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HP 334A - Mystery Parts on A5 Board
I have a 334A whose AUTO function is not working correctly. It seeks an initial null then drifts well off of that null.
I've been checking the voltages and waveforms on the A5 board and have bound TP5 is completely dead. I've checked everything I can think of so far and still haven't found it; however, in my exploration of that board, I found some components that don't appear to be on either of the schematics I have and not sure what they are. There are a few of them and in two cases, they're tied from collector to base for two of the transistors. I'm attempting to attach pictures that show these parts but if that fails, I'll add these to an album. If they do come through, I'm talking about the darker brown components that look a bit like a resistor but are marked a bit differently (e.g. red black black orange brown. My presumption that is 200,000 with the brown being a tolerance or tempco indicator but don't know. Anyone recognize these? BTW, the serial number prefix for mine is 1140A and one of the manuals I have is valid for the serial number; however, I'm not sure if there may be some Service Notes that may have included those parts. I have a lot of microfiche and the index for the 334A mentions quite a few updates that are not part of a manual (at least I don't think they are). Unfortunately, the only microfiche I have is a 1972 version so it's quite a bit older than mine. Thanks, Barry - N4BUQ |
Re: Are there any HP CRT refrenece documents?
Here is a list I have compiled. It is nowhere near complete; I hope it is correct. Jeremy HP CRTs G-205E-2 ?175A Oscilloscope (P31) The following all carry the first four digits "5083-" 0353 130C Oscilloscope 0722 132A Oscilloscope (dual gun) 0652 140A Oscilloscope 9093 140T Oscilloscope 1452 141A Storage Oscilloscope 2587 141T Storage Oscilloscope 2511 141T Storage Oscilloscope 1752 143A Oscilloscope (P31) 1722 143A Oscilloscope (P2) 1751 143A Oscilloscope (P?) 1732 143A Oscilloscope (P7) 1442 143A Oscilloscope (P11) 0842 H30-175A Oscilloscope, high writing-rate CRT 3552 1740A Oscilloscope 5070 1741A Storage Oscilloscope 9023 180E Oscilloscope 1952 181T Storage Oscilloscope 5791 8510 Network Analyzer 3975 Unknown, seen for sale on eBay 1875 Unknown, eBay rectangular 6589 Unknown, eBay rectangular 5732 Unknown, eBay rectangular 6577 Unknown, eBay rectangular 5751 Unknown, eBay rectangular 5723 Unknown, eBay rectangular On Mon, Apr 27, 2020 at 11:08 AM walter shawlee <walter2@...> wrote: With Tektronix, there is both a detailed CRT data dump, and a "used in" index for CRTs, but I have never found anything similar for HP.? does anyone know of any hp CRT reference data out there?? any info appreciated, as I have failed to find any for 30+ years. It seems like it must exist but I just don't know how to fin dit. |
Re: Wanted: HP 8445b Preselector
I have one - need your e-mail
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Quoting garp6 <hrgerson@...>: hi, |
Re: [hp70k] msib sniffer/injector interest query
Tried since a long time ! It is derived from the Hughes/Delphi connector line but specialy manufactured for HP. Delphi, of course, refused to sell to anybody outside HP. See the mechanical design guide I sent to davidandlaura and uploaded by them. On Monday, April 27, 2020, 07:53:22 PM GMT+2, Mark Kahrs <mark.kahrs@...> wrote: Speaking of the MMS series, has anyone tried to find that connector?? HPAK calls it "proprietary"...? The closest I've found was a Packard-Hughes series (now Delphi): But they don't seem to offer the 50 pin version. On Mon, Apr 27, 2020 at 2:15 AM David & Laura <davidandlaura@...> wrote:
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Are there any HP CRT refrenece documents?
walter shawlee
With Tektronix, there is both a detailed CRT data dump, and a "used in" index for CRTs, but I have never found anything similar for HP.? does anyone know of any hp CRT reference data out there?? any info appreciated, as I have failed to find any for 30+ years. It seems like it must exist but I just don't know how to fin dit.
best regards, walter (walter2 -at- sphere.bc.ca) sphere research corp. |
Re: [hp70k] msib sniffer/injector interest query
Speaking of the MMS series, has anyone tried to find that connector?? HPAK calls it "proprietary"...? The closest I've found was a Packard-Hughes series (now Delphi): But they don't seem to offer the 50 pin version. On Mon, Apr 27, 2020 at 2:15 AM David & Laura <davidandlaura@...> wrote:
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Re: How to check the accuracy of an HP 5342A frequency counter
Another thing that can happen to an Rb source is that its built-in OCXO may age/drift too far out of its normal range, for the correction action to properly lock it to the Rb signal. However, the lock indication should not come on in this case, so there is probably something else going on.
I'm not familiar with the Rb in question here, but I know for instance, that old ones like my Efratom M-100s, have provisions for adjusting the OCXO back to a proper tuning range to acquire lock. One of my units had a part failure in its PLL, and was stuck way off in frequency until that was fixed, and the OCXO readjusted. It also properly indicated the failure by never indicating a lock, until after it was fixed. It's odd that you get a lock, with it apparently so far off. If you have a detailed manual for the unit, you should study it to see the internal frequency plan. A definite, constant offset from the desired frequency could be a result of the control loop locking to a wrong harmonic from the internal synthesizer, due to a part failure or misadjustment. That's the only way I can picture getting an actual, valid lock indication, yet wrong frequency. Most Rbs synthesize a very particular frequency from the 10 MHz OCXO reference, then multiply it up to the ~6.8 GHz Rb resonance, then use phase detection techniques to steer the OCXO in the right direction and place to get and hold a particular difference between the Rb resonance and the synthesized harmonic. There are various frequency plans used, but this difference frequency is often set up to be in the 100 Hz to 300 Hz range. Your 170 Hz error falls in this range, so I can picture maybe the unit has slipped a cog, so to speak, and is locked to a wrong harmonic, or on the wrong peak of the phase detector signal. If you can find a coarse adjustment on the Rb's internal OCXO, you can try tweaking it toward the right frequency, as measured on your other gear - assuming now they are correct and the Rb is wrong. If the Rb isn't busted, you may find as you tweak, that the lock indicator will go out, then magically pop back on when the output frequency reads near 10.000000... MHz. If this happens, then you have reset it to the right cog, and it should be OK operationally, and likely more accurate than the other gear. Then you can look into fine adjustments and perfecting the setup. Good luck. Ed |
Re: How to check the accuracy of an HP 5342A frequency counter
Bob Albert
Complicating the issue is the presence of a frequency adjust trimmer on each unit, which presents an unknown as to whether it has been adjusted and by whom.? It's a strong possibility that this voting process is flawed, and that the one renegade reading could be the correct one. However with an arror of over 100 Hz at 10 MHz, comparison with WWV is easy and desirable. We are not agonizing over one part in 10 ^-11 here, but a sloppy 10 ^-5. Bob
On Monday, April 27, 2020, 10:14:54 AM PDT, Greg Muir via groups.io <big_sky_explorer@...> wrote:
The ¡°three oscillator¡± approach is a practice that has been used by NIST (NBS) for decades for comparison of their frequency & time standards.? It also provides a level of redundancy should there be a failure of one of the standards.? But now with improved methods of frequency/time generation (the current cesium fountain clock) it becomes more of a moot point as to what is accurate in their domain. ? The principle is simple: ? Compare source A against source B. Note frequency difference. But which source is off-frequency? Compare source a against source B against source C. Most likely you will see two sources that closely agree. More are better but there can be limits. ? Greg |
Re: How to check the accuracy of an HP 5342A frequency counter
The ¡°three oscillator¡± approach is a practice that has been used by NIST (NBS) for decades for comparison of their frequency & time standards.? It also provides a level of redundancy should there be a failure of one of the standards.? But now with improved methods of frequency/time generation (the current cesium fountain clock) it becomes more of a moot point as to what is accurate in their domain. ? The principle is simple: ? Compare source A against source B. Note frequency difference. But which source is off-frequency? Compare source a against source B against source C. Most likely you will see two sources that closely agree. More are better but there can be limits. ? Greg |
HP5351B High frequency input connector
The high-frequency input connector on an HP 5351B I just purchased appears to be missing the input connector. I believe it was an APC-3.5. There appears to be a missing insert. I'm looking for tips on how to repair or replace this connector. For my purpose a type N connector would be acceptable as a replacement. I have the service manual. It looks like there is a cable assembly. One part number for the APC-3.5 and one for the type N.
Thanks, Jim |
Re: Semiconductor test set advice
Quite complete info on the Tek 575/175 is here:
including 1963 catalogue pages, the Op/Serv manuals and the 'Some Transistor Measurements Using the Type 575' app note I'm about halfway thru re-doing. There were two versions: one with 0 to 20/200V Peak Voltage Range and the mod 122C with 0 to 20/200/400V capability. You might also want to dig up the three recent and quite good iterations of vacuum tube testers as they interface with a PC. They are the uTracer: the eTracer: and the much more ambitious, capable, costly and, I'm told, difficult to build RoeTest: Best, Bill Perkins |
Re: Semiconductor test set advice
On 4/27/20 12:38 PM, David C. Partridge wrote:
He sold himself to the company's (largely nontechnical) management asThe lead developer was unbelievable; his stated position was that any API (yes, API!) that hasn't changed in the past few weeks "isn't being updated" and is therefore "dead". Believe it or not, it actually went downhill from there.OMG who hired that idiot! a "cool" modern developer who could develop "cool" and "fresh" web interfaces. He went on to go from employee to contractor, then started his own consulting firm, still doing the same job for that same company, and bilked the company for large amounts of money. Beware the word "fresh" coming from "tweenager" software developers. -Dave -- Dave McGuire, AK4HZ New Kensington, PA |
Re: Semiconductor test set advice
...and we wonder these days why people have the attention span of a hyperactive gnat.? It aggravates me when they constantly make little changes to interfaces so that things that were there are either no longer there, or move a bit, or work differently.? It feels like gaslighting - I swear I did this last week, why does it not seem to work now?!? Design it then leave it the eff alone!!? There's something to be said for panels with knobs and switches on them - people are less inclined to rearrange them for? ?...reasons... -Pat On April 27, 2020 at 11:58 AM Dave McGuire <mcguire@...> wrote: |
Re: Semiconductor test set advice
The team lead on the C++ project I alluded to in another thread was like that. I found delicious irony in the outcome of the story. When ARCO got bought, BP was not allowed to keep ARCO's North Slope assets. As a consequence ConocoPhillips bought them and got the system I'd worked on. I learned from friends that they kept all my code in C & FORTRAN and pitched the C++.
The part that really blew my mind was there was a 6x differential in productivity. It took them 6 weeks to build the UI for 1 week of my work. I saw why when I was asked to fix a piece of the UI code as I'd run out of things to do and they were behind. It was a single, several thousand line function created by a UI builder and then hacked. I fixed it, but was so disgusted I told the project manager I would not work on any more of it. I signed my name to my code and included my ACM email address in the header comment. I got laid off not long after and ARCO was sold to BP a few months later. The saddest part of that project was sitting with another scientist while he was testing it. If you wanted to display 6 curves, it drew one, erased the screen, drew two, erased the screen and so forth until all of the traces had been drawn. This took about a minute and he would just giggle. And if you attempted to scroll up or down in the curves it repeated all the redraws. The team lead tried to get me to join LinkedIn so he could reference me. I declined. My first contract project was in active use for 12-14 years with about 1/2 that unmaintained. We had 12 user bugs the first year and it went to near zero. There were a pair of 15,000 line libraries in that package that *never* had a bug found. The single change was when Sun broke the C stdlib and failed to correctly set errno on a call to getcwd(3c). The fix was to test for a null pointer return on Sun systems. It also ran from the same source on AIX, HP-UX, IRIX, Ultrix, CLIX (Intergraph) in addition to SunOS/Solaris. Except for things like the Sun gaff the only #ifdefs were byte sex and FORTRAN RECL= bytes or words. It was a 500,000 line port from VAX FORTRAN & VMS to Unix. Lots of it written by scientists who were not good programmers. The coolest part of that project was the build system, YAMS, Yet Another Make System. You could create a directory, cd to it, and check out the source code. You could then open xterms on all the systems in that same directory and after making a change, could simultaneously compile and run the regression test suite on all platforms. This made everyone very sensitive to the language standards and portability. The IRIX and Ultrix ports were done as an afternoon lark by me when I didn't really have anything serious to do. Probably waiting for a staff meeting. Good programmers never have to modify their code unless someone else breaks theirs. Have Fun! Reg |
Re: Semiconductor test set advice
Sean, the option for the Tek 575 that's eluding you is Mod 122C - it adds a third range of 0-400V @ 0.5A to the 0-20V @ 10A and 0-200V @ 1A collector sweep supply of the standard instrument. -Pat On April 27, 2020 at 11:52 AM [email protected] wrote: |
Re: Semiconductor test set advice
On 4/27/20 10:02 AM, Reginald Beardsley via groups.io wrote:
Occulus, Thanks. Yahoo changed the interface so that it doesn't show unread messages in the SPAM bin :-(Actaully I think it's what a lot of the kids DO want. If it looks the same as it did yesterday, it's not "FRESH!" I worked with some developers a few years ago that were of that mindset. They were doing the web app and back end that talked to firmware I was writing. The lead developer was unbelievable; his stated position was that any API (yes, API!) that hasn't changed in the past few weeks "isn't being updated" and is therefore "dead". Believe it or not, it actually went downhill from there. -Dave -- Dave McGuire, AK4HZ New Kensington, PA |
Re: Semiconductor test set advice
Yeah, complete UI/UX changes with web services seem to be par for the course these days. Farcebook is a leading example. But I digress...
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Another thing to keep in mind with the Tek curve tracers is some of them develop HV transformer difficulties (lots of info about this+repair strategies on TekScopes); however, they are indispensable if you need to characterize high power parts. The 575 with a particular special option (name and number escapes me) is even better for this. I'd personally like to find a good one with that option as it would be a great curve tracer and would satisfy the itch to have one glowing Tek with vacuum tubes and ceramic strip construction. :o) It doesn't have blanking though, so things like families of curves will show retrace unlike a 577 or 576. The 577 also has the advantage of basically being made of standard 5000 series oscilloscope parts, unlike the 576 which is large and more complicated with the fiber optics to light the display annunciators. You can also get the 577 with a storage crt, but whether that crt will have any life left is questionable most likely. As I understand it, the semiconductor parameter analyzer that HP marketed was really more intended to be an analytical lab instrument mainly focused on characterizing lower-power parts, while Tek curve tracers often were used on production lines for matching components and stuff like that. This at least partially explains why a lot of 577 and 576 curve tracers that come up for sale are beat up pretty badly. And as you observed, good condition examples command high prices. I understand where you are coming from wanting to be able to do whatever measurement you need. I'm working to build up to that and also be able to calibrate my own stuff. Perhaps we can have a discussion offline about what you've found indispensable, as I believe our interests align quite a bit in the microwave realm. Cheers! Sean On Mon, Apr 27, 2020 at 07:02 AM, Reginald Beardsley wrote: Occulus, Thanks. Yahoo changed the interface so that it doesn't show unread messages in the SPAM bin :-( |
Anyone from HP that worked on the design of the 1700 Series Scopes?
I am trying to find details on parts used in the design of the 1703A and the 1707B. Specifically
the FET's used in Option 20 the Vertical Output Amplifier. These would be matched FET's HP Part number 1855-0085. These parts are not found in the cross reference so it would be good to know what the base part number is and it someone might know what the matching parameters are. I would like to clone this board (an perhaps make a wider bandwidth one) so having additional info on it would be great. I have the schematics for both of the designs that were used the one from the 1707B OPT 300 military scope and one from the 1703A. The 1707B one used a 2N4044 matched NPN? in a TO-78 can followed by a pair of 2N3906's. The 1703A one uses a matched pair of N-Channel JFETS followed by a PNP/NPN for output drive with a 741 op-amp. It's a clever design for the time using the op-amp for the DC path and using AC coupling for the high frequency (such as it was then) path. In any event finding the original parts in any quantity would be a problem so a re-design that uses modern parts would be better. I have already completed a PCB layout for the 1707B version using the original parts which got me thinking that others may want one as well so that led me to be thinking about something using modern op-amps, etc. So I am hoping that some there are some members of the group that worked on these scopes. Thank you, Sam W3OHM |