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Re: How much does 106 of Peter Keller's CRT books weigh?

snapdiode
 

Is there no special book rate you can get from the USPS?

https://faq.usps.com/s/article/What-is-Media-Mail-Book-Rate


Re: Asking for Help with Verifying Genuineness of 2465B from Ebay

Chuck Harris <cfharris@...>
 

Trace rotation can change if you bang the scope around....

But more likely is that "calibrated and tested" means that
it was calibrated and tested at some point in its life.

I would expect an A to be about 1ns rise time.

trise = 0.350ns/fbw(in MHz) -> 1ns.

I don't hold much confidence in the trise measurements
these scopes make for themselves...

Note, that the screen is all marked out for trise measurements.
The 0% and 100% markings at full scale are for the flat tops,
and flat bottoms of the waveform. The measurement is at the
10% and 90% graticule lines.

Many seem to think that the full scale is for the peak spike,
but it really isn't a part of the measurement.

-Chuck Harris

Mr. Eric wrote:

Thank you everyone.

Yes Zenith, I messed up the title and wrote 2465B, I meant 2465A in the title. Thank you for catching that.

It is definitely not a 2467, no microchannel plate crt.

So it sounds like the consensus is that a 670-9268-07 A1 board is a 2465A, and the 07 just refers to a revision of the board that was made after the published date of the 2465A/2467 service manual that I have and therefore the revision 07 is not mentioned in it.

The ebay seller was picky2000. I had searched the messages of this group and didn't find anything negative about this seller which is one of the reasons I bought it from him. What threw me off was that the description said calibrated and tested, but when I received it the trace rotation was wayyyy off and the geometry setting is noticeably off too. Voltage levels look good, but I only have a basic 15Mhz function gen to test with, I don't have a leveled sine-wave gen to do any better tests.

I did a basic bandwidth test using the leobodnar 30ps risetime pulsegen and I measured a risetime of 1.09ns on this 2465A. I have another 2467 that with the same test shows a risetime of 0.98ns. I was hoping that my 2465A would be a little closer to 1ns. According to what I have read 1.09ns indicates a BW of 0.35/1.09ns = 321.1Mhz (assuming a gaussian response). It was set to the 50ohm load setting. How accurate or adequate of a test this is, I'm not sure...

The 2465A does pass all self tests and the Cal 05 shows Hrs On 1508 PWR On/Off 620, I know the hours can be changed but the CRT looks really good, clean and crisp compared to my 2467 which has 22584 hours, so it would be nice to think that my 2465A actually does have 1508 hours.

Thanks for all the help everyone and sorry for messing up the title.






Re: How much does 106 of Peter Keller's CRT books weigh?

Renée
 

Dennis-
I have done similar and See, no good deed goes unpunished.
Do enjoy the journey...you were able too see and old friend.
You are greatly appreciated for all you do.
May you and your family have a Merry Christmas.
Renée

On 12/21/20 1:33 PM, Dennis Tillman W7pF wrote:
My original idea if I got orders for 10 to 15 of Peter Keller's CRT books
was to have him ship them to me and I would mail them out to the individuals
who ordered them.

(Please feel free to form a line and kick me for what happened next. You
might say I was off by a little bit!)
My bright idea to get a few of these wonderful books into member's hands
worked too well. I had 20 orders by later that first day. Job well done I
thought to myself. If only it had stopped there!

By the time the flood of emails finally stopped I had payments for 106
books. In postal terms this comes to five boxes of 20 books each weighing
42lbs (19Kg) and one box of 6 books. Total weight 222Lbs (101kg). The cost
to ship this to me was going to be VERY expensive.

I needed a new plan and fast. So I decided to drive to Peter's house to pick
them up. He lives exactly 4 hours, 191miles (307km) from me. It was nice to
see him and his wife in person once again. Plus this gave me a chance to
talk to Peter about optical experiments he used to do at Tek measuring the
response of phosphors. Peter also designed the optical portion of the J16
Digital Photometer and its optical heads as well as the J17 and J18.

I went to the Post Office today to check it out. The lines are impossibly
long with people mailing presents. That will not change until after
Christmas (Dec. 25 in the US). Since it will take me a few days to put the
books in corrugated mailers I should be ready to face the window clerk at my
local Post Office on Monday. I'm not sure how he / she will react when they
see me wheel in 106 individually addressed books but it will be a long
morning for both of us.

Dennis Tillman W7pF




Re: How much does 106 of Peter Keller's CRT books weigh?

 

On Mon, Dec 21, 2020 at 10:33 PM, Dennis Tillman W7pF wrote:


Since it will take me a few days to put the
books in corrugated mailers I should be ready to face the window clerk at my
local Post Office on Monday. I'm not sure how he / she will react when they
see me wheel in 106 individually addressed books but it will be a long
morning for both of us.
C'mon Dennis, I'd love to have my book soon but please wait until things won't be as busy! You may have to wait half a day until it's your turn, only to be sent away because they're too busy...

Raymond


How much does 106 of Peter Keller's CRT books weigh?

 

My original idea if I got orders for 10 to 15 of Peter Keller's CRT books
was to have him ship them to me and I would mail them out to the individuals
who ordered them.

(Please feel free to form a line and kick me for what happened next. You
might say I was off by a little bit!)
My bright idea to get a few of these wonderful books into member's hands
worked too well. I had 20 orders by later that first day. Job well done I
thought to myself. If only it had stopped there!

By the time the flood of emails finally stopped I had payments for 106
books. In postal terms this comes to five boxes of 20 books each weighing
42lbs (19Kg) and one box of 6 books. Total weight 222Lbs (101kg). The cost
to ship this to me was going to be VERY expensive.

I needed a new plan and fast. So I decided to drive to Peter's house to pick
them up. He lives exactly 4 hours, 191miles (307km) from me. It was nice to
see him and his wife in person once again. Plus this gave me a chance to
talk to Peter about optical experiments he used to do at Tek measuring the
response of phosphors. Peter also designed the optical portion of the J16
Digital Photometer and its optical heads as well as the J17 and J18.

I went to the Post Office today to check it out. The lines are impossibly
long with people mailing presents. That will not change until after
Christmas (Dec. 25 in the US). Since it will take me a few days to put the
books in corrugated mailers I should be ready to face the window clerk at my
local Post Office on Monday. I'm not sure how he / she will react when they
see me wheel in 106 individually addressed books but it will be a long
morning for both of us.

Dennis Tillman W7pF


Re: Asking for Help with Verifying Genuineness of 2465B from Ebay

TomC
 

On 12/21/2020 12:11 PM, Raymond Domp Frank wrote:

AFAIK, the 2467 has the BW of the 2465A, 2465B and 2467B both have a specified BW of 400 MHz.
Any of the above (whether 350 or 400) should be better than my 300 MHz 2465 that has a rise time measured at 0.91 nsec.


Re: Thoughts About Modern Tek Scopes

amirb
 

On Mon, Dec 21, 2020 at 01:06 AM, Jeff Dutky wrote:


I plan to get a modern DSO at some point, either a Rigol or Siglent 4 channel
scope at 100 or 200 MHz, but just saw a TDS5054 on eBay for about the same
price as the Siglent scope I've been thinking about. Aside from the higher
bandwidth, the 5054 also has separate controls for each vertical input, which
I would prefer to the the single multiplexed control on the Siglent (and most
modern low-end DSOs).

My only concern is that the 5054 is clearly running Windows, which I don't
like, but I feel that I should not dismiss it out of hand just because they
used an operating system I detest.

I don't expect a modern DSO to deliver the same kind of user experience that
I'm used to with the analog scopes from the 70s and 80s, but I'd like to know
what other people's thoughts on using a newer Tek scope are.

So my questions:

Is this a good scope?
Is it worth getting this rather than newer Chinese scope?
What about buying a non-working unit, are they repairable?

-- Jeff Dutky
two things that you'll lose over the chinese scopes that you mentioned are size/weight and record length. These TDS5000 series are pretty bulky and "loud" (like TDS7000 I assume) and the record length at maximum option is 8M single channel/ 2M four channel (that is if you have option 2M). If bench space is important, you probably need to stay away from TDS5000/7000
but I think on almost everything else they are superior to those chinese ones.
the computer side is easily repairable and even upgradable to better CPU and winxp but the acquisition board is hard or maybe impossible to repair depending on what the error is.
have a look at the datasheet...


Re: Thoughts About Modern Tek Scopes

 

On Mon, Dec 21, 2020 at 07:06 AM, Jeff Dutky wrote:


Is this a good scope?
Is it worth getting this rather than newer Chinese scope?
I won't comment, for fear of price increases

What about buying a non-working unit, are they repairable?
Price just came back down, unless a PSU issue.

Raymond


Re: Thoughts About Modern Tek Scopes

Roy Thistle
 

On Sun, Dec 20, 2020 at 10:06 PM, Jeff Dutky wrote:


but just saw a TDS5054 on eBay for about the same price as the Siglent scope
I've been thinking about.
A lot can happen in 6 days on Ebay. My guess is it won't go for less than 1000.00USD... which is a lot more than a Chinese manufactured oscilloscope, sold by a Chinese company.


Re: Thoughts About Modern Tek Scopes

amirb
 

On Mon, Dec 21, 2020 at 03:48 PM, Roy Thistle wrote:


On Sun, Dec 20, 2020 at 10:06 PM, Jeff Dutky wrote:


just saw a TDS5054 on eBay
I not saying someone can't, or shouldn't ... but, I wish people wouldn't post
links to Tek stuff for sale on Ebay... it probably causes someone I'd like to
pay more... and someone I wouldn't like to get more.
I second that but did he post a link? i dont think so. He has a good and valid question


Re: SUCCESS! The "sick" 475A is now the "fixed" 475A!

Dave Peterson
 

Jeff,
Just some thoughts from looking at the schematics:
Can you verify the effect of X-Y Time/Div setting on the emitter of Q1338? The entire circuitry around Q1338: wasn't your original issue with Z-axis blanking? That's one of the inputs, along with chop blanking and X-Y setting, which all affect this circuit.
The "Z-Axis Compensation" procedure examines the TP1364 voltages as well. Can you get a good waveform per the procedure with Time/Div at 0.05us (or is it 0.02us for 475A)? This might tell you if Q1338 and associated circuits are behaving as expected. Does the spot brighten when you push Beam Find?

Can you verify that the output of R1375 is varying appropriately? The 475 schematic has a note: ".100" at the cathode of 1373. Can't tell what this would/should be in X-Y mode, but I'd be curious to verify that the resistor divider and VR1374 are working.
Dave

On Monday, December 21, 2020, 02:55:33 AM PST, Jeff Dutky <jeff.dutky@gmail.com> wrote:

It looks like I might have declared success a little bit prematurely. While the Z-axis amp now works, I am having some trouble in the calibration process (and not simply because I don't have any of the calibration fixtures).

I did step 1: Adjust Power Supply DC Levels, and a little tweak brought the 50V supply up to just below the 50.25V maximum.

I skipped step 2: Check High Voltage Power Supply, because I (still) lack a high voltage probe, and because this is just a check, there is not process to make any changes if the supply does not meet the spec. (I've ordered an HV probe for my DMM and will check the HV test point when that arrives after Christmas).

Step 3: Adjust CRT Grid Bias is where my difficulty starts. I can't get a visible dot on the CRT at the  prescribed 15V level. I have to turn the intensity knob up almost to maximum, a reading of 24V at TP1364 before I see anything on screen. I also don't have any room to adjust the trim pot, R1375, to brighten the spot; R1375 is already turned to it's limit, and turning the other direction dims the spot on screen.

The result is that the remainder of the grid bias process fails because the trace brightness is much too low.

This seems a little odd, as under normal use I only need to set the brightness control at about the 40%/11 o'clock mark to get a visible trace, so I know that the CRT isn't pooping out. I suspect that there is still something broken in the Z-axis/beam intensity system.

I'm currently looking over the schematics to see what might be causing this, and to understand how I should go forward diagnosing it, but I would appreciate any suggestions.

-- Jeff Dutky


Re: Thoughts About Modern Tek Scopes

Roy Thistle
 

On Sun, Dec 20, 2020 at 10:06 PM, Jeff Dutky wrote:


just saw a TDS5054 on eBay
I not saying someone can't, or shouldn't ... but, I wish people wouldn't post links to Tek stuff for sale on Ebay... it probably causes someone I'd like to pay more... and someone I wouldn't like to get more.


Re: Asking for Help with Verifying Genuineness of 2465B from Ebay

 

On Mon, Dec 21, 2020 at 09:10 PM, Mr. Eric wrote:


Realistically, the seller probably just said calibrated and didn't actually
adjust anything,
I love this! As has been written before, "calibrating" in its pure sense means nothing more than comparing against something considered a standard. Without specifying the results, i.e. deviations, it means nothing.

That "standard" only makes sense if its deviations from some agreed standard are known and within specified limits. "NIST calibration" means compared against ...

Raymond


Re: Asking for Help with Verifying Genuineness of 2465B from Ebay

 

On Mon, Dec 21, 2020 at 08:58 PM, TomC wrote:


Using Leo Bodnar's pulse generator, my 2465 (no A or B) measures 0.91 nsec.
I've found the automatic parametric tests in this family inaccurate and varying in their results.
Of course, rise time measured depends on overshoot. Accepting 3% - 5% overshoot during rise time adjustment (not uncommon) results in significant shorter rise time than accepting "0%" overshoot.
Converting observed rise time into BW, especially with different step sources is not something to specify within 0.1%. 1% complies more with "the truth".

And your 2467 should certainly be substantially better.
AFAIK, the 2467 has the BW of the 2465A, 2465B and 2467B both have a specified BW of 400 MHz.

Raymond


Re: Asking for Help with Verifying Genuineness of 2465B from Ebay

Mr. Eric
 

Jeff,

That's very interesting, I had no idea that the local magnetic field would have such an impact. But that completely makes sense why its an operator control. Thanks for that info.

I will say though that after looking at the ebay images in more detail, the trace rotation is off in the seller's pictures as well =) Would this also have an effect on the geometry? I'm judging geometry by the delta_t cursor lines, they are mildly bowed in the center of the cursors toward the center of the crt. However this might just be a failure of understand on my part and the cursors being slightly bowed has no bearing on an actual signal...

Realistically, the seller probably just said calibrated and didn't actually adjust anything, or did the absolute bare minimum


Re: Asking for Help with Verifying Genuineness of 2465B from Ebay

 

On Mon, Dec 21, 2020 at 08:41 PM, Jeff Dutky wrote:


I'd expect that even the frame of a building, or nearby electrical,
laboratory, or medical devices could affect the rotation.
Gravity is a factor. Placing it vertically/horizontally makes a difference. Magnetism would be a very important factor were it not for the mu-metal shield around the CRT. Whether it deserves to be called "wayyyy off" is a matter of opinion. A change of rotation of one, max. two minor divisions across the horizontal would be normal under normal conditions..

Raymond


Re: Asking for Help with Verifying Genuineness of 2465B from Ebay

TomC
 

On 12/21/2020 11:26 AM, Mr. Eric wrote:

I did a basic bandwidth test using the leobodnar 30ps risetime pulsegen and I measured a risetime of 1.09ns on this 2465A. I have another 2467 that with the same test shows a risetime of 0.98ns. I was hoping that my 2465A would be a little closer to 1ns. According to what I have read 1.09ns indicates a BW of 0.35/1.09ns = 321.1Mhz (assuming a gaussian response). It was set to the 50ohm load setting. How accurate or adequate of a test this is, I'm not sure...
Using Leo Bodnar's pulse generator, my 2465 (no A or B) measures 0.91 nsec. So there seems to be something not right with your 2465A. It should be better than my 2465. And your 2467 should certainly be substantially better.

Did you have the horizontal sweep in X10 mode? I used X10 mode and the 0% 10% 90% and 100% graticule lines. Rise time measured using the cursor lines.

Tom


Re: Asking for Help with Verifying Genuineness of 2465B from Ebay

Jean-Paul
 

To Jeff: The TEK CRTs have a fine MuMetal CoNetic shield and are NOT affected by earht or other ext mag fiedls of normal gauss level.

To Eric: >>trace rotation was wayyyy off and the geometry setting is noticeably off too.>>

I have bought many 246x/A/B, never seen that isse.

For the GEOM and ROT "WAY OFF" the trimmers were either maladjusted and NEVER properly set OR the scope was poorly packed and the freight vibration somehow rotated the pots.

More likely scenario: Pots are old and scratchy.

Even if set, they may not have moved in decades.

EVERY old scope potentiomètre controls and trim pots may need cleaning and exercise.

I am sure our mavens like Chuck can shed more light on this.

Enjoy!

Jon


Re: TEK176 fixing a shorted wet tatalum capacitor

Roy Thistle
 

On Sun, Dec 20, 2020 at 01:33 PM, Paul Amaranth wrote:


Well that is an interesting project, hard to say if the sensor tip is
small enough or sensitive enough for similar work though.
The 546A used a tiny current transformer (shaped and shielded to be z-axis directed?)
This Bee thing... They claim to be using a Honeywell Z-axis anisotropic magnetostritive sensor (not a coil based sensor)... supposed good from a few tens of micro-gauss to 6 Gauss... it's about a mm^2 on end.
To me... and this is only my opinion... I don't know the design... but, I think...the Bee is not going to work the way Bee makers are claiming it will. I see evidence of marketing at work. Will some people get stung... could be... just could be.


Re: Asking for Help with Verifying Genuineness of 2465B from Ebay

 

Eric wrote:

What threw me off was that the description said calibrated and tested, but when I received it
the trace rotation was wayyyy off and the geometry setting is noticeably off too.
My impression (please correct me if I'm wrong) is that trace rotation is a correction for the local magnetic field, which is why it is an operator control. If the scope was calibrated (or even merely adjusted) to look good at one location (e.g. San Francisco) then it MUST be out of rotation at a significantly different location (e.g. Chicago). I'd expect that even the frame of a building, or nearby electrical, laboratory, or medical devices could affect the rotation.

-- Jeff Dutky

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