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.
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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.?
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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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
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Re: (OT?...) Sticky labels for aluminum and other typical materials panels
Glen, I was wondering about that - great piece of information.? Thank you. Radu.?
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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Re: HP 478A Thermistor Sensor. Input return loss and matching
In case any purists want to scoff at this matching technique and think it is a bodge, I suggest they take a look inside a typical HP power meter and look at how the 1mW oscillator is designed and how it achieves its output match. It uses a tiny series inductor to cancel out the capacitance of the capacitive divider used at the output of the oscillator. This ideally leaves a pure (series) 50 ohm source impedance at 50 MHz. This is how HP tried to get a very low source VSWR for their 1mW source at 50 MHz.
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Obviously, it's a good idea to try and trim the tiny inductance to be spot on and that is what I have done here in order to get a really low VSWR at 50 MHz.
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If it's good enough for HP then it's good enough for me :)
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Regards
Jeremy
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Re: HP 478A Thermistor Sensor. Input return loss and matching
On Sat, 17 May 2025, jmr via groups.io wrote: There are separate manuals for all those Hxx 478A sensors. There was a whole bunch of those, all seem to be nearly identical according to their manuals. H55 -- 00478-90029 H63 -- 00478-90030 H72 -- 00478-90031 H73 -- 00478-90032 H75 -- 00478-90033 H13 -- 00478-90036 They all use 0.1uF capacitors. There was also a 8478B option H01 with the same specs. No manual for that, just a product note telling it has a VSVR of 1.05 or less at 50MHz. And here is kinda addendum from HP (before Agilent/Keysight) for H75 that they suggest using along with original 478A 00478-90021 manual (attached, hopefully it will get through). Just to clarify, the latest service manual for the standard 478A sensor is available on the Keysight website and this lists the different internal circuits for the early and later variants of the standard sensor (as I have posted on this thread) and it provides a serial number checker in the appendix. This is how I know my sealed and unused sensor is one of the later types with a ferrite bead. It has a serial number greater than 65601 so the B changes in the manual apply to this sensor.
My early 478A sensor was probably made in the mid 1960s so it has the RC damper in it and no ferrite bead.
Note that this service manual doesn't cater for the H7x variants that use 0.1uF caps. My aim in this thread is to see how well I can improve the input VSWR of an early (or late) standard 478A sensor so it has a similar or better VSWR at 50 MHz compared to the H7x variants.
--
Regards
Jeremy --- * * KSI@home KOI8 Net < > The impossible we do immediately. * * Las Vegas NV, USA < > Miracles require 24-hour notice. * *
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Re: HP 478A Thermistor Sensor. Input return loss and matching
Here's a screenshot from my old Agilent VNA showing the input VSWR of my 478A sensor with the matching section added at the input. You can see that it now achieves a really low VSWR at 50 MHz.
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Because I've used low loss parts, there is no through loss penalty when the matcher is inline. This is because the approx 0.004dB mismatch loss caused by the capacitive input of the standard sensor is made up for by having the series matching inductor inline. However, due to the finite Q of the matching inductor the model predicts that there will be about a 0.004dB loss caused by the matching inductor. So the two cancel out. So when I next check my 1mW source from my power meter, I can do it with a 478A sensor that has very low input VSWR. Probably as low as the VSWR of the H7x variants at 50 MHz.?
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I don't need to worry about harmonics because the harmonic distortion levels from the 1mW source are very low. Better than -60dBc.
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--
Regards
Jeremy
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Re: HP 478A Thermistor Sensor. Input return loss and matching
On Sat, 17 May 2025, jmr via groups.io wrote: H72 is SPECIFICALLY designed for low frequency measurements, especially that 50MHz one. It is not high frequency device going into gigahertz range so it didn't require tiny special microwave capacitors with low inductance. All other 478A (except similar H75/H76, maybe some other Hxx) on the other hand are totally unsuitable for that 50MHz (and general low frequency) measurements. Those Hxx are special calibration devices, not general purpose power sensors. OK thanks. I think the standard 478A sensor uses a tiny (and very thin) SMD disc cap of about 1350pF for the AC ground end of the thermistor. The later 478A sensor uses 1200pF here.? I don't know what package type is used for the series blocking cap at the input.
Because the sensor is designed for use to 10 GHz I think this capacitor will have relatively low package inductance compared to a regular MLCC in a 1206 package.
I'm not sure what package the 0.1uF caps use in the H72 but if they are allowed to be as large as a 1206 MLCC then maybe a MLCC with a class 1 COG dielectric can be used here. This might help explain why the upper frequency range is much lower for the H72 version.
--
Regards
Jeremy --- * * KSI@home KOI8 Net < > The impossible we do immediately. * * Las Vegas NV, USA < > Miracles require 24-hour notice. * *
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Re: HP 478A Thermistor Sensor. Input return loss and matching
Just to clarify, the latest service manual for the standard 478A sensor is available on the Keysight website and this lists the different internal circuits for the early and later variants of the standard sensor (as I have posted on this thread) and it provides a serial number checker in the appendix. This is how I know my sealed and unused sensor is one of the later types with a ferrite bead. It has a serial number greater than 65601 so the B changes in the manual apply to this sensor.
?
My early 478A sensor was probably made in the mid 1960s so it has the RC damper in it and no ferrite bead.?
?
Note that this service manual doesn't cater for the H7x variants that use 0.1uF caps. My aim in this thread is to see how well I can improve the input VSWR of an early (or late) standard 478A sensor so it has a similar or better VSWR at 50 MHz compared to the H7x variants.
--
Regards
Jeremy
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Re: HP 478A Thermistor Sensor. Input return loss and matching
OK thanks. I think the standard 478A sensor uses a tiny (and very thin) SMD disc cap of about 1350pF for the AC ground end of the thermistor. The later 478A sensor uses 1200pF here.? I don't know what package type is used for the series blocking cap at the input.
Because the sensor is designed for use to 10 GHz I think this capacitor will have relatively low package inductance compared to a regular MLCC in a 1206 package.
?
I'm not sure what package the 0.1uF caps use in the H72 but if they are allowed to be as large as a 1206 MLCC then maybe a MLCC with a class 1 COG dielectric can be used here. This might help explain why the upper frequency range is much lower for the H72 version.
?
--
Regards
Jeremy
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Trevor Gale
Jared Cabot
Sergey Kubushyn