came with 1 vertical plugin, in the right slot, and the pull tab is missing. Is there an easy way to get it out without much disassembly? In the manual it seems the only way to get the black follower tracks out is to have their respective plugin removed to access the screws. When I select the empty left vertical plugin slot I get a flat trace slightly tilted clockwise, maybe 1 or 2 degrees.

I also discovered I was mistaken about the 2 dots, they actually appear to be the minimum and maximum of the right horizontal plugin from the calibrator signal I had plugged in. If I select chop with no signal I get 1 brighter dot from the right plugin, still nothing from the left.

I also did more testing on the scope's calibration. Last night after the scope was pretty warm I tried measuring a 1.6V battery at 1V/div which showed on the scope as about 3/4 of a division. This morning I tried the same with the scope cold and it came to almost exactly 1 division. This seems to follow my previous experience with the scope reading lower as it gets warm. The scope also seems to read slightly off on the frequency of the calibrator signal, each period shows as slightly less than 1ms. Of course that could be an issue with the calibrator.

Shane


Re: 475 With a bowed display. . . .Ideas?

Michael W. Lynch
 

On Sat, Aug 8, 2020 at 10:34 AM, Raymond Domp Frank wrote:


I'd think that's way out of range for the electrical Geometry adjustments that
you mentioned earlier, so probably something is wrong of the sort that Chuck
describes. It may be worthwhile to quickly check if the Geometry adjustment
pot's range reaches the intended 0 to +110V. It's GND-related, so not
dangerous to measure, unlike grid- and focus- voltage levels.
I was thinking of checking the Geometry Pot, just to mark it off the list of possibilities. If this pot is somehow defective, this might affect the range of Geometry adjustment.

Re. the "fisheye" appearance: Is the distortion mostly (radially) symmetrical?
In that case, I wouldn't think it could be just a moved magnet.
The marker peaks and lines are straight (more or less) but simply tilted in at the top. The tops of markers to the left of center lean in toward the center and those to the right do the same. The markers are a mirror image of one another, with the centerline being the mirror point. If that makes any sense.

Trying another CRT seems to make sense. Not too much hassle with a 465/475.
Just the usual care with the lingering anode voltage.
Yes! I will discharge before handling or removing, I have shocked myself before. One does not quickly forget a multi kV shock.
.
BTW, re. the first post, Michael wrote:

"Problem was C1442 was bad. High resistance and almost no capacitance, loading
the +15V supply."

The high resistance and low capacitance resulted in your meter showing that
the average or RMS voltage was too low so good regulation wasn't possible.
C1442 wasn't loading the +15V supply ("high resistance") but loading the 15V
supply wasn't possible, since the regulation circuit received practically
unbuffered rectified AC. It's probably what you meant.
Actually, I used the term "loading", as that was a typical cause of low DC voltage which I was familiar with, especially when "Bad" capacitors are concerned. I "assumed" loading, but after reading your comment, I realized that actual cause of the problem was that the regulation circuit simply could not cope with the unbuffered rectified AC. I knew there was a problem, but did not know the proper term to use to describe it.

One important lesson that I learned early on, was that all the power supplies need to be within specs before trying to make anything else work. This is the one thing that seems to be overlooked by novices like myself,

After isolating the +15V supply from the instrument and still having problems, there were a very limited number of parts that could be the cause. So my diagnosis was a process of elimination of the individual components and the bulk capacitors lke C1442 are the most likely and well know failure point.

I did not attempt to test the capacitor "in circuit". As a confirmation of the failure, I tested C1442 after I had removed it. The ESR showed about 1000 ohms and the capacitance at 196pF.

As always, I appreciate the education that I receive from everyone who has replied!

Sincerely,
--
Michael Lynch
Dardanelle, AR


Re: 2465 Fan Collet Thingy

Li Gangyi
 

Completely forgot the link, here it is.

https://www.thingiverse.com/thing:4564817

On Sun, Aug 9, 2020 at 1:24 AM Gangyi Li <li.gangyi@...> wrote:

Very quickly drew up a STL for people who wanna try 3D printing the
plastic bit, I believe the original part has a metal stud for the nut to
thread onto, you're gonna have to drill and tap the center for a stud.
Do let me know if you've tested it out and if it works good.

I have access to a small lathe, however I'm not equipped to do slits as of
yet, if there is interest I might get around to adding that capability.

On Sun, Aug 9, 2020 at 12:45 AM Chuck Harris <cfharris@...> wrote:

Log onto your groups.io account. It should open with your "my groups"
screen.
Click on "Tekscopes".

On the left side of the messages screen there is a list of areas
associated
with tekscopes. One of them is marked "FILES".

-Chuck Harris

Raymond Cote wrote:
And just WHERE IS THE FILES SECTION???
I dont see any link to it. Never have
In matters of style, float with the current. In matters of Principle,
stand like a rock. “. — Thomas Jefferson —

On Aug 8, 2020, at 06:55, Martin <@musaeum> wrote:

On Fri, Aug 7, 2020 at 01:55 PM, DaveC wrote:
Can you please provide a link to he location of these files? I looked
in the group files and there aren’t many. I didn’t see anything relating to
a collet.

Hi Dave,

it was explained somewhere in this thread: go into the files section
and search for "collet".

cheers
Martin







Re: 2465 Fan Collet Thingy

Li Gangyi
 

Very quickly drew up a STL for people who wanna try 3D printing the plastic
bit, I believe the original part has a metal stud for the nut to thread
onto, you're gonna have to drill and tap the center for a stud.
Do let me know if you've tested it out and if it works good.

I have access to a small lathe, however I'm not equipped to do slits as of
yet, if there is interest I might get around to adding that capability.

On Sun, Aug 9, 2020 at 12:45 AM Chuck Harris <cfharris@...> wrote:

Log onto your groups.io account. It should open with your "my groups"
screen.
Click on "Tekscopes".

On the left side of the messages screen there is a list of areas associated
with tekscopes. One of them is marked "FILES".

-Chuck Harris

Raymond Cote wrote:
And just WHERE IS THE FILES SECTION???
I dont see any link to it. Never have
In matters of style, float with the current. In matters of Principle,
stand like a rock. “. — Thomas Jefferson —

On Aug 8, 2020, at 06:55, Martin <@musaeum> wrote:

On Fri, Aug 7, 2020 at 01:55 PM, DaveC wrote:
Can you please provide a link to he location of these files? I looked
in the group files and there aren’t many. I didn’t see anything relating to
a collet.

Hi Dave,

it was explained somewhere in this thread: go into the files section
and search for "collet".

cheers
Martin







Re: Cut wiring harness

Roy Thistle
 

On Fri, Aug 7, 2020 at 09:18 AM, kim.herron@... wrote:


so large that you can't get the loom back in
place. ...stagger your repair splices so that
you can get it back together.
The obstacle that arose was the bulk, created by the accumulation of splices...getting the spliced loom back in position was not possible... staggering helps... also reducing the number of splices by replacing as many runs as convenient (some are usually easy to do... and then running a constructed loom (of those replacements) in parallel... or sometimes rerouting the new loom more conveniently. I've used inline multi-pole connectors... sometimes panel (or chassis mount) plug and socket... and sometimes terminal blocks (or stacked terminal blocks)... or retrofitted in a junction box.
Some insight is to be gleaned from the amazing number of wire T&M guys mannage to squeeze through the approximately 1cm. by 5cm. opening on the plugins for mux and switch plugins. (all the pairs are connected to screw down, or spring loaded, terminal blocks, on the plugin.) Some insight can be gained from pstn guys who used to do splicing, of multicondutor cable runs, all the time.
Signal carrying pairs need attention as to the point to point re-connection (and splicing), according to the wire/cable used (possibly length too, as well as shielding)... and of course routing.
Although you undoubtedly know, the 556 is almost symmetrical... so getting the power supply working first, and then one beam/channel working...before getting the other... might be a reasonable option.


Re: 7834 Missing Trace

Roger Evans
 

Two more thoughts - does the vertical plugin have an 'Invert' button? That would put the noise at the bottom of the screen if the calibrator is the culprit.

Have you tried all the different voltage output from the calibrator? Is the discrepancy the same for each and for any different V/div settings where you can make a meaningful measurement on two adjacent ranges eg 1V/div and 2V/div for the 4V calibrator output?

Roger


Re: 7834 Missing Trace

Roger Evans
 

You should be able to remove the bottom cover from the scope with a few screws. Whether this gives enough access to pull whatever is left of the release tab with a set of pointed pliers I am not sure. You could start a new thread here on 'how do I remove a 7000 plugin with a broken tab?'

What vertical plugin do you have? If it has two channels then I imagine by now you would have checked both. Nearly all vertical plugins have a 'var' setting which gives a continuously variable Volts/div but this should activate the '>' symbol on the readout and make it obvious that the V/div is not calibrated.

You can put a timebase in the vacant left vertical slot and on auto-trigger it should produce a vertical line if you select the empty slot for the horizontal mode. The line should shift up and down with the position control of the timebase and you might see if the top end displayed any noise (not a very convincing test). If you can arrange for both timebases to trigger from the same external input (maybe the cal output but now you are only relying for it for a trigger signal) then you should get some diagonal lines and any noise would be a bit more obvious. This is all dependent on the left vertical slot actually displaying a trace.

The journey is not ended yet!

Roger


Re: 2465 Fan Collet Thingy

Chuck Harris
 

Log onto your groups.io account. It should open with your "my groups" screen.
Click on "Tekscopes".

On the left side of the messages screen there is a list of areas associated
with tekscopes. One of them is marked "FILES".

-Chuck Harris

Raymond Cote wrote:

And just WHERE IS THE FILES SECTION???
I dont see any link to it. Never have
In matters of style, float with the current. In matters of Principle, stand like a rock. “. — Thomas Jefferson —

On Aug 8, 2020, at 06:55, Martin <@musaeum> wrote:

On Fri, Aug 7, 2020 at 01:55 PM, DaveC wrote:
Can you please provide a link to he location of these files? I looked in the group files and there aren’t many. I didn’t see anything relating to a collet.
Hi Dave,

it was explained somewhere in this thread: go into the files section and search for "collet".

cheers
Martin





Re: 475 With a bowed display. . . .Ideas?

Chuck Harris
 

Hi Michael,

The spot we see is a picture of the active cathode
area, as is collimated and distorted by the grids,
anodes and lenses in the CRT.

Because of slight manufacturing variations that can
make for beam motions that would cause the beam to
completely miss the concentric holes in the shields
and anodes, there is a need for one or two steering
magnets judiciously placed on the neck of the CRT.

If one is missing, your spot could on a worst case
disappear completely. In a less drastic case, it would
chop off part of the circular spot leaving semi circular.

Tektronix used cellophane tape to hold the magnets (if any)
in place on the neck. One steers the beam horizontally,
and one steers it vertically. I have seen the cellophane
tape with empty pockets where the magnet used to go. Usually
the magnet is stuck on the inside of the mumetal shield.

The various elements after the gun that deflect, magnify,
and distort the spherically projected image into a
flat image for display on the screen all affect the
circularity of the spot by making it look like the
wind smeared its shape... they make its shape look more
comet like in appearance.

To be as distorted as you describe (I wish I read that
earlier), you have to have one of your astigmatism,
geometry, or focus elements that is electrically in the
wrong place in the tube. If it is truly like a fish eye
lens, centered on the center of the screen, you probably
have a bad power supply going to one of the pots that
drives the astigmatism, geometry or focus grids.

This is just a guess, but in any case, it is time for you
to verify that all adjustment pots in that area are properly
fed, good, and are somewhere in the center of their range.

Pay particular attention to any circuit complexity that
exists around these grids. Sometimes there are transistorized
distortion circuits that are supposed to warp things into
flat for the screen.

-Chuck Harris

Michael W. Lynch via groups.io wrote:

On Sat, Aug 8, 2020 at 08:22 AM, Chuck Harris wrote:


Typically, when a proper application of the Geometry,
Focus, Astigmatism, Trace Rotation, and other affiliated
adjustments results in a screen that just doesn't look
as pretty as we would like, it means that there has been
an outside physical influence on the CRT (READ: OOPS! BANG!
$%^! & #!!*^! Why Me???)
No signs of major trauma, but this is still a possibility. What confuses me in this regard is the fact the the unfocused spot on the CRT is beautiful and round, one of the best I have ever seen.

The Mumetal shield can get bent, or magnetized.
Not bent, but magnetized? VERY POSSIBLE. I am curious how such magnetization can occur as this issue has come up in other threads as well?

One of the steering magnets (held with Scotch tape) can fall off
of the CRT neck, causing the beam to partially strike one
many internal shield electrodes that looks like a hole in
a plate of metal.
I can look at this when I pull the CRT. Would this not distort the unfocused spot (mentioned above) somehow?

Or, it can be that we are much more nit-picky than tektronix
was originally.
I'm just not that picky. I do not think I am asking too much for the markers to be vertical and consistent across the entire viewing area (or at least within one minor division). If it was just one minor division of deviation, I could live with this, but the outermost vertical markers are about 6 minor divisions "leaned in" at the top of the marker. It is almost like looking through a "fisheye" lens.

If you carefully read the specifications in the manual, you
will often find that we have been spoiled rotten by all of
the CRTs we get that are much better than the specifications
say they could be...
I totally agree. The CRT is one of those items that is a source of constant amazement for me. How they work and withstand decades of use and many times abuse. They are a marvel.

Bottom Line, sounds like I need to pull the CRT and inspect it for obvious damage. I can try another "known good" CRT, as I have one or two that produce very good and well aligned traces in other machines.
if a "Good CRT" shows the same symptoms in this chassis, then I need to look elsewhere.

I was thinking that I had missed some other related adjustment? I guess not?

Thanks for the valuable input.


Re: eBay / PayPal Changes and our alternatives

Dick Wilson at DiLette Sales <cmdrdick42@...>
 

Eastern Airlines had a high concentration of refugees from Cuba. I suppose that I should have said Cuban Americans. They were known to be staunch supporters of their unions and willing to fight for their rights. My own route often included Miami as a layover. I partied with and know several of them personally. I supported their cause. Carl Icahn was a cold blooded corporate raiding SOB whose greed had no bounds.

On Friday, August 7, 2020, 12:28:15 PM EDT, DaveC via groups.io <davec2468=yahoo.com@groups.io> wrote:

Cubans?

Dave


... What totally shocks me given the high percentage of Cubans that were affected, is that he is still walking around.CmdrDick


Re: 2465 Fan Collet Thingy

saipan59 (Pete)
 

And I would add for folks that are going to fabricate a piece: Don't overlook *wood* as a possible material. Wood comes in a zillion types (at a woodworker's supply store), and some types have very useful properties for "making stuff", while being easier to work with (perhaps) than metal or plastic.

Pete


Re: 2465 Fan Collet Thingy

saipan59 (Pete)
 

Hi Ray,
I see the "Files" section in the menu on the left side of the page, when looking at this page:
https://groups.io/g/TekScopes/topics

Here's a link to the "collet" search, which then shows a PDF file:
https://groups.io/g/TekScopes/filessearch?q=collet

Pete


Re: 2465 Fan Collet Thingy

Dave Daniel
 

On Aug 8, 2020, at 12:10, Raymond Cote <@Bluegrass> wrote:

And just WHERE IS THE FILES SECTION???
I dont see any link to it. Never have
In matters of style, float with the current. In matters of Principle, stand like a rock. “. — Thomas Jefferson —

On Aug 8, 2020, at 06:55, Martin <@musaeum> wrote:

On Fri, Aug 7, 2020 at 01:55 PM, DaveC wrote:
Can you please provide a link to he location of these files? I looked in the group files and there aren’t many. I didn’t see anything relating to a collet.
Hi Dave,

it was explained somewhere in this thread: go into the files section and search for "collet".

cheers
Martin





Re: 2465 Fan Collet Thingy

Raymond Cote
 

And just WHERE IS THE FILES SECTION???
I dont see any link to it. Never have
In matters of style, float with the current. In matters of Principle, stand like a rock. “. — Thomas Jefferson —

On Aug 8, 2020, at 06:55, Martin <@musaeum> wrote:

On Fri, Aug 7, 2020 at 01:55 PM, DaveC wrote:
Can you please provide a link to he location of these files? I looked in the group files and there aren’t many. I didn’t see anything relating to a collet.
Hi Dave,

it was explained somewhere in this thread: go into the files section and search for "collet".

cheers
Martin




Re: 7834 Missing Trace

sdferg7@...
 

The trace only gets fuzzy when I have the calibrator signal plugged in, and only the top half. The issue still comes and goes, usually after I change a setting, e.g. the vertical channel. With no signal the only time the trace flickers from moving up and down is when it goes through the trigger.

Unfortunately the scope only came with 1 vertical plugin, in the right slot, and the pull tab is missing. Is there an easy way to get it out without much disassembly? In the manual it seems the only way to get the black follower tracks out is to have their respective plugin removed to access the screws. When I select the empty left vertical plugin slot I get a flat trace slightly tilted clockwise, maybe 1 or 2 degrees.

I also discovered I was mistaken about the 2 dots, they actually appear to be the minimum and maximum of the right horizontal plugin from the calibrator signal I had plugged in. If I select chop with no signal I get 1 brighter dot from the right plugin, still nothing from the left.

I also did more testing on the scope's calibration. Last night after the scope was pretty warm I tried measuring a 1.6V battery at 1V/div which showed on the scope as about 3/4 of a division. This morning I tried the same with the scope cold and it came to almost exactly 1 division. This seems to follow my previous experience with the scope reading lower as it gets warm. The scope also seems to read slightly off on the frequency of the calibrator signal, each period shows as slightly less than 1ms. Of course that could be an issue with the calibrator.

Shane


Re: Tektronix 2230

satbeginner
 

Hi Saroj,

I was busy expanding the GridTied Solar panels we have here, hence again my later response.

In terms of temperature, my personal feeling is: The lower, the better.
In my 2215A('s) I have seen temperatures around 60 - 63 Celsius, a temperature I feel comfortable with.
But on the other hand, you have a 2230, so more electronics to power, so maybe higher temperatures in that scope...

In terms of electrical isolation you must keep using the Mica or more modern isolator, but I would add a TO-220 heatsink at both sides of the metal frame where the FET is mounted.
A bit like in this picture: https://groups.io/g/TekScopes/photo/64919/4?p=Name,,2215+repair,20,1,0,0
The addition of the two TO-220 heatsinks will improve lowering the FET's temperature, also with the FAN mounted in place.
Also, do put that little screw in the side panel back in when you close up the scope, that also helps cooling that part of the power supply.

This brings me to the Molex connector you still see in that picture: I never liked them.
They are very susceptible to corrosion, so it is easy to develop an extra serial resistance which will affect the operating settings of the FET, and might even rise the temperature.

So, in addition of what you see in the picture mentioned above, I would solder the wires directly to the FET after mounting it to the metal frame.

Have a nice weekend,

Leo


Re: 475 With a bowed display. . . .Ideas?

 

On Sat, Aug 8, 2020 at 04:40 PM, Michael W. Lynch wrote:


If it was just one minor division of deviation, I could live with this, but
the outermost vertical markers are about 6 minor divisions "leaned in" at the
top of the marker. It is almost like looking through a "fisheye" lens.

I'd think that's way out of range for the electrical Geometry adjustments that you mentioned earlier, so probably something is wrong of the sort that Chuck describes. It may be worthwhile to quickly check if the Geometry adjustment pot's range reaches the intended 0 to +110V. It's GND-related, so not dangerous to measure, unlike grid- and focus- voltage levels.

Re. the "fisheye" appearance: Is the distortion mostly (radially) symmetrical? In that case, I wouldn't think it could be just a moved magnet.

Trying another CRT seems to make sense. Not too much hassle with a 465/475. Just the usual care with the lingering anode voltage.


BTW, re. the first post, Michael wrote:

"Problem was C1442 was bad. High resistance and almost no capacitance, loading the +15V supply."

The high resistance and low capacitance resulted in your meter showing that the average or RMS voltage was too low so good regulation wasn't possible.
C1442 wasn't loading the +15V supply ("high resistance") but loading the 15V supply wasn't possible, since the regulation circuit received practically unbuffered rectified AC. It's probably what you meant.

Raymond