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Date
GPIB/HPIB cables

 

Hi all,
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If anyone is interested, Sphere Electronics has some gpib cables going cheap.
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Regards,
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Warren
Re: HP 3403C True RMS Voltmeter display fault

 

Polymer capacitors are readily available for voltages of 100 and under although modern low ESR electrolytics make perfectly fine replacements for tantalums and are, of course, available in a wider range of voltages..? As for the radial leaded packages very small diameter PTFE tubing is readily available for only a few dollars - dress the leads with it or just put down the appropriate sized pieces of Kapton tape over any traces that may be a shorting hazard.? It will not as rigid of a attachment as a axial package but unless the item will be in a fairly high vibration environment that doesn't matter - and if so, use a dab of the appropriate adhesive.
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Hal
Re: HP8510C TRL Calibration

 

I note the HP8510C driver, so i should be able to use this to access the 'switch terms. Also i'm interested to see how fast it reads the s-parameters! Thank you for this, N
Re: HP8510C TRL Calibration

 

However, when i run from the PC and file data, the first line in the s2p file is: !HP8510C.07.14: Aug 26 ?1998, so that indicates a different software version. (well the monitor is CRT, so pretty old, so perhaps that's got a different software version, or the number was not update when other software was updated.
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?
Re: HP8510C TRL Calibration

 

I've been looking at scikit-rf to do the TRL calibration and it mentions using the 'switch terms' to improve the calibration. I'm just wondering, how do i read the switch terms from the HP8510C, which appear to be for source port 1: ratio a2/b2 and for source port 2: a1/b1?
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During measurement i can get the s-parameters ok, but it's not clear how you can measured these ratios, or measure a1, b1, a2, b2 seperately and calculate the ratios in the PC. If i can get that right i'll be able to do all calibratoin in the PC, which would be much faster than in the HP8510C.
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Thanks, N
Re: Shipping overseas?

 

Hey,

in the past, I used Stackry and was happy with their service. MyUS was also great when it came to handling and shipping but their small print can inflate your budget. This is 5 yr old info.

Cheers,
Gabor


On Wed, Mar 5, 2025 at 4:36?PM Gary Hitchner via <talgarth=[email protected]> wrote:

HP list,

I have attempted to assist a current HP list member in Germany with boards from a 8660C.

The Post Office is telling me they cannot ship electronics to Germany.? (From the US). ??Parts, vintage, boards, doesn’t matter.

Do I have the customs form filled out wrong?? Anybody have a explanation or know how to get this done?

I did try UPS, they quoted a price which is a significant percentage of my monthly income.

Thanks for any ideas, explanation,

Gary

WA2OMY

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?

?

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Re: HP8510C TRL Calibration

 

Hi Ed, i did manage to get the NI GPIB / USB to laptop interface working. In terms of running the 8510C from the laptop it seems to work quite well but only with uncalibrated data. From the Operation and Programming Manual i tried all fives forms of data transfer: FORM1 to Form5. FORM1 was a little tricky and the manual doesnt really explain for format well. After trial and error all forms were giving the same numerical values, which gave some confidence that i had the programming correct. FORM5 was the fastest, collecting data for a 801 point sweep in about 6 seconds. Slow by today's standards, but not bad for vintage 1991.
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However, when i ask it to do calibrated data, the machine peeps indicating there's an error and still continues to show data transfer increase from 6 seconds to 100 seconds, so clearly that's not much good.
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How do i find which software version i have running. On the display i see the information: HP 8510C Monitor C.02.16 March 9 1991, so is C.02.16 the software version number?
Re: HP PN 04194-81803 What is it?

 

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It is an analog to digital converter from the 4195A.

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From: [email protected] <[email protected]> On Behalf Of Steve - Home via groups.io
Sent: Wednesday, March 5, 2025 9:32 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP PN 04194-81803 What is it?

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Francesco,

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From the Keysight parts finder, the picture shows that part number has several discrete components on a circuit board. Three ICs, and numerous R and C. No commercial equivalent but might be reparable. From the part number it appears to be from a 4194A Impedance Gain-Phase Analyzer.?

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Steve

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?



On Mar 5, 2025, at 8:30?AM, Francesco Ledda via groups.io <k5urg@...> wrote:

?

I am trying to find out if there is an equivalent commercial PN to replace an 04194-81803.

?

Thank you, Francesco Ledda
Shipping overseas?

 

开云体育

HP list,

I have attempted to assist a current HP list member in Germany with boards from a 8660C.

The Post Office is telling me they cannot ship electronics to Germany.? (From the US). ??Parts, vintage, boards, doesn’t matter.

Do I have the customs form filled out wrong?? Anybody have a explanation or know how to get this done?

I did try UPS, they quoted a price which is a significant percentage of my monthly income.

Thanks for any ideas, explanation,

Gary

WA2OMY

?

?

?

?
Re: HP PN 04194-81803 What is it?

 

开云体育

Francesco,

From the Keysight parts finder, the picture shows that part number has several discrete components on a circuit board. Three ICs, and numerous R and C. No commercial equivalent but might be reparable. From the part number it appears to be from a 4194A Impedance Gain-Phase Analyzer.?

Steve



On Mar 5, 2025, at 8:30?AM, Francesco Ledda via groups.io <k5urg@...> wrote:

?

I am trying to find out if there is an equivalent commercial PN to replace an 04194-81803.

?

Thank you, Francesco Ledda
Re: HP 3403C True RMS Voltmeter display fault

 

开云体育

50+ years ago, 400 Hz power supply plugged into 60 Hz source. Runs for a few minutes and then throws its guts all over the bench. Back before the days of power supplies that work from 48 - 440 Hz, 100 - 240 vac. But you only do it once ?

Steve


On Mar 5, 2025, at 9:13?AM, Jim Ford via groups.io <james.ford@...> wrote:

?Yep, I have seen the fireworks in the lab, too. ?Been a while, fortunately. ?More than 25 years ago we had a technician who installed a few tant caps backwards into a VMEbus chassis. ?Blam, molten metal shot across the lab! ?Fortunately nobody was hurt.

Jim Ford?
Laguna Hills, California, USA


On Mar 4, 2025, at 9:30?AM, Dave Daniel via groups.io <kc0wjn@...> wrote:

?
I'll add that since, in general, modern caps are smaller than vintage caps, make sure the the voltage rating of the new cap provides sufficient margin over the voltage rail. For instance, Tektronix often used caps rated for +15v on +12v rails. In all the cases where I have recapped equipment, a modern +25v cap was smaller in physical size than the original +15v caps.

DaveD
KC0WJN


On Tue, Mar 4, 2025 at 12:14 ed breya via <eb=[email protected]> wrote:
Arnaud, you can replace Ta caps with alternatives in most applications, so there's no need to spend too much for an original type. Usually ones that burn out are in supply bypassing spots, which are not critical. The main issue then is space available for new parts, since the common fix is to go with a much larger capacitance (and physical size) aluminum electrolytic type to get ESR comparable to the Ta ones. I'd say put in an Al cap of at least 2-10 times as much C as the original Ta, with enough V rating for the supply voltage. Or, use the biggest C that can physically fit into the space available. You can look at various brands and families of caps to choose the lowest ESR you can find, but they won't be dramatically different.
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Another option is to go with an OSCON organic dielectric type Al cap. These are built for low ESR and can beat Ta in this respect, so fitting is easier. The problem here is that (I think) OSCONs are only available in radial mount style (can with leads out the bottom), so trickier to fit in axial-lead spots. If axials are available, then no problem.
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Remember this all only applies to supply bypassing spots. Sometimes Ta is needed for particularly low DC leakage and better stability like in timing circuits. Ones in these kinds of spots hardly ever fail because they're not stressed. Supply bypassing ones fail a lot, but value stability and leakage hardly matter here, so bigger Al types or OSCONs (which have the worst leakage) work just fine to get decent ESR.
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Ed
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?
Re: HP 3403C True RMS Voltmeter display fault

 

开云体育

Yep, I have seen the fireworks in the lab, too. ?Been a while, fortunately. ?More than 25 years ago we had a technician who installed a few tant caps backwards into a VMEbus chassis. ?Blam, molten metal shot across the lab! ?Fortunately nobody was hurt.

Jim Ford?
Laguna Hills, California, USA


On Mar 4, 2025, at 9:30?AM, Dave Daniel via groups.io <kc0wjn@...> wrote:

?
I'll add that since, in general, modern caps are smaller than vintage caps, make sure the the voltage rating of the new cap provides sufficient margin over the voltage rail. For instance, Tektronix often used caps rated for +15v on +12v rails. In all the cases where I have recapped equipment, a modern +25v cap was smaller in physical size than the original +15v caps.

DaveD
KC0WJN


On Tue, Mar 4, 2025 at 12:14 ed breya via <eb=[email protected]> wrote:
Arnaud, you can replace Ta caps with alternatives in most applications, so there's no need to spend too much for an original type. Usually ones that burn out are in supply bypassing spots, which are not critical. The main issue then is space available for new parts, since the common fix is to go with a much larger capacitance (and physical size) aluminum electrolytic type to get ESR comparable to the Ta ones. I'd say put in an Al cap of at least 2-10 times as much C as the original Ta, with enough V rating for the supply voltage. Or, use the biggest C that can physically fit into the space available. You can look at various brands and families of caps to choose the lowest ESR you can find, but they won't be dramatically different.
?
Another option is to go with an OSCON organic dielectric type Al cap. These are built for low ESR and can beat Ta in this respect, so fitting is easier. The problem here is that (I think) OSCONs are only available in radial mount style (can with leads out the bottom), so trickier to fit in axial-lead spots. If axials are available, then no problem.
?
Remember this all only applies to supply bypassing spots. Sometimes Ta is needed for particularly low DC leakage and better stability like in timing circuits. Ones in these kinds of spots hardly ever fail because they're not stressed. Supply bypassing ones fail a lot, but value stability and leakage hardly matter here, so bigger Al types or OSCONs (which have the worst leakage) work just fine to get decent ESR.
?
Ed
?
?
HP PN 04194-81803 What is it?

 

开云体育

I am trying to find out if there is an equivalent commercial PN to replace an 04194-81803.

?

Thank you, Francesco Ledda
Re: HP3325A Trouble, Calibration FAIL 2 & 3

 

Meanwhile i found a bad (high resistance) hf transistor Q219, located in the amp. It is a MM4018, which is not available. Can I use a 2N5160?
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This is from the specs a similar type: PNP, 40V,hfe 10, ~400Mhz.?
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And I was wondering that the SINE amplitude calibration still passes, I thought it would use the amp and attenuator as well.
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Ralf??
Re: Manual for HP 466A amplifier

 

Thanks to all for the information on the HP-466A!
Hope I can help others from my HP experience ('77-'2001).? ?
Re: HP 478 A? Thermistor mounts

 

I have, as listed in the 1994 Options List, an HP-478A-H63, which is spec'd to operate from 100 KHz to 1 GHz and it really does respond that low and lower. It belonged to HP Division 4 (does anyone know that division?) and was last calibrated in 1981, according to the cal sticker. It works very well and is great for calibrating RF voltmeters that operate in the "less than 1 GHz" range such as my HP-411A RF Millivoltmeter.

Jeremy
N6WFO
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On Tue, Mar 4, 2025 at 3:04?PM Paul Bicknell via <admin=[email protected]> wrote:
Hi David? Thank you found the information so made a new file HP 478A? and put the information in there?
Regards :Paul?
Re: HP 478 A? Thermistor mounts

 

Hi David? Thank you found the information so made a new file HP 478A? and put the information in there?
Regards :Paul?
Re: HP 3403C True RMS Voltmeter display fault

 

Hey again,
Here are the photos. The one with the big blob is the blown one. It does melt with the iron so it's indeed solder. Thanks for the info on possible replacements.
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?
Re: HP 478 A? Thermistor mounts

 

Here are the 478A options listed in the 1994 options list, that is on the web somewhere.
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David
HP 478 A? Thermistor mounts

 

Re HP 478 A? Thermistor mounts? could someone –please direct me to a listing of the different options? for example? ?HP 478 A - H75?

also interested in any one that uses the H75 option

Regards Paul?
561 - 580 of 150752