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  1. HP-Agilent-Keysight-Equipment
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Expanded Topics Messages
Date
Re: Meaning of red sticker on equipment

 

Miscellaneous stickers could mean anything, from a problem, to drawing attention to certain things for the operator, or even that it's been inventoried during asset accounting. I remember many years ago, whenever it was inventory season, accounting would have new recruits do the physical work of finding everything, listing it, and marking it to avoid confusion later. These people were typically totally clueless about what things were, and just needed to find the stuff - we would often find stickers on CRT faces and such afterward.

The black on the connectors is just tarnish on the silver plated parts, and should not affect operation.

Ed
Meaning of red sticker on equipment

 

Hi,

I received a test fixture for a 4145A today (from Ebay, listed used) and
noticed a little red sticker on the unit that wasn't in the
listing. I've attached a picture. What does this mean?

I've seen a red sticker before on a unit I bought broken, so I sort of
assumed this meant the device was non-functional. Is this correct?

The test fixture has a few broken fingers (image also attached). I'm
less worried about this since I have a direct replacement for it, but
still annoyed.

More concerning is that the center conductor for one of the triaxial
connectors looks very blackened (third image, though unfortunately hard
to make out in the image). Is this likely to impair functionality, and
should I be concerned?

Finally, the center conductors for the BNC connectors look sick
(blackened in the same way as one of the triaxials). This should be
easier to replace.

I did not pay a "for parts or not working" price for this and the
pictures made the unit look ok with the description stating "in very
good condition" (in retrospect I should have asked for better images).

Thoughts? I'm well within my 30 day window so I can return it or ask for
a partial refund.

Thanks
Matt

IMG_0940.JPG
IMG_0941.JPG
IMG_0942.JPG
IMG_0944.JPG

Re: hp 35670A option 1D2 swept sine

 

¿ªÔÆÌåÓý

Thanks,

Yes I have slowly come to the realisation that all this is stored in U27 on A7. This is I believe a 24Co1 EEPROM.

Thanks for the help.

?

Mark

?

From: [email protected] <[email protected]> On Behalf Of nj902 via groups.io
Sent: Friday, 11 June 2021 3:08 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] hp 35670A option 1D2 swept sine

?

The swept sine is very nice to have.? I paid them $1500 for the option upgrade.

As with the 35665A, when you ordered an option upgrade, they sent you a disk with the code to enable it on your serial number.

The analyzer's serial number and firmware options are stored in EEPROM (U27)

If you can find a suitable 'donor' image, you can replace or reprogram your EEPROM to add all the options.

Re: Need info on TO-3 transistor insulator

 

Thanks Walter,

I did run across that same document, which briefly compares hard anodized with some others, but without specific part numbers. I was hoping to find actual specs for these parts, but it looks like info is indeed sparse. Your mentioning it made me look at the app note again, and more closely. By putting the "datasheet" and the app note info together, I think it will be close enough. The app note describes the hard anodized as 20 mils thick, and so does the datasheet, so that was probably the standard thickness for those things.

According to the app note charts on pages 5 and 6, the hard anodized is superior (but not by all that much) to mica, and quite a bit better than sil-pads of various types, in the TO-3 "greased" configuration. Only BeO and bare (non-insulated) are significantly better. I'll go with about 0.3 deg C/W nominal, for estimating.

I'll need to dissipate about 220 W worst case among three transistors. This is for my inductor test (in conjunction with the HP4276A) fixture project. I was originally going to use some modern big (TO-264 I think) MOSFETs that I have on hand, that are DC-SOA rated, but the shunt drain capacitance is huge, especially running with such low overhead - not good for this sort of thing. I found I have a bunch of nice old-school 2N6283 Darlingtons (TO-3), and decided to go with bipolar. The C-E operating limits and such puts it on par with the MOSFETs overhead-wise, but with about ten times less - and more predictable - capacitance. This is the nonlinear Miller C that I'll be trying to compensate for with some trick circuitry. There's also quite a lot of fixed C due to the insulators. I was quite surprised at how much it can be - I never considered or measured it until this application came up. With mica, I found about 200-300 pF from the TO-3 case to heatsink. Interestingly, the hard anodized landed in the same range.

I'm not too worried about the breakdown voltage - the maximum excursion of the collectors is limited to the -12 V supply, and possibly up to +40 V clamping level for any inductive kickback. Even if an insulator should fail, the collectors are the output of the current source, and would just short to earth ground. If the current setting is in the high (0-20 A) range, the fault tripper will kick it out of the range, to a safe level, to avoid melting any power cords or cables.

The thermal resistance is mostly important for quietness, actually. I have a nice big flow-through setup worked out, and would like to set the fan to a low, constant speed. It's capable of a helluva lot of cooling if I wear earmuffs. The better the transistors connect with the heatsink, the slower I can run it.? I can make it shift up if necessary, but more complicated.

Ed
Re: Off topic - IRF attenuators

 

¿ªÔÆÌåÓý

Thanks guys.

?

Kind regards

?

Colin

?

From: [email protected] <[email protected]> On Behalf Of george edmonds via groups.io
Sent: Thursday, June 10, 2021 7:48 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Off topic - IRF attenuators

?

For Marconi?

/g/Marconi-Test-Instruments

For IFR

/g/IFR-Monitors

George G6HIG

Re: Off topic - IRF attenuators

 

For Marconi?

/g/Marconi-Test-Instruments

For IFR

/g/IFR-Monitors

George G6HIG
Re: Off topic - IRF attenuators

 

¿ªÔÆÌåÓý

Its originally an Marconi signal generator--please go to the marconi group and you will be helped.

Hardy

?

Fra: [email protected] [mailto:[email protected]] P? vegne af Roy Thistle
Sendt: 10. juni 2021 20:09
Til: [email protected]
Emne: Re: [HP-Agilent-Keysight-equipment] Off topic - IRF attenuators

?

On Thu, Jun 10, 2021 at 06:59 AM, Colin Smithers wrote:

where I should ask

It a sig gen... but the cats on
/g/IFR-Monitors
... they might have some know too.


Virusfri.

Re: Off topic - IRF attenuators

 

On Thu, Jun 10, 2021 at 06:59 AM, Colin Smithers wrote:
where I should ask
It a sig gen... but the cats on
/g/IFR-Monitors
... they might have some know too.
Re: Hp8558b spectral analyzer (2/2)

Bob Stewart
 

You might check the diodes in the first mixer.? Don't disturb the trimmer screws.

Bob


On Thursday, June 10, 2021, 11:03:46 AM CDT, Gerard <kabupos@...> wrote:


hello,

News from the internal attenuator of this 8558B HP
As this is a mechanical attenuator (Action of a rotary button only), I did this little test.
Disconnect in and out attenuator.?it is autonomous now
Sending a sinusoidal signal 10 MHZ with a generator via a resistor of 50 ohm
Oscilloscope measurement input and output.

As I turn the button, the signal drops out (constant input).
The method is not very academic and I am not amused to convert to DB.?I am allergic to all measures in DB (LOL)

I think it works, because it¡¯s a constant decay, even if you only see a few millivolts 3 notches before the end of the rotation. (For only 0.3v input)
I did not want to force too much the signal to the enter?
I think it¡¯s not burned, so I¡¯m gonna look at something else

cdt

Re: Need info on TO-3 transistor insulator

walter shawlee
 

The only info with real specs I found on this topic is an old Motorola/ON App note, AN-1040D, it does discuss these anodized transistor insulators towards the end of the article. you can find it from ON semi here:

https://www.onsemi.com/pub/Collateral/AN1040-D.PDF

I would not be so keen to use these older anodized insulators in actual life, I see zero advantage compared to more
modern techniques, and I doubt the voltage breakdown is as good as even poor film, pads or mica.
all the best,
walter? (walter2 -at- sphere.bc.ca
sphere research corp.
Re: Capturing screenshots on 8934C

w9dkc
 

I have the correct cable. I used it about 8 years ago. It worked. I'm starting to think there may be an issue with the 8924
More FETs and Picoampere diodes added to the stuff page

walter shawlee
 

I just posted a nice assortment of FETs, including duals, Tek and HP parts, and J-series JFETs to the stuff page. I also added the amazing JPAD picoampere leakage diodes from Siliconix, which are ideal for input protection. Some amazing discrete parts are all here in one place:
?
https://www.sphere.bc.ca/test/stuffday.html#fets
?
I will try and add more Tek/HP items up this weekend, they are just sitting here, it's just hard to get all the photo prep, clean up and testing done in a timely manner.
?
All the best,
walter (walter2 -at- sphere.bc.ca)
sphere research corp.
https://www.sphere.bc.ca/test/stuffday.html
Re: hp 35670A option 1D2 swept sine

 

The swept sine is very nice to have.? I paid them $1500 for the option upgrade.

As with the 35665A, when you ordered an option upgrade, they sent you a disk with the code to enable it on your serial number.

The analyzer's serial number and firmware options are stored in EEPROM (U27)

If you can find a suitable 'donor' image, you can replace or reprogram your EEPROM to add all the options.
Re: Hp8558b spectral analyzer (2/2)

 

"I am allergic to all measures in DB"

Maybe this will help:
Re: HP 3457A mains voltage setting

 

¿ªÔÆÌåÓý

On 2021-06-10, at 13:52, cheater cheater <cheater00social@...> wrote:

Thanks everyone. The cap seems to have some sort of positioning arrow
that indicates either 120 or 240 mains AC. But I guess that doesn't
matter.

I understand why you might be misreading that. ?
See Figure 1; as you can see I¡¯m in 230-V-land.
The grey thing is a fuse holder (Figure 2).
You want to put in an 80 mA timed (tr?ge) fuse, ¡°80 mAT¡±.
Note that this is a 3AG [0] US automotive form factor (6.3x31.8 mm), which is harder to get outside NA than the ubiquitous 5x20 mm glass fuses.

Oh, and if the backplane looks like I¡¯ve been at it with a pair of end-cutters, that is because that is indeed what I did to get out the Schaffner line filter *before* it exploded.

PUBLIC SERVICE ANNOUNCEMENT:
You really **never** want to apply line voltage (and certainly not 230 V) to a HP 3457A that has been in storage for a while [1]. ?
Get a replacement [2] for the line filter and get familiar with end-cutters, hacksaws, drills, whatever you like to remove the rivets that hold in the original line filter bomb.

Gr¨¹?e, Carsten (I think I have 5 HP 3457A meters, and a lot of end-cutters)


[0]:
[1]:
[2]:?
Of course, you can decide you are angry at Schaffer¡¯s mistake 35 years ago and buy from a different source.
Re: Late model 5340A manual

 

That's always the first place that I look... The latest he has is for 1532A.

Hal
Re: Hp8558b spectral analyzer (2/2)

 

hello,

News from the internal attenuator of this 8558B HP
As this is a mechanical attenuator (Action of a rotary button only), I did this little test.
Disconnect in and out attenuator.?it is autonomous now
Sending a sinusoidal signal 10 MHZ with a generator via a resistor of 50 ohm
Oscilloscope measurement input and output.

As I turn the button, the signal drops out (constant input).
The method is not very academic and I am not amused to convert to DB.?I am allergic to all measures in DB (LOL)

I think it works, because it¡¯s a constant decay, even if you only see a few millivolts 3 notches before the end of the rotation. (For only 0.3v input)
I did not want to force too much the signal to the enter?
I think it¡¯s not burned, so I¡¯m gonna look at something else

cdt
Service manuals needed

 

Greetings to all,

I am still seeking any service information and? service manuals? for

HP 3805 Distance Meter
HP 3810 Total Station

These are land surveying instruments and I am really impressed by their construction.??
I have the operation manuals.

I have many vintage items of HP equipment and really enjoy using them.

73 Gordon WA4FJC
gpbatey compuserve com
IFR 1500 High Loop alignment

 

I have a IFR that had some PS issues due to a cap shot in the?
output amp, all that is cured.
This unit was pretty well behaved right up to 530 MHz send and receive,?
crisp CRT, keyboard works, right on the money level and freq wise, sensitivity, measurements etc
after 530 MHz would appear to be out of lock.

Tried to align high loop but do not have the TF 30 mentioned in the service manual,?
tried to wing it, now lots of? spurs.
Any suggestions on a TF 30 work around, or I would pay someone to do this alignment
as I am short on time,
Regards,

Mike
402 510 2040 for you old school guys
Re: Off topic - IRF attenuators

 

¿ªÔÆÌåÓý

Hi

Try Marconi group!

Regards

Hardy

?

Fra: [email protected] [mailto:[email protected]] P? vegne af Colin Smithers
Sendt: 10. juni 2021 15:59
Til: [email protected]
Emne: [HP-Agilent-Keysight-equipment] Off topic - IRF attenuators

?

Apologies ¨C but secretly I reckon someone here will know the answer to this, or at least where I should ask.

?

I have just acquired an IRF2025 with an attenuator that is dodgy down at -60Bm and below. I read that dodgy attenuators are not uncommon in this series.

?

What is the not uncommon fix, does anyone know please?

?

Thanks

?

Colin Smithers


Virusfri.

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