Re: Issues with HP 8902A Measuring Receiver
On Tue, 13 May 2025, Raymond Boute via groups.io wrote: Can't tell about anything else, but OUT OF LOCK LED on Synchronous Detector is normal. It ONLY locks at some ranges/modes and unlocked most of the time. There is a test (don't remember which one) for Synchronous Detector, you should see that LED turning OFF several times. It is ON most of the time. I have a 8902A with ALL options, including that rare Opt.50 (002 030 032 037 050) which I had calibrated by Keysight last year -- it passed everything without any adjustments. BTW, I also have a 8663A generator that was never calibrated and I added Opt.002 from a parts donor without any adjustments (all connectors are on the front panel so there are 3 BNC connectors on the right). Surprisingly, it passed the Keysight calibration last year with flying colors, no adjustments necessary. Quite impressive pieces of equipment! To anyone with HP 8902A know-how,
I just acquired a HP 8902A Measuring Receiver (SN 2834A) that was clearly dropped by FedEx during transport, most likely by the customs inspectors. The lower back bumpers are broken off (taking small pieces of the frame with them); there is no visible internal damage.
Some quick initial experiments revealed the following.
?? (i) On startup, there are no error messages, but after about 10 seconds the controller seems to be cycling through some subprogram causing continuous clicking of a relay. All voltages are "in the green" (LEDs on the regulator board).
?? (ii) The 42.0 SPEC command (display software date) yields 61.1987.
?? (iii) With a 7 MHz signal above -6 dBm, I obtain power readings about 1 dB off the mark, below -6 dBm the readings abruptly drop far lower.
?? (iv) No frequency readings could be obtained.
?? (v) On A23 (sampler), the NO HF VCO and OUT OF LOCK lights are on.
The service manual files are at the copy center (the brain prefers paper).
Questions:
a. Any direct suggestions based on the above random tests?
b. Is there a command for starting a fully-fledged test sequence?
c. The "Basic Operation and Application Guide" seems to be a running ad for the HP 11722A Sensor Module.
??? To what extent is this useful/indispensable?
??? Can one calibrate the HP 8902A without the sensor?
Any further suggestions would also be much appreciated.
73
Raymond ON4DBV
--- * * KSI@home KOI8 Net < > The impossible we do immediately. * * Las Vegas NV, USA < > Miracles require 24-hour notice. * *
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Re: HP Basic for Windows 6.33, printed documentation
It is probably easiest to use something like VMWare player for stuff like this. I use that a lot, with FreeDOS to run various utilities that will not even run on Windows.
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Issues with HP 8902A Measuring Receiver
To anyone with HP 8902A know-how,
I just acquired a HP 8902A Measuring Receiver (SN 2834A) that was clearly dropped by FedEx during transport, most likely by the customs inspectors. The lower back bumpers are broken off (taking small pieces of the frame with them); there is no visible internal damage.
Some quick initial experiments revealed the following.
?? (i) On startup, there are no error messages, but after about 10 seconds the controller seems to be cycling through some subprogram causing continuous clicking of a relay. All voltages are "in the green" (LEDs on the regulator board).
?? (ii) The 42.0 SPEC command (display software date) yields 61.1987.
?? (iii) With a 7 MHz signal above -6 dBm, I obtain power readings about 1 dB off the mark, below -6 dBm the readings abruptly drop far lower.
?? (iv) No frequency readings could be obtained.
?? (v) On A23 (sampler), the NO HF VCO and OUT OF LOCK lights are on.
The service manual files are at the copy center (the brain prefers paper).
Questions:
a. Any direct suggestions based on the above random tests?
b. Is there a command for starting a fully-fledged test sequence?
c. The "Basic Operation and Application Guide" seems to be a running ad for the HP 11722A Sensor Module.
??? To what extent is this useful/indispensable?
??? Can one calibrate the HP 8902A without the sensor?
Any further suggestions would also be much appreciated.
73
Raymond ON4DBV
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HP 8340B/8341B SYTM pictures
Does anybody have a knowledge of what the inside of the 8340B SYTM looks like or what components are around the PIN diode? Pictures would be helpful if anybody has taken theirs apart for fun.
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The block diagram shows 1000 Ohm resistor in series with the PIN diode bias shown in the figure below.
My low band output power is attenuated some of the time, with lower frequencies attenuated more than higher.
There appears to be running at least 1mA from PIN bias to the PIN diode which may be and indication to why my low band is sometimes attenuated.
Do PIN diodes generally start to leak current when close to total failure?
?
?
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Re: Weird HP 11880A N-Adapters
Hi from the manual of the probe , you can see that the adpater 11880A to N , is made to provide a 50 ohm termination.  Regards Maurizio IZ1MDJ
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After 5 years of non-use, the HP 8713B does not start and after switching on only the display and the LED on the CPU board flicker. In stand-by mode, the green and red LEDs light up, which is normal.?
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When I remove the A3 board, the analyzer starts and error messages are displayed on the monitor.
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All 4 LEDs on the power supply are green.
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Has anyone experienced this??
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I have checked the electrolytic capacitors but all are ok.
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Does anyone have an idea what it could be?
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Thank you,
Franz
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Re: HP Basic for Windows 6.33, printed documentation
I'm actually surprised you could still get that mouldy oldie going in a 64-bit PC VM. There's probably the case to made for keeping an older 32-bit Lenovo/IBM Thin Client or laptop around for these kinds of applications in future. 64-bit isn't going away. Old applications like HP Basic 6.33 are.
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Weird HP 11880A N-Adapters
Hello HP fans,
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I was tinkering with my HP 85024A and some unexpected measurements made me to question my setup.
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Short to the point : I use a HP11880A N Adapter to link my probe to a N socket, and the reading is around -5dB from what I expected. The measured levels are perfect without the adapter.
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It appears that my HP11880A N Adapter exhibit a 50¦¸ DC resistance to ground.
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In the 85024A Technical Overview 5968-2101E, page 4 told us 1M¦¸/0dB ; suggesting that the adapter should be a simple coax line without any DC resistance to ground.
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I checked the same adapter in the box of my HP 41800A probe and, guess what, the 11880A adapter also exhibits 50¦¸ to ground.
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I feel like missing something big...
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Might someone of you folks enlighten this debate ?
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Best Regards,
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Fran?ois / F4HTX
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Re: (OT) Affordable PCB fabrication (-> tariffs/US...)
In the distant past,I used to do a lot of business with Bay Area Circuits. Ihave looked at their pricing in the last couple of years, and it seemed ok for larger than oshpark stuff and quantitys. BobH
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The auction does show the manual and it is correctly listed
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Looks like it is a software option for the 35660A that extends the unit with instrument basic
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Turns out there is another option, 35681A - 'Analysis pack' - for the 35660A - has anyone got a copy of this one?
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Peter
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Well, HP made a 3586A/B/C Selective Level Meter. Does the manual on the auction show a photo of the manual with "35680A" printed on the cover?
I came across an HP manual marked 35680A on a well known auction site.? A brief search does not seem to return any hits.
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Anyone in the group know what it is?? Seems like it might be some sort of low frequency analyzer - 3562A, 35660A, 35665A, 35670A?
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Peter
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Answering my own question - looks like it is the HP Instrument Basic option for the 35660A
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I came across an HP manual marked 35680A on a well known auction site.? A brief search does not seem to return any hits.
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Anyone in the group know what it is?? Seems like it might be some sort of low frequency analyzer - 3562A, 35660A, 35665A, 35670A?
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Peter
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Re: HP Basic for Windows 6.33, printed documentation
In case this is of use for others at some point
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Whilst I was able to install and use HP Basic 6.33 on machines with recent 64-bit operating systems, I was not able to save programs in a windows compatible file format.??
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It was necessary to revert to a 32-bit Windows XP installation to get things to work correctly
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With the 32-bit OS installation?
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CONFIGURE SAVE ASCII OFF - will cause HP basic to save files in plain 'DOS' ASCII that is visible in Windows i.e. CAT in the HP BASIC interpreter will show the files and the files will be visible if you inspect the destination directory from Windows
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CONFIGURE SAVE ASCII ON - will cause the interpreter to save files in LIF ASCII
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Peter
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Re: HP 8591e Power supply
Hi Georges,
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I have a HP8595E with a problem of power supply. The power supply doesn't start when the line switch is on, all the power-supply LEDs remain off. I check the shematic diagram and i find a diode failed (short circuit) CR306 (HSMS-2800) on the PSU control board.?
I don't understand the function of the AOP U303D on the shematic diagram, so i unsoldered this diode CR306 and i don't replace it immediatly because i didn't have any. I then tried without this diode and the power supply was running well.?
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VSTBY is 15V, the voltage on the pin 10 U303D (KS_EN) is about 6V (VRAIL is about 320V and the resistor divider 632K and R311 12K1 provide this voltage). The voltage on pin 11 U303D is 7,5V by the divider resistor R309/R310 100K/100K. So the output pin 13 of U303D is Hi arround 13 V. When the switch line is on, the PWRON_L is connected to the FB_GND and so the there is no signal on TR301-7 and on the? anode of CR302, voltage on pin 6 of U303B is 0V the power supply is on.?
With these diode CR3036 on short circuit it was impossible to start the power suply because event if? there is no signal at the output of T301-7 and the anode of CR302, the output of U303D maintains a voltage on pin 6 of U303B and pin 8 U303C.
So what is the function of this U303D ? in my opinion the output of U303D never gone 0V and even if this output is at 0V (it would be possible if the +VRAIL failed) what? would be the desired function knowing that the shutdown of the power supply is conditioned by a hight level on the anode of CR306.?
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Best regard.
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Re: (OT) Affordable PCB fabrication (-> tariffs/US...)
Hi Anders,
That's a good point. I have noted Aisler. Thanks.
Renaud
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Re: (OT) Affordable PCB fabrication (-> tariffs/US...)
I used to use PCBWay, but switched to Aisler since I am in Europe. They take KiCAD files directly and prices are reasonable. For me it is an ethical issue as well. Greater chance that EU suppliers pay their workers decent wages and that their processes are environmentally sound.
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Re: HP34401 Multimeter - 4 wire mode wont zero
I would blame the switch. Over the years, I have found front/rear selector switch problems on most of my higher resolution DMMs that have that feature, and I have deleted it where possible. If you don't need it, it is usually easy to bypass one way or another - like soldering jumpers across or rewiring around contacts, or total elimination of the switch. If you do need it, then some Deoxit treatment usually helps. Sometimes just working it lots of times (a hundred or more is not too many in some cases) can fix it. Not using the gear for long periods aggravates the dry contact situation, and so does not exercising all the system contacts with enough signal power. It's a common problem, and there are ways to restore proper operation without too much grief.
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Ed
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HP34401 Multimeter - 4 wire mode wont zero
Hi all,
I hadn't used my HP33401 on 4 wire mode in years and I suddenly needed it to measure some current shunts when I noticed an issue.
On 4 wire mode, with the leads shorted, on 6 digit mode, it wont zero. The last 3 digits fluctuate about. Its a little more stable on the rear terminals which has me thinking its the front/rear switch rather than something else.
A search of the net seems to suggest that the switch might be the issue but I thought I'd ask here first before I go disassembling anything and poking about :)
So... is this a common error for 4 wire low ohms mode ?
Is it the switch ?
Is the switch sealed or open enough to squirt some contact cleaner in there ?
If the switch needs to be replaced, are they commonly available ?
If its not the switch, is it some other common fault ?
The meter is fine on all ranges and within spec when tested against other meters and my little transfer standard.
Any help appreciated.
thanks
Tim
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Re: (OT) Affordable PCB fabrication (-> tariffs/US...)
My boards are about 150x150mm and about 100x200mm or so, and so OSH Park is out of the question (price would be prohibitive, and worse, no volume discount...). For small projects, though - small sized prototyping boards - OSH Park is great and I always use them.?
But what I'm looking for is a place with good options (ENIG, 2oz Cu, fingers, 30deg beveling, etc.) and good pricing for low volume production. Low volume meaning 10-20 boards?at a time, not three...?
If anyone's reluctant to share?their?fabricator on the forum, please feel?free to do so offline to me directly. I'm always choosing local/domestic products and manufacturing (when possible), but in this case every place I could find that's domestic makes those riser cards simply impossible to make.? Radu.?
? ?I never send PCB orders offshore.? For "work work", my customer
requirements nearly always involve domestic production.? For prototypes,
personal projects, or other low-volume stuff I usually use OSH Park.
? ? ? ? ? ? ? ?-Dave
On 5/11/25 14:14, Radu Bogdan Dicher via wrote:
> Still hoping for some good input. Or maybe everyone's hunkering down
> waiting for this to blow over? Or maybe everyone stacked up for a smooth
> transition through some months of turbulence?
> Thank you,
> Radu.
>
> On Thu, May 8, 2025 at 12:04?PM Radu Bogdan Dicher via
> <> <vondicher=[email protected]
> <mailto:[email protected]>> wrote:
>
>? ? ?Hi all,
>? ? ?This may of particular interest to US members, but I am wondering
>? ? ?how others are handling the effect of tariffs (in particular with
>? ? ?China) on your PCB fabrication needs. Though I should say,
>? ? ?recommendations on reliable, good fabricators is likely information
>? ? ?that everyone could use.
>? ? ?I have two raiser cards I designed (for Fluke
>? ? ?instrumentation/calibrating equipment), and maybe I should just wait
>? ? ?for all this to blow over (assuming it settles somewhere different
>? ? ?than where we are), but I'd rather plan for tough times. I used to
>? ? ?use JLCPCB, but with the additional costs triggered by the tariffs,
>? ? ?I may be looking at about two or three times the cost (rather closer
>? ? ?to the latter than the former), and that just makes is unfeasible to
>? ? ?offer this product. At what hobbyists are willing to pay for
>? ? ?something like this (which, myself being one, I fully understand),
>? ? ?I'd be losing money on each one I'd make.
>? ? ?Are there some good options others have figured out where tariffs
>? ? ?are not quite so onerous?
>? ? ?I looked, for instance, at a place in India, which looks decent
>? ? ?enough and not crazy expensive - though distinctly more expensive
>? ? ?than JLCPCB - but they don't seem to have some of the capabilities I
>? ? ?want, such as beveled card edge and so on. Their features seem to be
>? ? ?about half as many as a place like JLCPCB offers.
>? ? ?There are some places in the US - and OSH Park need not apply, as
>? ? ?these are large and really need volume discounts - but they seem to
>? ? ?be very low tech in terms of getting online quotes (=0 capabilities
>? ? ?for such at what likely is the most affordable ones) and so it's
>? ? ?very hard and time intensive to investigate. But if any of you knows
>? ? ?a good, affordable and reliable place, I'd love to hear about it.
>? ? ? From what I gather, at this point, offshoring this kind of thing is
>? ? ?by far the most affordable and ultimately lucrative option.
>? ? ?particularly at hobbyist level.
>? ? ?With some places that can price me upon uploading my gerbers, I'm a
>? ? ?bit antsy about giving them away. I heard stories where once
>? ? ?uploaded, you essentially are giving away your IP and the design may
>? ? ?pop up in mass production somewhere.
>? ? ?Thank you,
>? ? ?Radu.
>
>
--
Dave McGuire, AK4HZ
New Kensington, PA
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Sergey Kubushyn
Anders