Re: Sphere Inc's HP (and Tektronix) Parts Inventory - tekandhpparts.com
Hi Dave,
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Post on TekScopes2 going up now.? Thanks for the reminder.
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Regards,
Tom
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Re: Sphere Inc's HP (and Tektronix) Parts Inventory - tekandhpparts.com
Thank you for the suggestion Radu.? We agree completely and it is on the "to do" list once we get reasonably close to completing a first pass inventory.? In the meantime, I'm happy to go snap a picture for anyone needing it.
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Regards,
Tom
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Hi David,
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Schematics are available (the CLIP from Artek under E4401B) but they only have ONE of the (at least) two versions of the RF Deck. The version in the CLIP is the same as that documented in the Signal Path video. The CLIP says the assy# is E4403-60057. So you should check yours prior to purchasing. As far as I know, schematics for the newer versions are not available.
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Good luck!
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Mark
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Re: HP 8568B Instr Check Light?
Just a follow up.? I finally picked up the unit today for $190.? Turns out you guys nailed it.? The 50 pin connector was broken and the seller probably did not have it seating properly.? I fixed the connector up a little to get the pins in order, carefully plugged the units together, and it is working.? Looks like the connector is available for about $20, so I will be ordering one.?
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It is a nice clean unit.?
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Re: how to convert HP83711B to 83712B!
"tom_iphi via groups.io" <iphi@...> writes: Hi folks, I have converted my HP83711B signal generator into an HP83712B and have added options. See here how I did it: /g/HP-Agilent-Keysight-equipment/files/All%20HP,%20Agilent%20and%20Keysight%20instruments%20in%20folders%20by%20part%20numbers/A%2080000%20to%2089999/83711B%20and%2083712B%2020GHz%20signal%20generators/HP83711B_to_HP83712B.pdf
Maybe useful to someone or just fun to read. Thanks a lot, very interesting read! I also upgraded my 83752B with a 24V step attenuator, while the original one uses 15V. Also seems to work fine. One the 8375X series, there's a attenuator calibration table to compensate each attenuator setting. Does the 8371X have such tables?
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Re: Sphere Inc's HP (and Tektronix) Parts Inventory - tekandhpparts.com
Did you send this message to the TekScopes2 forum as well? I haven't seen this on that forum.
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As many may remember, Walter Shawlee II passed away September of 2023.? Since that time, his wife Susan, and children, have been busying themselves with the task of liquidating much of the electronic goodness that Sphere Research had accumulated.? Susan intends to continue to make their collection of slide rules, nixie tubes and various other items available.? Additionally, she is continuing in her effort to find homes for the remaining equipment.? Please do visit Sphere¡¯s site and help.
Sphere¡¯s inventory of Tektronix and HP parts has found a new home with us.? We have the beginnings of a website (), with the intention of continuing to make these parts available to the Tek and HP enthusiast community.
A bit about us:
1)? The goal of the website is to continue to make Sphere¡¯s inventory available to the people like us that enjoy collecting, repairing and making use of these amazing examples of engineering and manufacturing.
2)? A secondary goal is to ¡°pay back¡± our retirement account of the funds used to buy the parts.? It is truly secondary, and may never happen, but who knows?
3)? We are retired, have three children, farm 20 acres of grass hay, tend to cows, sheep, horses and chickens, and have FAR too many hobbies and other responsibilities to have taken on another, but here we are¡.?
4)? Our website is an amateur work in progress.? Please read the home page posts for information on the site and on our progress.? Tek items will be posted first, followed by HP and then ¡°other¡± semiconductors and who knows what else. ?There is much awaiting inventorying, so if you don¡¯t see the part you are interested in, please contact us directly (tom@...) and we will let you know if we have it.? Also, items showing zero inventory are just awaiting an accurate count, so please inquire if you need something showing zero inventory.? Look for announcements on the homepage as we complete the inventorying and pricing of each group of parts.? Please be patient as we get the website, inventory and pricing figured out.? Feedback is, as they say, a gift, so please share any constructive advice or suggestions for the site that you may have.? The suggestion "You should have your head examined" has already been given!? :)
We can¡¯t ever hope to duplicate the knowledge that Walter possessed, but will do our best to provide you with the right parts for your project.? We look forward to getting to know our new customers, and will work hard to earn your trust.?
Thank you,
Tom and Darla Norman
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Re: (OT?...) Sticky labels for aluminum and other typical materials panels
I've had a TZ machine for years. Labels (black on clear) that I put up 20 years ago still look fine.
Paul
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On Sun, May 18, 2025 at 09:52:30AM -0600, Glen Hoag wrote: When discussing P-Touch labels, bear in mind that M-type machines are a thermal ink process and TZ-type machines use a thermal transfer process that is self-laminating.
M-type is substantially more prone to fading than TZ.
-- Paul Amaranth, GCIH | Manchester MI, USA Aurora Group of Michigan, LLC | Security, Systems & Software paul@... | Linux/Unix - We don't do windows
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Re: Sphere Inc's HP (and Tektronix) Parts Inventory - tekandhpparts.com
Tom, Darla, Thank you for taking on this sizable project, and all the luck with succeeding with it! I'm sure a lot of us here will help.
I know this will take a good amount of time, but one useful thing you could seek to put together is pictures of the items listed. This will greatly shorten the time it takes people to make a decision over whether they want it, need it, what it actually?is, etc. I'm positive it'll greatly help just moving inventory to people who need it.?
Hope this helps.? Radu.?
toggle quoted message
Show quoted text
As many may remember, Walter Shawlee II passed away September of 2023.? Since that time, his wife Susan, and children, have been busying themselves with the task of liquidating much of the electronic goodness that Sphere Research had accumulated.? Susan intends to continue to make their collection of slide rules, nixie tubes and various other items available.? Additionally, she is continuing in her effort to find homes for the remaining equipment.? Please do visit Sphere¡¯s site and help.
Sphere¡¯s inventory of Tektronix and HP parts has found a new home with us.? We have the beginnings of a website (), with the intention of continuing to make these parts available to the Tek and HP enthusiast community.
A bit about us:
1)? The goal of the website is to continue to make Sphere¡¯s inventory available to the people like us that enjoy collecting, repairing and making use of these amazing examples of engineering and manufacturing.
2)? A secondary goal is to ¡°pay back¡± our retirement account of the funds used to buy the parts.? It is truly secondary, and may never happen, but who knows?
3)? We are retired, have three children, farm 20 acres of grass hay, tend to cows, sheep, horses and chickens, and have FAR too many hobbies and other responsibilities to have taken on another, but here we are¡.?
4)? Our website is an amateur work in progress.? Please read the home page posts for information on the site and on our progress.? Tek items will be posted first, followed by HP and then ¡°other¡± semiconductors and who knows what else. ?There is much awaiting inventorying, so if you don¡¯t see the part you are interested in, please contact us directly (tom@...) and we will let you know if we have it.? Also, items showing zero inventory are just awaiting an accurate count, so please inquire if you need something showing zero inventory.? Look for announcements on the homepage as we complete the inventorying and pricing of each group of parts.? Please be patient as we get the website, inventory and pricing figured out.? Feedback is, as they say, a gift, so please share any constructive advice or suggestions for the site that you may have.? The suggestion "You should have your head examined" has already been given!? :)
We can¡¯t ever hope to duplicate the knowledge that Walter possessed, but will do our best to provide you with the right parts for your project.? We look forward to getting to know our new customers, and will work hard to earn your trust.?
Thank you,
Tom and Darla Norman
|
Sphere Inc's HP (and Tektronix) Parts Inventory - tekandhpparts.com
As many may remember, Walter Shawlee II passed away September of 2023.? Since that time, his wife Susan, and children, have been busying themselves with the task of liquidating much of the electronic goodness that Sphere Research had accumulated.? Susan intends to continue to make their collection of slide rules, nixie tubes and various other items available.? Additionally, she is continuing in her effort to find homes for the remaining equipment.? Please do visit Sphere¡¯s site and help.
Sphere¡¯s inventory of Tektronix and HP parts has found a new home with us.? We have the beginnings of a website (tekandhpparts.com), with the intention of continuing to make these parts available to the Tek and HP enthusiast community.
A bit about us:
1)? The goal of the website is to continue to make Sphere¡¯s inventory available to the people like us that enjoy collecting, repairing and making use of these amazing examples of engineering and manufacturing.
2)? A secondary goal is to ¡°pay back¡± our retirement account of the funds used to buy the parts.? It is truly secondary, and may never happen, but who knows?
3)? We are retired, have three children, farm 20 acres of grass hay, tend to cows, sheep, horses and chickens, and have FAR too many hobbies and other responsibilities to have taken on another, but here we are¡.?
4)? Our website is an amateur work in progress.? Please read the home page posts for information on the site and on our progress.? Tek items will be posted first, followed by HP and then ¡°other¡± semiconductors and who knows what else. ?There is much awaiting inventorying, so if you don¡¯t see the part you are interested in, please contact us directly (tom@...) and we will let you know if we have it.? Also, items showing zero inventory are just awaiting an accurate count, so please inquire if you need something showing zero inventory.? Look for announcements on the homepage as we complete the inventorying and pricing of each group of parts.? Please be patient as we get the website, inventory and pricing figured out.? Feedback is, as they say, a gift, so please share any constructive advice or suggestions for the site that you may have.? The suggestion "You should have your head examined" has already been given!? :)
We can¡¯t ever hope to duplicate the knowledge that Walter possessed, but will do our best to provide you with the right parts for your project.? We look forward to getting to know our new customers, and will work hard to earn your trust.?
Thank you,
Tom and Darla Norman
|
Re: (OT?...) Sticky labels for aluminum and other typical materials panels
Glen, I was wondering about that - great piece of information.? Thank you. Radu.?
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When discussing P-Touch labels, bear in mind that M-type machines are a thermal ink process and TZ-type machines use a thermal transfer process that is self-laminating.?
M-type is substantially more prone to fading than TZ.?
On May 18, 2025, at 02:25, Mark Moulding <mark@...> wrote:
? That's actually , and I think they're great - I use them quite a bit.? They have their own specialty CAD package to design a front panel, which is extremely easy to use.? As you add features (engraved lettering, corner radiusing, round or square holes, stand-offs, etc.), you can click a button at any time to find out how much the panel will cost.? For what you get, the prices are pretty reasonable,considering that what you get are extremely first class panels.? They do the paint back-fill oepration, plus you can have the panel powder-coated.? I've attached a picture of a half-sized HP 2100 computer I've been building - I think it turned out pretty well...
~~
Mark
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Re: HP8757A Display Problem (Scalar Network Analyzer)
Hi again Philip.
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When I isolate the display susystem as both you and the 1345A manual says, I do get the test pattern which you show (and with which I am familiar as it is also found under the SYSTEM -> MORE -> DISPLAY -> SERVICE -> TEST PATTERN keys).
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However it it shown with different parts of it in sequence - so that it appears to 'flash' (if one was not aware of how it should look then one would think the display was simply flashing on-and-off).
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Ergo, it seems that there's a problem on this display unit, but I am not sure how to extract the board and work on the unit - I must try again this evening.
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Thank you again for your inputs here.
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Re: HP8757A Display Problem (Scalar Network Analyzer)
Isn't the 1345A the smaller ~5" version used in eg. 3577VNA?
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Ulf
SM6GXV
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Re: (OT?...) Sticky labels for aluminum and other typical materials panels
When discussing P-Touch labels, bear in mind that M-type machines are a thermal ink process and TZ-type machines use a thermal transfer process that is self-laminating.?
M-type is substantially more prone to fading than TZ.?
toggle quoted message
Show quoted text
On May 18, 2025, at 02:25, Mark Moulding <mark@...> wrote:
? That's actually , and I think they're great - I use them quite a bit.? They have their own specialty CAD package to design a front panel, which is extremely easy to use.? As you add features (engraved lettering, corner radiusing, round or square holes, stand-offs, etc.), you can click a button at any time to find out how much the panel will cost.? For what you get, the prices are pretty reasonable,considering that what you get are extremely first class panels.? They do the paint back-fill oepration, plus you can have the panel powder-coated.? I've attached a picture of a half-sized HP 2100 computer I've been building - I think it turned out pretty well...
~~
Mark
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Hi Group,
My E4407B has the problem of 'LO unlock'. I am in the process of repairing the unit by replacing a frequency divider. I am following the youtube video in the SignalPath channel. Before replacing the component I would like to check the rest of the system as much as possible. The problem is that I cannot find the schematics for the unit. It is not part of the service's manual. I would like to know if somebody could help me with this.
Regards, David. -- David Rodriguez Callsign: M0KGE Location: Cambridge, UK
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Re: 1 mw - 0dbm lab calibration
Hi Harke, thanks!
It's interesting to see the return loss plot of the 8478B sensor out to 3 GHz.
I've started a thread about the input return loss of the 478A sensors and how they have changed internally over the years.
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Regards
Jeremy
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Re: HP 478A Thermistor Sensor. Input return loss and matching
The other thing to bear in mind is that the latest 478A service manual clearly shows that all versions of the standard 478A sensor (note that this doesn't include H7x options) can be used with both the 431 and 432 power meters. So I don't think the RC damper is essential for the 431 power meter as the service manual shows the 431 being used with the later 478A sensor that has the ferrite but no 2.7R + 460pF RC damper network.
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Also, the reactance of a 460pF capacitor at 10kHz is about -35,000 ohms so there seems little point putting a 2.7R resistor inline with such a high reactance at 10kHz. So I'm not convinced this RC network in the early 478A sensor type is a necessary requirement for the 431 power meter operation with its 10kHz bias system.
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Regards
Jeremy
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Re: HP 478A Thermistor Sensor. Input return loss and matching
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Just to keep things in perspective, the input VSWR will be a function of the design of the 478A sensor and will also be affected by the performance of the 432A power meter to some degree. However, if a healthy 432A power meter is used and a typical 478A sensor is used that has the same blocking caps shown in the service manual then I think that the input VSWR at 50 MHz is typically going to be about 1.07:1 at 50 MHz.
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Mine has been 1.07:1 for over 30 years for example. The source VSWR of a typical HP 1mW reference (50 MHz) is spec'd to be better than 1.06:1 and I would expect it to be a bit better than this in reality. The mismatch uncertainty between 1.07:1 and 1.06:1 is about +/- 0.01dB. I've done load pull testing on my Anritsu 1mW source that suggest it has a VSWR much lower than 1.06:1 and in this case the mismatch uncertainty falls below +/- 0.01dB.
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However, if lots of 1mW references were being measured and they had a spread in source VSWR that covered all phase angles of a 1.06:1 VSWR then this could cause some spread in results for someone trying to get repeatable results below about +/- 0.01dB using DC substitution when comparing a H72 sensor against a standard 478A sensor. But I'd argue that the drift caused by handling the 478A sensor would cause similar spreads unless some time and care was taken when doing the comparisons.
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In theory at least, adding the matching section would minimise the spread seen with the standard sensor but I'm not sure it is really that worthwhile to chase down errors in the ballpark of +/- 0.01dB unless this is being done at a decent calibration/metrology lab.
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--
Regards
Jeremy
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Re: HP8757A Display Problem (Scalar Network Analyzer)
Philip, I thank you for the information; yes it may be that we were typing at the same time! I shall look further this morning and see what I find.
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Re: (OT?...) Sticky labels for aluminum and other typical materials panels
That's actually , and I think they're great - I use them quite a bit.? They have their own specialty CAD package to design a front panel, which is extremely easy to use.? As you add features (engraved lettering, corner radiusing, round or square holes, stand-offs, etc.), you can click a button at any time to find out how much the panel will cost.? For what you get, the prices are pretty reasonable,considering that what you get are extremely first class panels.? They do the paint back-fill oepration, plus you can have the panel powder-coated.? I've attached a picture of a half-sized HP 2100 computer I've been building - I think it turned out pretty well...
~~
Mark
?
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Re: Looking for service manual/schematic for early E3611A DC Power Supply
Thanks for all the info!
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Unfortunately, none of those schematics match the layout in my instrument. For example, the PCB I have has no C20 (connected to pins 2 and 3 of U4), or any provision for C20 to be fitted.
A few resistors in my instrument are different values too, as are all the opamp part numbers.
I also have an R21, that doesn't seem to exist on the schematics as well.
I found the following resistors are different values:
R14 is 33R instead of 1K
R15 is 8.45K instead of 6.19K
R28 is 8.2K instead of 6.81K
R33 is 6.19K instead of 5.23K
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I also found the current pot was only a single turn (factory fitted) so I replaced it with a 10 turn pot. I think it was the same value but it was so long ago that I can't remember.
Also the output binding posts were red/red/black instead of red/black/green (for +ve/-ve/GND) so I changed the colours, but that would have no affect on the operation.
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I'm not sure what is up with this instrument, but I am pretty sure that I am the first one inside as far as I can tell, as I replaced the original leaking capacitors, and the solder joints look untouched (until I replaced caps etc).
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I'm having a problem where all the functions appear to work, except when pressing the Current Set button, where the display shows between multiple amps across the range of the current control, which is far too high for the instrument to be capable of.
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I'm thinking of just changing the resistors to match the schematic, to see if that will pull things into line.
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