Mike

Thank you very much for your reply.

Armed with your practical experience I very cautiously measured my 11970A and obtained 0.72V in got directions. I checked it afterwards and all is well, great sign of relief ;-)

Once again many thanks

73 de G8KHU

The 500 MHz - 18 GHz input is the tricky part of the 5342A. I happen to own 2, plus a parts mule in my cellar. The high input range uses HP custom built circuits making repair uncool at best, impossible at worst unless you find a parts mule.

Wilko

开云体育

What are they = expensive! I am currently bringing three 8601A's up to spec and decided to try this company to purchase some misc parts for them. Well, I saw your post and decided to request a quote for your parts. Attached is the quote I just received (yesterday).

On 4/20/24 07:49, Bepi wrote:

I am jumping in this discussion because I am trying to restore a 130 scope too and , being unexperienced, I need advice.
I have just started testing by powering the scope slowly with a variac. All went well up to 70 to 80 V when the main fuse blew, a 2 A fuse. Started again and now the new fuse seems to hold for hours with a total consumption of roughly 1 A at 115V, it's nominal line voltage. Does anybody know what the blown fuse was likely due to? Capacitors? I have been warned that capacitors are the main cause for failures after long periods of inactivity. No sign of a CRT luminous spot. I checked the AC voltages at the transformer secondaries and they are all ok. What's next? I imagine the DC HV voltages. Any special precautions other that the obvious ones? They all seem in the hundredths of V from the schematics. I still worry about the blown fuse, do I have to check insulations at low voltage before powering up? Are the PS capacitors the ones I need to be particularly cautious about? Should I check them separately at low voltage?

Fuse fatigue. Fuses do simply wear out, as with most everything else.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA

开云体育

---

After a bit more playing about, I think some of the fast and slow ripple is due to the limitations of the Vrms measurement that I have done with the scope. The accuracy of this is limited by the scope itself and also by the 5GSa/s sample rate. The scope can compute Vrms on a cyclic basis or on the display data and both methods have their accuracy limitations in this case. The impact of this is fairly minor though. The rest of the ripple will be a combination of ripple in the probe and some minor mismatch uncertainty in the test setup.

I think the reason I'm getting good results is because I'm using a scope with >1GHz bandwidth.

The input of a typical scope isn't 1Meg Rp in parallel with (say) 15pF Cp at RF frequencies. The 1Meg Rp only applies at very low frequencies. At RF frequencies the Rp will fall as the frequency increases. Cp will also change with frequency. It generally falls up at higher frequencies. Different scopes will show a different Cp and Rp vs frequency characteristic. This will make it harder to achieve consistent probe compensation up at UHF especially if you use an old and relatively slow scope like a Tek 2465A to test a 500MHz probe. I've not measured Rp and Cp for a 2465A but it isn't going to look the same as the Cp and Rp of a much faster scope that has lower Cp to begin with.

That's partly why I think it going to be better to look at a pulsed waveform using a decent pulse generator as I demonstrated earlier. My fastest homebrew pulser probably has a rise-time of about 400ps and it is adequate for testing a 500MHz scope probe. I've got another one that has a rise-time of about 2ns. I've got a faster BJT based pulser but it doesn't give a flat square wave output. The rise-time of the 2465A is going to be about 1ns and I think this scope would still be able to demonstrate how much better a genuine 10073C probe performs compared to (say) a Tek P6139A when using the pulse test method. By better, I mean how much flatter the pulse waveform looks after the initial rising edge has finished. The 10073C has the advantage that it is a 2.2Meg probe and this makes it easier to compensate across LF-UHF when compared to the 10Meg P6139A probe.?

I am jumping in this discussion because I am trying to restore a 130 scope too and , being unexperienced, I need advice.
I have just started testing by powering the scope slowly with a variac. All went well up to 70 to 80 V when the main fuse blew, a 2 A fuse. Started again and now the new fuse seems to hold for hours with a total consumption of roughly 1 A at 115V, it's nominal line voltage. Does anybody know what the blown fuse was likely due to? Capacitors? I have been warned that capacitors are the main cause for failures after long periods of inactivity. No sign of a CRT luminous spot. I checked the AC voltages at the transformer secondaries and they are all ok. What's next? I imagine the DC HV voltages. Any special precautions other that the obvious ones? They all seem in the hundredths of V from the schematics. I still worry about the blown fuse, do I have to check insulations at low voltage before powering up? Are the PS capacitors the ones I need to be particularly cautious about? Should I check them separately at low voltage?

I just received from Ebay an original manual (mod 25 to 724) with schematics which are completely readable, in the fine print parts too, which is not the case for the one I found on the web. If anybody needs them i'll be more than happy to make copies, in fact I think I'll post a new high res copy on this group. I still have the problem to find out which modifications have occurred in my model which is N 2482, if anybody knows I would be happy to find out, thanks, Bepi

I just received from Ebay an original manual (mod 25 to 724) with schematics which are completely readable, in the fine print parts too, which is not the case for the one I found on the web. If anybody needs them i'll be more than happy to make copies, in fact I think I'll post a new high res copy on this group. I still have the problem to find out which modifications have occurred in my model which is N 2482, if anybody knows I would be happy to find out, thanks, Bepi

Hello there!

My microwave counter is faulty. Time ago, it stops counting sometimes. Nowadays, it counts sometimes. I'm talking about 500 MHz to 18 GHz input. Always shows zeros in the display.


Anybody knows about this fault? The front end sensor wears? It is a pity, I heard about this model that the N connector input is sensitive above 5 dBm (I always have an attenuator attached) and I don't remember put more power than that, but...

Thanks to everybody who answer me :)

开云体育

I ordered a manual set for an 8018A a few days ago and got the download link about 3 hours later

Vewr occasionaly at rallies I've come across 11970 series harmaonic mixers at very good prices - assuming that they are working.....
If they are dead they are a very expensive reminder of caveat emptor :)

Is it safe to field test them with a DVM on the diode test setting measuring the IF output port (and being very careful about static discharge)?

Measuring my DVM it produces 2.3V open circuit and has a short circuit current of 0.8 mA. As the mixer maximum imput level is +20 dBm, and I believe a 4:1 impedance transfor in the waveguide input, that would equate to 100 mW into 200 Ohms giving 4.4 V rms and 22 mA rms. Just looking at the numbers it seems to me that it should be OK - BUT I'd really appreciate the input of those with more knowledge about these mixers that I have.

Dave G8KHU

开云体育

I just acquired an?HP 3585B Spectrum Analyzer with what the previous owner describes as a "no horizontal sweep" problem. I have downloaded the operating and service manuals for the unit and I am starting to make my way through them to get familiar with the unit.?
If anyone has experience with these units and can give me an idea on how to start troubleshooting this problem it would be a great help. I would like to have some idea on where to start and what to look for before I start tearing it apart. I do a lot of RF and computer repair, but this seems to be a whole different level that what I am used to. So i am reaching out to the members of this forum to acquire some of their expertise.
Any help would be greatly appreciated.

?

It's pretty easy to put modern mass storage on these machines. Keeping them running isn't anywhere near as difficult as people commonly say.

-Dave

On April 19, 2024 5:59:38 PM "si_emi_01 via groups.io" <wellington@...> wrote:

Yes, that was a rack mountable HPIB/RS232/HP-IL System Controller often used in the 1990s for EMI Testing. It was often configured for HPIB Interface with HP-8566 Spectrum Analyzer/RF Preselector/Quasipeak Detector/Plotter hardware.

It doesn't have a lot of memory (8MB Max), and has a 68030 processor.

It runs HP Basic/Rocky Mountain Basic, HP Pascal and an old HPUX Unix.

It came with the HPIB Interface, if you need that, make sure it is there.

The one I have in storage was used for EMI testing with an HP-8566B system. It has the 5.25" 40MB Hard Disk Drive and 4MB of RAM.

The Hard Drive in these uses the old MFM Drive Technology. I would think it is quite old by now needing replacement - like the one in your picture. I don't know if anyone ever tried to use a larger drive in it.

Haven't powered it up for decades.

Ross


-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Razvan Popescu via groups.io
Sent: Friday, April 19, 2024 2:33 PM
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] Can anyone recognize this HP Computer? Workstation?

Hello,

I was looking for an HP 9000 series 300 to run the HP BASIC software and I found this one in the photo attached.

Does anyone recognize the model number? Looks interesting to have the display integrated to put it in the rack.

I only found logic analyzers from early 90's that have a similar case style.

Thanks,
Razvan

--
Dave McGuire, AK4HZ
New Kensington, PA

There wasn't enough resolution in the image to know for sure.?? It could be a R/332 (Motorola 68030 processor) or R/382 (Motorola 68040 processor) rack-able workstation.

Both are useful when running HPBASIC/300 or HP_Pascal/300.

They both have an old school touch-screen that use a matrix of LEDs/Optical Sensors to determine user input.? They were designed to be used in more industrial or clean-room environments, in which workers may have gloved hands, so capacitance style touch-screen technology wouldn't work.

I have a R/332 and it works great.

Let me know if you want/need an example of using the touch-screen in HPBASIC programs...

Francis

Yes, that was a rack mountable HPIB/RS232/HP-IL System Controller often used in the 1990s for EMI Testing. It was often configured for HPIB Interface with HP-8566 Spectrum Analyzer/RF Preselector/Quasipeak Detector/Plotter hardware.

It doesn't have a lot of memory (8MB Max), and has a 68030 processor.

It runs HP Basic/Rocky Mountain Basic, HP Pascal and an old HPUX Unix.

It came with the HPIB Interface, if you need that, make sure it is there.

The one I have in storage was used for EMI testing with an HP-8566B system. It has the 5.25" 40MB Hard Disk Drive and 4MB of RAM.

The Hard Drive in these uses the old MFM Drive Technology. I would think it is quite old by now needing replacement - like the one in your picture. I don't know if anyone ever tried to use a larger drive in it.

Haven't powered it up for decades.

Ross

Did you select the correct vendor & partnumber? EPROMs can be identified by a programmer using their electronic ID. The programmer can make use of that info to optimise (= speed up) programming for example. An ID check error in my experience smells like the wrong part/vendor has been selected in the programmer software.

Wilko