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.
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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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Re: Another 3GHz 53132-68003 Chanel 3 option design for the 53131A and 53132A
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
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-----Message d'origine----- De?: [email protected]< [email protected]> De la part de Razvan Popescu via groups.io 贰苍惫辞测é?: 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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Re: 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
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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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Re: HP 3852A firmware update issue
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I Measured:
The Diameter of the pin itself to be 40 Thousands of an inch which is very close to ONE mm.
This corresponds to the ID of the O Ring
The OD is twice that so the Cross Section is .5 mm..? OD= 2XCS + ID
So I think VK2BEA is quite correct.
I do not have Metric measurement tools so I have to translate from the measurements on my English micrometers and calipers
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I used these o-rings from 'The O-Ring Store' on the attenuator from the 8595E (a 33321 attenuator I think).
https://www.theoringstore.com/store/index.php?main_page=product_info&cPath=368_12_2185&products_id=43455
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Do these look correct???
https://www.ebay.com/itm/293851527865?itmmeta=01HX2WM6F270SAZY0X9KSYJH67&hash=item446aea7ab9:g:4NcAAOSwC7Vh1id6&itmprp=enc%3AAQAJAAAA4NyxuU3mlUEZV%2Bn9csEzewYdmbqpmPKU2zfXTNMFqmn8eaEDgCi3paQRuFWeIRfM%2FDoLlVjIxoJ%2FR0dl8MmaBF9jq3BOVXcW20QC4dgpmEEGmh3sQP%2FKY6GaYJNwisDDlQTrSR2GMhOtwoz5QboqhdRA9j45ejvMbJ86V21tFz3d2gJNUfYPaBpMGrUdCRVQLnB%2FqwIN7EQZAhaSXHi5ZNV--jLUlx1cBNT%2B0fVai4RYtWrI3BBxl0dkpZDeX0DQ1fCJpGK0SDf4xeXLO9VkA2xw6bRFIwty%2B4WpTsGf%2BvMW%7Ctkp%3ABk9SR9bn0NzoYw
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On Sat, May 4, 2024 at 08:51 AM, Radu Bogdan Dicher wrote:
I've used Amazon as source of o-rings when I repaired my 8657B. But to your pertinent point, I think I'd go McMaster-Carr or similar today:?.
McMaster-Carr is also my normal go-to for quality O-rings. I checked there, but they don't go as small as the 1 mm ID/2 mm OD that others called out. Buna-N is certainly the best choice of material. I don't know about this application. Would the durometer (hardness) matter here? Buna-N O-rings can be bought in a range of durometers, where 70 is the norm, but harder and softer versions are available. Try Apple Rubber. They have LOTs of choices in small sizes.?
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Re: HP 400H AC VTVM Difficulties
The 400H is just the higher precision version of the HP 400 family, which had a VERY long history with HP, probably over 30 years, so there are lots of versions, usually differentiated by changes in the serial prefix. (The earliest models did not have a prefix.)
The very first thing to do with any member of this family is to replace all 4 of the large cylindrical capacitors. If yours are still the originals, they will be leaky by now. One of them is in the PS and minor leakage won't be a problem, but you might as well replace all of them while you're at it.
The other 3 are interstage plate to grid coupling capacitors. Leakage here will raise the grid voltage of the following stage, pushing that stage toward saturation, poor performance, lots of heat dissipation, and reduced tube life. Good quality Mylar caps make better than original replacements. Each of these three also has a mica cap in parallel with it, and sometimes I've found one of those to also be leaky. Check each grid voltage to see if it agrees with the schematic.
Once you get these fixed, you can move on to the problem you asked about. I don't have any specific recommendations for that problem, but I'd suspect a problem with poor contact in the range switch. Treatment with Deoxit followed by Shield should be good for this.
If you continue to have problems, post your serial numbers/prefixes so we know what version you're working with. I probably have 5 different manuals for the HP400 series, and I'm sure I'm still not completely covered.
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Re: BOONTON 8900B PEAK POWER CALIBRATOR
To avoid trampling over another group bandwidth i suggest you as this on the Marconi group.io pages for this question.
And definatly off brand topic, has anyone any details/specs on a Marconi TM9701 VHF/UHF Detector, test accessory. Its an accessory with both a positive and negative output via seperate diodes. Id like to test it but manufacturers specs would be handy.
I suspect it may be possible to help you out.
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On 3 May 2024, at 22:17, Pete Harrison via groups.io <rockfisher@...> wrote:
? Hi all, i appreciate this isnt a HPAK instrument but being Boonton it kinda is :)
Has anyone got a full service manual for these please. Ive managed to find one online but it doesnt have a circuit diagram.
I also have a pdf of Boontons no35 notebook? by G.Raymond. Polen who designed the instrument, but id really like the full manual if possible and it will save me trying to draw out the circuit by hand.
?
And definatly off brand topic, has anyone any details/specs on a Marconi TM9701 VHF/UHF Detector, test accessory. Its an accessory with both a positive and negative output via seperate diodes. Id like to test it but manufacturers specs would be handy.
Many thanks in advance Pete Harrison.
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HP 3852A firmware update issue
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PAI had a minimum order of 100, but when I went up to 500 they started to seem really worth it.? The worst thing about doing a bulk buy was having to count out all those little bags of 50 :^)? I've had no complaints since.
Dan
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I asked Precision for a quote, I guess we will see Monday.
Wally
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Re: BOONTON 8900B PEAK POWER CALIBRATOR
Many thanks David, somehow i missed that in my search.
Regards Pete
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Re: HP 400H AC VTVM Difficulties
Since you're okay on the 1mV to 300mV ranges and the trouble starts when you advance to the 1V range, I'm staring at your x1000 range attenuator.? Look for an open there.
What's your serial number?? There were several distinct versions of the circuit as time went on, and the range attenuator was one of the blocks affected.? The early version was known for high noise level.
I've attached repair notes for my 400D which is the same as the 400H except for a lower quality meter movement.? Mine is
Serial Prefix 017.? The notes include a partial bibliography of different versions of the manual.
Dave Wise
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Since the problem appears to be a residual reading at the lowest ranges and the grid of V2 helps, you might want to rule out spurious noise getting to V2. Multi MHz oscillation in the V1 stage comes to mind.
I'd check (with a 50 MHz or better 'scope) at the grid of V2. The "phase of the moon" observation supports this hypothesis. Perhaps one or more of the capacitors in the V1 circuit is bad.
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Re: Another 3GHz 53132-68003 Chanel 3 option design for the 53131A and 53132A
Hi Ed, ? Both 53132A do not count if there is no signal at their CH3 input. ? I bought these 2 PCBs on eBay, I think they are clones. ? For 12.4GHz option, the board is identical to this one: For the 3GHz option, I cannot find the information. ? Yves ? Yves:
Thanks for the update.
Do the boards count randomly when there is no input?
Were these the OEM options or clones?
ed
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fenugrec
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