Re: Help Needed- Distortion display using HP334 or equiv.
Thanks! I¡¯ll head over there when I get time . Those old app notes contain a wealth of information, and were intended to teach users, unlike what we get today.
Just like the the theory of operation sections of the old ( circa 60¡¯s / 70¡¯s) service manuals. The current ones have little or no info, as ¡°there are no user serviceable parts inside ¡°¡.
The new scopes are nice , but not something you¡¯d be able to repair like the older ones.
I¡¯ve used some of the high end DSA types (DSA 70804, ?GHz BW) for serial differential data investigations, and it was great, just not repairable. And not small- almost the size of my 555!!!
Thanks again-!
Randy
On Tue, Jan 14, 2025 at 04:45 PM, Randy Newman wrote:
Excellent!
Thanks.
?
Thanks again for the info - I¡¯ll go dredge for Tek & HP App notes - another old favorite. Am familiar with w140 for Tek stuff. Need to brush up on source for HP app notes. Agilent used to host them, but not sure anymore.
?
Randy
?
Randy,
Surf over to .? There, you'll find bunches of App Notes, Bench Briefs, manuals for lots of the OLD equipment, catalogs, and a lot of history.
Cheers,
DaveM
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Re: Help Needed- Distortion display using HP334 or equiv.
On Tue, Jan 14, 2025 at 04:45 PM, Randy Newman wrote:
Excellent!
Thanks.
?
Thanks again for the info - I¡¯ll go dredge for Tek & HP App notes - another old favorite. Am familiar with w140 for Tek stuff. Need to brush up on source for HP app notes. Agilent used to host them, but not sure anymore.
?
Randy
?
Randy,
Surf over to .? There, you'll find bunches of App Notes, Bench Briefs, manuals for lots of the OLD equipment, catalogs, and a lot of history.
Cheers,
DaveM
|
Re: Help Needed- Distortion display using HP334 or equiv.
Excellent! Thanks.
I happen to have a 200CD, stock, so not modified for the low distortion mode. ?
Re: Jim Williams, one of my favorite app note authors. I used to read them from end to end gleaning lots of good info. Also Bob Pease!!
Btw: I¡¯m primarily an analog guy. My day job is in a lab where we have all sorts of data buses, as well as some analogs. Lots of integration work, as well as interface design. Keeps my brain functional, and is great fun.
In reality, it¡¯s all analog anyway when you get down to signal propagation anyway. Also have read Signal propagation books by Dr.Howard Johnson. Great stuff!
Thanks again for the info - I¡¯ll go dredge for Tek & HP App notes - another old favorite. Am familiar with w140 for Tek stuff. Need to brush up on source for HP app notes. Agilent used to host them, but not sure anymore.
Randy
Tek 555, 7834,7633,7623, Data Precision D6100 Waveform Analyzer (M6800 CPU!!), HP, Fluke, and others.
On Tue, Jan 14, 2025 at 9:33?AM Froggie the Gremlin via <jonpaul= [email protected]> wrote: Hello again,
Sid used the same HP 336, but modified it for improved noise floor, hum and THD.
The generator is also critical, I think he had an HP204 also modified
See Jim Williams Linear Technology note (43?) on low distortion audio generator
HP or Tektronix or other DA all have distortion product output, it is the signal fundamental nulled out of the input.
Scope X- input to DUT
Scope Y- distortion output.
See Tek, AP and HP app notes on audio distortion measurement
Beware of amplifer output overload, use appropriate load and Attenuator
Amicalement
Jon
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Re: Help Needed- Distortion display using HP334 or equiv.
Hello again,
Sid used the same HP 336, but modified it for improved noise floor, hum and THD.
The generator is also critical, I think he had an HP204 also modified
See Jim Williams Linear Technology note (43?) on low distortion audio generator
HP or Tektronix or other DA all have distortion product output, it is the signal fundamental nulled out of the input.
Scope X- input to DUT
Scope Y- distortion output.
See Tek, AP and HP app notes on audio distortion measurement
Beware of amplifer output overload, use appropriate load and Attenuator
Amicalement
Jon
|
Re: Tektronix 1503C EL Display...
Hi Burt,
$30.00 is a good price, even if only for parts. The YT-1 printer is a very nice thing to have. These have their own problem though: The rubber pinch roller usually has a flat side or is even (partially) disintegrated/reduced to gum. If yours is fine, that's an exception. These printers are quite reparable though: I repaired my two devices after finding rubber rollers from photocopiers where I could get the rubber sleeves from their steel axes and fit them to and on the YT-1's. Disassembly and reassembly of the YT-1 is a bit of a hassle though.
?
Now here's where I made a mistake: I didn't notice/remember you have a 1503C, not a 1502C. The 1502C is used for relatively short cables (from an inch or so up to 600m) and employs the fast and vulnerable circuits that I was referring to, whereas the 1503C can be used for longer cables only (up to some 15km) and does not employ a fast-rise pulse like the 1502C but a half-sine "pulse". Its send-and receive-circuits are much more robust. The length resolution of the 1503 is much less than that of the 1502, a few decimeters I guess.
?
Do you have a service manual for your 1503C? If not, it should be downloadable from the Internet. The L/R sampler board (leftmost when looking at the front) is where the pulses are generated and received. I would not associate "Intermittent stranges" with a breakdown of the pulse generator/receiver but an adjustment possibly.
?
Raymond
?
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Re: Tektronix 1503C EL Display...
Raymond,
?
Again, thanks for your comments.? The spare one with the defective display came with a YT-1 printer that works great.? In fact, according to the print out, the spare unit works fine, except for the display.? I purchased it off eBay for under $30.00 including shipping.? I couldn't pass it up.
?
You mention the assembly generating and sensing the pulse, where is that physically within the instrument?? I suspect I'm beginning to see some intermittent stranges in the trace, both on the screen and in the printout, although the grid and labels are solid.
?
I've been saving all of your comments in my "Tektronix 1503C" folder.? They're really appreciated!
?
Burt, K6OQK
Glendale, CA
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Re: Help Needed- Distortion display using HP334 or equiv.
On Mon, Jan 13, 2025 at 07:47 PM, Randy Newman wrote:
Hi All: a bit off topic, but saw some mention of display of distortion components by John-Paul (in thread about tube scope probes). This was done at Marsntz, and Sequerra back in the day by their analog guy.
In the HP 334 manual, there are tantalizing mentions of this ability, and a diagram showing distortion products from a CRT I suspect. However, there is no hookup diagram, nor instructions on how to accomplish this display feat.
?
Hoping someone has information to connect the proverbial dots here.
?
Thanks in advance!
?
Randy
?
Tek 555, 7834, 7633,7623, HP, Fluke, and others.
?
?
Randy,
It's very simple.? The distortion products are available at the Output jacks at the lower right corner of your 334 meter.? Just use a coax/jumper wires/scope probe to connect the Output from the 334 to your scope vertical input.? The scope will display all of the noise and distortion present in the input signal (after the 334 has been properly tuned, of course).
?
Cheers,
DaveM
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Help Needed- Distortion display using HP334 or equiv.
Hi All: a bit off topic, but saw some mention of display of distortion components by John-Paul (in thread about tube scope probes). This was done at Marsntz, and Sequerra back in the day by their analog guy.
In the HP 334 manual, there are tantalizing mentions of this ability, and a diagram showing distortion products from a CRT I suspect. However, there is no hookup diagram, nor instructions on how to accomplish this display feat.
?
Hoping someone has information to connect the proverbial dots here.
?
Thanks in advance!
?
Randy
?
Tek 555, 7834, 7633,7623, HP, Fluke, and others.
|
Re: Tektronix 1503C EL Display...
toggle quoted message
Show quoted text
On Jan 13, 2025, at 4:26 PM, Raymond Domp Frank via groups.io <hewpatek@...> wrote:
? On Mon, Jan 13, 2025 at 03:45 PM, Burt K6OQK wrote:
I came across another 1503C that has a defective display - a huge black area on the screen.? I don't believe tat display is salvageable, so it will makes a good cadaver display to experiment on.
Hi Burt,
That *may* be good news but remember: The backlight has a very limited life and it's no biggie to find a replacement and put it in. Fun to play with the defective TDR though.
Another vulnerable part in the 1503C or actually, in all fast TDR's is the assembly generating and sensing the pulse. A spare one from the defective 1503C may come in handy at some stage.
?
Good luck and have fun!
?
Raymond
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Re: Tektronix 1503C EL Display...
On Mon, Jan 13, 2025 at 03:45 PM, Burt K6OQK wrote:
I came across another 1503C that has a defective display - a huge black area on the screen.? I don't believe tat display is salvageable, so it will makes a good cadaver display to experiment on.
Hi Burt,
That *may* be good news but remember: The backlight has a very limited life and it's no biggie to find a replacement and put it in. Fun to play with the defective TDR though.
Another vulnerable part in the 1503C or actually, in all fast TDR's is the assembly generating and sensing the pulse. A spare one from the defective 1503C may come in handy at some stage.
?
Good luck and have fun!
?
Raymond
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TEK 492 Spec Analyz advice, parts
Bonjour, we recieved a fine TEK 492 SA, circa 1980s..1990s, fine condition CAL in 2007. SN B055xxxx
Will post photo album.
Q: Do these have the notorius SMD lytics on some PCB that leak and corrode ?
Which PCBs are suseptible?
WTB: For nonprofit museum , restoration to original condition:
Original TEK front cover
small knob (intnesity, etc)
complete service manual (2 vol, binders) original printed version
MANY THANKS !!
Have an absolutely fantastic day!
Jon
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Re: Tektronix 1503C EL Display...
Hi Raymond, and thanks for your reply.? Your comments are most helpful.? I came across another 1503C that has a defective display - a huge black area on the screen.? I don't believe tat display is salvageable, so it will makes a good cadaver display to experiment on.? I'll report my discoveries to the group.?
?
Thanks,
?
Burt, K6OQK
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Re: Tektronix TDS754D - failing acquisition module tests
Jared and all, Well, I'm happy I held onto that cork. The error is back, essentially the same (regarding U208), just a slightly different address. I'm thinking I may need to recheck that U208 for other connectivity issues (than shorts). Maybe swap another one from the set I have here. Radu.?
On Sat, Jan 11, 2025 at 8:41?PM Jared Cabot via <jaredcabot= [email protected]> wrote: Good to hear ypu got it working!
?
Removing the front panel plastic is easy, just grab to top edge and curl your fingers along the back edge at the top and firmly but carefully lift and pull forward, it will unhook and come away.
Once you do it, it'll be clear how.
?
Try cleaning the buttons and contacts thoroughly.
I wash the rubber membrane with dish soap, then finish with cleaning the carbon contact pads and the PCB with alcohol.
?
If the buttons are still not good, I have had good results with conductive ink.
I found the stuff from 'Bare Conductive' works well to paint a bit onto the rubber pad.
I only used it because it was available locally, but any similar product would work fine.
?
?
Jared.
?
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Re: Tektronix TDS754D - failing acquisition module tests
Good to hear ypu got it working!
?
Removing the front panel plastic is easy, just grab to top edge and curl your fingers along the back edge at the top and firmly but carefully lift and pull forward, it will unhook and come away.
Once you do it, it'll be clear how.
?
Try cleaning the buttons and contacts thoroughly.
I wash the rubber membrane with dish soap, then finish with cleaning the carbon contact pads and the PCB with alcohol.
?
If the buttons are still not good, I have had good results with conductive ink.
I found the stuff from 'Bare Conductive' works well to paint a bit onto the rubber pad.
I only used it because it was available locally, but any similar product would work fine.
?
?
Jared.
?
|
Re: Tektronix TDS754D - failing acquisition module tests
SPC test also completed successfully.? Radu.
On Sat, Jan 11, 2025 at 8:20?AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: There's one issue left, though. One of the buttons on the side of the screen - the one on the right side at the top - is not working well. There's no feel of actuation, so there's something mechanical happening there that needs to be addressed. I'll investigate how to pop the front panel - I think it just needs a vigorous pull to pop out, if I recall correctly - and then see what could?cause this.? Any thoughts on this appreciated.? Radu.?
On Sat, Jan 11, 2025 at 8:08?AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Update on this. (I'm starting to register some success working through my backlog of projects) The second hypothesis above proved to be correct. Running a bunch of self tests seemed to point to errors originating in U207, U208, U214, U216. I replaced those with used but tested chips from a very kind and helpful EEVBlog-er, and I had fewer?errors but still some. The latest tests showed some persistent errors with U208, which I tested for shorts pin to pin?and I determined I had one short. I don't love those SOJ packages! Whoever thought turning the?pins under the body was a good idea... Once that was fixed, it seems to pass all tests. I'm holding off on popping the cork until I give it a good run to make sure there's nothing still happening under long?duty conditions (the initial problems were reported to occur after hours of running). I think that's because the failure of these modules is indeed due to the heat from U200 nearby (which has a decent sized heatsink).? Good news!? Radu.?
On Mon, May 20, 2024 at 8:03?AM Froggie the Gremlin via <jonpaul= [email protected]> wrote: Dear Radu:
About the SMD caps my experience was with 2465B scopes, I had only one TEK digital, TDS540 so no personal knowlege re the SMD cap leakage on yours.
About soldering and desoldering difficulet PCBs, yes TEK had some 4..6 layer PCB with VERY tight or overplated thru holes and pads.
We use ONLY 63/37 or 60/40 LEADED solder, best diameter is 0.032" or 0.81 mm.
Kester 44 OR rosin core flux.
We use our Metcal SP-200 high frequency smart heat solder station (my design 1992)
Suggest to BEWARE ANY EBAY/ALIXPRESSS? ?solder, wire etc.
Bon chance,
Jon
|
Re: Tektronix TDS754D - failing acquisition module tests
There's one issue left, though. One of the buttons on the side of the screen - the one on the right side at the top - is not working well. There's no feel of actuation, so there's something mechanical happening there that needs to be addressed. I'll investigate how to pop the front panel - I think it just needs a vigorous pull to pop out, if I recall correctly - and then see what could?cause this.? Any thoughts on this appreciated.? Radu.?
On Sat, Jan 11, 2025 at 8:08?AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Update on this. (I'm starting to register some success working through my backlog of projects) The second hypothesis above proved to be correct. Running a bunch of self tests seemed to point to errors originating in U207, U208, U214, U216. I replaced those with used but tested chips from a very kind and helpful EEVBlog-er, and I had fewer?errors but still some. The latest tests showed some persistent errors with U208, which I tested for shorts pin to pin?and I determined I had one short. I don't love those SOJ packages! Whoever thought turning the?pins under the body was a good idea... Once that was fixed, it seems to pass all tests. I'm holding off on popping the cork until I give it a good run to make sure there's nothing still happening under long?duty conditions (the initial problems were reported to occur after hours of running). I think that's because the failure of these modules is indeed due to the heat from U200 nearby (which has a decent sized heatsink).? Good news!? Radu.?
On Mon, May 20, 2024 at 8:03?AM Froggie the Gremlin via <jonpaul= [email protected]> wrote: Dear Radu:
About the SMD caps my experience was with 2465B scopes, I had only one TEK digital, TDS540 so no personal knowlege re the SMD cap leakage on yours.
About soldering and desoldering difficulet PCBs, yes TEK had some 4..6 layer PCB with VERY tight or overplated thru holes and pads.
We use ONLY 63/37 or 60/40 LEADED solder, best diameter is 0.032" or 0.81 mm.
Kester 44 OR rosin core flux.
We use our Metcal SP-200 high frequency smart heat solder station (my design 1992)
Suggest to BEWARE ANY EBAY/ALIXPRESSS? ?solder, wire etc.
Bon chance,
Jon
|
Re: Tektronix TDS754D - failing acquisition module tests
Update on this. (I'm starting to register some success working through my backlog of projects) The second hypothesis above proved to be correct. Running a bunch of self tests seemed to point to errors originating in U207, U208, U214, U216. I replaced those with used but tested chips from a very kind and helpful EEVBlog-er, and I had fewer?errors but still some. The latest tests showed some persistent errors with U208, which I tested for shorts pin to pin?and I determined I had one short. I don't love those SOJ packages! Whoever thought turning the?pins under the body was a good idea... Once that was fixed, it seems to pass all tests. I'm holding off on popping the cork until I give it a good run to make sure there's nothing still happening under long?duty conditions (the initial problems were reported to occur after hours of running). I think that's because the failure of these modules is indeed due to the heat from U200 nearby (which has a decent sized heatsink).? Good news!? Radu.?
On Mon, May 20, 2024 at 8:03?AM Froggie the Gremlin via <jonpaul= [email protected]> wrote: Dear Radu:
About the SMD caps my experience was with 2465B scopes, I had only one TEK digital, TDS540 so no personal knowlege re the SMD cap leakage on yours.
About soldering and desoldering difficulet PCBs, yes TEK had some 4..6 layer PCB with VERY tight or overplated thru holes and pads.
We use ONLY 63/37 or 60/40 LEADED solder, best diameter is 0.032" or 0.81 mm.
Kester 44 OR rosin core flux.
We use our Metcal SP-200 high frequency smart heat solder station (my design 1992)
Suggest to BEWARE ANY EBAY/ALIXPRESSS? ?solder, wire etc.
Bon chance,
Jon
|
Re: An excellent fully functional 485 for sale
Attach thenn to your message, or upload them to a website like Dropbox or other free service and provide a link.
On Sat, Jan 4, 2025 at 9:48?AM Lawrance A. Schneider via <llaassllaaass= [email protected]> wrote:
Other people get their pictures on their posts.? I don't what I did wrong.? Any help??
?
Thank you, ? ? ? ? larry
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On 1/4/25 07:48, Lawrance A. Schneider via groups.io wrote: Other people get their pictures on their posts. I don't know what I did wrong. Any help?? I found a setting of thunderbird to show attachments inline and turned it on. Do you use thunderbird? If you are meaning creating an attachment, same question: Do you use thunderbird? Otherwise, with web UI of groups.io, I don't know...
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Re: An excellent fully functional 485 for sale
Other people get their pictures on their posts. ?I don't what I did wrong. ?Any help??
?
Thank you, ? ? ? ? larry
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Froggie the Gremlin
Burt K6OQK
Jared Cabot
Michael A. Terrell