HP 70K/HP 70000 Modular Measurement System Thread - Page 1
Forum section: electronics / testgear

author: VE7FIM
author_rank: Contributor
timestamp: January 26, 2017, 04:37:05 am
content: We need a thread covering the HP 70000 (HP 70K) product line, also known as the Modular Measurement System (MMS), so here goes:The HP 70K was an extensive series of products manufactured by HP between based around two modular chassis and a series of modules that could be assembled to construct a variety of instruments, including spectrum analyzers, DMMs, oscilloscopes, digitizers, microwave switching and more. These products were extremely well built, and many systems are still operational today. The HP 70K product line was some of the first that required computer-controlled calibration and diagnostics, so one of the challenges of maintaining these systems is setting up an HP 300 based computer system with the right software.There's a fair amount of information about there about these products out there. Here are some good starting points:Restoring a Classic Spectrum Analyzer -http://www.vectis-research.com/Blog/files/SpectrumAnalyzerPart1.htmlHP Document Index -https://medium.com/p/master-hp70k-document-index-4fb5fd6e7d90HP 70K info at PRC68 -http://www.prc68.com/I/HP71100C.htmlSignal Path Teardown -https://www.eevblog.com/forum/testgear/video-teardown-analysis-part-salvage-from-an-hp-microwave-analyzer/So, if you have any resources, projects, teardowns, etc, post them here!Here's part of our HP 70K setup, which we use as an SDR front-end and for signal analysis:

author: VE7FIM
author_rank: Contributor
timestamp: January 27, 2017, 05:44:02 am
content: Looks like someone in the MMS marketing team was a Zelda fan.

author: pa3gyf
author_rank: Newbie
timestamp: February 13, 2017, 12:58:56 am
content: Count me inthough you might want to consider joininghttps://beta.groups.yahoo.com/neo/groups/hp_agilent_equipment/infoAnother resource:http://artekmanuals.com/manuals/hp-manuals[yes, it costs money; but this guys takes the effort to scan rare manuals into pdf].I'm currently trying to upgrade the firmware on my 70900a, in order to be able to use a 70300a tracking gen. I purchased recently. I'm also about to complete some Java software that gets/displays traces and does configuration through gpib (Prologix Ethernet).And of course I went through the usual routine of replacing some electroliths/fuses/semi-rigids and the Li-battery to get the unit to work.Interesting setup, BTWBR

author: VE7FIM
author_rank: Contributor
timestamp: February 28, 2017, 04:06:51 am
content: Thanks! I'm working on an SDR-based module that will replace the 70902A/70903A, but I don't have much spare time.Already on that mailing list, and Artek has some great scans. I purchased a few of their CLIP scans.Good luck with the firmware upgrade, it can be tricky without replacing the process (or memory) board — do you have a HP 9000 system set up?Here's a few more interesting resources:Hugo Vifian's retrospectives on "Project Redwood"http://hpmemoryproject.org/timeline/hugo_vifian/hp_santa_rosa_00.htmThe MMS catalog (see the top ofhttps://medium.com/p/master-hp70k-document-index-4fb5fd6e7d90) has lots of detailed information on the MMS product line, and the various modules and systems that were built as of 1998.It's such a shame that this product line ended up being dropped.

author: rickells
author_rank: Regular Contributor
timestamp: October 26, 2017, 02:35:22 pm
content: hi,I recently acquired an HP 70001 mainframe + HP 70206a display with several standard modules (900a/b, 902a, 903a, 905a, 908a).It did not come with the HP MSIB MMS cables.I found two web links to make the MSIB cables:http://www.rbarrios.com/projects/HP-MSIB/http://www.prc68.com/I/HP71100C.htmlAlso, a link on the repair of a 70004a display unit:http://www.rbarrios.com/projects/HP70004/Any others that folks are aware of ??will be testing it out, soon.Would be interested in exchanging info and experiences.

author: pquadrat
author_rank: Regular Contributor
timestamp: February 05, 2018, 09:05:06 pm
content: Hi,I am another HP 70000 SA owner. I got the system some years ago, and recently did a little upgradefrom a 70904A (100Hz to 2.9GHz) to the 70908A (100Hz to 22GHz) frontend.The system consist of:HP 70004A Display with 4 slots:HP 70902A IF moduleHP 70903A IF moduleHP 70900A LOHP 70001A Mainframe 8 slots:HP 70310A frequency reference (to be able to feed 10MHz from my Z3801A to the system)HP 70300A tracking generator up to 2.9GHzHP 70700A digitizerHP 70908A RF Section up to 22GHzA HP 70904A and a 70905A are also here, but I think I will sell one of them.The 70900A is running with the processor board of a 70952A optical spectrum analyzer, which contains the latest firmware and works great.But I have a problem (not sure if it is a problem):The system has the 70300A Tracking Generator (20Hz-2,9GHz) included. When I check the frequency of thetracking generator (span 0Hz, not sweeping), it is off for a different amount depending on resolution BW of the analyzer.But the offset is constant even for very different output frequencies:Center Freq. Res. BW Output Freq. Offset1 MHz 10 1.000.018,00 1830 1.000.022,00 22100 1.000.026,00 26300 1.000.037,00 371k 1.000.055,00 553k 1.000.030,00 3010k 1.000.405,00 40530k 998.530,00 -1470100k 993.780,00 -6220300k 1.030.028,00 300281M 1.037.528,00 375283M 1.337.528,00 33752810 MHz 10 10.000.018,00 1830 10.000.022,00 22100 10.000.026,00 26300 10.000.037,00 371k 10.000.055,00 553k 10.000.030,00 3010k 10.000.405,00 40530k 9.998.530,00 -1470100k 9.993.780,00 -6220300k 10.030.028,00 300281M 10.037.528,00 375283M 10.337.528,00 337528100 MHz 10 100.000.018,00 1830 100.000.022,00 22100 100.000.026,00 26300 100.000.037,00 371k 100.000.055,00 553k 100.000.030,00 3010k 100.000.405,00 40530k 99.998.530,00 -1470100k 99.993.780,00 -6220300k 100.030.028,00 300281M 100.037.528,00 375283M 100.337.528,00 337528As You can see, the offset is allways the same regardless the center frequency, but I think it should bemuch closer to the CF.All equipment runs from the same 10MHz reference. The SA seems to be accurate in CF, and the 300MHzon the front to the LO is also perfect.No errors show up. Output frequencies are stable.Any ideas what to check?

author: VE7FIM
author_rank: Contributor
timestamp: February 07, 2018, 08:34:49 am
content: I have a similar setup, and I haven't observed this particular problem.Do you know what specific firmware revision you have in your 70900A?I'll switch out my 70900B for a 70900A later this week, and run some tests to see if I can reproduce this behaviour.Does the problem persist if you swap out the 70908A RF section for a 70904A?

author: jfphp
author_rank: Regular Contributor
timestamp: February 07, 2018, 05:41:29 pm
content: There is a tracking adjust like for other TG. One oscillator is not synthesyzed and tracking drift is specified.

author: pquadrat
author_rank: Regular Contributor
timestamp: March 07, 2018, 02:21:41 pm
content: I did a firmware upgrade on a new acquired 70900B Local Oscillator Module, and would like to share what I did:On the main logic board (with the 68020 CPU) is a daughter board with firmware and RAM. The firmware is in 8 27C010 PLCC EPROMs:I removed all 8 EPROMs with my hot air gun (carefully) :Then I soldered 8 new PLCC32 sockets on the board. Tried it with hot air, but moved to hand-solder them. Be carefull to get every pin to solder well:I put the latest 70000 Series Firmware (961024 (B06.04)) in 8 new flash chips (AM29F010-12), put them in the sockets and it worked fine.For another HP 70900A, some time ago I bought a HP 70952B optical spectrum analyzer module (non-working, cheap), it has a complete 70900B mainboard in it. You can put it into the 70900B LO, and it has the newest firmware and processing power! And the firmware/RAM board of the 70952B also has 1MB RAM instead of 256KB. Boards looks the same as the 256KB board, not shure if swapping the RAM chips will do it.

author: pquadrat
author_rank: Regular Contributor
timestamp: March 07, 2018, 06:06:39 pm
content: Next firmware module upgraded, this one without sockets:I used flash ROM chips (AMD AM29F010-120), You can also use 27C010-120 or -150 EPROMs. I do not know if to fast ones make trouble (sometimes they can).Programmed with a MiniPro TL866CS programmer, connected over USB, using a PLCC to TIMM adapter (see first picture).I now have the older firmware versions 920724 and 940120 available as BIN files.You can find the newest version here:http://ftb.ko4bb.com/getsimple/index.php?id=manuals&dir=HP_Agilent/HP_70900_Modular_Measurement_System

author: VE7FIM
author_rank: Contributor
timestamp: March 16, 2018, 09:20:54 am
content: Quote from: pquadrat on February 05, 2018, 09:05:06 pmI tried to reproduce this problem with my system, but was unable to.Can you upload a photo of the rear of your system? The Tracking Adjust is only +/- 500 Hz, where the Tracking Offset is up to +/- 10 MHz, and is done via the 21.4 MHz input, so an issue with the 21.4 MHz input that could be related to what you are seeing.P.S. Impressive soldering job there on the firmware upgrade!

author: pquadrat
author_rank: Regular Contributor
timestamp: March 21, 2018, 02:36:45 pm
content: Quote from: VE7FIM on March 16, 2018, 09:20:54 amJust a quick reply: I was able to solve the problem, I used a differnet set of SMB cables, I think one of my interconnect cables has a problem. After working on the system, the issue disappeared once, but came back soon. But now I think it is working reliable.

author: pquadrat
author_rank: Regular Contributor
timestamp: March 21, 2018, 02:54:41 pm
content: I had to replace the YTO module on one of my 70900B (took it from my 70900A, which was working fine). I got it adjusted, without the help of the old BASIC maintenance software. I found the software on Keysight's web site, but was not able to see the BASIC code, it is a "packed" BASIC format.Sometimes it is referred as "Module Verification Software", sometimes "Operation Verifcation Software". Is this the same? Is this also the software for calibration/adjustements?Does anyone know how to make the files readable? I do not want to set up a HP 9000 series 300 computer, I just want to send the rightHP 70000 instructions directly via GPIB.Thanks

author: pquadrat
author_rank: Regular Contributor
timestamp: March 21, 2018, 04:36:21 pm
content: Quote from: pquadrat on March 21, 2018, 02:36:45 pmPlease ignore the things I have written above. The cables were not the cause, this issue occurs with one of my two HP 70902A IF sections. With the other 70902A in the system, all is fine, and the output frequency of the tracking generator is correct. Problem is, this IF section has a noise problem.

author: VE7FIM
author_rank: Contributor
timestamp: March 29, 2018, 02:02:07 am
content: Quote from: pquadrat on March 21, 2018, 02:54:41 pmUnfortunately, the HP 70K verification and calibration software is written in Rocky Mountain Basic, and uses pre-compiled routines that aren't easy to translate or emulate on other platforms.While one could watch the GPIB traffic to reverse engineer what the software is doing to the MMS module, the conditional logic and calibration constants still would need to be extracted from the software.As an aside, this _would_ be a good approach to make re-loading the firmware on a 70700A easier. This is a common problem, since when the battery goes on this module, the firmware is lost ("pgm gone").Getting a 9000 Series 300 system up and running is the easiest way to run this software.

author: Raindog
author_rank: Contributor
timestamp: May 08, 2020, 02:11:57 am
content: Greetings all. I have been piecing together a HP 70K series spectrum analyzer for my small home test and measurement lab. So far things are working, however the battery in the HP 70900A local oscillator is bad, does anyone know where I can get a suitable replacement battery (i.e. Digikey / Mouser)? I can open the oscillator and look but I'd rather open it just once when changing it out. I also have a bad battery in the HP 70206A display unit but that one is ordered and I'm waiting for it to show up. Despite these issues I really like the modular approach to these instruments. Many leaps and bound over my other spectrum analyzer (HP 853A w/ HP 8557A).

author: 0culus
author_rank: Super Contributor
timestamp: May 08, 2020, 03:17:41 am
content: Quote from: Raindog on May 08, 2020, 02:11:57 amI'm not super familiar with these instruments (I prefer the menu-less UX of the 8568/8566 personally), but have you tried looking for manuals? Keysight hosts tons of manuals for obsolete HP and Agilent gear, for example.

author: Raindog
author_rank: Contributor
timestamp: May 08, 2020, 05:56:52 pm
content: I have been going to the Keysight and downloading all the manuals I can find for the modules I have and future modules I will install later. The documentation for the HP 70900A module is pretty detailed but I haven't been able to find schematics or parts lists (yet). I figured I'd at least post the question here since someone somewhere has had to deal with this issue before. My first choice was the HP 856x series but had a difficulty finding one that wasn't all beat up, had previous calibration stickers removed improperly or wasn't over priced. But all in all I like the 70k for the flexibility.

author: 0culus
author_rank: Super Contributor
timestamp: May 08, 2020, 09:13:36 pm
content: Quote from: Raindog on May 08, 2020, 05:56:52 pmUnfortunately the 70000 series came at a time when CLIP manuals were becoming rarer. I’d be surprised if some manual doesn’t tell you what battery it needs though.I was lucky enough to find a NOS 8566B. Feel free to PM if you want pics. Don’t want to derail your thread.

author: 0culus
author_rank: Super Contributor
timestamp: May 09, 2020, 03:46:04 pm
content: @Raindog:https://groups.io/g/HP-Agilent-Keysight-equipment/message/83947?p=,,,20,0,0,0::Created,,70900A+battery,20,2,0,24815627I may have found your answer.

author: Raindog
author_rank: Contributor
timestamp: May 10, 2020, 02:28:33 am
content: Thanks! I had a sneaky suspicion that it was the same battery used in the HP 70206A display only with leads attached. One is on the way, Both of these batteries are in the AA form factor and I have discovered a regular 1.5v AA can be used in a pinch in the 70206A if need be, at least long enough to get rid of the confidence check error on boot up. WOW, a NOS HP 8566B, that's quite the score. Most HP 8566B's I find on eBay are pretty beat up with an array of issues ranging from gouged front panels, missing knob caps, missing or broken rack handles, etc. Every now and then you can find a nice one.A buddy of mine who used to work for Motorola rescued one that was headed to the dumpster, all because they couldn't find one of the interconnect cables. Other instruments rescued form the dumpster included several HP 8590, 8560 spectrum analyzers, Tektronix 24xx series scopes (one is a Tektronix 2465 I got for free) and a mint Bird 43 watt meter with slugs I paid $30 for. It's astonishing what is thrown away all because they don't want to spend the time to auction it off.Once again, thanks for the help!

author: 0culus
author_rank: Super Contributor
timestamp: May 10, 2020, 03:54:23 am
content: Quote from: Raindog on May 10, 2020, 02:28:33 amYou're welcome! Please come share some pictures of your 70k system-in-progress in the TEA thread!https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/Beware that if you are looking for help stopping the Test Equipment Acquisition habit, it is the WRONG place!!!Also,hereis the post where I shared pics of my 8566B and accessories. And I agree with you, it's simultaneously amazing and sad what gets thrown away amongst rather expensive test equipment. In many cases, minimal effort is needed to get it working again if you can get your mitts on it.

author: K9DTV
author_rank: Contributor
timestamp: April 08, 2021, 08:47:29 am
content: Figured I would show off my system.70001A with fan mod.70004A firmware 7.0870100a70700a70900b option 51270902a70903a70910a70911a option 004 and 00570810b70820a89410 all software and hardware optionsWould love to talk about it. also have 9000/300 systems

author: K9DTV
author_rank: Contributor
timestamp: April 09, 2021, 01:29:51 am
content: I just get IDC connectors off ebay and use ribbon cable.I then just cut the 5th and 6th wire and solder the 5th and 6th wires together on each of the ends only.It is fast and easy and works great.Edited to make directions more clear.Added another picture of cable to make clear ends of cable.

author: K9DTV
author_rank: Contributor
timestamp: April 09, 2021, 08:22:52 am
content: Battery for 70kFor units like 70900b manufacture part number TL-5104/P Digikey p/n 439-1013-NDFor units like 70100a manufacture part number BR-2/3AT2SPN Digikey p/n P201-NDFor units like 70205A manufacture part number TL-5104/P Digikey p/n 439-1012-NDThere was a 2/3A used without tabs, but I think HP stopped using it, so I did not list it.

author: pquadrat
author_rank: Regular Contributor
timestamp: April 09, 2021, 08:24:57 am
content: At this time I have three 70000 systems, never could stop collecting these modules...@K9DTV:Do You have a 900/300 system running with the calibration software for the 70k system? I have a 900/382 controller with HP-UX running, but did not get it ready to talk to the 70k.The system with the 70911A (Opt 001 (70Mhz IF), 004, 005) can connect to a 89600S system.And I finally managed to upgrade the RAM/ROM Boards not only to current firmware, but also to 1MB RAM (Option "512"). If anyone is interested, I can post how to do it.Peter

author: K9DTV
author_rank: Contributor
timestamp: April 09, 2021, 08:38:53 am
content: yes, you never have just oneI have 4 9000/300, only one running with a os and it's ws with basic 6.2 on top.I have the software from hp on my PC, but dont understand how to get it installed on the 9000/300I am running b.06.03 on the 70900b's with the DLP for the 70911a.

author: pquadrat
author_rank: Regular Contributor
timestamp: April 09, 2021, 08:56:05 am
content: Quote from: K9DTV on April 09, 2021, 08:38:53 amI have to work out how to get the DLP to my 70900B, but at this moment I have no time for it.I was able to get RM Basic running on HP-UX, and to start sthe 70k-Software, but I have to invest more time, which I do not have right now.Do You know if the DLPs are in the software package? As far as I know, there is no way to save a DLP out of the 70900B?-Peter

author: K9DTV
author_rank: Contributor
timestamp: April 09, 2021, 09:06:06 am
content: @pquadratI do not think the DLPs are in the software package from HP's site.It does have all the test and cal software for the system.It also has the RAM software for units like the 70700.I found no way to download the DLP from the 70900b to the ram card or disk drive unit.Wish I know more about RMB and how they archived this software.

author: pquadrat
author_rank: Regular Contributor
timestamp: April 10, 2021, 06:14:24 am
content: Quote from: K9DTV on April 09, 2021, 09:06:06 amI think I did uncompress the software successfully, they did it under HP-UX. But I did it a year ago, so I have to take a look again.Problem is, the file format of the basic files can only viewed under RM Basic, its no text file format.For a HP 900 0300 running only RM basic without HP-UX, I think we need to create LIF fomatted floppy disks. I did this years ago with a DOS PC for other old HP stuff.-Peter

author: K9DTV
author_rank: Contributor
timestamp: April 10, 2021, 06:58:56 am
content: Quote from: pquadrat on April 10, 2021, 06:14:24 amI need to know how to decompress the files under DOS and transfer the files to an LIF formatted drive under DOSor a GPIB drive under control of win 98.I have a 9000/382 with a SCSI drive that does not boot, can see the partition under windows 98, but can't seem to copy it or view it's data.Jim

author: K9DTV
author_rank: Contributor
timestamp: April 10, 2021, 05:28:52 pm
content: It turns out there is a way to copy out the complete memory of the 70900B.This is done by using the USTATE command (see attachment).also you can use Save Memory on the 70004a and save it to the MSIB memory card.You have to use save as... first to pick where you want to save the data.This can be HP-IB or MSID or internal.(added) use the menu item 'Save Memory' with a 70004A.However you will need a card the size of the ram in your controller.In the case of the option 512 you need a 85705a memory card (if 70900b memory is full. 256K if running just Rx_Mode Software).I have tried this with a 128K memory card and it does start copying, but then errors out with card full.If you have a HP floppy drive system, this could be saved to disk.Selecting and formatting the drive can be found under Menu...Misc...More...Catalog & MSI...Saving and restoring can be found under State.

author: K9DTV
author_rank: Contributor
timestamp: April 10, 2021, 08:40:45 pm
content: I can confirm that a 70004A and 9122D is able to copy the contents from the 70900B option 512 memory.And then copy it to another system, as I have just done it.Update: I have just saved the program to a hp 85702A 128k memory card.I did this by purging all the saved state files from the controllers memory( 70900B).After recalling to the controller, all that needs to be done is set your default configuration and save it to the controller.So I now have two cards and a few floppies loaded with the program and (4) 70900B (opt 512) with the program installed.Jim

author: pquadrat
author_rank: Regular Contributor
timestamp: April 15, 2021, 10:05:09 am
content: I will try it with my 9122 Floppy drive i a few days.

author: pquadrat
author_rank: Regular Contributor
timestamp: April 27, 2021, 07:25:29 pm
content: Quote from: pquadrat on April 15, 2021, 10:05:09 amI was able to format a disk with my 7122D drive, and to write state and memory to it, and read it back in.I found a DLP disk image with the customer demo Programhttp://www.ko4bb.com/getsimple/index.php?id=manuals&dir=HP_Agilent/HP_70000here, tried to write it to a DD floppy with an old 486 PC, but after writing 70 tracks, I get an error, like "Disk is not ready" or so. But it may be this specific PC which does not work with teledisk, I have to try others.Is there a tool to access the files on a LIF disk from a PC (DOS)?And, some time ago, I was able to unpack the archives with the basic programy on a hp-ux machine. If anyone want thems, please let me know. But it is not clear-text basic, You neet HPs RMBASIC to read or run them.Next step it to get the hp-ux machine to talk to the 70000.-Peter

author: pquadrat
author_rank: Regular Contributor
timestamp: April 28, 2021, 03:40:43 pm
content: I was able to write the TD0 file with the DLP program to a floppy disk without errors:0. Use an old PC, 386 or 486 with DOS 6.22 or so1. Format the floppy with HP LIFUTIL, DD double sided2. use Teledisk 2.16 (2.11 does not work) to write the image.But when I try to load the DLP into the 70900B, I get error 2055, bad file format. I think the LIF header is drong.I can save and load states to the floppy without problems.Any tips?Edit:With the method above I had SUCCESS with the 71910A receiver personality software, which can be found as a TD0 disk image on groups.io

author: K9DTV
author_rank: Contributor
timestamp: April 29, 2021, 04:12:55 am
content: Quote from: pquadrat on April 28, 2021, 03:40:43 pmFirst, I used the 70K system to format the disk.Next I downloaded the memory from the 70900BThen I uploaded it to another 70K systems 70900B.Is this the software you are taking about in the group.io?https://groups.io/g/HP-Agilent-Keysight-equipment/topic/24910293?p=,,,20,0,0,0::,,,0,0,0,24910293I have not looked at this before, so I will look in to it.You could also send me a PM and maybe I can just send you a disk.I think you have have two ram cards and you could send one to me and I could load it on it for you.Jim

author: pquadrat
author_rank: Regular Contributor
timestamp: April 29, 2021, 07:22:18 am
content: These two disks are the ones I found:Receiver Personality:https://groups.io/g/HP-Agilent-Keysight-equipment/files/Above%2070000%20MMS/71910A%20Receiver%20Personality%20DLPDemo DLP:http://www.ko4bb.com/getsimple/index.php?id=manuals&dir=HP_Agilent/HP_70000The receiver personality works, I can load it, but the customer demo DLP doesn'tI can write and read states etc. to a disk and read them back, no problem. It just does not accept the demo DLP.

author: K9DTV
author_rank: Contributor
timestamp: April 29, 2021, 10:32:50 pm
content: Quote from: pquadrat on April 29, 2021, 07:22:18 amThe Demo DLP is for the 9000/300 computers, the stuff I am working with right now is the 70900 DLP

author: tkamiya
author_rank: Super Contributor
timestamp: April 30, 2021, 12:50:20 am
content: HT Basic from here works. Run time and development versions are pretty expensive but demo works for 30 minutes at a time. (It can run under modern Windows)https://transera.com/

author: K9DTV
author_rank: Contributor
timestamp: April 30, 2021, 02:24:28 am
content: In order to work with any of the 9000/300 software, I need to get my 382 up and running.It's current state is no hard drive, I need an image of a working system With the cal and test software for the 70k.Or some help in getting this setup.Picture is of one complete system, but would like to get a 70620B and 70340A with two options.Fixed typos.

author: K9DTV
author_rank: Contributor
timestamp: April 30, 2021, 02:25:25 am
content: Quote from: tkamiya on April 30, 2021, 12:50:20 amI will have to check that out, thank you.

author: pquadrat
author_rank: Regular Contributor
timestamp: April 30, 2021, 02:15:57 pm
content: Quote from: K9DTV on April 29, 2021, 10:32:50 pmYou are right! I expected it to be the Demo DLP package which I had on one of my 70900Bs. Still looking for it. It runs directly on the 70900B.

author: K9DTV
author_rank: Contributor
timestamp: May 01, 2021, 04:41:49 pm
content: Quote from: pquadrat on April 30, 2021, 02:15:57 pmI did some checking and this disk is to be run on the 70900 directly.This manual talks about it on manual page 1-23 or pdf page 32https://www.keysight.com/us/en/assets/9018-40123/installation-guides/9018-40123.pdf

author: Marian.MQH
author_rank: Newbie
timestamp: May 20, 2021, 10:30:59 am
content: Hello,I have an HP70k spectrum analyzer, consisting of the following blocks:HP 70601A RF ( 0...26,5GHz )HP 70906A Preselector ( 50k...26,5GHzand 70900A, 70903A, 70902A, 70004A 70311AI intend to improve its parameters by adding HP 70620A (Preamplifier 2-22GHz).My question is whether my HP 70k will work with this type of preamplifier (in its operating range 2..22GHz) ?Thank you in advance for any help.Marian

author: ruhnet
author_rank: Newbie
timestamp: June 03, 2021, 08:41:33 pm
content: Quote from: Marian.MQH on May 20, 2021, 10:30:59 amMarian, I would think it would at least partially work, but your readings could possibly be a bit off, depending on how the 70900 deals with the preamp being in the system. There's not documentation on non-standard configs like that, so it's mostly trial and error to see how it will behave. In general though, the system usually "tries" to work even with non-standard setups, but you sometimes get strange or off behavior.The 70620 sends gain/flatness information to the 70900 so it can give you an accurate amplitude reading over the full frequency range. Whether or not the 70900 interprets that data correctly in the frequencies below 22GHz with a 70620A depends on how that data is used vs how it is done with the 70620B. I have a feeling it will work correctly, but I have not tried it.I have a 70908A 22GHz RF section, and a 70600A 22GHz preselector that was intended to go with a 70905A RF section. I tried putting the 70600A in the chassis with my 70908, hoping that I could use the 70600A preselector independently via the tune voltage input. As I mentioned above, the system "tried" to work, but it wasn't a useful result. The 70900B saw the unit, and did not complain about it, but IIRC it blanked the trace below 3 GHz and above a certain range (maybe for the first band of the preselector---I don't remember the details exactly). The tune voltage did control the preselector correctly within one band, but the 70900 would not make it switch bands, since it wasn't paired with a 70905 input section, even though my 70908A is also 22GHz.But I do not believe there are any band changes or anything like that with the 70620A preamp, just the calibration data as I mentioned above, so it is likely to work, and in the worst case probably just give some amplitude error (the microwave preamp is spec'd at +/-2.8dB over the range from 2-22GHz.) If it did show amplitude errors, you could measure the gain at various frequencies yourself with another instrument, and print out a correction table, or even generate a correction line that you could load in the analyzer and add to the trace to make it display accurately. Give it a shot and let us know how it goes!Edit: Also, make sure your 70900A has a firmware version late enough (900314 or later) to work with the 70620A.

author: Marian.MQH
author_rank: Newbie
timestamp: June 06, 2021, 08:40:59 pm
content: RUHNET, Thank you for your comprehensive answer to my question. I bought the HP70k (70601A, 70606A, 70900A, 70903A, 70902A) from a recycling company with the intention of recovering the elements - the visual condition of this equipment turned out to be so good that I decided to complete it. In another company, I bought more blocks (700004A, 70311A) and after I made the HP-MSIB cables myself, the analyzer started.The software version is 900316 (at least this is what the display of the analyzer displays for a moment after switching on). Before mounting the preamplifier, I set its jumpers (ROW and COLUMN).After switching on, there were alarms 2025 and 6010, and when attempting to calibrate 2032. I checked the HF amplifier module outside the analyzer, which works OK. Due to other activities (testing AGC system for Tracking Generator SA FSEB30 R&S, which I made myself), I put off testing with HP70k.I will be grateful for any further advice.GreetingsMarian

author: ruhnet
author_rank: Newbie
timestamp: June 07, 2021, 03:05:37 am
content: Hmm, well unfortunately those errors look like either the preamp module is faulty, or that the 70900A is refusing to work with it, since the matching 22GHz RF section isn't installed. The 2032 upon CAL seems like it is wanting to communicate with the 22GHz RF section (probably to combine its flatness cal data with the flatness cal data from the preamp) and of course can't find it in the system. The other two errors are slave module communication errors, so it's either having trouble talking to the 70620 itself, or because of wanting to combine it with a 22GHz RF section.I guess the way to know which situation is happening (faulty module vs refusal to control) would be to test in a 22GHz system.But if that isn't an option one thing you could do though, since you have already tested and determined the actual amp is working, is to remove/disable some of the control circuitry in the 70620, and just power the internal preamp itself from the mainframe as a "dumb" accessory. This should let you use it at least, and you could apply amplitude correction to your measurements manually. You could drill a hole in the middle front panel and put a switch to control the path switching relays inside to insert/remove the preamp from the signal path. Or just leave it in the path all the time and connect/disconnect externally with a short jumper like it was intended to have between its output and the RF section.

author: Marian.MQH
author_rank: Newbie
timestamp: June 13, 2021, 11:15:21 am
content: Hello,Thanks for helpful information, as I wrote recently I am dealing with the AGC system for my TG FSEB30 (I have attached a photo of my project).After installing 70620A, the analyzer does not work properly. It displays only the trace of 3 ... 6.55GHz (LO range) with the signal at 3.61GHz (-2.57dBm) and does not react to the signal applied to the input.It is not possible to check block 70620A in another analyzer, I am not sure if such a device is in Poland.It will remain a modification of block 70620A, getting rid of the signal pins (leaving only the power to the amplifier and relays) and, as you wrote, mounting the switch on the front panel.It may not be "elegant", but it will sometimes allow you to take measurements.You mentioned previously about problems with the preselector, fortunately my 70906A analyzer works OK - I can't imagine measurements without it due to the large number of false signals (low IF frequency).Thank you very much Greetings.Marian

author: Paul B
author_rank: Contributor
timestamp: January 24, 2022, 07:06:10 pm
content: Hi allMy name is Paul Bicknell and I live on the south coast in EnglandAlthough I am new to this site I have been playing with HP 70 K for a few years nowAnd I might know a few of you from the Groups IO siteI am presently trying to decide on the replacement capacitors to rebuild the power supplies in3 off 70900 A local oscillators that have failedMy next project is to modify a 70900 B local oscillators to haveThe latest firmware and 512 K of memory upgradealso the receiver personality could anyone please help me with the followingDear PQUADRAT Could I take you up on your offer of how you did your upgradeAlso could you please let me have the make and part numbers of the sockets you usedFor your upgrade of the firmware memory ?Also What equipment do I require to program the firmware / ROM chips for the 70900B ?Could you also explain the memory upgrade hopefully a picture before and after the 512 K memory upgradeI have a 8705A 512K memory card how can I find out what is on it ?Can anyone help me with putting the receiver personality onto the 8705A 512K memory card ?Regards Paul PS sorry about the long list

author: pquadrat
author_rank: Regular Contributor
timestamp: January 24, 2022, 08:03:24 pm
content: Quote from: Paul B on January 24, 2022, 07:06:10 pmHi Paul,For the capacitors I use good quality Panasonic ones, working perfect.All my picture of the upgrade are in this thread. I don't have more.the RAM Chips are: TC551001BFL-70The EPROMs are Intel N27C010-150, AMD AM27C010-150, or Flash chips 28F010 also work.ROM content is on the net, You will have it.I did use sockets on the first one, PLCC28 sockets should fit. But I had more problems with the sockets, so I soldered the other two boards without sockets.For the RAM Upgrade, You have to change one PAL. Type is PALCE16V8. Not many programmers can programmers can program it. File is attached.Soldering the ROMs is not that easy, I had to improve my soldering skills. RAMs are easier.-Peter

author: pquadrat
author_rank: Regular Contributor
timestamp: January 25, 2022, 08:50:32 am
content: This is the PAL content for the 1MB Upgrade.In the previous thread it was the version for the 256kB version.

author: Paul B
author_rank: Contributor
timestamp: January 25, 2022, 02:52:52 pm
content: Hi PeterThank you for your return email unfortunately i am not that good with software and computers and dealing with the firmwareso i might require a bit of help so could we possibility exchange email addresses ? as i am also new to this siteRegarding memory up grades from HP documentation on 70900B withe date code 901008 and laterRAM memory is 128 K and 700K with the Option 512 but you refer to 256 K and 1024 K could you please explain the differenceBest Regards Paul

author: pquadrat
author_rank: Regular Contributor
timestamp: January 25, 2022, 08:14:43 pm
content: Paul: PM sent.

author: Paul B
author_rank: Contributor
timestamp: January 27, 2022, 08:40:13 pm
content: Hi Peterjust a line to create a bit of trafficregarding the Groups IO site and the HP 70000 group hopefully you would agree that the site holds more data on HP 70000 than any other site availableRegards Paul

author: cncjerry
author_rank: Unknown
timestamp: February 01, 2022, 07:04:15 am
content: Jealousy starts every time I see something about the MMS!I got really close to purchasing one and then Covid hit, work was busy etc. I am out of room and thought I could consolidate down to an MMS from an 8566B, 8568B with TG and 85685 preamp and an 8568A that has the upgrade. I also have an R&S FSB and an Advantest R3131a with the TG. I figure if I sell those five units I should get close to a 7k analyzer in price. I had originally wanted the 7K for the spectrum analyzer and phase noise test set, but I have PN covered now and the phase noise setup on the 7k is pricey.Though I don't read much about it, I see there is a 70703a scope module but it doesn't strike me as general purpose. I have a gaggle of scopes but if I can get everything out and free up space, it would be great.I would like to build out the spectrum analyzer and then add a tracking generator. Can you build a network analyzer into an MMS?ThanksJerry

author: pquadrat
author_rank: Regular Contributor
timestamp: February 01, 2022, 08:44:53 am
content: I think the scope module is no replacement for a real scope.>I would like to build out the spectrum analyzer and then add a tracking generator.I did the same, that is what the 70k system can do best, replace the 8566B/8568B.Be carefull when buying a system that the YIG of the 70900B is still good.

author: Paul B
author_rank: Contributor
timestamp: February 02, 2022, 08:19:49 pm
content: Regarding up grading to a 70 K systemfirst it would be good to know your location as i might be able to help you . Personal i am south coast UKit sounds like you have a good set up at present regarding tracking generator what frequency do you want to go to ?units that go to 2.9 Ghz are easily available but the 2.7 to 18 ghz i think are few and fareI personalty do not put all my eggs in one basket and would not recommend it so use the 70 K as an analyser & individual units for scope , power , frequency generator / counteryes thy were designed to be able to build exclusive test set ups but that was when you had 10 systems to play withnow the big thing if you think you will reduce your equipment then ask those that run 70 K most will probably have several systemsas in a typical bench might have a spectrum analyser , optical analyser , transition analyser each with there own displaybut also a host of supplies possibly made into a second spectrum analyser system others have then gone for a dedicated computer for the 70 KPaul

author: cncjerry
author_rank: Unknown
timestamp: February 04, 2022, 10:48:56 pm
content: I am in the US, west coast, San Francisco bay area. I was just wondering about the scope, and after the comments I see, I'll forget that component as I have all the scopes I need. I have the TG for my FSB and that goes to 5Ghz but I've yet to install it.I have to make space before I do anything. There are a lot of modules available locally, just never know what is good. I'm putting in another workbench and was hoping to have the MMS on there. I just wish all this stuff wasn't so heavy because every time I move one my back is sore for a month.

author: Paul B
author_rank: Contributor
timestamp: February 05, 2022, 02:06:51 pm
content: I stayed away from the 70K equipment beaus i did not know how to confider it but a bought a working system to start withif you are going to start then best advise is to get a 70004 display and then a local oscillator and test it for errors in the 70004 display thendepending on the firmware level get an IF and an RF section so you can make a system all inside the 70004 displayonce you have a working system it will put a smile on your facePaul Bregarding heavy equipment make the bench so you can eater work behind it or twist it around to configure the rear connections after you have installed the 70K modules

author: cncjerry
author_rank: Unknown
timestamp: February 05, 2022, 02:59:15 pm
content: I plan to put a flat caster setup under whatever I put on the new bench that is heavy. I saw one the other day and cant find it now that was sort of triangular and had somewhat flat wheels. Thanks for the advice on how to get started. It makes sense and just what I was looking for.

author: cncjerry
author_rank: Unknown
timestamp: February 05, 2022, 10:08:12 pm
content: with regards to the caster comment above, of course the wheels weren't flat... I guess I meant low. That's one of the reasons I dont have my 8568b / 85685b stack working - I can't get behind it.I started looking for a 70004 and it seems like they jumped up in price compared to the last time I looked. Usually in the bay area you can find almost anything with local pickup for a reasonable price.

author: Paul B
author_rank: Contributor
timestamp: February 05, 2022, 11:15:15 pm
content: I have bought 70004 display units from traders for £150 / $200 but i would expect to pay up to $ 400 and no moreThe 70900A is prone to more problems than the B version but we think a capacitor replacement might raper the faulty A versionsI am just setting up to try to raper 3 off 70900 A unitsI think a reasonable price for a working A version is $300 and $500 for a working B version the common fault is unable to lock VCObut this might not be a problem if testing the system with power meter modules that are actually the cheapest modual available at less than $100 eacha 70 k stack consisting of a 70004 and a 70001 rack can be twisted around on a bench to reveal the back without to much effort it is only fractionally taller and heaver than the 8568b / 85685b stackIf you want i can direct you to a site i have populated with manuals and has more information on HP 70 K than any other site in the would about 100 free manuals plus moreRegards Paul B

author: cncjerry
author_rank: Unknown
timestamp: February 06, 2022, 06:37:40 pm
content: Paul, send me the site via PM or post if you like. I'll keep looking for a good price on the 70004 and build from there. I'll probably start clearing out the analyzers in the meantime.

author: Paul B
author_rank: Contributor
timestamp: February 06, 2022, 09:23:54 pm
content: Hi you say (I'll probably start clearing out the analyzers in the meantime.)hopefully not any HP 70 KPaul B

author: Paul B
author_rank: Contributor
timestamp: May 19, 2022, 03:32:50 pm
content: High PeterSorry for the long delay and any questions I might repeatI have recently gon through COVID not a problem but I think I now get out of breath quickerYou refer to a link in your past Email but unfortunately I cannot open it can you please advise meAs I want to recap 3 off 70900 local oscillators hopefully return them back to good working orderFailing that has anyone found a replacement yig for the 70900 unitsRegards Paul B paul@bicknells.f2s.com cell + 44 (0) 7719 208 048

author: TerraHertz
author_rank: Super Contributor
timestamp: September 03, 2022, 01:02:37 am
content: Possibly, I may have caught the HP 70000 MMS bug. Catching covid in March wasn't a problem, but I think the MMS bug may be quite harmful. Myo-wallet-itis, or even SADS. (Sudden Affordability Death Syndroms)Just arrived: a 70001A Mainframe with 70841B Pattern Generator and 70311A 3.3GHz Clock Source.Heavy thing, 70lb. Naturally the US seller's packing was laughably inadequate and it got some dinged corners in the USA leg of its journey. After it reached the reshipper in LA I had it repacked in foam-in-place, so no more damage on the way to Sydney.Most physical damage is minor and already fixed, except for one thing. The modules are held in place by diecast metal screw retainers. Some box-drop impact sheared one of these retainers in half.These have an 8mm hex socket on the front and some unidentified thread internally. The mating screws are 5.8mm OD, 24 teeth/inch. Thanks HP, for not using a standard thread like M6 or 1/4" Whit.Well where am I going to find a replacement retainer? Any ideas?If someone has a broken HP 70000 system module they'd sell for spares, please let me know.Meanwhile it will be a while before I can test this thing. I have some manuals, more to find. I got the Artek CLIP packages for the 70001A and 70004A mainframes. In taking this mainframe apart to fix the metalwork I notice the power supply board has multiple RIFA caps in the mains input section. Those have to be replaced before I even turn it on. I have some HP 9000 systems but all still need work such as adding mass storage.

author: tautech
author_rank: Super Contributor
timestamp: September 03, 2022, 01:20:20 am
content: Any chance you had the manuals for these before purchasing one ?

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: September 03, 2022, 05:40:05 am
content: https://i.ebayimg.com/images/g/9PgAAOSwsNxi5qfq/s-l1600.jpghttps://www.ebay.com/itm/334518729652?hash=item4de2debbb4:g:9PgAAOSwsNxi5qfq&amdata=enc%3AAQAHAAAAoIdnrID8wtr4whBb44jJidLvKHV%2FAITKiZsMPpsnftHXtQfk4vPE0wYq4e0%2Fq7rigspPbCojtfW8Ay%2F41huus1hiy8qqjn%2B6tdl%2BedjSJQ8FGjSo%2B7z64LvWXG2XZw4obTyCUBP6xUBJMw2oCnZojQJ9snHtlDoP9LL6gfylM0ION0k0UbygG0qdp17jEwY%2Fht4hUs1aiqGmrfljgKjjym0%3D%7Ctkp%3ABk9SR4CjxJ3gYA

author: TerraHertz
author_rank: Super Contributor
timestamp: September 03, 2022, 06:17:57 am
content: Quote from: tautech on September 03, 2022, 01:20:20 amSome of them. More an exercise in checking out the availability of 70000-series manuals in general, and seeing what kind they are. A: well past the era when HP produced useful service manuals. Whether I can find CLIPs for these modules, don't know yet.Most of my time lately has been going into something else. Old mum's health declined, taken to hospital then moved to nursing home, bedridden and declining rapidly. Me being the only one to clear out her house urgently and arrange the house sale. Now my place is stuffed full of multiple generations of family relics, with the job of culling it down still remaining. That was the house I mostly grew up in too. Sad times recently.That mountain of manuals in the USA are still there, still mine. But I need to go there to handle the work myself, and a certain entity demands something before granting a visa, that I'm certainly not willing to accept. So just have to wait till something changes. Which comes first - nuclear WWIII, Neuremburg II trials, total economic collapse, civil war, or I scrape in and rescue the manuals, who knows.Added:SoundTech-LG, brilliant, thank you. Bought. I'm a bit overwhelmed with worries lately. That's my excuse for not thinking of that. I hope they are the same as the heavy metal module ones. It would seem sensible that they would be, but with HP... fingers crossed.

author: tautech
author_rank: Super Contributor
timestamp: September 03, 2022, 06:51:15 am
content: Quote from: TerraHertz on September 03, 2022, 06:17:57 amOh hell, yes there are times in our lives when it seems you just can’t get a break !Fingers crossed everything thing works out for the best for you.

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: September 04, 2022, 01:25:53 am
content: What would be brilliant, is if I could lose a 70000a Mainframe, a 70009 Display, and a lot of other stuff I'm not using...

author: gabor.dani
author_rank: Contributor
timestamp: September 18, 2022, 09:06:44 pm
content: Hi,Is there anyone who could post a video on youtube about HP 70004A with one of the spectrum analyzer modules (preferably 70908A, but no problem if other) installed and working in the following configuration:Cal signal connected, center 300 Mhz, span 1MhzReason for this:Amazingly, there is currently no video of 70004a in SA configuration anywhere and it would be nice to see how fast it sweeps.The only similar video is about 70206A graphics display:I would like to compare them before buying any of them.Thanks,

author: dxl
author_rank: Regular Contributor
timestamp: September 19, 2022, 04:16:54 pm
content: Quote from: gabor.dani on September 18, 2022, 09:06:44 pmI can't say how fast it would sweep at 1MHz span, but max sweep speed depends on the LO used: the 70900A had a minimum of 50ms, the 70900B had 10ms.

author: cncjerry
author_rank: Unknown
timestamp: October 06, 2022, 04:34:30 pm
content: I'm back. Locally there is a 70k Spectrum Analyzer config with a 70100A power meter & probe, 70310A precision frequency reference, 70902A IF section, 70900B local oscillator, 70908A RF section, 70300A tracking generator and the 70001A mainframe. It has the 70004 color display and manuals. I committed to it last night but haven't heard back this morning...I hope I didn't miss it by a few hours, ha! Price is $1,000 and that seems like a deal. All the cables are there and it operates. I was surprised that he has the manuals.I'll add the wider 70903A IF module and go from there. So now I am going to sell my 8568b with 85685a, my R&S FSB and I'm kicking around selling my 8566B but note, and reason for my post, that to get the MMS to 22Gig, you have to spend a fair amount of money. What modules do I need to take it to 22Gig?Thanks,Jerry

author: dxl
author_rank: Regular Contributor
timestamp: October 06, 2022, 05:54:02 pm
content: Quote from: cncjerry on October 06, 2022, 04:34:30 pmNot sure whether i get the question. If you have a 70908A with it, you have already a frequency range up to 22GHz? The only other option is the 70909A/70910A which go up to 26.5GHz, but they have no fundamental mixing.

author: cncjerry
author_rank: Unknown
timestamp: October 07, 2022, 02:08:19 am
content: yes, I just went back and looked and that does go to 22gig. I guess I was looking at the tracking generator and that is limited to 2.9gig.Other question, with the TG I can do scalar but is there a VNA option for the MMS?

author: cncjerry
author_rank: Unknown
timestamp: October 10, 2022, 01:41:39 pm
content: I posted this in the groups.io site about the sidebands I see in all signals, not just the cal posted here and was wondering if others see the same thing?Thanks

author: cncjerry
author_rank: Unknown
timestamp: October 15, 2022, 10:31:36 pm
content: if you have an MMS analyzer, if you wouldn't mind posting a picture or just the results as below:a view of the 300Mhz cal signal with:span: 1KhzRBW: 10.0hzVBW: 10.0hzatten: 10dBscale: 10dB per divRL: -10dBMy analyzer requires me to hit the reference line down once or twice to get to -10db.and if you don't want to post, find the 300Mhz peak and then check the dBc to the right or left at 120, 18, 240 or 300hz offset, whichever is highest. I'm seeing about -83dBc or so with my noise floor much lower, down around -90 or so. If I can get rid of the line noise...ThanksJerry

author: Oldtestgear
author_rank: Regular Contributor
timestamp: November 29, 2022, 12:50:40 pm
content: I have an early 70900a that is not working -- seems to loop around self test -- which I hope is down to an EPROM failure. Now the problem. Mine uses six 27512 EPROMs, not eight as used in later variants.Does anyone have a copy of the firmware I need for this one? Codes are:70900-8003170900-8003270900-8003370900-8003470900-8003570900-80036Any help appreciated as it would be nice to see if the firmware is the problem before trying any other options.I aslo bought a 70004a display from the same source which did have a dead EPROM but I copied the file from another display to get it working again.Thanks in advancePhil

author: gabor.dani
author_rank: Contributor
timestamp: January 29, 2023, 12:32:16 am
content: Does anyone have a working spare SYTFMD (5086-7741) YIG mixer up for sale for my HP 70908A RF section?

author: Doug Smith
author_rank: Newbie
timestamp: March 29, 2023, 08:44:00 pm
content: First post since joining, as am also looking for some advice after repairing a HP 70908 with LO and Multiplier unleveled errors. I'll get to that momentarily. I hope the following is of some assistance to you. If not, I hope I didn't insult your intelligence by going though it below.How did you conclude it was the YIG? It's probably the most unobtanium part of the 70908, and the setup is long and involved after replacement (software and dozens of HP instruments). I'd rule out everything else possible before concluding the YIG was defective. To troubleshoot the 70908, I had to arrange the 70310, 70902, 70900, and 70908 modules in a 70001 with the cover removed, as in the attached picture. I folded out the 70908 power supply board in the remaining space, to get at the adjustments. I had to verify the DC supply voltages and ripple, the LEDs on or off, the LO output at the rear, and voltages at A1 LOLA G1 G2 G3 and A2 Multiplier G1 G2 G3, and the LO out with another spectrum analyzer, to rule out a possible LO problem from the 70900. Note the warnings about extreme static sensitivity of these modules. The problem turned out to be the adjustment pots R11, R12, R13, R46, R47, R48 were open circuit or way off. I set R34 replacement to exactly the same resistance setting as the old one, and avoided touching R19, R21, and R23 as the setup is difficult.The problem with adjusting/calibrating the 70K units is not only the software running on HP BASIC on HP-UX controller 382, but also the large number of HP test instruments demanded by the software, and also the test constants buried in the software. If you don't have the instruments, the software won't run (ask me how I know) and you have to rewrite it for the instruments you have. In the repair above, I touched only the service manual adjustments that were straight-forward, and hoped the rest were close enough. I got lucky this time.About my question, for the audience's wisdom. After getting it working, I found that the voltages at A1 SW1 and SW2 were not +11 and -11, rather +11 and -2.6. I traced it back to two JFETs on A13, in a peculiar circuit. Here's what I think happens. Check me. Each is driven by an op-amp IC with output at either +11 or -11. When IC output is +11, the JFET gate is forward biased (Pull-up?), and when IC output is -11 the JFET gate is reverse biased to cutoff and the 380 ohm resistor feeds to the output. So analysis shows the only way the output can be -2.7 volts if the JFET is defective and pulling a lot of current from the +12 volt source. I'm also thinking the 2N4391 may not be the right choice because Vgs(off) is -4 to -10 volts, a large percentage of the +/- 12 volts available. Would a 2N4392 be better for this circuit? Or drive SW1 and SW2 directly from the IC's? They seen to have enough short circuit current to drive the ~600 ohm resistance presented by SW1 or SW2. Or does it even matter if it works? What do you think?All for now. Doug

author: K9DTV
author_rank: Contributor
timestamp: November 11, 2023, 04:14:57 am
content: Quote from: cncjerry on October 10, 2022, 01:41:39 pmHope this is what you wanted.Added another picture with AVG on as you had it on in yours.

author: K9DTV
author_rank: Contributor
timestamp: November 11, 2023, 04:56:04 am
content: Quote from: Oldtestgear on November 29, 2022, 12:50:40 pmThere is a site that has images of the 70900a roms, and I know I have a spare 70900a rom board with the last update for the 128k dip rom boardYou may want to PM me so we can figure something out to get you fixed up.This board came with with 70900A Serial Numbers 2817A01886 to 2833A02083 Part number 70900-60114.Software is version 880314 Revision B.00.00 code name Cheetah32K usable ramSupports the following hardware:70205A, 70206A, 70300A, 70310A, 70600A, 70601A, 70620A, 70700A, 70810A, 70900A,70902A, 70903A, 70904A, 70907A, 70905B, 70906A, 70906B, 90707A, 70908AThis revision introduced the new menu style, with firmkeys on the left.This also allowed use of the 70620A preamp.As long as the Controller board is 70900-60111 this will work (note I have this board as well)Going over all this, you would need the Controller board 70900-60111 and the rom/ram board 70900-60114, it can be updated to 70900-60126 rom/ram code name Cheetah 2Date code 880901 rev b.01.00 this add module 70301A tracking gen.Hope this info helps.Added picture of the board I have, and more info about the board.had some wrong info, fixed that.added a few more picturesBoard is no longer available as a member has asked for itMaybe they will posted their older board for someone in need.

author: K9DTV
author_rank: Contributor
timestamp: November 11, 2023, 05:02:27 am
content: I am still looking for help setting up an HP 9000/300 series computer to work with my MMS system.I have like four systems, from a 68010 at 12MHz to the 68030 system with gobbs of ram.This includes setting up the software for the system and installing all the test and cal software for the MMS system.Its been years and not had any luck, anyone willing to help?

author: K9DTV
author_rank: Contributor
timestamp: November 11, 2023, 07:33:55 am
content: Quote from: cncjerry on October 07, 2022, 02:08:19 amThe 70820A Microwave Transition Analyzer does VNA

author: K9DTV
author_rank: Contributor
timestamp: November 19, 2023, 02:41:33 am
content: Picked up a new toy for my 70K system last night and figure I would show it off.It is a 70951B and picked up off eBay for cheap (cough, cough).Unit was unopened and reported as bad, pictures of the it confirmed this, but was an easy fix.Anyone that has one of these I would love to talk to you about it.Anyways on with the equipment porn!

author: materialsguy
author_rank: Newbie
timestamp: November 21, 2023, 06:59:44 pm
content: Firmware Files Uploaded:I have uploaded 70100A Power Meter firmware files 1.21, 1.24, 1,27 to the groups.io files sectionhttps://groups.io/g/hp70000/filesand to KO4BB.--materialsguy

author: materialsguy
author_rank: Newbie
timestamp: November 21, 2023, 07:31:40 pm
content: Firmware Files Uploaded:I have uploaded 70004A Display Mainframe firmware v7.04 to the groups.io files sectionhttps://groups.io/g/hp70000/filesand to KO4BB.-materialsguy

author: cncjerry
author_rank: Unknown
timestamp: November 29, 2023, 04:47:14 pm
content: It turned out that my frame had a power supply problem. I bought another after finding out you cant shoot the power supply bugs without a load. I could have just swapped the caps but one was hard to find size-wise, I think it was on the +5v. New frame cost me less than $100 and problem fixed. Thanks for posting.Jerry

author: K9DTV
author_rank: Contributor
timestamp: December 16, 2023, 12:16:29 am
content: Today I received four DLP cards for the 7095x OSA.The DFB, FP, and LEDOPT 51 EDFA ASEOPT 52 EDFA TIMEOPT 53 EDFA NOISE GAIN PROFILEEasy to install and use, not used the EDFA as I have no doped fiber YET!The 70k System just gets more and more useful everyday it seems.

author: materialsguy
author_rank: Newbie
timestamp: January 30, 2024, 03:04:01 am
content: Firmware Files Uploaded:I have uploaded 70900A Local Oscillator firmware A.01.00 to the groups.io files sectionhttps://groups.io/g/hp70000/filesand to KO4BB. This is an early version of the firmware with the old menu system for the integrated CPU/ROM board (70900-60078). This board used six AM27C512 EPROMS.-materialsguy

author: coppercone2
author_rank: Super Contributor
timestamp: January 30, 2024, 04:10:18 am
content: my b fm reciever still bad because someone sent me the wrong floppy drive on ebay and I gave up

author: cncjerry
author_rank: Unknown
timestamp: February 03, 2024, 02:53:40 am
content: I'm trying to find the original module list prices for the MMS system. I'll admit to not searching too hard, 20 minutes on "the google" but if someone has a pointer, it would be appreciated. ThanksJerry

author: coppercone2
author_rank: Super Contributor
timestamp: February 03, 2024, 02:55:55 am
content: be ready for your time travel trip to 1985?

author: materialsguy
author_rank: Newbie
timestamp: February 03, 2024, 04:24:20 am
content: "I'm trying to find the original module list prices for the MMS system. I'll admit to not searching too hard, 20 minutes on "the google" but if someone has a pointer, it would be appreciated. Thanks"Now this is interesting. I was going to direct you to the HP Archive catalog section, but I see that the 1997 T&M catalog PDF version has no pricing. I know that the printed version (a book, really) does have pricing. I can scan some pages for you if you like.Or are you trying to go back even further?The 1986 catalog has pricing for the HP 70k system:http://hparchive.com/hp_catalogsShaun M.

author: Paul B
author_rank: Contributor
timestamp: June 27, 2024, 12:02:32 pm
content: Hi all I have been away from 70000 equipment for a time so just returningI have a number of 70900A units with no VCO lock has anyone hear fixed this fault by replacing the capacitors on the power supplysorry if I am repeating any questions but I have several interests and I forget things at timesI am Located in the UK and I am also trying to build 2 off HP 70000 receiversUnfortunately my Computer Skills are very basic so any help would be appreciatedPaul