Re: HP 400H AC VTVM Difficulties
On the front page of hparchive, in the paragraph “HP Archive’s purpose”, the next to last sentence contains a link to service notes. Then just search for 400.
Dave Wise
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On May 6, 2024, at 8:21 AM, Jim Adney <jadney@...> wrote:
?On Sun, May 5, 2024 at 07:39 PM, Dave Wise wrote:
You also need Service Note 400D-2C, attached here and hosted at ?.
Thanks for posting that Dave; I was not aware of that info. Is hparcive.com the site that people on this group are running? I tried to find out how you found the 400D-2C Service Note, but had no luck searching for it there. I was hoping to find more info, but
there's no link to a "Service Notes" section, and even a general search for 400D came up empty. So how did you find this?
Or did you know it was there because you were the one who put it there?
I'd say that the directory on the home page could use a Service Notes entry.
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Re: HP 400H AC VTVM Difficulties
On Sun, May 5, 2024 at 07:39 PM, Dave Wise wrote:
You also need Service Note 400D-2C, attached here and hosted at ?.
Thanks for posting that Dave; I was not aware of that info. Is hparcive.com the site that people on this group are running? I tried to find out how you found the 400D-2C Service Note, but had no luck searching for it there. I was hoping to find more info, but there's no link to a "Service Notes" section, and even a general search for 400D came up empty. So how did you find this? Or did you know it was there because you were the one who put it there? I'd say that the directory on the home page could use a Service Notes entry.
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Re: HP 8405A Vector Voltmeter Probes
The HP part number for the diodes might actually be 1901-0517 rather than 1901-1517. I really don't know how the HP system works. See below for a measurement of the probes from my really old HP 8405A for channel A and B. I didn't bother using a narrow RBW or averaging so the plot is a bit noisy once Rp is above about 40k ohms at lower frequencies.? I think these probes contain the original diodes. You can see that channel A and B both have an input capacitance of just under 2.5pF. The Rp is 100k as expected at low frequencies and this gradually reduces with increasing frequency (as expected). Both probes agree very closely for Cp and Rp vs frequency. Sadly, the 'repaired' channel B probe in the newer HP 8405A VVM shows about 4pF input capacitance and the Rp resistance is a fair bit worse up at VHF and UHF.? 
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Re: HP 8405A Vector Voltmeter Probes
Thanks. I still have a large bag of HP 5082-2800 glass diodes here in a little HP envelope dated 1974. There were originally 250 diodes in it but it's down to about 50 now.?
Once I know the HP 8405A is mine (I've made an offer) I plan to remove a good diode from the good probe and measure it on a curve tracer and also measure it on a VNA.
I've measured the input impedance of the probes across 2-1000MHz and it's easy to spot that the repaired probe has too much capacitance and the Rp is much lower up at VHF and into UHF.
I need to find diodes that give the correct input Cp capacitance and Rp resistance vs frequency when fitted to the probe.
I also need to check out the good P JFET on a curve tracer and measure its s-parameters using a VNA up to 1GHz or so. I've done this many times for N channel JFETs but not P channel.
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Re: HP 8405A Vector Voltmeter Probes
Someone on this site wrote IIRC, when I replaced these years ago, I just matched
pairs of 5082-2800 schottky diodes on a curve tracer, little black glass guys
with gold leads. Clear glass ones worked too! I used regular solder &
tweezers for heat sinks on the diode leads (3 hands). HP 8405 Vector VM &
3406 sampling RF VM, same probe design, basically. Sorry I can't give credit, this was saved in my notes but I should save the author.
Hi
I know this question has been asked numerous times on the internet and it has been discussed here before, but does anyone know the part number for the Schottky diodes in the HP 8405A sampling probes?
The black diodes in the probes of this particular vector voltmeter show three lines of text on the diode body.
HP 1
517
152
I assume this means HP 1517 followed by 152
I suspect the HP part number above will be for a matched set of diodes so this part number is for four diodes perhaps? So if this is the case, I would need to know the part number for a single (unmatched) diode.
Looking online I've found HP 1901-1517 and this cross references to 5082-5414.
I have another much older HP 8405A here and it has diodes with coloured bands.?
Orange White Orange? (393?)
Orange White Red (392?)
All research draws a blank in terms of finding a part number.
I'm aware of the Richard Carey W6RLC pdf document that suggest using 1N6263 diodes but looking at the datasheet, I think the 1N6263 is not going to be the same as the original diodes. I really want to restore this VVM to full working order and it has some issues with the probes. It looks like someone has fitted 1N6263 diodes to probe B to repair it but I want to do a proper job of restoring the performance of the probes. The P JFET has also been replaced as per the Richard Carey W6RLC pdf document. At some point I'll need to see if this JFET is OK to use. However, it's the diodes I'm most concerned about.
This HP 8405A is in excellent unmarked condition otherwise, and it's a late model made in 1986. It's not mine, but if the proper diodes can be found then I will probably buy it to replace my much older HP 8405A.
Thanks!
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HP 8405A Vector Voltmeter Probes
Hi I know this question has been asked numerous times on the internet and it has been discussed here before, but does anyone know the part number for the Schottky diodes in the HP 8405A sampling probes? The black diodes in the probes of this particular vector voltmeter show three lines of text on the diode body.
HP 1
517
152
I assume this means HP 1517 followed by 152 I suspect the HP part number above will be for a matched set of diodes so this part number is for four diodes perhaps? So if this is the case, I would need to know the part number for a single (unmatched) diode. Looking online I've found HP 1901-1517 and this cross references to 5082-5414. I have another much older HP 8405A here and it has diodes with coloured bands.? Orange White Orange? (393?) Orange White Red (392?) All research draws a blank in terms of finding a part number. I'm aware of the Richard Carey W6RLC pdf document that suggest using 1N6263 diodes but looking at the datasheet, I think the 1N6263 is not going to be the same as the original diodes. I really want to restore this VVM to full working order and it has some issues with the probes. It looks like someone has fitted 1N6263 diodes to probe B to repair it but I want to do a proper job of restoring the performance of the probes. The P JFET has also been replaced as per the Richard Carey W6RLC pdf document. At some point I'll need to see if this JFET is OK to use. However, it's the diodes I'm most concerned about. This HP 8405A is in excellent unmarked condition otherwise, and it's a late model made in 1986. It's not mine, but if the proper diodes can be found then I will probably buy it to replace my much older HP 8405A. Thanks!
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Hello to All,
We are trying to repair an Agt N5230A-220 of one of our customers but we cannot find the fault.
The VNA starts, displays the boot options, but does not boot to the OS, it shuts down then restarts (see video 1).
We tested the CPU and it works (see video 2). Is this an Agilent OS problem?
If anyone can help us I would appreciate it.
Video 1: https://photos.app.goo.gl/iauBvVwxhFiXgSqX6
Video 2:
Thanks in advance.
BR.
Antoine
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Re: Another 3GHz 53132-68003 Chanel 3 option design for the 53131A and 53132A
Yves:
So the 12GHz board likely has a divide by 512 so the hardware sees the same frequency range as the 3GHz board and the X4 scales it up to the correct frequency for display.
At 18MHz the 12GHz board output would output a bit over 35MHz.
Thanks for posting the text file with the necessary changes.
ed
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McMaster doesn’t have quite the correct combination of size. You can get the exact size from Precison Associates or Apple Rubber.
The nominal size is 1mm ID cross section 0.6mm, BunaN medium hardness (70A durometer) - credit to Don Bitters for sharing the specifications numerous times.
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Re: 85097A VNA ECal controller replacement
Hi
I'm interested in your E-cal controller as well, for the hp 8510C that I have as well too. I think it would be a popular option for a few of us.
I also believe it would be a popular replacement for the old hp controller that some may have as well due to the age and slowness of the controller. Please keep us up to date. I would be even interested in it more if you had it as a kit or completed
device, as I'm time poor.
Thanks
James
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Hi,
Interesting project. I am interested to use it with an 8510C.
Please post updates.
Thanks,
Razvan
On 06/05/2024 05:14, bagojfalvibagoj via groups.io wrote:
> Hi All,
>
> I made some good progress with the ECal controller replacement. It's
> effectively an 85097A but with opensource software using scikit-rf.
> If you're into python you can check out the code on github:
> OwlvilleWol/VnaCalWizard (github.com)
> <>
>
> I plan to post my hardware implementation too, but I have to work on the
> docs and I'm not overly happy with it anyway.
>
> image.png (1136×852) (ibb.co) <>
> image.png (639×852) (ibb.co) <>
>
> I wanted to be smart and use an Ftdi usb device instead of an arduino to
> avoid having to maintain two sets of code, but I regret it now as the
> solution is not as elegant as I hoped for and the port direction changes
> of the Ftdi chip make EEPROM readouts very slow.
> The program is written so that that has to be done only once though,
> then, if present, standards data are loaded from touchstone files on
> disc. (This could be a way to re-characterize the ECal devices without
> having to write data back to them.)
>
> I can cal my 8720C with it, although the top-level functions are still
> missing. I'll be finishing that and add a few features such as multiple
> ECal units covering the frequency range and pre-characterized adapter
> (gender changer) removal.
> My python is not very good so it's rough around the edges, but I tried
> to separate functional blocks for easy additions/modification/reuse.
> E.g. the ECal class has a separate hardware abstraction layer so the
> Ftdi based interface could be easily replaced with something else, while
> keeping everything above intact.
>
> Let me know if you're interested in replicating and
> testing/using/improving this.
>
>
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Re: HP 400H AC VTVM Difficulties
Some pictures of mine, first is a later 400D from the Bedford factory (E310 prefix) and the second is a older 400H (sn 1621), the older one has a capacitive attenuator, with a selection of knackered bumble bee paper caps, not the worst I've seen.
David
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Re: simplified 1GC1-4210 replacement for ESA E44xx LO unlock
Thanks, it's working now.
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On 06/05/2024 02:06, fenugrec via groups.io wrote: When I click on the link I get Error 404 for the 7Zip file.
Oops, looks like I messed up a link ref. Should be fixed now.
I also finally got around to piecing together bits of video detailing
the repair,
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Re: 85097A VNA ECal controller replacement
Hi,
Interesting project. I am interested to use it with an 8510C.
Please post updates.
Thanks,
Razvan
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Show quoted text
On 06/05/2024 05:14, bagojfalvibagoj via groups.io wrote: Hi All,
I made some good progress with the ECal controller replacement. It's
effectively an 85097A but with opensource software using scikit-rf.
If you're into python you can check out the code on github:
OwlvilleWol/VnaCalWizard (github.com)
<>
I plan to post my hardware implementation too, but I have to work on the
docs and I'm not overly happy with it anyway.
image.png (1136×852) (ibb.co) <>
image.png (639×852) (ibb.co) <>
I wanted to be smart and use an Ftdi usb device instead of an arduino to
avoid having to maintain two sets of code, but I regret it now as the
solution is not as elegant as I hoped for and the port direction changes
of the Ftdi chip make EEPROM readouts very slow.
The program is written so that that has to be done only once though,
then, if present, standards data are loaded from touchstone files on
disc. (This could be a way to re-characterize the ECal devices without
having to write data back to them.)
I can cal my 8720C with it, although the top-level functions are still
missing. I'll be finishing that and add a few features such as multiple
ECal units covering the frequency range and pre-characterized adapter
(gender changer) removal.
My python is not very good so it's rough around the edges, but I tried
to separate functional blocks for easy additions/modification/reuse.
E.g. the ECal class has a separate hardware abstraction layer so the
Ftdi based interface could be easily replaced with something else, while
keeping everything above intact.
Let me know if you're interested in replicating and
testing/using/improving this.
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Re: Another 3GHz 53132-68003 Chanel 3 option design for the 53131A and 53132A
Hello Yves,
I was thinking the same that something is not right in the firmware.
I found the same thread on EEVblog late last night. For me it is more
work to be done since my 53181A and 53132A both have no option so I need
to maybe install the zero ohm R334 resistor and also the U14 socket.
When I will have time I will open my counters and check the motherboards
first.
Would be great news if you can confirm this info and the cloned 12.4GHz
work by default without any scale adjustment.
There is also an 18GHz version from the same seller on eBay and I wonder
that one how it would work since HP never had 18GHz version released.
They say you need the 3GHz option already installed and working and
after that you need to set scale to 4.0 to have the 18GHz option working
correctly. Maybe the hex values modification in firmware tells it what
divider or IF to use so maybe other values (or the same values as 12GHz)
will make it working fine without scale adjustment.
Thanks,
Razvan
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On 05/05/2024 23:32, Yves Tardif via groups.io wrote: Hi Razvan,
I have option 124 on my hp53132A and it's a clone bought on eBay.
The scale used is 4, because by default, the internal divider is positioned
for a 030 or 3GHz option.
But I found on the EEVblog site, it seems to me, the following file
concerning the activation of the correct divider depending on the option.
I'll try this approach when I have some free time.
Yves
-----Message d'origine-----
De?: [email protected]
<[email protected]> De la part de Razvan Popescu via
groups.io
Envoyé?: 5 mai 2024 16:58
??: [email protected]
Objet?: Re: [HP-Agilent-Keysight-equipment] Another 3GHz 53132-68003 Chanel
3 option design for the 53131A and 53132A
Hello Ed,
I saw how the 3GHz board works regarding the divider but I didn't see any
original board more than 3GHz.
I didn't buy any cloned boards because I saw you need to use the math
function scale set to 4.0. I think they do divide by 128 also for the 12GHz
board but they should do probably divide by 512.
How is the original 12Ghz prescaler board working in regards to the divider?
I got the PCBs for the 3GHz version but I didn't order the parts to build
them. I will install the 3GHz prescaler first until I find a prescaler that
doesn't need the scale set to 4.
Razvan
On 04/05/2024 13:22, Ed (scskits) via groups.io wrote:
Razvan:
The 3GHz board is a divide by 128, with a max output of 23.4375MHz at 3GHz.
That has to get to the main board through the ribbon cable, not the
best way to connect.
At 12GHz the output would be almost 100MHz so I think that the higher
frequency option boards likely have an additional divider to keep the
output at a reasonable frequency.
There are two pins (CH3CODE0 and CH3CODE1) on the connector that are
used to tell the main board that one of the options is installed.
I would think that a combination of those pins would select one of the
three options or no option.
I will try to see what effect they have later this weekend.
ed
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85097A VNA ECal controller replacement
Hi All,
I made some good progress with the ECal controller replacement. It's effectively an 85097A but with opensource software using scikit-rf.
If you're into python you can check out the code on github:
I plan to post my hardware implementation too, but I have to work on the docs and I'm not overly happy with it anyway.?
I wanted to be smart and use an Ftdi usb device instead of an arduino to avoid having to maintain two sets of code, but I regret it now as the solution is not as elegant as I hoped for and the port direction changes of the Ftdi chip make EEPROM readouts very slow.
The program is written so that that has to be done only once though, then, if present, standards data are loaded from touchstone files on disc. (This could be a way to re-characterize the ECal devices without having to write data back to them.)
I can cal my 8720C with it, although the top-level functions are still missing. I'll be finishing that and add a few features such as multiple ECal units covering the frequency range and pre-characterized adapter (gender changer) removal.
My python is not very good so it's rough around the edges, but I tried to separate functional blocks for easy additions/modification/reuse. E.g. the ECal class has a separate hardware abstraction layer so the Ftdi based interface could be easily replaced with something else, while keeping everything above intact.
Let me know if you're interested in replicating and testing/using/improving this.
|
I just received that Leo Bodnar fast risetime test unit and tried it with my two fastest scopes, a HP 54542A digital and a Tektronix R7103 analog with intensifier CRT.? Screen shots below.
According to the old rule of thumb, for an analog scope BW * risetime = 0.35 and 0.45 for digital scopes.
The 54542A is spec'd as a 500 MHz scope.? According to the old rule of thumb then, the apparent BW of the 54542A is around 725 MHz.
The R7103 has a 1 GHz BW spec so based on the rule of thumb it comes in right at 1 GHz.
Just playing around.
Has anyone else done this and has some numbers?
Peter
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Re: HP 400H AC VTVM Difficulties
I know the manual you are using, Kenneth Kuhn's museum site hosts it at ?.? You also need Service Note 400D-2C, attached here and hosted at
?.? In a 400H of your serial number, HP may have used an earlier style of 1000x range attenuator; the Service Note calls it the "capacitive" attenuator.? Troubleshooting and calibration is different
from the later "resistive" attenuator which is what we would call a normal "compensated" attenuator.? The Service Note has instructions for determining which kind of attenuator you have, although you can also just take off the shield and trace out the circuit.?
Look at the paragraphs headed "INPUT DIVIDER CIRCUIT IDENTIFICATION".? The key is the bottom end of 10 Meg resistor R4.? If it goes straight to the bottom of trimmer cap C4, it's the "resistive" attenuator; if there's a 10K resistor between those points, it's
the "capacitive" divider and the special procedures apply.
Also look at the cathode resistors on V3, V4, and V5.? 120R is the oldest EC level, 100R is newer and allows a simplified LF calibration.? I bet you're 120R.
HTH,
Dave Wise
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Thank You gentlemen for your responses.?? I should have thought to include the instrument serial numbers because I had trouble finding a matching manual on the internet.... but I dropped the ball.?? I will therefore remedy this immediately.
The failed instrument is serial number 5025.
The good instrument is serial number 4939.
The scope that I am using is a Tektronix 465B with 100 MHz bandwidth.?? I also have a 200 MHz bandwidth digital scope should it be necessary to have the extra bandwidth or in case it is desirable to post waveform captures.
The manual I'm using is entitled "400D/H?? Vacuum Tube Voltmeter".?? The frontispiece shows two photos of the instrument with captions describing the models covered as the Model 400D, serial 17971 and above and the Model 400H, serial 2238 and above.?? The manual
has a copyright date of 1955 and a publication number of 400DH001-1.
I will have to order some capacitors as I don't think I have enough of the correct values in stock.?? With the Group's permission, I will post additional results as I get them.
I have saved Dave Wise's text document and will read it over for additional information as soon as practical.
Thanks again,
--
Jim Thorusen
KB6GM
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Re: simplified 1GC1-4210 replacement for ESA E44xx LO unlock
When I click on the link I get Error 404 for the 7Zip file.
Oops, looks like I messed up a link ref. Should be fixed now. I also finally got around to piecing together bits of video detailing the repair, https://youtu.be/SJsw54jveQs
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Re: HP 400H AC VTVM Difficulties
Thank You gentlemen for your responses.?? I should have thought to include the instrument serial numbers because I had trouble finding a matching manual on the internet.... but I dropped the ball.?? I will therefore remedy this immediately.
The failed instrument is serial number 5025.
The good instrument is serial number 4939.
The scope that I am using is a Tektronix 465B with 100 MHz bandwidth.?? I also have a 200 MHz bandwidth digital scope should it be necessary to have the extra bandwidth or in case it is desirable to post waveform captures.
The manual I'm using is entitled "400D/H?? Vacuum Tube Voltmeter".?? The frontispiece shows two photos of the instrument with captions describing the models covered as the Model 400D, serial 17971 and above and the Model 400H, serial 2238 and above.?? The manual has a copyright date of 1955 and a publication number of 400DH001-1.
I will have to order some capacitors as I don't think I have enough of the correct values in stock.?? With the Group's permission, I will post additional results as I get them.
I have saved Dave Wise's text document and will read it over for additional information as soon as practical.
Thanks again,
--
Jim Thorusen
KB6GM
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