Date   

Re: T0-39 to T0-92

exojam825@...
 

Oz,

So it would depend on what board they would be going in?

Thanks, James


Re: 2465B VERT CAL 02 + CAL 01

Chuck Harris
 

Hi Jean-Paul,

Ok, then I guess I am puzzled about the whole 2901 thing,
as the PG506 can drive most of these pulsers just fine...
turn to HV pulse, max pulse amplitude, adjust the pulser's
bias control, and away you go.

Any out-of-range indication that isn't corrected immediately
will cause the out-of-range bit to be set on the calibration
constant as it is stored. There is no reason for you to
go forward with an known out-of-range indication. Figure
what is wrong, and correct (usually your mistake) it.

-Chuck Harris

Jean-Paul wrote:

Chuck: Miscommunication:

CAL 01 use TG501
CAL 02 Use PG506,

ONLY for transient CAL was I reffering to the old 2901! It is used to just drive the TD pulser.

Yes I did finally finish CAL 01 and it is properl;y calibrated, my question was the internal flow of the CAL 01 when a limit is reached in a particular step.

Jon




Re: 2465B VERT CAL 02 + CAL 01

Jean-Paul
 

Chuck: Miscommunication:

CAL 01 use TG501
CAL 02 Use PG506,

ONLY for transient CAL was I reffering to the old 2901! It is used to just drive the TD pulser.

Yes I did finally finish CAL 01 and it is properl;y calibrated, my question was the internal flow of the CAL 01 when a limit is reached in a particular step.

Jon


Re: 2465B VERT CAL 02 + CAL 01

Chuck Harris
 

First let me state, that in the 10+ years I have been calibrating
2465 scopes, I have never found one that didn't meet its CAL01
calibration without any problems. Never a limit that I couldn't
fix by properly following the instructions... Never.... not once.

If you are using a 2901 as your marker generator, I think
I can see your problem. The 2465 needs 1,2,5,10 marker sequences,
and the 2901 is only 1,5,10, requiring you to punt for the 2 values.

Step 19 needs a 2us pulse, but you only have 1us, or 500ns available,
which allows you to overlap the marker pulses on your bench scope
on the wrong pulse. You are aiming for overlap on pulses that are
2us apart, but if you use 1us pulses, you can get your overlap on
1us, 2us, or 3us spacing, and never know it. It is all in how you
set your bench scope's holdoff control.

You really need to use the marker pulses tek says you should if you
want to be successful.

If you don't really care all that much, do it the 2465 way, and forget
the bench scope and B gate signal method, and just use your eye on
the graticule lines. Or do that using your 2901, and do the overlap
on the closest pulse after you line things up by eye.

The procedure cannot iterate, as everything is digital, and comes
out exactly the same every time. You simply adjust until you reach
the tolerance they suggest in the table, and you are done. I always
adjust to the closest I can reach, but settle on the same point each
time, or I would have to do the back and forth forever.

My tunnel diode pulser needs a minimum of 50Vpp to work properly.

Jean-Paul wrote:

Dear Chuck, many thanks for these precice diagrams. I found it easier to count the number of pulses per division, as you have mentioned in an earlier post.

I did the entire CAL in sequence, PSU, DAC REF and CRT CAL as you reccomend

Confusion/iteration:

Step 19 >>hits limit
Step 20>> may hit limit or be OK
next step returns to 19 same problem

When I said Iteration I mean the procedure should iterate between limit steps and converge but it does not)

_________________________________________

NOTES:

a. Checked A1 IC temps after hours on:

U800, one hybrid 38-42 deg C
all other hybrids 28-32 deg C

Applied small fan. All IC temps on A1 now 25-28 deg C (used IR probe)

b. Discovered that the TU-5 pulser (and probably other TEK TD pulsers) can operate from the ancient TEK 2901 time mark generator.

You take the 25V 1 K ohm marker amplifier output! I set the gen for 10 or 100 usec markers.

This is very convenient as the 2901 is a small self contained generator.

Enjoy!

Jon




Re: T0-39 to T0-92

Oz-in-DFW
 

the power dissipation capability and parasitics are different even if the die is the same. If the application is low power and non-critical, it should be fine.


Re: 2465B VERT CAL 02 + CAL 01

Jean-Paul
 

Dear Chuck, many thanks for these precice diagrams. I found it easier to count the number of pulses per division, as you have mentioned in an earlier post.

I did the entire CAL in sequence, PSU, DAC REF and CRT CAL as you reccomend

Confusion/iteration:

Step 19 >>hits limit
Step 20>> may hit limit or be OK
next step returns to 19 same problem

When I said Iteration I mean the procedure should iterate between limit steps and converge but it does not)

_________________________________________

NOTES:

a. Checked A1 IC temps after hours on:

U800, one hybrid 38-42 deg C
all other hybrids 28-32 deg C

Applied small fan. All IC temps on A1 now 25-28 deg C (used IR probe)

b. Discovered that the TU-5 pulser (and probably other TEK TD pulsers) can operate from the ancient TEK 2901 time mark generator.

You take the 25V 1 K ohm marker amplifier output! I set the gen for 10 or 100 usec markers.

This is very convenient as the 2901 is a small self contained generator.

Enjoy!

Jon


Re: 2247A PSU Troubleshooting

Chuck Harris
 

Getting bit by the anode voltage on a charged CRT feels
about the same as a good winter carpet zap to a light
switch.

It is startling, but hardly harmful for most normal folk.

Voltage jumps the gap, but for your life, current is where
the damage is at. A 10uf cap charged to 400V is way more
dangerous to your life than any CRT.

-Chuck Harris

Richard in NC via Groups.Io wrote:

I was only referring to the linemans glove for the high voltage on the 2nd anode when it was removed from the tube. Not to wear. I used to repair TV sets for Heathkit years ago when I was recently out of high school. I have been bit by 40kv before. Luckily most of my electronics repair career was in 2 way communications and later medical electronics in a hospital.

73 Richard W4MCD




Re: 2247A PSU Troubleshooting

Richard in Edenton NC
 

I was only referring to the linemans glove for the high voltage on the 2nd anode when it was removed from the tube. Not to wear. I used to repair TV sets for Heathkit years ago when I was recently out of high school. I have been bit by 40kv before. Luckily most of my electronics repair career was in 2 way communications and later medical electronics in a hospital.

73 Richard W4MCD


Re: 2465B VERT CAL 02 + CAL 01

Chuck Harris
 

Hi Jean-Paul,

I'm not sure what you mean by "was very long", and iteration
has no place in this calibration.

Newbies often get confused by tektronix's counts of marker
numbers, and graticule lines. A clue would be that the
markers are always lined up on graticule lines.

Every step that says 2 and 10 means:

|..|..|..|..|..|..|..|..|..|..|
o..*..o..o..o..o..o..o..o..*..o

Every step that says 4 and 28 means:
|..|..|..|..|..|..|..|..|..|..|
ooo*ooooooooooooooooooooooo*ooo

And 3 and 19 means (I have to change the scale):

|...|...|...|...|...|...|...|...|...|...|
o.o.*.o.o.o.o.o.o.o.o.o.o.o.o.o.o.o.*.o.o


Where "*" is the highlight marker, and "o" is a marker.

This is why it is *very important* to do the entire CRT
ADJUSTMENTS section before you do CAL 1, 2, 3... If you
don't, you will not be able to line the markers up with the
graticule lines, and you will get limits errors.

When you do the CAL 1 marker stuff, several steps will first
tell you to align 2 and 10, and then tell you to align 4 and 28.

Both steps are inter-related. You do the best overlay as you
can with 2 and 10... usually perfect, and then try to get as
close as you can with 4 and 28... usually off one or two small
divisions. The routine will bop you back to the 2 and 10 check,
and then to the 4 and 28 check. If you don't change anything, you
will then move on to the next step.

-Chuck Harris

Jean-Paul wrote:

Dear Chuck
Mille mercis encore for all your sage advise and experience!

I finished the cal of #1, 2467 OPT 06/09 ser B0104xx. I had every cal cable, test fixture and generator. All went fine but a few questions please.

1/ CAL 01 HOR was very long, at 3 steps for B sweep, I could not align traces and hit limits, so the procedure would step back and reiterate many times. The result did not converge to a solution, the bench scope trace separation got worse or better each time, but did not close for about 20 iterations each of the 3 steps.

Perhaps my initial pulse count was off?
Is it better to approach a limit and then end step or to hit the limit and end step?
How does the test program converge if you hit limits? After hours I finally finished and it IS calibrated!

2. This is an early unit, thru hole A5 with separate RAM and battery. I used the closest manual, for 2467: SN B011246 and above, the UIT is SN B0104xx

For CAL 06, transient response near the end, the scope steps deviated, with many additional steps not in the manual.
I just passed thru all of those and the result seems OK. Do you have any manual for this low SN 2467? (at least for CAL 06)?

Now just Three more to go, 2465B/2467B with better manuals, this old brain may still have a few neurons to spare..
As I follow the CAL procedures and finish, I can only marvel at the engineering and performance of these 30 years old machines!

Happy to have your comments and guidance!

Bon journée,

Jon


Re: 2247A PSU Troubleshooting

Richard in Edenton NC
 

If this helps, I had the same issue when I troubleshot my IFR1500 power supply. With isolation of my DUT and my test meter. So I ended up measuring my voltages in the power supply using a portable DMM that it battery powered. Plus I unplugged the power supply each time I needed to move the probes. Then only plugged it in once I was clear the device and DMM. It's slower but you only risk a DMM and not getting shocked.

And leave 1 hand in your pocket so you don't grab anything and create a path across your body if you accidentally slip.

73 Richard W4MCD


Re: 2465B VERT CAL 02 + CAL 01

Jean-Paul
 

Dear Chuck
Mille mercis encore for all your sage advise and experience!

I finished the cal of #1, 2467 OPT 06/09 ser B0104xx. I had every cal cable, test fixture and generator. All went fine but a few questions please.

1/ CAL 01 HOR was very long, at 3 steps for B sweep, I could not align traces and hit limits, so the procedure would step back and reiterate many times. The result did not converge to a solution, the bench scope trace separation got worse or better each time, but did not close for about 20 iterations each of the 3 steps.

Perhaps my initial pulse count was off?
Is it better to approach a limit and then end step or to hit the limit and end step?
How does the test program converge if you hit limits? After hours I finally finished and it IS calibrated!

2. This is an early unit, thru hole A5 with separate RAM and battery. I used the closest manual, for 2467: SN B011246 and above, the UIT is SN B0104xx

For CAL 06, transient response near the end, the scope steps deviated, with many additional steps not in the manual.
I just passed thru all of those and the result seems OK. Do you have any manual for this low SN 2467? (at least for CAL 06)?

Now just Three more to go, 2465B/2467B with better manuals, this old brain may still have a few neurons to spare..
As I follow the CAL procedures and finish, I can only marvel at the engineering and performance of these 30 years old machines!

Happy to have your comments and guidance!

Bon journée,

Jon


Re: MR501 photo album uploaded

Glydeck
 

Walter,

Nicely done! Thank you for sharing.

George KD6NEW

On Jul 22, 2019, at 10:39 AM, Mike Dinolfo <mdinolfo@erols.com> wrote:

Walter:
Could you provide a url to the on-line photo(s)? I looked at w140.com, and on the Tekscopes groups.io site, but I couldn't locate it/them. Although it's probably staring me in the face as I type.

Thanks!
Mike Dinolfo N4MWP



Re: MR501 photo album uploaded

Mlynch001
 

Nice! Now if I can only find one of these rare plug-ins for my TM506. I like projects like this, even though I probably would not use this too much.

Thanks Walter!

--
Michael Lynch
Dardanelle, AR


Re: MR501 photo album uploaded

 

the album is here:
https://groups.io/g/TekScopes/album?id=93348
currently the first album in our photo section, so it should have been easy to find...

-walter

--
Walter Shawlee 2
Sphere Research Corp. 3394 Sunnyside Rd.
West Kelowna, BC, V1Z 2V4 CANADA
Phone: +1 (250-769-1834 -:- http://www.sphere.bc.ca
+We're all in one boat, no matter how it looks to you. (WS2)
+All you need is love. (John Lennon)
+But, that doesn't mean other things don't come in handy. (WS2)
+Nature is trying very hard to make us succeed, but nature does not depend on us.
We are not the only experiment. (R. Buckminster Fuller)


Re: 2247A PSU Troubleshooting

Ken Eckert
 

Rule I was taught when I was a young sprog, one hand in the pocket. Most
dangerous shock is hand to hand, goes right across the chest, and your
heart.

But then I started my career on vacuum tube/transistor equipment. B+ of
400V was routine!

On Monday, July 22, 2019, <tekscopegroup@miwww.com> wrote:

If you are not able, unwilling or scared to get an occasional nip while
working on scopes or any other electronic equipment with voltages higher
than 40-50v probably best to stay away from them in the first place. Trying
to work on any electronic circuit while wearing linesman gloves is a silly
overoptimistic thought. Just implement safe practices that make sense for
the equipment that you plan on working on and that's it. If you ever get
some sort of Jacobs Ladder electric arc project going, then buy those
linesman gloves, and get a pair of round welders glasses as well to go with
the mad scientist outfit ;-)




Re: 2247A PSU Troubleshooting

tekscopegroup@...
 

If you are not able, unwilling or scared to get an occasional nip while working on scopes or any other electronic equipment with voltages higher than 40-50v probably best to stay away from them in the first place. Trying to work on any electronic circuit while wearing linesman gloves is a silly overoptimistic thought. Just implement safe practices that make sense for the equipment that you plan on working on and that's it. If you ever get some sort of Jacobs Ladder electric arc project going, then buy those linesman gloves, and get a pair of round welders glasses as well to go with the mad scientist outfit ;-)


Re: MR501 photo album uploaded

 

Walter:
Could you provide a url to the on-line photo(s)? I looked at w140.com, and on the Tekscopes groups.io site, but I couldn't locate it/them. Although it's probably staring me in the face as I type.

Thanks!
Mike Dinolfo N4MWP


Re: 2247A PSU Troubleshooting

 

Good Lineman's gloves are expensive.

Regards

On 7/22/2019 10:51 AM, Chuck Harris wrote:
I would be truly frightened, for your equipment's sake, if
you were to start poking around in it, wearing such a clumsy
linesman's glove.

Working in linesman's gloves will be quite similar to working
in a pair of boxing gloves.

PPE like a linesman's gloves will be unuseable for any real
testing and repair of test instruments, and will require you
to keep taking them off to probe this, or adjust that, or
adjust your glasses, or scratch yourself, and you will soon
find yourself caught doing unsafe things without your PPE.

Linesman's gloves are meant for people who work with large
wrenches, and hammers, and test equipment that comes attached
to 10 foot fiberglass poles. They are as much to keep splinters
out of your fingers, as they are to keep you from being distracted
by a little otherwise harmless tingle from a capacitively coupled
floating power line.

It is far better for you to learn to work safely, then it
is for you to delude yourself into thinking that any gimmick can
protect you from your unsafe practices.

-Chuck Harris

Richard in NC via Groups.Io wrote:
Nielson I like the idea of using a linemans glove. Where would I go about finding one for sale?

73 Richard W4MCD




MR501 photo album uploaded

 

I just added some initial photos showing the before and after of the MR501 converted to a curve tracer. works very well, now I just have to re-do the faceplate. The album is called:
MR501/SC501 conversion to "Huntron Tacker".
The schematic IS INCLUDED! I left the horizontal gain pot installed, so the display can be sized right as the range switch is changed. the vertical gain pot is removed, and will get set for nominal full scale deflection.

I think I may add a 10V zener on a switch across the test port, so I can cal the graticule for 1V/div, allowing it to accurately check low voltage zeners (10 divisions on the faceplate). this was one of the already modded MR501's used in some kind of receiver, as shown on the W140 site, mine said SC501 on the faceplate, but was really an MR501 inside. The mod can be done to an SC501 as easily.

more to follow once I get the front finished. This will certainly be more use to me than the raw plug in was.
you could also just add these few parts to a blank plugin (wired to the floating 25V winding), and jumper it to an existing SC502-504 scope, works fine either way. it's a quick project.
all the best,
walter (walter2 -at- sphere.bc.ca)
sphere research corp.


Re: Vintage 7104 with all 4 plugs , lookg for trade or sell

 

I did not get a PM
Your emall address is missing the domain ?

What is your full email address?

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