Re: 85672A Spurious Response Utility for an 8563E
On 4/17/2025 12:59 PM, zgoode via groups.io wrote: Page 4-11 of the operating manual for the 85620A mass memory module shows how to copy DLP's to the cards and how to copy from the cards to the module.? It looks very straightforward. However, if you try to copy this 85671A DLP from the mass memory module to a card, it will only allow around a column of files to be copied.? The complete Phase noise utility consists of about three and a half three column pages of files when in the memory module. In any case the Phase Noise utility is limited in use compared to the 3048 system. Dan ac6ao
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Re: 85672A Spurious Response Utility for an 8563E
If you have what is needed to run HPDrive, perhaps you could connect a mock 9122C on your PC with the 8563E and copy the file from HP-IB mass storage?
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Page 4-11 of the operating manual for the 85620A mass memory module shows how to copy DLP's to the cards and how to copy from the cards to the module.? It looks very straightforward.? I'm still trying to figure out how to pull out to a file over HPIB or
AUX-port that can be uploaded here since I don't think any computer can read those cards (that I am aware of)
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Re: HP8754A VNA Resurrection
"Sounds like a problem I fixed on the one I have- no sweep. I assume you could put a length of line in S21 mode and see the dot rotate as you change frequency manually?"
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Sorry I'm a bit late answering this; didn't have access to the analyzer.
I assume you mean with the S-parameter test set with an RF patch cable between ports 1 & 2. Polar display, so should be a dot. Does indeed rotate around the rim of a circle several times as the frequency is increased (manual tuning Zero span/CW) when in B/R mode. HOWEVER, it's not a dot, but once again an *arc* I'm getting, just like the test I did with those two similar dummy loads a few ohms apart. Don't understand why I'm seeing arcs instead of dots with anything other than a dead short or complete open attached to port 1 (and now this transmission test of yours too).
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Re: HP8754A VNA Resurrection
Sigh... I think I'm failing to understand something here. I'd assumed the input to the VTO *should* be a regular sawtooth waveform and not 'jumping around all over the place' but now I'm not so sure that the latter is actually the intended behaviour. The little inset diagram of the expected waveform does kind of resemble what I'm seeing on my scope. Damn! Why are these thing so complicated??
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- Jinxie
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Re: HP8754A VNA Resurrection
Trickier to break the loop on this old beast. Unlike later HP analyzers, this one doesn't have any nice convenient internal smb 'patch leads' to easily break and re-make connections.
Just to be clear, as far as I know, the phase detector is outputting zero volts since the 'unlock' light on the front panel is not lit - but *does* light up when R, A or B leads are removed from the front. The jittery voltage is what's being fed into the 'VTO' (section 10 in the diagram) which sweeps from 5-30Mhz according to the DC control voltage of between 2.5V and 10V. This is *supposed* to be a nice, regular saw-tooth waveform, the speed of which can be controlled by the sweep knob on the front panel. But it's jumping around all over the place so badly it's barely able to complete even one cycle uninterupted. If it's the sawtooth generator part of the PLL which is faulty, then it shouldn't be necessary to break the loop at all, I'd have thought, since the sawtooth generator will be independent of whatever the rest of the loop is doing.
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Re: HP853A+8559A spectrum analyzer.
Aarnaud, Do check the 200V supply pass transistor for the 158V supply. If it is open and has associated resistors and capacitors, it may read 200V with no load, but as soon as a load is applied (a plug-in) no current flows through the pass transistor and you get a spurious supply voltage, 12V.
Don Bitters
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Re: 85672A Spurious Response Utility for an 8563E
Page 4-11 of the operating manual for the 85620A mass memory module shows how to copy DLP's to the cards and how to copy from the cards to the module.? It looks very straightforward.? I'm still trying to figure out how to pull out to a file over HPIB or AUX-port that can be uploaded here since I don't think any computer can read those cards (that I am aware of)
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Re: 85672A Spurious Response Utility for an 8563E
Given that option T01 for the 85620A mass memory module removes the card interface, there definitely has to be a way to read/write programs, either through the auxiliary interface or the HPIB interface of the SA.? I'm going through the manual for the 85620A right now to see if I can find anything about loading programs without the memory cards.
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Re: 4342A Q-Meter Lubrication
I've been lucky. No lubrication problems with my HP 4342A.
I've written several utilities for the 4342A. One lets you remote a large coil that interacts with the enclosure to obtain unbiased readings. The utility use the telegraphers equation to compensate for the inductance and Q change the leads cause. Other utilities compensates for the Q of an auxiliary capacitor used to extend inductor measurement range and do the calculations necessary to determine capacitor Q.
Brian
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Re: 85672A Spurious Response Utility for an 8563E
On 4/17/2025 10:58 AM, zgoode via groups.io wrote: I'd also love to find a copy of this program and the 85671A one as well. I have the 85671A Phase Noise Utility installed in my mass memory module and would like to get it out and saved, presumably on to some memory cards.? Is this possible?? Meanwhile I keep a fresh battery installed :^) Dan ac6ao
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Re: 85672A Spurious Response Utility for an 8563E
I'd also love to find a copy of this program and the 85671A one as well.? Keysight's only response I've gotten is that I should buy a new spectrum analyzer with the new software.
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This morning, I swapped the 03 board from the good meter into the bad meter. The bad meter GPIB worked correctly, receiving commands and sending measured values out. I replaced the good board into the original meter and it still works. I put the bad board back into the bad meter, and low and behold, the GPIB works on the bad meter now.
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One of the first things that I did when I found a problem with that meter was to wiggle all the connectors on that board. The process of swapping the boards requires a lot more flexing and force than I like to put on boards. The problem may be a cracked trace or some such mechanical problem, or it is possible that the problem was just oxidized pins with very low currents. While I had the PCB out, I looked it over carefully and did not see any dubious looking solder joints or scratches on the board. I will be curious to see if the meter continues working now,
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If nothing else, I learned a lot more about what is going on in the GPIB cable, and I have 2 working meters for the efforts.
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Thanks everybody who pitched in with suggestions,
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BobH
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Re: 4342A Q-Meter Lubrication
On Wednesday 16 April 2025 01:45:13 pm nkirkby via groups.io wrote: The frequency adjustment knob was easy to lubricate with WD-40 after removing the top and bottom panels.? WD40 is NOT a lubricant! It consists of kerosene and "petroleum distillates", which is pretty thick stuff and what remains after you apply it and the kerosene evaporates. (...) The bushings must have been lubricated with something which turned very sticky over the years. The bearings all rotated very smoothly. Fortunately whatever lubricant was in there was just very viscous and there was no metal-on-metal galling. The result is that I was gradually able to get the shaft to move outwards by applying pressure to the inside end while rotating the indicator wheels relative to one another. After getting just a little bit of penetrating oil in there, everything spun freely. Lubrication is not one single component, but a range of components. What happens over time is that the lighter fractions gradually evaporate, leaving the thicker stuff behind, which is not really enough to provide proper lubrication. This, I suspect, is why fans get noisy after some years. If you have something that won't rotate freely you need to do a two-step process. The first step is to use liquid wrench, PB Blaster, or similar stuff to get all of the old lubricant out. Then you need to clean all of that out, and only then apply some new lubricant. I've been doing it that way for years, and it works well for me... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Re: HP8754A VNA Resurrection
He is correct, I would break the loop right after the phase detector, where the derived DC is driving the loop. Use a low noise source (battery & pot?). Watch the behavior of the RF output, is it dirty or (drifting slowly) CW carrier. Divide and conquer! Will point the way to the faulty stage. Jeff Kruth
In a message dated 4/17/2025 12:04:29 PM Eastern Standard Time, roy@... writes:
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On Wednesday 16 April 2025 01:03:56 pm Jinxie via groups.io wrote:
> Where do you even *start* with such a problem in a loop? It could be *any* sub-circuit being the culprit!
Open the loop...
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
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85672A Spurious Response Utility for an 8563E
Hey All,
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I stupidly let the battery in my 85620A go flat, and I've lost my 85672A utility on the card :(
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Does anyone either have or know where I can grab a copy of this to replace it?
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Thanks,
TonyG
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Re: HP8754A VNA Resurrection
On Wednesday 16 April 2025 01:03:56 pm Jinxie via groups.io wrote: Where do you even *start* with such a problem in a loop? It could be *any* sub-circuit being the culprit! Open the loop... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Re: HP853A+8559A spectrum analyzer.
The plug-in 100V will output 100V when the test lead is ground as per the manual. The LED does not lit so I suppose it's dead.
When a plug-in is inserted I can see the protection being grounded by the plug-in as expected, but the voltage output drops to 12V.
I'm expecting either the supply can't deliver the load, or there's something shorted in both the plug-ins. I'll probe Q3 to see if it's limiting.
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Re: HP853A+8559A spectrum analyzer.
I add: the 100V plug-in supply powers the vertical driver of the plugin that then go to the deflection plate, so a lack of 100V is a very good candidate for the no vertical on the screen. We'll see if it helps.
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Re: HP853A+8559A spectrum analyzer.
Okay I found out what the deflection board does, sorry It's my first time working on a CRT. Indeed they were not making contact. I'm not the first one to work on it, there's a ton of little stuff that isn't bolted and what not.
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I've checked the supplies. The mainframe regulated +158V is derived from the +200 unreg, so it seems the +200V is working but not the regulator. Looking at the schematics I suppose one transistor or one Zener has failed. This supplies the CRT and the XYZ amplifier, I hope they haven't suffered from this.
The +100V plugin supply is of similar design says the manual, with the added protection. It can be disabled by grounding the ENABLE point. Normally this is done by the plugin itself, so we'll see if this is mainframe or plugin side.
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I've added the schematics for your convenience.
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Arnaud.
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Be sure to check the HPIB/GPIB mounted connector on the back of the troublesome HP3456, use a magnifier to look closely.? I have seen HPIB/GPIB connectors that don't allow all the control/data lines to connect due to either contamination on the contacts or physical damage preventing electrical connection (i.e. bent, broken or mangled contacts) or foreign conductive material shorting contacts together (i.e. steel wool or wire strands).?
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Jinxie
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