Thanks guys. now I know where to file it.
Wally
|
I think your memory is pretty good -- it's mine that is untrustworthy! But if the -2803 is indeed a matched pair of 1N5711 or 1N6263 Schottkys, it would serve well in those probes.
--Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University i
Stanford, CA 94305-4070
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On 1/16/2022 16:03, Richard Knoppow wrote: ?? I wonder if those are the diodes used in the 8405A Vector Voltmeter probes?? I used to change these out when they got zapped. -hp- supplied a little kit. Its been a lifetime since I saw any so my memory may be wrong.
On 1/16/2022 3:34 PM, Tom Lee wrote:
Those are Schottky diodes. Lots of uses for matched Schottky pairs, as you can imagine. IIRC those are basically 1N5711s.
--Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 1/16/2022 14:44, Wallace Gasiewicz via groups.io wrote:
Have One of these small axial lead diodes
Number on Diode:
HP2
309
941
Number on HP envelope 5082-2308
Matched Pair
Any idea of the application
|
I wonder if those are the diodes used in the 8405A Vector Voltmeter probes?? I used to change these out when they got zapped. -hp- supplied a little kit. Its been a lifetime since I saw any so my memory may be wrong.
toggle quoted message
Show quoted text
On 1/16/2022 3:34 PM, Tom Lee wrote: Those are Schottky diodes. Lots of uses for matched Schottky pairs, as you can imagine. IIRC those are basically 1N5711s.
--Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 1/16/2022 14:44, Wallace Gasiewicz via groups.io wrote:
Have One of these small axial lead diodes
Number on Diode:
HP2
309
941
Number on HP envelope 5082-2308
Matched Pair
Any idea of the application
--
Richard Knoppow
dickburk@...
WB6KBL
|
Those are Schottky diodes. Lots of uses for matched Schottky pairs,
as you can imagine. IIRC those are basically 1N5711s.
--Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 1/16/2022 14:44, Wallace Gasiewicz
via groups.io wrote:
toggle quoted message
Show quoted text
Have One of these small axial lead diodes
Number on Diode:
HP2
309
941
Number on HP envelope 5082-2308
Matched Pair
Any idea of the application
|
Have One of these small axial lead diodes
Number on Diode:
HP2
309
941
Number on HP envelope 5082-2308
Matched Pair
Any idea of the application
|
Stuff season closing shortly + Data I/O Gang Programmer
We will shut down the stuff page at the end of the month to re-stock it, and many HP/Tek spares items as well as the FETs?will disappear then.??https://www.sphere.bc.ca/test/stuffday.html
There is a lot of new stuff to go up, including many interesting calibration and high end test items. I also just found another Data I/O 288 gang (8) programmer with the MOD87XX Intel 40 pin MCU programmer module. I thought somebody was looking for a way to do some MCU programming recently, so if you need such a gadget, please? contact me now before we load it to the site.
There will be more Tek and HP knob lots and other trim parts to go up in the new page, and if you have any special requests, please email me directly, we will do our best to accommodate you.
Best wishes for everybody in the new year,
walter (walter2 -at- sphere.bc.ca)
sphere research corp.
https://www.sphere.bc.ca/test/index.html
|
Re: What would happen if I let the battery in my HP 54622D oscilloscope run down?
I know I need to not let the battery in my HP 3478A DMM run down so o don¡¯t lose calibration, but it just came to my attention that the HP 54622D also has a backup battery. What is lost if that battery runs down?
I didn't realize that there's a battery in these scopes. There's no mention of this in the "service" manual, other than a mention of its existence. I'm curious to know, now, as well.
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Re: 8640B Scruffy and does jot tune Frequency
James bonjour, BRAVO, 8640B is a classic cavity resonator and still the lowest spurious and emission generator. We have three of these. Varios fine options:
Add 512...1024 MHz band
Add output reverse RF protection (IMPORTANT easy to blow hybrid output amp, HP special;! )
Add high acc TCXO check rear panel for options installed.
1/ For sure knobs are not original and band /attn/gears are probably in poor cond.
2/ Check PSU, then gears, then behavior on all bands.
3/ Suspect scratchy or intermittent buttons can controls.
4/ BAMA, Artech and HP vintage should have PDF and printed manuals, be sure it is for your particular SN
Highly recommend the printed bound as the foldouts and flowcharts etc are essential to fix.
Bon Chance
Jon
|
Re: Counterfeit circuit breakers (was:Re: [HP-Agilent-Keysight-equipment] OT: Mains Safety PSA)
Thanks, but this had nothing to do with the circuit breaker. This was not a question of too much current but rather too little current to start the pump and too much of that was being turned into heat in the pressure switch contacts.?
Jeremy Nichols wrote on 1/16/2022 1:51
PM:
<snip>
We had a fire in our
home due to exactly that situation. The pressure switch on our water
pressure tank gradually became corroded until it could not pass enough
current to start the pressure pump. As a consequence, the tank kept
¡°calling for water¡± but there was none.
Hello--
IIRC, there was (and still may be) an influx of fake circuit breakers,
and a web search
pulled up youtube references? from as late as January 2021.
Eaton was one of the victims--search...
Eaton counterfeit circuit breakers
73--
Brad? AA1IP
|
Counterfeit circuit breakers (was:Re: [HP-Agilent-Keysight-equipment] OT: Mains Safety PSA)
Jeremy Nichols wrote on 1/16/2022 1:51
PM:
<snip>
We had a fire in our
home due to exactly that situation. The pressure switch on our water
pressure tank gradually became corroded until it could not pass enough
current to start the pressure pump. As a consequence, the tank kept
¡°calling for water¡± but there was none.
Hello--
IIRC, there was (and still may be) an influx of fake circuit breakers,
and a web search
pulled up youtube references? from as late as January 2021.
Eaton was one of the victims--search...
Eaton counterfeit circuit breakers
73--
Brad? AA1IP
|
Re: 8640B Scruffy and does jot tune Frequency
Look for a service manual that covers your instrument¡¯s serial number prefix.? The 8640B went through a number of design changes during the years it was produced.? One of these changes was a drastic replacement in the FREQ RANGE and DEVIATION
switches.? The newer design was fine when it was new but is now a notorious failure point.? Be very careful disassembling an instrument that contains the new-style switches, it¡¯s likely that tiny tiny bits ¨C that are inconvenient to replace - are lying loose
in the bottom.
?
As mentioned before, another notorious failure point is broken gears in the same RANGE/DEVIATION assembly.? A few people have made replacements, or sometimes repair of the old ones is possible.
?
HTH,
Dave Wise
?
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From: [email protected] < [email protected]>
On Behalf Of Kuba Ober via groups.io
Sent: Sunday, January 16, 2022 9:49 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] 8640B Scruffy and does jot tune Frequency
?
Screws look typical of this case style. Black knobs themselves are replacement perhaps, since they should be a different, light style, but the skirts look factory. I suggest not tinkering with it without a thorough clean up outside and
then inside. It¡¯ll go easier that way, and there are bits inside where you won¡¯t want any dirt to go into.
This generator has a cavity oscillator inside and there¡¯s quite a bit of mechanical transmission around that. If something is seized you¡¯ll potentially propagate the damage by turning controls. Once it¡¯s clean and open, you¡¯ll see which
controls are just switches or potentiometers, and which ones drive transmissions/mechanical contraptions.
Then you¡¯ll start with the basics: get the service manual and make sure all power supplies are correct and clean. Go from there and ask here :)
16 jan. 2022 kl. 12:37 em skrev James Sawle (MD0MDI) <james@...>:
?I have just acquired a rather tatty 8640B Sig Gen, but having never restored one of these before I thought would ask a few questions to those that know better.
Certainly not the cleanest, Power on and displays 10MHz but display does not change when you rotate the Frequency Tune knob, so I am thinking possibly plastic gearing gone?
Can anyone clarify if these four screws in the top are factory? kind if looks like a bodge to me and possibly been played with, but I could be wrong? hopefully someone wiser can let me know?
Also on the front panel are two knobs that look wrong? are they?
Any guidance with this unit would be very much appreciated?
James
Attachments:
|
Greg wrote, in part:
¡°?As for things running warm to the touch it is best to check outlets and other apparatus to make sure that gradual heating is not causing oxides to form on the contact surfaces thereby increasing resistance which often times will cause the heating to increase exponentially until failure or fire occurs.??A small amount of heating may be normal given the current of a device but it can also cause an increase in problems if it gets out of hand.¡±
We had a fire in our home due to exactly that situation. The pressure switch on our water pressure tank gradually became corroded until it could not pass enough current to start the pressure pump. As a consequence, the tank kept ¡°calling for water¡± but there was none.?
The current that turned into heat in the switch contacts eventually caused the switch assembly and its plastic cover to burn. Fortunately, this set off a smoke alarm, waking me at (of course) 0400. I put out the fire with an extinguisher and called 911 for backup. Minimum damage, and when I replaced the pressure switch I added a thermal fuse.?
I later discovered that the pressure pump had gotten hot enough that the plastic piping was severely bulged, although it did not fail.?
-- Jeremy Nichols
6.
|
Steve,
Did you get the sensor with it? If not, stand by for sticker shock¡
The 8991A is not an advanced version of the 437, it is a pulse power measuring instrument designed specifically for pulse-modulated signals. It will measure rise and fall times, pulse width, PRI, PRF, peak power, average power, etc. The 43x-series are designed for CW power measurement.?
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On Jan 16, 2022, at 11:36 AM, Stevegibson@... wrote:
?I landed myself a hp8991a peak power meter as part of a clearance and wondered what the difference is between this power meter and power meters like the 437b.
Is this device an enhanced version of conventional power meters like the 437b, where it can do the same as those devices plus a bit more, or is it a totally different animal with limited use cases?
|
Re: 8640B Scruffy and does jot tune Frequency
Hi,
Possibly stating the obvious, but do you know that you have to
select the internal counter with the Counter Mode switches (middle,
front)?
to start with, you want:
INT/EXT? - in? (it looks like it may be Out)
All the others out...
and the ext ref toggle switch at the rear top left to INT (down)...
The two knobs have been replaced by non-HP ones...
Regards,
Julian
On 16/01/2022 17:26, James Sawle
(MD0MDI) wrote:
toggle quoted message
Show quoted text
I have just acquired a rather tatty 8640B Sig Gen, but having
never restored one of these before I thought would ask a few
questions to those that know better.
somm.
Certainly not the cleanest, Power on and displays 10MHz but
display does not change when you rotate the Frequency Tune knob,
so I am thinking possibly plastic gearing gone?
 sommsommsomm
Can anyone clarify if these four screws in the top are factory?
kind if looks like a bodge to me and possibly been played with,
but I could be wrong? hopefully someone wiser can let me know?
 somm
Also on the front panel are two knobs that look wrong? are they?
Any guidance with this unit would be very much appreciated?
James
|
Several insurance companies employed by my clients here in the US require periodic inspection of the service entrance panels and other AC circuitry with a FLIR thermal imager to ascertain that there is no potential for overheating and a fire.? The real advantage to this is that it can see trouble spots that may not seem obvious to the casual passerby.
?
As for things running warm to the touch it is best to check outlets and other apparatus to make sure that gradual heating is not causing oxides to form on the contact surfaces thereby increasing resistance which often times will cause the heating to increase exponentially until failure or fire occurs.? A small amount of heating may be normal given the current of a device but it can also cause an increase in problems if it gets out of hand.
?
There are fastener torque requirements for service entrance panel hardware but seem to be applied mostly on an ad-hoc basis.? Although torque requirements have been set forth in both several states as well as in the National Electrical Code I have not come up against any electrical inspectors who have brought the issue up.? This may not be the case for extremely high current service applications.
?
?
?
?
Also keep in mind that the reliability of the connection is only as good as the quality of cleanliness of the connection interface.? Any increase in joint resistance may eventually cause trouble.
?
AN earlier mention was made of aluminum wiring being ¡°¡popular for a few years.¡±? It¡¯s surprising to see that many utility companies still use aluminum drops when connecting between the poles and customer premise weatherheads.? As for internal wiring any you will probably find a preponderance of aluminum used in homes built between 1965 and 1972.? Use of it is still allowed if the proper installation procedures are followed.
?
Personally I live in a 72 year-old home with copper wiring.? The only downside is that the wiring insulation is of the rubber/cloth type but fortunately the installation is not of the knob-and-tube type.? The wiring is of a 2-wire NM type (without ground) and has been going through a gradual update to 3-wires as remodels occur.
Aside from all of this, make sure that the batteries in your smoke detector(s) are in good shape.
?
Greg
|
Re: 8640B Scruffy and does jot tune Frequency
Screws look typical of this case style. Black knobs themselves are replacement perhaps, since they should be a different, light style, but the skirts look factory. I suggest not tinkering with it without a thorough clean up outside and then inside. It¡¯ll go easier that way, and there are bits inside where you won¡¯t want any dirt to go into.
This generator has a cavity oscillator inside and there¡¯s quite a bit of mechanical transmission around that. If something is seized you¡¯ll potentially propagate the damage by turning controls. Once it¡¯s clean and open, you¡¯ll see which controls are just switches or potentiometers, and which ones drive transmissions/mechanical contraptions.
Then you¡¯ll start with the basics: get the service manual and make sure all power supplies are correct and clean. Go from there and ask here :)
Cheers, Kuba
toggle quoted message
Show quoted text
16 jan. 2022 kl. 12:37 em skrev James Sawle (MD0MDI) <james@...>:
?I have just acquired a rather tatty 8640B Sig Gen, but having never restored one of these before I thought would ask a few questions to those that know better. Certainly not the cleanest, Power on and displays 10MHz but display does not change when you rotate the Frequency Tune knob, so I am thinking possibly plastic gearing gone? Can anyone clarify if these four screws in the top are factory? kind if looks like a bodge to me and possibly been played with, but I could be wrong? hopefully someone wiser can let me know? Also on the front panel are two knobs that look wrong? are they? Any guidance with this unit would be very much appreciated? James
Attachments:
|
Re: 8640B Scruffy and does jot tune Frequency
The inability to change frequency via the Frequency Tune knob could be several things.? Until you open it up and take a cursory look around, it's difficult to say.
The four screws should be the undercut, 82-degree, PosiDriv screws.? Not easy to find and many times have been replaced with ordinary flat-head screws which keep the top in place but are not original.
The two knobs appear to be a hybrid of the original flanged part and some other type of knob.
Good luck with it.? The 8640B is a very nice generator.
Thanks,
Barry - N4BUQ
From: "James Sawle (MD0MDI)" <james@...>
To: "HP-Agilent-Keysight-equipment" <[email protected]>
Sent: Sunday, January 16, 2022 11:26:14 AM
Subject: [HP-Agilent-Keysight-equipment] 8640B Scruffy and does jot tune Frequency
I have just acquired a rather tatty 8640B Sig Gen, but having never restored one of these before I thought would ask a few questions to those that know better.
Certainly not the cleanest, Power on and displays 10MHz but display does not change when you rotate the Frequency Tune knob, so I am thinking possibly plastic gearing gone?
Can anyone clarify if these four screws in the top are factory? kind if looks like a bodge to me and possibly been played with, but I could be wrong? hopefully someone wiser can let me know?
Also on the front panel are two knobs that look wrong? are they?
Any guidance with this unit would be very much appreciated?
James
|
8640B Scruffy and does jot tune Frequency
I have just acquired a rather tatty 8640B Sig Gen, but having never restored one of these before I thought would ask a few questions to those that know better.  Certainly not the cleanest, Power on and displays 10MHz but display does not change when you rotate the Frequency Tune knob, so I am thinking possibly plastic gearing gone?  Can anyone clarify if these four screws in the top are factory? kind if looks like a bodge to me and possibly been played with, but I could be wrong? hopefully someone wiser can let me know?  Also on the front panel are two knobs that look wrong? are they? Any guidance with this unit would be very much appreciated? James
|
I landed myself a hp8991a peak power meter as part of a clearance and wondered what the difference is between this power meter and power meters like the 437b.
Is this device an enhanced version of conventional power meters like the 437b, where it can do the same as those devices plus a bit more, or is it a totally different animal with limited use cases?
|
Re: 140 Series mainframes
Hello! I finally dug my way back to where I have some HP 140 series mainframes just sitting.
There is 2 140B, 1-141A, 1-140A, and a 141T. These are looking for new homes either whole or as parts. Their heritage is unknown and its not worth the time for me to check them, I have just too much going on. They are not all beat up and I suspect the usual culprits if they do have problems: LV power supply issues, old caps, etc.
I am open to offers on any or all. I can pull them down for subassemblies, etc, if no one wants them in one piece.
I have found FED-EX "Home" is not too bad for shipping. If you do want something, send your address so I can figure price.?
If its easier, I can put them on eBay.
Thanks for the BW.
Jeff Kruth
?
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Froggie the Gremlin
Jeremy Nichols
James Sawle (MD0MDI)