Date   
Re: 2215 problem

Bob Albert
 

Alex, as soon as I get the nerve I will see what I can do.  But I just might stack two supplies with a diode in between to get the 43V. 
What I do know is that the guys at Tektronix who designed this had no concept of what service people have to do.  Oh so clever and so possible to package in a small box.  Yeah I would love to see those engineers in a small box.
Just getting to the power switch is an exercise in lost screws and dangling boards.  The only thing that keeps me going is how nice the unit is when it works.  Maybe I will cobble up a 43 Volt power supply to run it, rather than fix its own problems.  I could put such a unit nicely out of sight on the desk.  After all, power supplies were one of my specialties in my engineering days.
Bob

On Friday, May 31, 2019, 10:14:31 PM PDT, <tekscopegroup@...> wrote:

On Fri, May 31, 2019 at 06:15 PM, tom jobe wrote:
Thanks Everyone,
I've been enjoying this recent 2215 discussion! I have never owned one
but have wondered what they were all about.
Tom, as far as I know, the 2215/A is basically a 2213/A only with dual time base. No other differences, I think.

Alex

Re: Does anyone have a spare tektronix 013-0208-02 hook adapter?

Stephen Hanselman
 

I’ll look in my spares on Monday. We have 400 or so probes. And a BIG box of spare parts.

Regards,

Stephen Hanselman
Datagate Systems, LLC
3107 North Deer Run Road #24
Carson City, Nevada, 89701
(775) 882-5117 office
(775) 720-6020 mobile
s.hanselman@...
www.datagatesystems.com
a Service Disabled, Veteran Owned Small Business
DISCLAIMER:
This e-mail and any attachments are intended only for use by the addressee(s) named herein and may contain legally privileged and/or proprietary information. If you are not the intended recipient, any dissemination, distribution or copying of this e-mail and any attachments is strictly prohibited. If you have received this e-mail in error, please immediately notify me and permanently delete the original and all copies and printouts of this e-mail and any attachments.

On May 31, 2019, at 21:26, tekscopegroup@... wrote:

Noticed that one of my P6137 probes came with the wrong witch's hat and was causing erratic behavior. Upon closer examination I noticed the internal mating point of the hook adapter to the probe tip is actually too wide and designed for a wider 3.5mm probe tip (it works just fine if I use it with the 013-0202-02 2.5-to-3.5mm adapter). I compared it to the working adapter of the other probe and a smaller gap at the mating point is immediately apparent.

So looking at the Subminiature (2.5mm) Probe System Accessories diagram at the link bellow, it seems I am in need of the correct hook adapter which is PN 013-0208-02, but there are currently none on ebay.

http://w140.com/tekwiki/wiki/File:Subminiature_probe_system_accessories_1.jpg

Anyone have one 013-0208-0x kicking around that they want to sell? Even a used one in good shape would be fine.
Paypal & ship to zip 33152 FL.

Thanks for looking.
Alex



MASTECH MS8911 LCR meter would i buy again

George Livanes
 

One of the Forums suggested buying a MASTECH MS8911 surface mount LCR meter
Bought mine from dadatim2015 on ebay for around $43 US
Arrived very quickly from Hong Kong (to Australia)
Using Five LCR meters and my own sub, sub, standards I determined it is
within specs for all ranges except inductors under about 50 Micro henries where
mine Is way out (I measured at all the frequencies)
It defaults to the 100Hz setting in automatic mode (I think I would have preferred 1K)
If you select 1kz will sometimes show overload so you need to start with the 100Hz
It gives you an automatic D measurement, for caps, at the 100 Hz frequency (which is normal freq for D) together with the value for caps.....
so to get an ESR value you need to go to the AC resistance mode and select the highest frequency
10 KHz (ESR normally measured at 100 kHz but found readings to be very close to the
100 kHz used in 3 other ESR meters). Also has a DC resistance mode
Personally, after reading many forums measuring ESR, using any meter in circuit, is definitely a waste of time
It uses a large (25mm) coin battery (a little hard to get and a little expensive) and I suspect it chews some juice...
Shuts down automatically quite often which I find annoying
I like that you can select 0.5v or 0.1v test voltage to stop diodes from conducting
Takes a couple of seconds for an automatic reading but quite reasonable
In summary I would buy it again, nice little meter and quite accurate.
Its economical (would not buy the cheaper Mastech version) and very handy for us old timers
for sorting surface mount chips
Naturally you have to discharge caps before measuring as the meter may not have a lot of
Protection ??
George

Re: DSA602A Random Power Off

Egge Siert
 

Hi Will,

It looks to me as a Thermal Cut-Off issue. All three fans must turn freely and with good speed.

Succes,

Egge Siert

Re: 2215 problem

tom jobe <tomjobe@...>
 

As for the differences between the 2215 and the 2215A that have been involved in this discussion, have a look at this post from almost 15 years ago.
https://groups.io/g/TekScopes/topic/7632008
It was written by one of the very best people we ever had on Tekscopes named Denis Cobley, and the Tekscopes message archive still has many of his excellent posts.
Denis actually made a living fixing test gear!
tom jobe...

https://groups.io/g/TekScopes/topic/7632008

On 5/31/2019 10:14 PM, tekscopegroup@... wrote:
On Fri, May 31, 2019 at 06:15 PM, tom jobe wrote:
Thanks Everyone,
I've been enjoying this recent 2215 discussion! I have never owned one
but have wondered what they were all about.
Tom, as far as I know, the 2215/A is basically a 2213/A only with dual time base. No other differences, I think.

Alex

Re: Strange 7854 problem with bracket holding digital boards

Fred S.
 

Usually this is symptom of a poor contact somewhere. Have you tried to unplug then plug all boards firmly in their connectors, one by one? Eventually, clean their pcb's edge connectors before reinserting them.

Max

Yes, that was my first thought as well. I cleaned all PCB edge connectors and the motherboard connectors. They don't seem to be sensitive, if I move or push the boards while running. If the bracket is in and it boots, knocking on the bracket makes it fail immediately. Looks to me more like a short.

--
Best regards,

Fred S.

Re: Does anyone have a spare tektronix 013-0208-02 hook adapter?

tekscopegroup@...
 

On Fri, May 31, 2019 at 10:42 PM, Stephen Hanselman wrote:
I’ll look in my spares on Monday. We have 400 or so probes. And a BIG box of
spare parts.

Regards,
Stephen Hanselman
Thank you.

Re: 2215 problem

Bob Albert
 

It's been established that the power supply issues in the 2215 were important enough to warrant a major redesign.  I just wish it were more serviceable.
Today my plan is to use an external 43 Volt power supply to try to isolate the problem.  If the problem is in the A18 board which I think is the first regulator, I may just run it from an external supply.  Otherwise, my work is cut out for me to find the problem in the downstream circuitry.
Thankfully this isn't a digital oscilloscope; I am ready to consider those unrepairable.
One of the main reasons this unit is so difficult to service is that it's the result of serious attempts to meet competition.  Just as in automobiles, the Asians present formidable challenges and the westerners have their work cut out for them to match price and performance, including package dimensions.  As a result, I am nearly overwhelmed.
Bob

On Saturday, June 1, 2019, 12:53:08 AM PDT, tom jobe <tomjobe@...> wrote:

As for the differences between the 2215 and the 2215A that have been
involved in this discussion, have a look at this post from almost 15
years ago.
https://groups.io/g/TekScopes/topic/7632008
It was written by one of the very best people we ever had on Tekscopes
named Denis Cobley, and the Tekscopes message archive still has many of
his excellent posts.
Denis actually made a living fixing test gear!
tom jobe...

https://groups.io/g/TekScopes/topic/7632008









On 5/31/2019 10:14 PM, tekscopegroup@... wrote:
On Fri, May 31, 2019 at 06:15 PM, tom jobe wrote:
Thanks Everyone,
I've been enjoying this recent 2215 discussion! I have never owned one
but have wondered what they were all about.
Tom, as far as I know, the 2215/A is basically a 2213/A only with dual time base. No other differences, I think.

Alex


Re: Weird(?) behaviour in tek 492BP power distribution - Please help

 

Hi Folks,
I have been poking with the deflection board while I wait for the HV module and the extension cards, checking diodes and transistors in place for shorts, but I could not find any.
Unfortunately the test result for the output FET's (Horizontal and vertical) where not conclusive, but since it is a multi-layer board, I would not like to desolder all of them just to check.
However, I found another "strange behavior":---- If I remove the metallic shield from the board and put it back on the instrument, there is no change in the values of the +300V and +100V.
The problem comes back if I reinstall the shield, even if I do not install the heat sink screw support- The +300V drops to +250V ans the +100V goes up to +145V.
The funny thing is that pin 34 on the motherboard header is connected to the chassis ground, and I have checked the connections from pin 34 on the MB to Chassis and pin 34 on the to the deflector board connector to ground and they are ok.
Note that there is no HV module plugged.
I could not understand why establishing a mechanical connection of the deflection board ground to the chassis could make any difference since the is a electrical connection doing the same thing.
Also since this board is not connected to the +100V header I don't understand how the aforementioned mechanical connection can influence this voltage.

Re: 2215 problem

Bob Albert
 

I applied 40 Volts to the scope and it works.  So the problem is on the A18 board.  So do I repair it or replace with my own linear supply I can design?
First I will take at least a casual look at A18 and see if perhaps the solution is easy.  I will replace the broken IRF820 then see what else might be going on.
Bob

On Saturday, June 1, 2019, 9:03:35 AM PDT, Bob Albert via Groups.Io <bob91343=yahoo.com@groups.io> wrote:

It's been established that the power supply issues in the 2215 were important enough to warrant a major redesign.  I just wish it were more serviceable.
Today my plan is to use an external 43 Volt power supply to try to isolate the problem.  If the problem is in the A18 board which I think is the first regulator, I may just run it from an external supply.  Otherwise, my work is cut out for me to find the problem in the downstream circuitry.
Thankfully this isn't a digital oscilloscope; I am ready to consider those unrepairable.
One of the main reasons this unit is so difficult to service is that it's the result of serious attempts to meet competition.  Just as in automobiles, the Asians present formidable challenges and the westerners have their work cut out for them to match price and performance, including package dimensions.  As a result, I am nearly overwhelmed.
Bob
    On Saturday, June 1, 2019, 12:53:08 AM PDT, tom jobe <tomjobe@...> wrote:

As for the differences between the 2215 and the 2215A that have been
involved in this discussion, have a look at this post from almost 15
years ago.
https://groups.io/g/TekScopes/topic/7632008
It was written by one of the very best people we ever had on Tekscopes
named Denis Cobley, and the Tekscopes message archive still has many of
his excellent posts.
Denis actually made a living fixing test gear!
tom jobe...

https://groups.io/g/TekScopes/topic/7632008









On 5/31/2019 10:14 PM, tekscopegroup@... wrote:
On Fri, May 31, 2019 at 06:15 PM, tom jobe wrote:
Thanks Everyone,
I've been enjoying this recent 2215 discussion! I have never owned one
but have wondered what they were all about.
Tom, as far as I know, the 2215/A is basically a 2213/A only with dual time base. No other differences, I think.

Alex


Re: 2215 problem

Bob Albert
 

It's working!  I replaced the FET and hooked up all the wires and plugged it in and now I have a working 2215.
I put it back into the case and it's where it belongs.  I didn't replace all the various shields and covers so if I have problems I know what to do.
Thanks to all for your help in this seemingly overwhelming task but common sense and perseverance prevailed.
Bob

On Saturday, June 1, 2019, 1:49:35 PM PDT, Bob Albert via Groups.Io <bob91343=yahoo.com@groups.io> wrote:

I applied 40 Volts to the scope and it works.  So the problem is on the A18 board.  So do I repair it or replace with my own linear supply I can design?
First I will take at least a casual look at A18 and see if perhaps the solution is easy.  I will replace the broken IRF820 then see what else might be going on.
Bob
    On Saturday, June 1, 2019, 9:03:35 AM PDT, Bob Albert via Groups.Io <bob91343=yahoo.com@groups.io> wrote:

  It's been established that the power supply issues in the 2215 were important enough to warrant a major redesign.  I just wish it were more serviceable.
Today my plan is to use an external 43 Volt power supply to try to isolate the problem.  If the problem is in the A18 board which I think is the first regulator, I may just run it from an external supply.  Otherwise, my work is cut out for me to find the problem in the downstream circuitry.
Thankfully this isn't a digital oscilloscope; I am ready to consider those unrepairable.
One of the main reasons this unit is so difficult to service is that it's the result of serious attempts to meet competition.  Just as in automobiles, the Asians present formidable challenges and the westerners have their work cut out for them to match price and performance, including package dimensions.  As a result, I am nearly overwhelmed.
Bob
    On Saturday, June 1, 2019, 12:53:08 AM PDT, tom jobe <tomjobe@...> wrote:

As for the differences between the 2215 and the 2215A that have been
involved in this discussion, have a look at this post from almost 15
years ago.
https://groups.io/g/TekScopes/topic/7632008
It was written by one of the very best people we ever had on Tekscopes
named Denis Cobley, and the Tekscopes message archive still has many of
his excellent posts.
Denis actually made a living fixing test gear!
tom jobe...

https://groups.io/g/TekScopes/topic/7632008









On 5/31/2019 10:14 PM, tekscopegroup@... wrote:
On Fri, May 31, 2019 at 06:15 PM, tom jobe wrote:
Thanks Everyone,
I've been enjoying this recent 2215 discussion! I have never owned one
but have wondered what they were all about.
Tom, as far as I know, the 2215/A is basically a 2213/A only with dual time base. No other differences, I think.

Alex


Re: Weird(?) behaviour in tek 492BP power distribution - Please help

Karin Johnson
 

I don't have one of these instruments, but and this may be a very long shot. Is it possible that one of the harmonica connectors is off by one pin??? Some time ago I was restoring a Tek 7934 and when I put one of the harmonica connectors back to its appropriate mating pins on one of the boards, I found that I installed it incorrectly. It was shifted off by one pin and all of the appropriate connections were none the less incorrect. I only found it by very careful inspection of all the connectors.
Just a thought for you.

Karin

tektronix475 fault hv section? no trace

Jiří Kauč
 

Hi everyone, I have tektronix 475 with issue in hv section, z-axis amp or dc restorer.

I have checked everything on primary site of T1320, all transistors, diodes, resistors and caps - changed almost everyone. Also checked all in-power lines (110, 50, 5, -8 and +15unreg. -> OK). I removed T1320 and made some measurement on it. Seems its working correctly.

So what is going on.:

Oscillator doesnt work if U1321 or T1321 (pin 24 or 25) is connected. When everything is connected I measure over 3 volts on base of Q1306. Causes high frequency noise - I dont really knew what its. Without U1321 and T1320 (pin 24) its .6 volts - no noise.

Measurement on T1364 says: (35,49 kOhms to GND), 5volts without beam, 25 volts with beam. All transistors in this section are good. I removed them from the board and checked. Also all voltages seems to be good (arround transistors).

Attachment:

First photo: T1320 and U1321 connected, measured on collector of Q1318- 0.1ms, 5v/div. ; 3,5 volts on base Q1306. - https://1drv.ms/u/s!AiionITw-oM2goUMdRsIzY_isOnNcA

Second photo: U1321 disconnected, measured on collector of Q1318- 0.1ms, 5v/div. ; 0.68 volts on base Q1306. - https://1drv.ms/u/s!AiionITw-oM2goUO0lT9n6yDFey-9Q

Third photo: U1321 and T1320 (pin 24) disconnected, measured on collector of Q1318- 20us, 5v/div. ; 0.66 volts on base Q1306. - https://1drv.ms/u/s!AiionITw-oM2goUNsa7TzMKtFVZcyQ?e=Fgz4Kp

Please, I spent days on it, im really depressed.

PS: I dont have high voltage probe, i cannot check high voltage.

Re: 2215 problem

tekscopegroup@...
 

Great, now you only need to find out what did you fix without knowing what it was that was wrong. If your IFR820 had the pins connected via a 3-pin plug in socket that is a well known failure point. i believe there is a service note that instructs to solder the wires directly and bypassing the socket altogether. So maybe the simple act of unplugging and plugin back the connector reestablished proper contact.

Re: 2215 problem

Bob Albert
 

No this one was soldered in.  But the lead broke off so easily I wonder how secure it was.  In any case, I did not recinstall the heat sink (not that it is much of one anyway) so I ran the unit for over an hour with no problems.  If it fails I have a spare part and all the pieces I have left over so no problem.
I was very happy to see that only 40 Volts did the job of making the unit work, not the 43 V that is supposed to be applied.  My supply tops out at exactly 40V and I would have had to bring a second unit over.  And the current draw wasn't much.
I tested the 'scope in its intended application, a monitor for my ham station.  It shows the receiver audio on one trace and the transmit RF on the other (via a pickup loop).
Interestingly, when I shut off the scope the trace disappears immediately.  When I switch it on, there is a delay of about 5-10 seconds, even if I have just shut it off.  I wonder if there is a time delay built in.  I also think I may have precipitated the failure due to confusion about the timing.  I recall switching it on and waiting and then it worked.  There was a problem with the power switch so it didn't always switch off.  So I would push and hold the switch a few times to get it to switch off.  Then I switched it on and no trace, so I punched the switch a few more times.  I suspect that created enough of a transient to cause a failure, as that's how a switching supply will fail.  Transients kill them.  Analog circuits, not so much.  Anyway, I sprayed the switch while it was apart and it seems reliable now.
Bob

On Saturday, June 1, 2019, 4:56:30 PM PDT, <tekscopegroup@...> wrote:

Great, now you only need to find out what did you fix without knowing what it was that was wrong. If your IFR820 had the pins connected via a 3-pin plug in socket that is a well known failure point. i believe there is a service note that instructs to solder the wires directly and bypassing the socket altogether. So maybe the simple act of unplugging and plugin back the connector reestablished proper contact.

Re: 2215 problem

magnustoelle
 

Good job, Bob!
Delay on power-up is natural, as the CRT‘s filament is heating up. Powering unit down brings the acceleration HV down immediately, so no trace; which us also natural in my humble opinion.
Cheers,
Magnus 

No this one was soldered in.  But the lead broke off so easily I wonder how secure it was.  In any case, I did not recinstall the heat sink (not that it is much of one anyway) so I ran the unit for over an hour with no problems.  If it fails I have a spare part and all the pieces I have left over so no problem.
I was very happy to see that only 40 Volts did the job of making the unit work, not the 43 V that is supposed to be applied.  My supply tops out at exactly 40V and I would have had to bring a second unit over.  And the current draw wasn't much.
I tested the 'scope in its intended application, a monitor for my ham station.  It shows the receiver audio on one trace and the transmit RF on the other (via a pickup loop).
Interestingly, when I shut off the scope the trace disappears immediately.  When I switch it on, there is a delay of about 5-10 seconds, even if I have just shut it off.  I wonder if there is a time delay built in.  I also think I may have precipitated the failure due to confusion about the timing.  I recall switching it on and waiting and then it worked.  There was a problem with the power switch so it didn't always switch off.  So I would push and hold the switch a few times to get it to switch off.  Then I switched it on and no trace, so I punched the switch a few more times.  I suspect that created enough of a transient to cause a failure, as that's how a switching supply will fail.  Transients kill them.  Analog circuits, not so much.  Anyway, I sprayed the switch while it was apart and it seems reliable now.
Bob

On Saturday, June 1, 2019, 4:56:30 PM PDT, <tekscopegroup@...> wrote:

Great, now you only need to find out what did you fix without knowing what it was that was wrong. If your IFR820 had the pins connected via a 3-pin plug in socket that is a well known failure point. i believe there is a service note that instructs to solder the wires directly and bypassing the socket altogether. So maybe the simple act of unplugging and plugin back the connector reestablished proper contact.

11801 software error

Jerry
 

A person I've bought some gear from unearthed an 11801. The original problem with the unit was the power switch of all things. I had swapped in an 11301 power supply when it wouldn't come up and after screwing around I found the power switch. I then got it to come to an operating screen by skipping the tests and taking the battery backup packs off of u500 and u501. I had found these hints around on the web.

I'm getting a trace but after a while I get and error across the top, "Software Error" with some hex code underneath. Any ideas?

The guy wanted $100 for it with the SD-24 sample head. I told him I didn't have time to mess with it and he gave it to me with the proviso that If I saw some value I would give him the cash or return it. It's an interesting unit but the last thing I need is another scope. But If I can clear up this error, I might keep it.

Unless I get some hints on here about the software error I'm going to enable the diagnostics again and see where they lead me. There must be some RAM failing or ROM that isn't being read correctly as it heats up.

Thanks

Jerry

Re: TDS744 not 'A' has a problem , help needed

Brian
 

Hi Stephen ,I have been thinking about the manual calibration process and your suggestion that I should be prepared to spend a whole day doing it . I am very unlikely to be able to spend a whole day just doing that without interruptions , is it possible to do the calibration in stages or does it all have to be done in one unbroken run ?
Brian

On Friday, 31 May 2019, 20:36:25 BST, Brian via Groups.Io <brianas1948=yahoo.co.uk@groups.io> wrote:

Hi Stephen ,
I'm pleased to hear it can all be done manually and it will be great to know how you get on with the calibration and to know your setup . When I know that I can check my gear and see if I can match the spec where its needed - for frequency accuracy if needed I have counters operating up to 40GHz should I need to use a sig gen thats not one of the synthesized ones .
Brian

    On Friday, 31 May 2019, 01:32:32 BST, Stephen Hanselman <kc4sw.io@...> wrote:

Brian,

I have a 540 waiting for me after the 8566 and 8662.  Yes the process can be done manually. It’s sort of amusing that they imply automatic, but their equipment call out is all manual.

I’ll try and get my system up on Friday and get the configurations I use

Regards,

Stephen Hanselman
Datagate Systems, LLC
3107 North Deer Run Road #24
Carson City, Nevada, 89701
(775) 882-5117 office
(775) 720-6020 mobile
s.hanselman@...
www.datagatesystems.com
a Service Disabled, Veteran Owned Small Business
DISCLAIMER:
This e-mail and any attachments are intended only for use by the addressee(s) named herein and may contain legally privileged and/or proprietary information. If you are not the intended recipient, any dissemination, distribution or copying of this e-mail and any attachments is strictly prohibited. If you have received this e-mail in error, please immediately notify me and permanently delete the original and all copies and printouts of this e-mail and any attachments.
On May 30, 2019, at 14:29, Brian via Groups.Io <brianas1948=yahoo.co.uk@groups.io> wrote:

Hi Steve , how strange it needs the info in both places , I'll make notes so I dont forget that . I do have extended memory cards for the old PC's but I think I am likely to use windows 95/98 when I get around to doing this and then I'm sure it can use virtual memory on the hard disk if there is not enough main memory - I still have copies of s/w like ramdoubler if things get desperate .I have copies of the cal s/w from a guy on EEblog who put up the files for 500,600,700 series scopes , I have not run them yet so I hope there are no problems .Can the whole process be done manually as I am more likely to try that because the instruments I have are almost certainly not compatible with the GPIB cal s/w , some do not have a GPIB port at all .
Its good to speak to someone who has done it as it makes it feel so much more possible for me to do it
Brian

    On Thursday, 30 May 2019, 21:58:02 BST, Stephen Hanselman <kc4sw.io@...> wrote:

I suspect you have a better shot at it than I did.  One other thing when setting up the PC set files and buffers up a good bit also add some more memory above the base 640K.  also the config file for the cal software has a line that alleges to define the place it looks for the HPIB card.  It has two possible "places", I'll look later, and you need to put the card info into both of them.  This even happened on my Tek DM system.


Have you got the cal program files?

steve

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Brian via Groups.Io
Sent: Thursday, May 30, 2019 1:06 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] TDS744 not 'A' has a problem , help needed

Hi Steve , thank you for that . I have heard several ideas about the NVRAM contents , one is said to hold just saved waveforms and setups and the other holding cal data and installed options , cant remember which is said to do what so I'll need to search EEblog again . I have heard it said also that there are a couple of NVRAM chips underneath the acquisition pcb , little 8 pin chips , that hold factory cal data but that it is only a copy of one of the Dallas chips and is there for emergency's for use at a cal center , those 2 chips are there even on my non A version . The same source if I remember correctly said that the system does not actually use this data it relies on the Dallas chip .
I have a Fluke DC calibrator and 6.5,7.5 and 8.5 digit DVM's. Signal generators , I have synthesized gen's up to 18GHz but their output is too low , but I do have a couple of small  1MHz - 5GHz amps with output up to 20dBm that might make it possible . the final output will not be levelled directly but the input will be , to make certain I do have HP438A power meter and sensors , I also have a RACAL true RMS voltmeter that is good to 2GHz .Unlike some here I do have several old PC's with windows 95/98 could even run windows 3.11 , I have also the NI PC2A GPIB cards and drivers and a copy of the cal s/w

I am in the UK if you hadnt guessed so I think we are more than just a few miles apart or I would be happy to join you for that after school project Brian

    On Thursday, 30 May 2019, 20:32:31 BST, Stephen Hanselman <kc4sw.io@...> wrote:

I've heard the talk flow both ways but to my knowledge the calibration data is held in NVRAM on the Acquisition pca not in the Proc.  I've looked in several of the Dallas Chips and mostly what you see is empty space.  I suspect, but have no proof, that these things are used to store trace data.  I have taken non-working (fails SPC etc) and swapped in working calibrated Acq and had it remember it's calibration data.

Calibration requirements are actually fairly lax.  You need a good, accurate DC source, DMM, and after that almost any reasonable sig gen would work.  I have SG503 and SG504 the scope tells you if the particular signal you are looking at from the "SG's" is correct and then goes off and calibrates itself.  The initial DC calibrations are critical  however.  The las thing is a HPIB based controller to run the test suite.  I tried several incarnations and finally bought a Tek Data Manager.  Given no experience and all manual TE I would plan on a full day for the cal, and be prepared to become extremely bored.

If you look at your diagnostics screen where it shows SPC, Voltage ref, Frequency...... there are 4 states Initialized (after cold start), running, passed, failing.  I found out the hard way that even when you pass the CVR testing voltage ref may say "running"  although not next in the sequence you have to run probe comp to get it to read "passing"  there are a few other gotchas in the software similar to this.

If you were close by I'd tell you to bring it in as an afterschool project, but...

Hope this helps you a bit.  Like they say though, your mileage may vary

steve

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Brian via Groups.Io
Sent: Thursday, May 30, 2019 8:19 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] TDS744 not 'A' has a problem , help needed

Hi Stephen , fortunately the scope remembers the date and the clock is running fine . I have NVRAM back-up s/w from EEBLOG so hopefully it will keep a record of the contents assuming it works on the much older scopes but I cant see why it shouldnt . I do have some GPIB experience and enough gear to connect to the scope .The scope does have nice options for me 13,1f,2f,2m so I dont really want to loose any of themThe Dallas chips are DS1650Y and DS1486 , I understand that one of them holds calibration data - I dont know that even with the gear I have a complete recalibration would be possible so I need to keep that info as intact as possible for as long as I can . Any calibration equipment that I dont currently have will take time to get hold of as I am retired and only a hobbyist/collector .

    On Thursday, 30 May 2019, 16:03:41 BST, Stephen Hanselman <kc4sw.io@...> wrote:

Brian,

Changing out these chips is not really a problem. While they do keep some scope specific info I’ve operated 540A’s without the chip.  If you have a vanilla model, no options I’m not sure it’s worth the effort.  EBay, yes I know, has some replacements, when you look at the offerings look for one that has a “+” in the part number. So it seems like these are newer ones. The Tek forum has a thread that gives the cross wiring needed to program the Dallas chip in a more common NVRAM environment.

On the other hand if your scope remembers the date and time the chip is probably ok, for a while.

My technique is to add fresh solder to each pin and then heat the pin, not the board, and suck it out.  I then insert a socket.  So far I have not had an issue with losing data in the chip.

As it stands I have good images for the 540, 540A, and 540B.

Regards,

Stephen Hanselman
Datagate Systems, LLC
3107 North Deer Run Road #24
Carson City, Nevada, 89701
(775) 882-5117 office
(775) 720-6020 mobile
s.hanselman@...
www.datagatesystems.com
a Service Disabled, Veteran Owned Small Business
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On May 30, 2019, at 07:53, Brian via Groups.Io <brianas1948=yahoo.co.uk@groups.io> wrote:

Hi Bob , thank you . That was only the second one of those scopes I've had anything to do with , I am mostly 500 series + 661 and 564 along with 7000 series and 24XX .  My first one was a TDS420A with a dead PSU , changing the caps revived it , nothing else was wrong with it . The TDS744 was also one that did not start up , after sorting out the PSU the other faults showed themselves , it was the first time fixing a component level fault on an acquisition pcb . I now have to do something about the Dallas chips they are dated '93!!

    On Thursday, 30 May 2019, 15:26:46 BST, Bob Koller via Groups.Io <testtech=yahoo.com@groups.io> wrote:

Well done!



















Re: 7A13 relay substitution report

tomford717@...
 

Hi Fabio,

I'm going through the same 7A13 repair as you are. My Tek relays are failing and three rotors have fallen out of the air-variable input tuning caps.

I chose the Fujitsu NA12W-K as my replacement relay and decided to replace them all. The Fujitsu is rated at 220 VDC and has good specs
at 100MHz. I made a pcb adapter board to simplify the wiring. Only two different pcb patterns were needed to satisfy all of the Tek relay pin-outs.

I included an SMT full wave bridge on the pcb to convert the Fujitsu relays to non-polarity coil types. I've replaced all relays and the four input
attenuator variable caps. The DC offset and gain calibration has gone well. I am partially done with the RF cal and so far, the 3dB BW has been
good to 100MHz using a 50 Ohm source.

My concern now is BW performance when the input attenuators are in operation. I have taken capacitance measurements of the Tek, Fujitsu,
and Omron G6K relays. They all measure about the same when separate. When I mount the Fujitsu relay to the adapter board, the capacitance
between the armature to the open contact jumps from 0.3pF to about 1.7pF. The pcb adapter adds roughly 1.3pF to all four inter-electrode
points I've measured. I'm using a DE-5000 LCR meter @100KHz. I have pics of my progress so far if anyone has an interest.

Thanks,
Tom Ford

Re: 11801 software error

 

You need to have good batteries for those RAM chips. And you need to cycle the scope on and off several times so the data in the NVRAMs gets updated.

This might be a help:

https://www.mouser.com/ProductDetail/511-M48Z3570PC1

You need to order two of them.

Also, If you got the SD-24 in the deal, you really scored. Especially if the SD-24 works.

Regards,

Tom

On 6/2/2019 1:47 AM, Jerry wrote:
A person I've bought some gear from unearthed an 11801. The original problem with the unit was the power switch of all things. I had swapped in an 11301 power supply when it wouldn't come up and after screwing around I found the power switch. I then got it to come to an operating screen by skipping the tests and taking the battery backup packs off of u500 and u501. I had found these hints around on the web.

I'm getting a trace but after a while I get and error across the top, "Software Error" with some hex code underneath. Any ideas?

The guy wanted $100 for it with the SD-24 sample head. I told him I didn't have time to mess with it and he gave it to me with the proviso that If I saw some value I would give him the cash or return it. It's an interesting unit but the last thing I need is another scope. But If I can clear up this error, I might keep it.

Unless I get some hints on here about the software error I'm going to enable the diagnostics again and see where they lead me. There must be some RAM failing or ROM that isn't being read correctly as it heats up.

Thanks

Jerry