Re: HP8903B - Plotting from HP-IB
OK, found: pressing the right mouse button a menu appears with also the item to delete the track.
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Re: Scoping the Power Rails [8566B]
First, make sure that you don¡¯t have any ground loops.? I suggest you to power the 8566 and your scope from the same outlet.? ? Best, Francesco K5URG ?
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From: [email protected] < [email protected]> On Behalf Of Jinxie Sent: Sunday, February 27, 2022 4:00 PM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] Scoping the Power Rails [8566B] ? Okay, that's all understood now and thanks for the clarification, guys.
In order to properly eliminate the possibility of these spikes being a red herring I'm going to have to get creative with the probe grounding, clearly. This is where an extender board would be really useful. What a pity I don't have one!
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How does R1 act as a fuse in the HP 3048A option K23 DC Blocking Filter?
I'm looking at the schematic for the HP 3048A option K23 DC blocking
filter. I've attached a simplified version of this schematic for
convenience. Note that I've omitted the circuitry related to reverse
polarity (switch and diode protection). But, I don't need that to
address my question.
The manual states that the 51.1ohm R1 acts as a fuse protecting the DC
blocking filter (C3-16) from a large input DC voltage (K23 is rated for
+/- 30 V). C3-16 are rated for 50 VDC. How does this fuse action work
and how can we ensure it's reliable?
The description of R1 in the manual is:
RESISTOR 51.1 1% .05W TF TC=0+-100
I believe TF stands for thin film. So, the power rating of the resistor
is pretty low. Maybe that gives a hint. There's no DC current path
through R1. But, the startup ramp of a DC voltage is AC. Broadly, it
seems like we need to identify the scenario(s) in which there is a
voltage across R1 creating a short-duration power dissipation that
greatly exceeds R1's power rating. Because there's no DC current path,
we need to rely on a large, short-duration excess of power rather than a
steady excess of power to blow R1.
Current can either flow through C1 or L1 out of R1. C1 will present a
low impedance, but only at high frequencies (|Z_R1|=|Z_C1| at
663MHz). L1 will slow the voltage rise across C3-16. Presumably, the
goal is for R1 to blow open before the voltage across C3-16 exceeds the
voltage rating. If I make the initial ramp rate very fast I can greatly
exceed the 1.6V R1 rating, but only for a very short time. How can I be
sure to destroy the resistor? And, if I destroy it, how can I be sure it
will blow open? The NASA reliability design handbook (MIL-HDBK-338B)
gives the failure mode distribution for film resistors as (p. 7-198):
| failure mode | probability |
| <l> | <c> |
|------------------+-------------|
| open | 0.59 |
| parameter change | 0.36 |
| short | 0.05 |
Wouldn't it be easy to bypass the protection and exceed the capacitor's
voltage rating by supplying a ramp that's just slow enough that C1 looks
like a high-impedance?
There's a limiter across the output, but no proper fuse to blow if one
of these diodes starts to conduct. It seems like the 11848 or 3561 input
is pretty exposed in this case.
Thoughts? Maybe R1 isn't just a normal resistor?
Thanks
Matt
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Re: Boot Diskette HP1650/1651
On 2022-02-27 17:40, Bill Weinel wrote: All,
I am in dire need of a boot diskette for an HP 1650/1651 Logic Analyzer (Rev. 1.00) which I have restored. I have (so far) been unsuccessful in finding one. Should anyone have one to spare or know where one may be found, please drop me an email off the list. Many thanks in advance.
All the best,
Bill
Diskette images may be found at
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Re: HP-8753E Reading HPGL Files
All:
While going through the Firmware Revision notes, I found an interesting entry on Version 7.66 of the firmware:
- Added ripple limit and bandwidth limit tests
- Added JPEG and CSV (Comma Separated Values) file format
If reading the manual alone, this was not clear at all. I have enclosed a copy of what a typical .jpg file looks out of the VNA directly. To access this feature I did the following steps.
- SAVE/RECALL? - SAVE FILE FORMATS - Graph Format = JPG - Filetype = Graphic - Save File
Hope this saves someone else sometime.?
Rich? 
On Sunday, February 27, 2022, 04:21:05 PM EST, Rich Miller via groups.io <av8torrich@...> wrote:
I am now editing those files inside of the 7470 emulator. I have also been able query the VNA at Address 16 for them using this toolkit. Looks like I can choose from a great many formats besides .bmp to save these files. In the past, I had always used the emulator to seek plots directly from the machine. I never knew it could convert these files into various formats.?
Rich?
On Sunday, February 27, 2022, 04:15:46 PM EST, nj902 <wb0emu@...> wrote:
John's 7470 program will render an HPGL file which you can capture as a .BMP file and then tweak in your computer such as to add a box border.
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Re: Scoping the Power Rails [8566B]
If the spikes are at line frequency, then I'd suggest turning off
LED or Fluorescent lamps and see if it makes a difference.?
You could always remove the ground wire, and use the probe as a
sniffer to see if the radiation is more obvious at any place in
the equipment.? Or shop, for that matter.
an experiment would be to wrap the ground line around the probe
body and then ground the tip.
Another might be to wrap the probe (with grounded tip) in the old
standard aluminum foil, that may or may not tell you something.
If, of course, you put a shorting plug on the scope's input
instead of a probe and still get those spikes, that tells you
something quite different.
Harvey
On 2/27/2022 4:59 PM, Jinxie wrote:
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Okay, that's all understood now and thanks for the clarification,
guys.
In order to properly eliminate the possibility of these spikes
being a red herring I'm going to have to get creative with the
probe grounding, clearly. This is where an extender board would be
really useful. What a pity I don't have one!
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Re: Scoping the Power Rails [8566B]
On 2/27/22 16:59, Jinxie wrote: Okay, that's all understood now and thanks for the clarification, guys.
In order to properly eliminate the possibility of these spikes being a red herring I'm going to have to get creative with the probe grounding, clearly. This is where an extender board would be really useful. What a pity I don't have one! You could try slipping a few ferrite beads on the probe's ground lead. I'm not sure that'd help, but it might; does anyone else have any thoughts on that? -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: Scoping the Power Rails [8566B]
Okay, that's all understood now and thanks for the clarification, guys.
In order to properly eliminate the possibility of these spikes being a red herring I'm going to have to get creative with the probe grounding, clearly. This is where an extender board would be really useful. What a pity I don't have one!
|
Re: Boot Diskette HP1650/1651
On Sun, Feb 27, 2022 at 1:40 PM Bill Weinel <tube.radio@...> wrote:
All,
I am in dire need of a boot diskette for an HP 1650/1651 Logic Analyzer
(Rev. 1.00) which I have restored. I have (so far) been unsuccessful in
finding one. Should anyone have one to spare or know where one may be
found, please drop me an email off the list. Many thanks in advance.
If you have a PC with a 3.5-inch floppy drive that you can set up to boot into real mode DOS to create floppies from ImageDisk images, there are some 1650A disk images here:
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Re: HP instruments with stereo FM composite signal output capability + HP8904A Option 001 question
Radu and all,
?
I did come across the ¡°microprecision¡± website but have not contacted them.? From past experience I have had little luck dealing with these sorts of business because they want for? you to send your unit in for repair ($$$).? I may try but have little hope.
?
I am also aware that that these products were marketed under the ¡°National¡± brand but have never seen any documentation relating to this name also from searching.?
?
The VP-7635x unit is a close match but has a few added features as seen on the front panel.? But, again, searches for any service information brought up nothing although there was found a specification sheet for this model.? I did find an operating manual for the 7637 but it is a totally different unit.
?
Greg
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Boot Diskette HP1650/1651
All,
I am in dire need of a boot diskette for an HP 1650/1651 Logic Analyzer (Rev. 1.00) which I have restored. I have (so far) been unsuccessful in finding one. Should anyone have one to spare or know where one may be found, please drop me an email off the list. Many thanks in advance.
All the best,
Bill
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Re: HP Masked Microcontroller Question
Thanks
Yes, I see what you mean.? I too understood that mask programming the main counter processor was expensive and HP likely purchased a lifetime supply of the 1820-2131 parts.? There is, however, some communication data between the GPIB processor and the main counter processor,?? HP must have thought ahead during their original design to allow the facility to communication with another peripheral such as the GPIB microcontroller.
Thanks
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Re: HP-8753E Reading HPGL Files
I am now editing those files inside of the 7470 emulator. I have also been able query the VNA at Address 16 for them using this toolkit. Looks like I can choose from a great many formats besides .bmp to save these files. In the past, I had always used the emulator to seek plots directly from the machine. I never knew it could convert these files into various formats.?
Rich?
On Sunday, February 27, 2022, 04:15:46 PM EST, nj902 <wb0emu@...> wrote:
John's 7470 program will render an HPGL file which you can capture as a .BMP file and then tweak in your computer such as to add a box border.
|
Re: HP-8753E Reading HPGL Files
John's 7470 program will render an HPGL file which you can capture as a .BMP file and then tweak in your computer such as to add a box border.
|
Re: HP Masked Microcontroller Question
On 2022-02-27 15:39, Jim Flanagan wrote:
Searching the service manuals for the HP5315A/B, HP5316A and HP5316B counters, I noticed that the
part number specified for the microcontroller is the exact same: 1820-2131.? Since these are all mask programmed, I am curious
if the firmware is the same between all 3 versions of the counter.? This seems unlikely.? However,? the service manual parts list appears to imply that the masked micro is the same.? I would have thought that if the firmware changed (say due to the addition of GPIB) that the microcontroller part number would be different.
Does anyone have any knowledge/thoughts regarding this?
Take care -
Jim
It seems pretty reasonable to me, the 1820-2131 seems to be the main processor running two pretty similar counters that where likely designed at the same time, the one big difference being the 5316 has HPIB, but the HPIB has its own processor which I assume handles the HPIB protocol as will as pushing the buttons to set up functions on the counter.? It would be a simple matter for the main processor to ignore features that are not present.? There would be a big cost advantage to having them all use the same main processor as setup for mask programming is expensive to set up so the more parts produced with the same mask the cheaper it gets. It seems that the 5316B added some additional HPIB functions so that would suggest that the 6801 processor (also masked) used for the HPIB may have changed. Paul.
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HP Masked Microcontroller Question
Searching the service manuals for the HP5315A/B, HP5316A and HP5316B counters, I noticed that the
part number specified for the microcontroller is the exact same:? 1820-2131.? Since these are all mask programmed, I am curious
if the firmware is the same between all 3 versions of the counter.? This seems unlikely.? However,? the service manual parts list appears to imply that the masked micro is the same.? I would have thought that if the firmware changed (say due to the addition of GPIB) that the microcontroller part number would be different.?
Does anyone have any knowledge/thoughts regarding this?
Take care -
Jim
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I have mostly RF switch plug ins that i use but i have some terminal plugs laying around that might fit
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On Feb 27, 2022, at 13:05, Lothar baier via groups.io <Lothar@...> wrote:
?Which plug ins do you have? I might have some terminal blocks laying around
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Which plug ins do you have? I might have some terminal blocks laying around
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Re: Scoping the Power Rails [8566B]
On Sun, Feb 27, 2022 at 07:49 AM, Dave McGuire wrote:
As Harke said a few minutes ago, look at probe grounding. This is
often dismissed as one of those "That can't happen!" things, but it's a
very common and widely-misunderstood problem.
Always connect your probe's ground as close to the monitored circuit
node as possible, and keep the probe's ground wire as short as possible.
Jinxie, Your spikes do sound a lot like what you'd see from excessive probing inductance caused by a large loop area from the ground lead. One simple test I often do to determine whether my probing is creating high-frequency content in the measured signal is to manually decrease the loop area by pushing the ground lead wire up against the oscilloscope probe body (basically, you want to minimize the area created by the main part of the probe and ground lead). If this decreases the amplitude of the spikes, that's a good indication that the high-frequency content is a result of poor probing and not a signal present in the DUT. Matt
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Difference between HP 10501A/10502A/10503A and 11170A/11170B/11170C BNC cable assemblies
In the 1983 catalog, HP lists 2 different sets of BNC cables: the 10501/2/3A
series and the 11170A/B/C series (p. 640). Both are listed as using
50ohm coaxial cable. The first series says it uses UG-88C/U BNC (m)
connectors and the second series uses BNC (m) connectors. What are the
differences between these cable assemblies (apart from any length
differences)?
Any idea what type of coaxial cable HP used for these? How do they stand
up to cables today? I did find one picture of the bag for the 11170C
online that said the cable was double shielded, and with the label HV
(presumably, high-voltage). So, maybe the 11170 series is designed for
high voltage applications? I would imagine that also improves the
isolation characteristics.
Thanks,
Matt
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Attilio
Dave McGuire
Jinxie
Bill Weinel
