Date   

Re: Time for an inventory or size really does matter

Chuck Harris <cfharris@...>
 

In the usual basement shop, with a ceiling full of exposed
floor joists, it is easy to install lift points between the
joists, using 2x4 framing hangers, and short sections of iron
pipe. Then you use a come-a-long to give the heavy instrument
some altitude. Don't stand underneath it!

That is how I put my machines on their bench stands, and how
I got my fluke HV AC calibration amplifier, all 140lbs, in its
rack.

Consumer grade block and tackle sets have too much friction to
be of much use. To effectively use a block and tackle, it needs
to have ball bearings in its pulley sheaves.

-Chuck Harris

Harvey White wrote:

On Sun, 14 Apr 2019 06:29:59 +0000 (UTC), you wrote:

Yeah; ;-) except dollies can't lift from the top. My hand truck gets a lot of use...
Hmmm, swing out arm with a block and tackle?

Harvey



-Dave
On Saturday, April 13, 2019, 7:25:45 AM PDT, Harvey White <madyn@dragonworks.info> wrote:

On Fri, 12 Apr 2019 23:44:32 +0000 (UTC), you wrote:

A buddy of mine has one, and it works really well- I think he's gotten away with lifting 700lbs with it.
I have an air powered hoist rated at 300, which is all I'd put my garage roof through without extra support (I've done 900lbs with a chain hoist and supports). What I really need is a hoist that folds up, doesn't have long extensions, fits through a narrow door way, has large wheels so it works over grass/dirt/transitions, can lift via a table or sling, and can handle anything form a scope to a pallet of scopes... we can dream...
Part of this sounds like a refrigerator dolly....

Harvey


Re: Time for an inventory or size really does matter

Harvey White
 

On Sun, 14 Apr 2019 06:29:59 +0000 (UTC), you wrote:

Yeah; ;-)  except dollies can't lift from the top.  My hand truck gets a lot of use...
Hmmm, swing out arm with a block and tackle?

Harvey



-Dave
On Saturday, April 13, 2019, 7:25:45 AM PDT, Harvey White <madyn@dragonworks.info> wrote:

On Fri, 12 Apr 2019 23:44:32 +0000 (UTC), you wrote:

A buddy of mine has one, and it works really well- I think he's gotten away with lifting 700lbs with it.
I have an air powered hoist rated at 300, which is all I'd put my garage roof through without extra support (I've done 900lbs with a chain hoist and supports).  What I really need is a hoist that folds up, doesn't have long extensions, fits through a narrow door way, has large wheels so it works over grass/dirt/transitions, can lift via a table or sling, and can handle anything form a scope to a pallet of scopes...  we can dream...
Part of this sounds like a refrigerator dolly....

Harvey




When I last moved one of my 19" racks (full), I had to lay strips of plywood and masonite across the back yard- that wasn't a fun move!
-Dave
    On Friday, April 12, 2019, 11:15:20 AM PDT, Michael A. Terrell <terrell.michael.a@gmail.com> wrote:

https://www.harborfreight.com/500-lbs-capacity-hydraulic-table-cart-61405.html










Re: More Complete List of Concept Series and Measurements Concepts Books

Dave Daniel
 

Yep.

Mouse over the links; a "blue" link will resolve directly to the PDF. A "red" link resolves to the login page, which indicates that the file is not yet ready to be accessed.

I don't know why the latter is true, but apparently that's the way it currently works.

DaveD

On 4/14/2019 5:40 AM, Dave Voorhis wrote:
Looks like the manuals linked in blue are downloadable. The ones in red appear not to have been uploaded yet.

On 14 Apr 2019, at 10:26, David C. Partridge <david.partridge@perdrix.co.uk> wrote:

TekWiki < http://w140.com/tekwiki/wiki/File:062-053.pdf>

At the bottom there's a bit that says "Pages that link to this page" and a
highlighted link "Manuals" which takes me to a list of manuals.

When I click a pdf filename I get the complaint to which I referred.

D.

-----Original Message-----
From: TekScopes@groups.io <mailto:TekScopes@groups.io> [mailto:TekScopes@groups.io <mailto:TekScopes@groups.io>] On Behalf Of Dave
Daniel
Sent: 14 April 2019 01:51
To: TekScopes@groups.io <mailto:TekScopes@groups.io>
Subject: Re: [TekScopes] More Complete List of Concept Series and
Measurements Concepts Books

Which website

Sent from a small flat thingy

On Apr 13, 2019, at 19:45, David C. Partridge
<david.partridge@perdrix.co.uk> wrote:
Hmmm when I go back to the manuals page and try to click on any of the pdf
files for that manual or other manuals, I get a page that says:

Login required
Please login to upload files

Dave


Re: some way to get alternating display of two different sweep rates on a 7904A?

John Griessen
 

On 4/14/19 5:51 AM, Albert Otten wrote:
It works fine when you use 2 time bases and horizontal ALT.
Yes, I got good results following the manual sec 2 p 5-7 -- like this:


https://www.cibolo.com/forsale/Tek-7904A-ALT-ALT-14.jpg

Before that screenshot, I had trigger problems with one time base, and I cleaned card edge contacts
and was then able to get triggering with the first two time bases.


Re: 7S12 with S-4 and S-53 troubleshooting

Nenad Filipovic
 

Thank you all for your advice, I just tested the sampling gate of my S-4
and believe it's good. Since I don't have a curve tracer, I improvised one
using a 7854, 7A26 and 7A22 driven by a triangle ramp from FG504 (-5V to
+5V, as the S-4 instruction manual says, 1.5kΩ for current limiting). I
took some fiddling to get accurate measurements, I uploaded everything to:
https://groups.io/g/TekScopes/files/S-4%20sampling%20gate%20diode%20test%20measurements

There are 4 sets of measurements:
01 - forward bias of both diode groups, 1mA/div vertical scale (1Ω current
sensing resistor), 2Hz triangle ramp frequency
02 - reverse bias of individual diodes, 10μA/div (1Ω current sensing
resistor), 2Hz triangle ramp frequency
03 - reverse bias of individual diodes, 1μA/div (10Ω current sensing
resistor), 2Hz triangle ramp frequency
04 - reverse bias of individual diodes, 1μA/div (100Ω current sensing
resistor), 0.02Hz triangle ramp frequency

Measurements 01 and 04 are valid (with minor offset errors), the rest may
be interesting for the curious. Measurement 02 showed that diodes C and D
are different from the rest, having a lower forward bias resistance.
Measurement 03 is with higher vertical sensitivity, and it showed notable
hysteresis in the reverse bias region of diodes C and D (what is shown is
the positive slope of the ramp). Reducing the frequency from 2Hz to 0.02Hz
eliminated the hysteresis (never would have thought that reverse recovery
could be so slow, but yet its <1μA we're looking at here) and increasing
the current sensing resistor to reduce hum/interference led to measurement
04.

The S-4 manual says "...vertical deflection factor of 0.001mA/div will
probably include some hum loops..." and "any one diode that shows any
discernible leakage is a cause to reject a whole Sampling Gate....". So if
I'm to trust my measurements, I'd say this one is alive and well? :)

I did not find any info on how to test the snap diode. Any suggestions?

Best Regards, Nenad


Re: some way to get alternating display of two different sweep rates on a 7904A?

Albert Otten
 

It works fine when you use 2 time bases and horizontal ALT.
With just one time base it works the way I said. Then with AC triggering it works regardless the relative vertical position of the traces, but this is tricky. When you separate the traces further (with one of the Position knobs) then also both traces get dimmer: after a trace switch the AC trigger coupling needs time to settle to the new DC level. With sine wave input in stead of square wave you should also see a horizontal shift in trace trigger points to the top of the lower waveform and the bottom of the upper waveform think (I didn't try).

Albert

On Sun, Apr 14, 2019 at 02:05 AM, John Griessen wrote:


On 4/13/19 3:59 PM, Albert Otten wrote:
Hi John,

Step 19 requires that the A time base can be triggered from both 7A plugins
at one and the same trigger level. As you noted that was problematic and you
chose to set the level correct for the left 7A; hence the right 7A won't
trigger the time base; the sweeps stop unless you set AUTO.
Likely you use DC triggering. And you positioned the traces in the upper
half and in the lower half, so at quite different DC levels and hence trigger
output levels. What happens when you move one trace up or down, or when set
the time base for AC triggering?

Instead of trying AC, I tried another scope and it works fine, and the lights
say right vert A, and left vert A when in ALT and
ALT. That gives tow traces with different time bases. Here's a photo:

https://www.cibolo.com/forsale/Tek-7904A-ALT-ALT-14.jpg


Re: More Complete List of Concept Series and Measurements Concepts Books

Dave Voorhis
 

Looks like the manuals linked in blue are downloadable. The ones in red appear not to have been uploaded yet.

On 14 Apr 2019, at 10:26, David C. Partridge <david.partridge@perdrix.co.uk> wrote:

TekWiki < http://w140.com/tekwiki/wiki/File:062-053.pdf>

At the bottom there's a bit that says "Pages that link to this page" and a
highlighted link "Manuals" which takes me to a list of manuals.

When I click a pdf filename I get the complaint to which I referred.

D.

-----Original Message-----
From: TekScopes@groups.io <mailto:TekScopes@groups.io> [mailto:TekScopes@groups.io <mailto:TekScopes@groups.io>] On Behalf Of Dave
Daniel
Sent: 14 April 2019 01:51
To: TekScopes@groups.io <mailto:TekScopes@groups.io>
Subject: Re: [TekScopes] More Complete List of Concept Series and
Measurements Concepts Books

Which website

Sent from a small flat thingy

On Apr 13, 2019, at 19:45, David C. Partridge
<david.partridge@perdrix.co.uk> wrote:

Hmmm when I go back to the manuals page and try to click on any of the pdf
files for that manual or other manuals, I get a page that says:

Login required
Please login to upload files

Dave


Re: More Complete List of Concept Series and Measurements Concepts Books

 

TekWiki < http://w140.com/tekwiki/wiki/File:062-053.pdf>

At the bottom there's a bit that says "Pages that link to this page" and a
highlighted link "Manuals" which takes me to a list of manuals.

When I click a pdf filename I get the complaint to which I referred.

D.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Dave
Daniel
Sent: 14 April 2019 01:51
To: TekScopes@groups.io
Subject: Re: [TekScopes] More Complete List of Concept Series and
Measurements Concepts Books

Which website

Sent from a small flat thingy

On Apr 13, 2019, at 19:45, David C. Partridge
<david.partridge@perdrix.co.uk> wrote:

Hmmm when I go back to the manuals page and try to click on any of the pdf
files for that manual or other manuals, I get a page that says:

Login required
Please login to upload files

Dave

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Soren
Jorvang
Sent: 13 April 2019 14:52
To: TekScopes@groups.io
Subject: Re: [TekScopes] More Complete List of Concept Series and
Measurements Concepts Books

On 13 Apr 2019, at 14.58, Chuck Lippmeier <chuck@lippmeier.com> wrote:
I also have a Tek book named, "Semiconductor Diodes and Transistors
Programmed Instruction Volume I Basics", Tek Pub 062-0053-00. Printings
in
1963, 66, 67 & 68. Inside it mentions that there is also a Volume II
"Diode
Devices". Volume I is the most in depth study of semiconductor physics
I've
ever seen. That's saying something since I have a BS in electronics. I'd
very much like to own/read other "Programmed Instruction" Tek books
(especially Vol 2 and any volumes in this series) but this is the only
one
I've ever seen.
http://w140.com/tekwiki/wiki/File:062-053.pdf

Also, http://w140.com/tekwiki/wiki/Concepts_Series


--
Soren






Documentation on and Accessoires for LV511.

Egge Siert
 

Hi to All,

Acquired recently a LV511 System (Mainframe and Testhead). On this moment I'am looking for additional Documentation and Accessoires. I allready have its User Manual. The LV511 is in fact an "upgraded" DAS9200. A system I allready own and which is working flawlessy in combination with a simulated X-Windows Terminal.

Because of VintageTek Org Scanning Service (as a way to support them) I mailed them for the missing Documentation (with PN's). They confirmed the existence/availability of this Documentation and they will look for it. That was one month ago. A renewed request gives till now again no follow up. For me this is now a dead end (sorry to say). Therefore this request on TekScopes.

Greetings and in advance thank you for any help in this,

Egge Siert


Re: Time for an inventory or size really does matter

Dave Seiter
 

Yeah; ;-)  except dollies can't lift from the top.  My hand truck gets a lot of use...
-Dave

On Saturday, April 13, 2019, 7:25:45 AM PDT, Harvey White <madyn@dragonworks.info> wrote:

On Fri, 12 Apr 2019 23:44:32 +0000 (UTC), you wrote:

A buddy of mine has one, and it works really well- I think he's gotten away with lifting 700lbs with it.
I have an air powered hoist rated at 300, which is all I'd put my garage roof through without extra support (I've done 900lbs with a chain hoist and supports).  What I really need is a hoist that folds up, doesn't have long extensions, fits through a narrow door way, has large wheels so it works over grass/dirt/transitions, can lift via a table or sling, and can handle anything form a scope to a pallet of scopes...  we can dream...
Part of this sounds like a refrigerator dolly....

Harvey




When I last moved one of my 19" racks (full), I had to lay strips of plywood and masonite across the back yard- that wasn't a fun move!
-Dave
    On Friday, April 12, 2019, 11:15:20 AM PDT, Michael A. Terrell <terrell.michael.a@gmail.com> wrote:

https://www.harborfreight.com/500-lbs-capacity-hydraulic-table-cart-61405.html





Re: More Complete List of Concept Series and Measurements Concepts Books

Dave Daniel
 

Which website

Sent from a small flat thingy

On Apr 13, 2019, at 19:45, David C. Partridge <david.partridge@perdrix.co.uk> wrote:

Hmmm when I go back to the manuals page and try to click on any of the pdf
files for that manual or other manuals, I get a page that says:

Login required
Please login to upload files

Dave

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Soren
Jorvang
Sent: 13 April 2019 14:52
To: TekScopes@groups.io
Subject: Re: [TekScopes] More Complete List of Concept Series and
Measurements Concepts Books

On 13 Apr 2019, at 14.58, Chuck Lippmeier <chuck@lippmeier.com> wrote:
I also have a Tek book named, "Semiconductor Diodes and Transistors
Programmed Instruction Volume I Basics", Tek Pub 062-0053-00. Printings in
1963, 66, 67 & 68. Inside it mentions that there is also a Volume II
"Diode
Devices". Volume I is the most in depth study of semiconductor physics
I've
ever seen. That's saying something since I have a BS in electronics. I'd
very much like to own/read other "Programmed Instruction" Tek books
(especially Vol 2 and any volumes in this series) but this is the only one
I've ever seen.
http://w140.com/tekwiki/wiki/File:062-053.pdf

Also, http://w140.com/tekwiki/wiki/Concepts_Series


--
Soren






Re: 577 Curve tracer ringing CRT and noisy step generator

Dave Voorhis
 

On 13 Apr 2019, at 23:30, wilson2115@outlook.com wrote:

Dave

You mnetion your display filter doesn't appear to work, mine didn't appear to either. In the manual it stated when using the filter the rate of change must be very slow as I guess it takes time for the filter to react, I thought maybe from that its uses are limited and maybe helps with very low sensitivity. I will try playing around with the filter more and observe the results
The Display Filter on mine causes the display to vertically shrink and distort. I suspect failure of one of the two diodes and/or capacitors in the filter.


Re: some way to get alternating display of two different sweep rates on a 7904A?

John Griessen
 

On 4/13/19 3:59 PM, Albert Otten wrote:
Hi John,
Step 19 requires that the A time base can be triggered from both 7A plugins at one and the same trigger level. As you noted that was problematic and you chose to set the level correct for the left 7A; hence the right 7A won't trigger the time base; the sweeps stop unless you set AUTO.
Likely you use DC triggering. And you positioned the traces in the upper half and in the lower half, so at quite different DC levels and hence trigger output levels. What happens when you move one trace up or down, or when set the time base for AC triggering?
Instead of trying AC, I tried another scope and it works fine, and the lights say right vert A, and left vert A when in ALT and ALT. That gives tow traces with different time bases. Here's a photo:

https://www.cibolo.com/forsale/Tek-7904A-ALT-ALT-14.jpg


Re: More Complete List of Concept Series and Measurements Concepts Books

 

Hmmm when I go back to the manuals page and try to click on any of the pdf
files for that manual or other manuals, I get a page that says:

Login required
Please login to upload files

Dave

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Soren
Jorvang
Sent: 13 April 2019 14:52
To: TekScopes@groups.io
Subject: Re: [TekScopes] More Complete List of Concept Series and
Measurements Concepts Books

On 13 Apr 2019, at 14.58, Chuck Lippmeier <chuck@lippmeier.com> wrote:
I also have a Tek book named, "Semiconductor Diodes and Transistors
Programmed Instruction Volume I Basics", Tek Pub 062-0053-00. Printings in
1963, 66, 67 & 68. Inside it mentions that there is also a Volume II
"Diode
Devices". Volume I is the most in depth study of semiconductor physics
I've
ever seen. That's saying something since I have a BS in electronics. I'd
very much like to own/read other "Programmed Instruction" Tek books
(especially Vol 2 and any volumes in this series) but this is the only one
I've ever seen.
http://w140.com/tekwiki/wiki/File:062-053.pdf

Also, http://w140.com/tekwiki/wiki/Concepts_Series


--
Soren


Re: 577 Curve tracer ringing CRT and noisy step generator

DW
 

Dave

You mnetion your display filter doesn't appear to work, mine didn't appear to either. In the manual it stated when using the filter the rate of change must be very slow as I guess it takes time for the filter to react, I thought maybe from that its uses are limited and maybe helps with very low sensitivity. I will try playing around with the filter more and observe the results


Re: 577 Curve tracer ringing CRT and noisy step generator

DW
 

I will look into this, probe around, and see where the break in the chain is. Thanks for the helpful replies


Re: 577 Curve tracer ringing CRT and noisy step generator

DW
 

Yes I have the D1 version and no it was not turned on. I have turned it on and it works however, thanks for the reply


Re: some way to get alternating display of two different sweep rates on a 7904A?

Albert Otten
 

Hi John,

Step 19 requires that the A time base can be triggered from both 7A plugins at one and the same trigger level. As you noted that was problematic and you chose to set the level correct for the left 7A; hence the right 7A won't trigger the time base; the sweeps stop unless you set AUTO.
Likely you use DC triggering. And you positioned the traces in the upper half and in the lower half, so at quite different DC levels and hence trigger output levels. What happens when you move one trace up or down, or when set the time base for AC triggering?

Albert

On Sat, Apr 13, 2019 at 09:36 PM, John Griessen wrote:


I'm wanting to show 100X speed difference triggered off same signal's edge,
faster than chop allows,
so use vet mode ALT and horiz mode ALT.

I have these in slots left to right:

7A19, 7A26, 7B71, 7B92A

So far I find in the manual section 2 p 7 "slaved alternate" operation. I've
tested that my scope does that correctly
up to step 18 of prelim setup in
w140.com/Tektronix_7904A_OCRed_by_Tabalabs.pdf

Steps 15 16 17 18 are about vertical deflection system.

15 says connect calibrator to both L and R vertical amps, get a 2 div tall
signal displayed. (vert mode A was set)
16 notice only the pos knob of L amp affects trace. position trace to
upper half (yes)
17 set vert mode to Right. set R amp to display 2 div tall signal (yes,
requires changed A trigger level)
18 notice only the pos knob of R amp affects trace. position trace to lower
half (trace stops since A trig lvl different)
19 set vert mode to ALT, see two traces. (I only see one at a time unless
trig in auto)

in auto the rest of the steps match except the R vert trace is not triggered
-- it free runs with vert mode = Right.

Is the trigger used supposed to be with the vert mode chosen? If so, mine is
not using B trig with vert mode Right.
Checking another scope now. This 7904A, B010104, just came out of storage and
could be broken.


Re: some way to get alternating display of two different sweep rates on a 7904A?

John Griessen
 

I'm wanting to show 100X speed difference triggered off same signal's edge, faster than chop allows,
so use vet mode ALT and horiz mode ALT.

I have these in slots left to right:

7A19, 7A26, 7B71, 7B92A

So far I find in the manual section 2 p 7 "slaved alternate" operation. I've tested that my scope does that correctly
up to step 18 of prelim setup in w140.com/Tektronix_7904A_OCRed_by_Tabalabs.pdf

Steps 15 16 17 18 are about vertical deflection system.

15 says connect calibrator to both L and R vertical amps, get a 2 div tall signal displayed. (vert mode A was set)
16 notice only the pos knob of L amp affects trace. position trace to upper half (yes)
17 set vert mode to Right. set R amp to display 2 div tall signal (yes, requires changed A trigger level)
18 notice only the pos knob of R amp affects trace. position trace to lower half (trace stops since A trig lvl different)
19 set vert mode to ALT, see two traces. (I only see one at a time unless trig in auto)

in auto the rest of the steps match except the R vert trace is not triggered -- it free runs with vert mode = Right.

Is the trigger used supposed to be with the vert mode chosen? If so, mine is not using B trig with vert mode Right.
Checking another scope now. This 7904A, B010104, just came out of storage and could be broken.


Re: some way to get alternating display of two different sweep rates on a 7904A?

Doug Bercich
 

First, a disclaimer; I have a 7854 - not a 7904 - but they seem to have the same middle section and controls.

Set up 2 time base units as you need. Then you need to direct the triggering controls to the appropriate vertical plugins using the trigger source push buttons in that middle area; A is the left horizontal plugin, B is the right. Select either left or right vertical plugin as needed. Then use the right bank of illuminated buttons to chop or alternate the sweeps. Generally ALT works better for higher frequency sweeps while CHOP is better for slower stuff. I’m sure there are plenty of exceptions.

-d

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