"Dave Miller" <ve7hr@...> writes: That may well be the issue.
Do you happen to recall what the your LED¡¯s looked like. I am trying to determine if no keys are pressed are all the LED¡¯s on solid on the keyboard decode on the front left of
the unit with the cover off. I'm sorry, I don't recall, but I want to say that's correct. Since you have other units, I'd check the behavior against those. If those aren't accessible I can probably check mine for you. I haven't put it back in the rack yet, but I'd have to shuffle around a few things to get to it. Matt
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What¡¯s the serial number of your unit? HP got rid of the ROM/RAM board in put all the necessary ROM/RAM on an existing board after some revision.
Is your unit working? If so, your unit is almost certainly complete. Even if not, my guess is it¡¯s still probably complete.
Matt
On Sun, Feb 19, 2023 at 5:10 AM colingoode2000 via <colingoode2000= [email protected]> wrote: I have an 8662a oscillator which has a missing board may be two My question is what should be fitted in the right hand A2 slots coloured Green Blue Purple Grey and White I am missing a Rom Ram board but I have found two types available one for the White Slot and one for the Purple slot Do I need both or just one  ?
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Does an HP Transformer Specification Document exist ?
Did HP have a Transformer Specification Document ?
?
similar to the Tek version:
??
?
Trying to find a close replacement for a small? hp?? HV?? xfmr? ? ?
... hoped? to see if HP had anything close...
thank you,
rick
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Re: Advice on how to use an SA for test point troubleshooting
"Tony" <tonycox01@...> writes: I am troubleshooting a signal generator and the service manual says to check TP1 for 500MHz at +2-3dBm.
TP1 appears to be just a probe location on a trace (see attached image).
My question is what sort of probe should I attach to my spectrum analyser (8566B) to check the test point on the trace? Can I use a oscilloscope probe? If so, do I attach the probe ground lead?
I¡¯m used to using straight BNC-based input so this has me a bit unsure how to proceed.
I don¡¯t want to get an incorrect reading or worse, damage my SA! If you have it, I'd probably use a high-frequency passive probe for this. For example, the PMK PML series: I think Keysight and others just rebrand this for their high-frequency passive probes. The 50ohm-input terminated 10:1 and 100:1 versions will get you up to 1.5 GHz. If you use this with a scope you'll have to use it's 50ohm input or add a 50ohm pass-through termination. Of course, your SA is already 50ohm input so nothing additional needed there. If you use 100:1 division, the resulting signal will be on the weak side for an oscope, but your SA will see it fine. Of course you can also use a suitable active probe if you have that, but check it's damage levels first and make sure the signal is within those before using it (that actually goes for the 10:1 passive probe too, which can only handle 12V peak). In the likely scenario you don't have these, I'd just use something you do have (as others have suggested), such as a normal 10x probe and realize the attenuation at 500 MHz will be significant. You can solder in a coax cable too, but realize that you'll be loading down the circuit pretty badly. The capacitance of the cable will also present a significant load to the circuit. You might be able to solder a resistor in series to decrease the loading, but I don't know how easy it will be to get high-frequency performance doing this. As for damaging the SA, put a good DC block in series with the input. That should prevent damage in the case of DC voltages being present. I actually just leave DC blocks on my 8566's at all times and take them off if I ever need to see below the 10 MHz cutoff. If you're still worried, you can probe the signal first with other means (eg an oscope) to check for large DC voltages or even large AC swings, but this all seems unlikely to me. Matt
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Re: Advice on how to use an SA for test point troubleshooting
A x10 scope probe won't work well with a SA because the probe is made up of a 9M series resistance that works with the 'scopes 1M input resistance to make x10. The SA has a 50R input resistance, so instead of x10 you get x 180000.
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No, I would not use tuner cleaner or any of its descendants. 91% IPA, sprayed liberally (eg. soak it!) does everything that is required. Use a spray bottle, like is used for ordinary window cleaner. Do not add lubricant! It will only make the springs sticky. Plain old 91% IPA as comes from the drugstore. -Chuck Harris On Sun, 19 Feb 2023 00:37:55 -0800 "tom_iphi via groups.io" <iphi@...> wrote: Many thanks for your thoughts and insights!
There are a few commercial sprays for solving contact/corrosion
problems. Here in Europe there are available e.g.
-Contact spray, which removes corrosion, but also contains some kind
of lubricant. So not a good idea? -Tuner spray, which was used in the
old days to clean TV tuners, evaporates without leaving residues. Any
experiences?
Tom DG8SAQ
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Re: HP 212A pulse generator - asbestos inside!
One thing that doesn't get mentioned much is the small particles of asbestos don't survive exposure to moderately high heat and to sunlight. Or, so said the engineering course I took on air pollution during the 1970's. The professor was a rabid environmentalist, so I doubt he would have just made up the information... It maybe interesting for some to note that back when I was in college, everyone was worried about the coming ice age... It was well known that the Sun's activity cycles caused ice ages, and one was long overdue... thousands of years overdue. -Chuck Harris On Sun, 19 Feb 2023 10:59:37 +0000 "Dave_G0WBX via groups.io" <g8kbvdave@...> wrote: Hi.
You left out one of the most common past applications for Asbestos...
It was a significant component material (among others) used in
vehicle brake linings (and clutch assemblies, where used.)
Contaminated dust was released (not just Asbestos particles) each
time you used the brakes... Cylinder head, and exhaust manifold
gaskets pre WW2 also contained it.
There is in an archive somewhere, an advertising film made by the
Asbestos industry, showing how important Asbestos is in such uses,
and what happens if you leave it out.? I haven't found that one yet,
but if you just search YouTube for "Asbestos", there are archival
movies that will make you shudder now!
Is close to what I recall, from about 3:30 min's.
How many modern H&S violations can you spot?
Where does all the dust from the cutting, drilling and grinding go?
Just makes you wonder...
Regards.
Dave G8KBV
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Hi Askild, I have the Artech manuals on the 866A that are wonderful scans. ?I will grab the 8663A set once I am about to work on the 8663A. The 2 8662A are enough of a handful.? They are apparently difficult twins. One is sitting in the corner pouting and ignoring me. The other one is not paying attention all the time.? Thanks for the reminder on other manual sources. I will grab them and compare.?
Dave
toggle quoted message
Show quoted text
On Feb 19, 2023, at 2:47 AM, Askild <megafluffy@...> wrote:
? Hi Dave,
One place you will find manuals for the 8662 and 8663 is at KO4BB
Regards, Askild
On Sun, Feb 19, 2023 at 6:57 AM Dave Miller < ve7hr@...> wrote: Matt, That may well be the issue.? Do you happen to recall what the your LED¡¯s looked like.? I am trying to determine if no keys are pressed are all the LED¡¯s on solid on the keyboard decode on the front left of the unit with the cover off. ?
I have 2 8662A and one 8663A so I will eventually figure out how they work.?
Thanks for your suggestion.?
Dave ? I also had a non-responsive keyboard on my 8663. It turns out the metal leaf contact under one of the Bill West keys had come loose and was in a perpetual depressed position. This was constantly interrupting the processor and preventing it from being interrupted by other key presses. I don¡¯t know if this is your issue but it could be worth looking into.
Matt On Sat, Feb 18, 2023 at 7:15 PM Dave Miller < ve7hr@...> wrote: I am working through my latest score of signal generators. Back is sore. Working on the light ones first. ?
I am puzzled with this 8662A. I am hoping someone who has been down this path before might give me some
pointers.?
Powers up with no errors.
No Smoke ?:-)
100.0000 MHz ?-30 dBm ? On display. ? Spectrum Analyzer confirms it is as advertised. Yay!!!?
It does not respond to any keypresses.
Pressing and holding select does not give you any codes.
Popped the top cover and all LED¡¯s on the key decoder board are on. Pressing all the keys in turn ?show a different ?code.? I have not checked them against the key tables yet.?
Is all LED¡¯s on with no keys pressed correct? ? I have not found that in the OSM yet. ?
Any suggestions?
Thanks
Dave
?
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Hi Paul, I probably did not explain properly. ? I am referring to the diagnostic LED¡¯s on the front most card on the left side of the card cage.? That one shows using 7 LED¡¯s which key has been pressed. From what I can deduce?
After looking at my 2 8662A¡¯s ( one that almost works and does respond to most of the keys properly) is that those 7 LED¡¯s are on 111 1111 there is no keys pressed. Any key pressed and one or more of the LED¡¯s goes out and the resultant code should match the key code in the schematic in the manual on sheet 2 and 3 I recall. ?
On both units the keys seem to match the manual.? On the unresponsive unit it appears the key codes are correct but the unit is not processing this information. Thus it¡¯s always stuck at 100.00 MHz and -30 dBm.?
On the almost working unit it seems to be processing most of the keys properly and adjust the output ? OST of the time properly but not always display proper information on display. ?Certain frequencies are not displayed properly but output on generator is correct. ?Some segment like the + on the dBm are always on. ? The almost working one is promising as I can control the frequency, output and sweep in most cases. ?
So to summarize from what I have seen all 7 Diagnostic LED¡¯s on key code board should be on with no key pressed. If they are not this would hint that there is a stuck key. Does this make sense. ? Dave
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On Feb 19, 2023, at 7:20 AM, paulswed <paulswedb@...> wrote:
? Oh my 8662 and 8663s are indeed heavy no more than one on the bench at a time... At least my bench. If all the displays are on thats like a power start up and then suspect the unit hangs. Definitely?seems like a cpu issue. Or a always on interrupt?as suggested above. If one of those spring leafs fall out, save it you can fix the switch it came from usually. Good luck Paul WB8TSL
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Re: Advice on how to use an SA for test point troubleshooting
Do you have a scope? If so try that first. Even if the BW is lower than 500MHz you should be able to see some signal and it will give you DC levels. That should let you determine if there are SA damaging voltages present. Given the power levels you suggest that should be ok for the SA. HP had some special cable assay¡¯s that would plug into the two ¡°sockets¡± shown. A 10X probe should be OK, AFTER checking for DC voltages and I would ground the probe. ?From the picture I¡¯d suspect that the other pin is a ground connection. Not knowing what the schematic says on that little circuit it¡¯s hard to guess. ?I think it looks like the black diode might be a PIN switch with the ¡°on¡± bias supplied through the glass diode. ?Another question would be where does the fat trace leading to the left of the black diode go? ?It is also DC blocked, so that could mean the PIN diode idea is OK. If that trace goes to an off board connector you could try sampling after the DC blocking cap or if it¡¯s a connector just pull that connector and see what¡¯s there. ?
Hope this helps a bit. ?Just make sure there are no DC voltages anywhere you try to monitor with the SA.?
Steve
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Re: 5086-7337 *Yig Oscillator issue*
Hi Ruben,
I was thinking of the main coil. The FM coil can be ignored for now, as it only affect the frequency a little. Probably good to check the heater and FET drive as well.
Regards, Askild
Hi Askild
You mean the main coil or the FM coil??
Maybe I should do a test setup and measure de current drawing of both coils, heater and final stage FET amplifier¡
Regards,
Ruben
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Re: Advice on how to use an SA for test point troubleshooting
dBm is a power reading, so it cannot be made without knowing
the impedance at the point of measurement. They probably mean
dBm @ 50 ohms.
I think you will be able to observe that the test point is at
some point on a trace that is designed to be a transmission line.
You will probably also see that the test point is surrounded by
ground plane.
Smart manufacturers will often design in a simple probe with a
simple connector at test points such as this, however, that is
not always done because of the line disturbance that a probe
and unused connector may cause at the test point.
What I would do is cut the extra connector off of a scrap 141
hardline jumper, and machine the cut end so that it can safely
engage both the test point and the ground plane that I assume
will be surrounding the test point. Attach the homemade 50 ohm
probe to a flexible cable that goes to your SA's input, and make
your measurement.
-Chuck Harris
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Show quoted text
On Sun, 19 Feb 2023 06:38:36 -0800 "Tony" <tonycox01@...> wrote: Hi,
I am troubleshooting a signal generator and the service manual says
to check TP1 for 500MHz at +2-3dBm.
TP1 appears to be just a probe location on a trace (see attached
image).
My question is what sort of probe should I attach to my spectrum
analyser (8566B) to check the test point on the trace? Can I use a
oscilloscope probe? If so, do I attach the probe ground lead?
I¡¯m used to using straight BNC-based input so this has me a bit
unsure how to proceed.
I don¡¯t want to get an incorrect reading or worse, damage my SA!
thanks
tony
Attachments:
photo-2.jpg:
/g/HP-Agilent-Keysight-equipment/attachment/132707/
|
Oh my 8662 and 8663s are indeed heavy no more than one on the bench at a time... At least my bench. If all the displays are on thats like a power start up and then suspect the unit hangs. Definitely?seems like a cpu issue. Or a always on interrupt?as suggested above. If one of those spring leafs fall out, save it you can fix the switch it came from usually. Good luck Paul WB8TSL
|
Re: 5086-7337 *Yig Oscillator issue*
Hi Askild
You mean the main coil or the FM coil??
Maybe I should do a test setup and measure de current drawing of both coils, heater and final stage FET amplifier¡
Regards,
Ruben
|
Re: HP 212A pulse generator - asbestos inside!
Greetings,
To add my less than 2 cent¡¯s worth. ?Many older appliances such as stoves, hot plates, and the like used asbestos insulated wire.
toggle quoted message
Show quoted text
On Feb 19, 2023, at 6:14 AM, Wallace Gasiewicz via groups.io <wallydoc@...> wrote:
We also had huge manufacturing lines dedicated to asbestos brake linings.
I do not have access to records anymore but I do not remember any cases of asbestosis in our brake workers.
There has always been a concern about any brake worker (mechanic) but it is difficult to track these individuals because lots of them switch jobs and frequently work as individuals, not employed by a big company. By the way, there is the same concern for isocyanate in auto body workers, but, I digress..
We did screen the brake lining workers for many years after the processes were eliminated, they were included in the asbestos exposure group and had the normal screening for this group as per OSHA and other guidelines. the operations had ceased before I was employed ( I am not quite that old), but I believe the dust was still present on overhead pipes and ducts and beams etc....I was in the plant years after the brake operations had ceased.
Just because I do not remember a case does not mean there were not any. From reports of the exposure the air was filled with dust in these operations.
I was and still am amazed that there were not a bunch of cases of asbestosis..
Probably has something to do with the physical and chemical composition of the asbestos product, being bound to other things,? etc... this observation of "low risk" has been observed by others and is documented in the literature.
There was also asbestos in other brakes and clutches, like the ones that stop the big several kiloton presses and other machines..These were replaced.
A big exposure was in boiler operations for insulation of boilers and pipes, Lots of plants had asbestos wrapped heating (and other ) steam pipes. These were not replaced as exposure was deemed to be bad when the asbestos was disturbed, much like the flooring issue (we had that also). But you never knew when someone would blast an old pipe in a renovation. We used to keep track of the places where asbestos was still in the plant.
Obviously the exposure was in servicing these lines and boilers. This is more like the shipyard workers exposure. But not as constant.
School "custodians" also had asbestosis from dust in schools.
All of these exposures are huge when compared to the insulating socks and other asbestos involved in electronic equipment.
But I sure would not snort the stuff. Or cut it etc...? Maybe someone knows if some old electronic boards had asbestos in them????
Lots of electronic guys like radio and radar tecks were involved in, or at least working right next to other shipyard processes and these other processes probably posed a much greater exposure than just the electronics.
Anyone in a shipyard was probably exposed to lots of asbestos.
On a lighter note did you know Charlemagne had a tablecloth made from asbestos? He would throw it into the fireplace at the end of dinner to clean it.? All to the amazement of his guests. (I read this on the internet, so I know it is true).
|
my working instrument has the same slots empty (it¡¯s difficult to see the light blue guide in this picture). The 8662A has a lot of variation in the card configurations over it¡¯s various versions and the online documentation that¡¯s available is very confusing and incomplete and sometimes contradictory.
tony
|
Advice on how to use an SA for test point troubleshooting
Hi,
I am troubleshooting a signal generator and the service manual says to check TP1 for 500MHz at +2-3dBm.
TP1 appears to be just a probe location on a trace (see attached image).
My question is what sort of probe should I attach to my spectrum analyser (8566B) to check the test point on the trace? Can I use a oscilloscope probe? If so, do I attach the probe ground lead?
I¡¯m used to using straight BNC-based input so this has me a bit unsure how to proceed.
I don¡¯t want to get an incorrect reading or worse, damage my SA!
thanks
tony
|
Re: 5086-7337 *Yig Oscillator issue*
Hi Ruben,
Have you checked the current through the tuning coil? Probably best to set the 8350 to CW, and try a few different frequencies.
Regards, Askild
Hello everyone!
Although this topic belongs to my 8350B restoration thread I did almost a year ago, I want to imprint some relevance. Shortly, my 8350B mainframe doesn¡¯t have main transformer. Instead of that I feed it with three external sources.
These days I managed to get a 83592A plugin in two separated parts sets. I have put them together and after some power supply issues (classic shorted tantalum), there¡¯s no errors displayed.?But no RF coming out.?Unleveled LED lits in the front panel.?Also no RF at the rear aux output, nor at the exit of YO itself (God shake! it¡¯s tricky to access microcircuits!).
Following the signal path and troubleshooting notes on the manual, I check that the +5, +20, -40 supplies for the YO are present. Also the ON -10 volt signal and the M composite signal on scope. At first glance, G bias signal (which should be -2 volt) was almost 0. I check the associated components and after turning a pot, -2 volt come back.
Still no signal at the output of the oscillator :(?
Is there any other way to check the YO before officially declaring it dead?
Regards,
Ruben
|
Hi
It would be worth checking carefully that your serial number needs the ¡°missing¡± boards. Not all of the slots are populated in those instruments. I know this because I thought my own instrument was missing some until I checked.
regards
tony
|
Re: HP 212A pulse generator - asbestos inside!
We also had huge manufacturing lines dedicated to asbestos brake linings.
I do not have access to records anymore but I do not remember any cases of asbestosis in our brake workers.
There has always been a concern about any brake worker (mechanic) but it is difficult to track these individuals because lots of them switch jobs and frequently work as individuals, not employed by a big company. By the way, there is the same concern for isocyanate in auto body workers, but, I digress..
We did screen the brake lining workers for many years after the processes were eliminated, they were included in the asbestos exposure group and had the normal screening for this group as per OSHA and other guidelines. the operations had ceased before I was employed ( I am not quite that old), but I believe the dust was still present on overhead pipes and ducts and beams etc....I was in the plant years after the brake operations had ceased.
Just because I do not remember a case does not mean there were not any. From reports of the exposure the air was filled with dust in these operations.
I was and still am amazed that there were not a bunch of cases of asbestosis..
Probably has something to do with the physical and chemical composition of the asbestos product, being bound to other things,? etc... this observation of "low risk" has been observed by others and is documented in the literature.
There was also asbestos in other brakes and clutches, like the ones that stop the big several kiloton presses and other machines..These were replaced.
A big exposure was in boiler operations for insulation of boilers and pipes, Lots of plants had asbestos wrapped heating (and other ) steam pipes. These were not replaced as exposure was deemed to be bad when the asbestos was disturbed, much like the flooring issue (we had that also). But you never knew when someone would blast an old pipe in a renovation. We used to keep track of the places where asbestos was still in the plant.
Obviously the exposure was in servicing these lines and boilers. This is more like the shipyard workers exposure. But not as constant.
School "custodians" also had asbestosis from dust in schools.
All of these exposures are huge when compared to the insulating socks and other asbestos involved in electronic equipment.
But I sure would not snort the stuff. Or cut it etc...? Maybe someone knows if some old electronic boards had asbestos in them????
Lots of electronic guys like radio and radar tecks were involved in, or at least working right next to other shipyard processes and these other processes probably posed a much greater exposure than just the electronics.
Anyone in a shipyard was probably exposed to lots of asbestos.
On a lighter note did you know Charlemagne had a tablecloth made from asbestos? He would throw it into the fireplace at the end of dinner to clean it.? All to the amazement of his guests. (I read this on the internet, so I know it is true).
|
RubenRubio
