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Did HP (or Tek, or anyone for that matter) make any oscilloscopes that were
SNIP <

----- Original Message -----
From: "Jeff Machesky" <jeff@... <mailto:jeff%40codebest.com>>
To: <hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>>
Sent: Sunday, December 30, 2012 2:31 PM
Subject: Re: [hp_agilent_equipment] Re: 3457a on the way

Todd, the battery is already on my list of to do items. The security
seal on the meter I've got on the way appears to have not been broken. I
assume this is from the last cal back in 98. The fact that it has a seal
on the case might be a sign that someone had done work internally,
perhaps just the offsets.

I have two options, check the battery and replace as needed when I get
the meter or wait until just before sending it off for cal knowing that
if I loose the cal data it's not the end of the world. I assume Agilent
isn't going to charge more because the cal data was lost? I think either
way I need to know what the voltage is of the battery and what type of
battery it is. Replacement of course would be done with a current
limited power source in place to act as the battery while it's being
changed. A bench supply with the voltage matched should do the trick.
I'm hoping it will already have the 3.4v battery to make my life a bit
easier. Not that I mind replacing a couple resistors.

Thanks,

Jeff

Why not just apply AC power while changing the battery. Just use an
ungrounded soldering iron.

Or is there some other thing I am not thinking about?

Todd, the battery is already on my list of to do items. The security
seal on the meter I've got on the way appears to have not been broken. I
assume this is from the last cal back in 98. The fact that it has a seal
on the case might be a sign that someone had done work internally,
perhaps just the offsets.

I have two options, check the battery and replace as needed when I get
the meter or wait until just before sending it off for cal knowing that
if I loose the cal data it's not the end of the world. I assume Agilent
isn't going to charge more because the cal data was lost? I think either
way I need to know what the voltage is of the battery and what type of
battery it is. Replacement of course would be done with a current
limited power source in place to act as the battery while it's being
changed. A bench supply with the voltage matched should do the trick.
I'm hoping it will already have the 3.4v battery to make my life a bit
easier. Not that I mind replacing a couple resistors.

Thanks,

Jeff

In order to use a HP 8757A SNA as a display, the noise figure meter 8970B

My datecode is only 2725 yelding E36 error. Bad luck!
To display firmware release enter 99.9 SP on the 8970B.
If someone could provide me with related ROM dump, would be great!

Did HP (or Tek, or anyone for that matter) make any oscilloscopes that
were
basically analog scopes, but with the ability to digitize what is seen
on
the display (at some lesser resolution than what you might be able to
see
on the actual display, presumably)? As I understand it - which may
admittedly be incorrect - some of the older spectrum analyzers are sort
of
like this.

So, this hypothetical oscilloscope type would basically have the analog
display "in parallel" with an ADC, such that you could look at the
screen
and see the waveform displayed like an analog scope, or use the ADC to
see
a digital approximation. (Presumably the digital stuff could also be
used
to capture and store one-shot things like a regular digital
oscilloscope.)
This would be opposed to a purely digital oscilloscope where the ADC and
memory is always between the signal and the display.

The reason for doing this, of course, would be that the analog display
would be "higher resolution" than the ability of the ADC, but the
digital
stuff would enable automation and storage ability. This would stop being
important once digital was high-enough resolution to look more or less
indistinguishable to humans.

Did such "hybrid" oscilloscopes ever exist? If so, what are some model
numbers?

Thanks for your time - sorry if that was a bit lengthy.

30/12/2012 23:27


I am lucky enough to have both the Fluke / Philips Combiscope and a
Tek 7854. The Combiscope is, in my humble opinion, greatly under rated.
It's so easy to use, small and relatively light, and my 2 channel
model has been 100% reliable. If it packed up I'd look for another. It
does look very "full" inside, and it does run very warm, as another
poster commented.

The 7854 is huge, heavy, dims the lights on power up, and I only
understand and use a fraction of it's abilities. The manual is vast,
and quite daunting to a casual user. It's saving grace is awesome
support on the Tek scopes' reflectors. If it does pack up there are
those able to help you fix it. I also like the availability of cheap
plug ins. I bought a sad and ratty looking 7B53A dual time base with
delay for next to nowt off the `Bay, and with the help of the forum
had it fixed up and calibrated inside a few hours. Must have been a
fabulous beast in its day, even now USB scope users see it and go off
wanting a "proper" scope unless they have spent a fortune on something
VERY high end.



--
Best Regards,
Chris Wilson.



------------------------------------

Yahoo! Groups Links

If the 'SELF TEST OK' message appears, there is no need to make any
'adjustments'. Just do the 'front panel CAL' if needed.

As I said, I would check it out, assume it is the best instrument in your
collection, send it to Agilent for CAL and see what you get.

I would appreciate knowing what 'REV?' and 'OPT?' says when you get a
chance. 'CALNUM?' would be interesting as well.

In the 3458A, the firmware is in an EPROM (6 EPROM's for the older units)
and can be removed, a socket placed, and easily upgraded by purchasing the
latest pre-programmed EPROM (or EPROM's for the older units) from Agilent.
The only problem is they have a $50 minimum for this $18 part for the

units.

My wife thinks I am going to appear on an episode of 'Hoarders'.

Joe

-----Original Message-----
From: hp_agilent_equipment@...

[mailto:hp_agilent_equipment@...

Sent: Saturday, December 29, 2012 8:01 PM
To: hp_agilent_equipment@...

Subject: Re: [hp_agilent_equipment] 3457a on the way

Wow, lots of replies all of a sudden. I'm already prepping the wife for
the $200 + price tag of calibration. Funny how when I was single I would
have about $800 in cash in my wallet at all times and now I beg for 20
bucks, Hmm. Sad part is I make about 4 times the money. In any event
I've not received to much feedback on the "Self Test OK" message the
seller had posted. Any comments? I'm too much of a skeptic when it comes
to eBay purchases. It's just a convenient place to purchase such goods.
Any feedback would be appreciated as to possible pitfalls regarding this
device. I like to prep for issues rather then build myself up for
failure. What do they say...it's better to be pleasantly surprised then
let down.

Thanks,

Jeff

On 12/29/2012 5:40 PM, J. L. Trantham wrote:

According to the manual, there are only two 'adjustments' that can be

on a 3457A, Input Offset Amplifier adjustment and AC Converter Frequency
Response, both needed only if there is a 'HARDWARE ERR' failure message
after 'TEST' is selected and then only if it is a specific 'AUXERR' or
16 or
256 is seen. Otherwise, all the calibrations are done from the front

with specific inputs from the front panel.

The CALNUM? is incremented by 'several digits' with a 'complete
calibration', one for each calibration point entered, per the manual.
Interestingly, when I sent my two 3458A's to Agilent for calibration,

CALNUM incremented by only 1. However, when I calibrated one of them
before
sending it to Agilent, (since I lost the data in the DALLAS CALRAM
chip that
I was removing) the CALNUM went from 1 to something like 34 or
something. I
don't recall. It seems that if you have the appropriate software to
run the
complete calibration protocol, it only increments by '1' instead of by

the data points entered. Such software exists for the 3457A but I have
never seen it available 'on theBay'. I suspect Agilent would have that
software and equipment to do that calibration and, thus, an Agilent
calibration may only increment the CALNUM? by 1.

When getting an Agilent calibration of the 3458A, you get 'As
Received' and
'As Completed' data. Very helpful to me in that the only two points my
'House CAL' of the one 3458A failed were the two 'midrange' AC Voltage
values. All else 'PASSED'.

I agree with Dave. If it's HP/Agilent, I prefer Agilent to do the CAL.

it's Solartron, I prefer AMETEK (Solartron), etc.

I believe that having some 'basic' professionally calibrated instruments
(DMM's, Noise Sources, Power Sensors, Frequency Standards (unless you
have a
GPSDO, CS Standard, etc.) etc.), that you can then use as 'transfer
standards' to do your own 'in house' calibration of other instruments,

very important if you want to set up a reliable workshop.

Of course, you will also need a 'stable' source of the various signals
that
you will use to be 'measured' by the various 'DUT's', such as

voltage, current, frequency, etc. The 3458A is relatively easy to
calibrate, requiring only 10.000000 VDC, 10000.000 ohms, and some AC
voltage
at various frequencies, IIRC. I have never CAL'd a 3457A but the 3478A
is a
multi-step process.

This whole thing can become very 'addictive'. Be careful.

Joe

-----Original Message-----
From: hp_agilent_equipment@...

<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...

<mailto:hp_agilent_equipment%40yahoogroups.com>] On Behalf Of David

Sent: Saturday, December 29, 2012 5:53 PM
To: hp_agilent_equipment@...

<mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: Re: [hp_agilent_equipment] 3457a on the way

On 29 December 2012 20:01, Jeff Machesky <jeff@...

<mailto:jeff%40codebest.com>
<mailto:jeff%40codebest.com> > wrote:

Thanks Dave, I actually have watched those videos. Bit drawn out like
most of his videos..but still good. Too much detail is not always a

thing.

I thought the bit showing the noise on the DVM was a bit silly when it
was connected to a DC power supply.

As for the 3457A, if it works I plan on getting it calibrated by

within the year. From what I understand it's about a $200 US

The meter was last calibrated in '98, so I'll be curious to see how
accurate it is when I get it.

I think the calibration service you chose might dictate whether you
get data about the condition when sent.

When I send mine in for cal, I'd like to know what was out and by how
much. But I'm not going to pay extra for a calibration service that
provides that. As far as I'm concerned, if Agilent calibrate it, then
it is OK. For me personally, it makes no difference whatsoever if it
has ISO, NIST or whatever calibration. But I'd prefer Agilent to
someone else.

I have calibration certificate here for an Agilent VNA calibration
kit. It was done by a calibration house in the USA. But from what I
can gather from reading the documentation, the equipment to calibrate
them is not available commerically. So it makes me wonder how a lab
can calibrate a cal kit, when the equipment to do it can't be bought.

I suspect there is a fairly cosy realationship between some test
equipment dealers and calibration facilities.

I plan on purchasing some
voltage references from the well known site as a basic test of the
3457A. I may even calibrate it based on those references if it's way

and later getting it NIST traceable calibrated.

I don't know if there are pots in there you can adjust with a trimmer,
or if it is all done electronically. You might find it is impossible
to calibrate yourself.

I never had any reason to look inside mine.

Dave

------------------------------------

Yahoo! Groups Links

It would be interesting to see if a newer rev is out there. My 3457A is s.n. prefix 2703, with rev 6,0 and option 0, CALNUM=34. I wonder if that's a default number for anything less than a full cal at Agilent? The last calibration was at least 6 years ago and performed by what was then Boeing Military Airplane Company's metrology lab. I need to open it up and check the battery condition.

Steve

On Dec 29, 2012, at 8:08 PM, "J. L. Trantham" <jltran@... <mailto:jltran%40att.net>> wrote:

If the 'SELF TEST OK' message appears, there is no need to make any
'adjustments'. Just do the 'front panel CAL' if needed.

As I said, I would check it out, assume it is the best instrument in

your

collection, send it to Agilent for CAL and see what you get.

I would appreciate knowing what 'REV?' and 'OPT?' says when you get a
chance. 'CALNUM?' would be interesting as well.

In the 3458A, the firmware is in an EPROM (6 EPROM's for the older

units)

and can be removed, a socket placed, and easily upgraded by

purchasing the

latest pre-programmed EPROM (or EPROM's for the older units) from

Agilent.

The only problem is they have a $50 minimum for this $18 part for

the later

units.

My wife thinks I am going to appear on an episode of 'Hoarders'.

Joe

-----Original Message-----
From: hp_agilent_equipment@...

<mailto:hp_agilent_equipment%40yahoogroups.com>

[mailto:hp_agilent_equipment@...

<mailto:hp_agilent_equipment%40yahoogroups.com>] On Behalf Of Jeff Machesky

Sent: Saturday, December 29, 2012 8:01 PM
To: hp_agilent_equipment@...

<mailto:hp_agilent_equipment%40yahoogroups.com>

Subject: Re: [hp_agilent_equipment] 3457a on the way

Wow, lots of replies all of a sudden. I'm already prepping the wife for
the $200 + price tag of calibration. Funny how when I was single I

would

have about $800 in cash in my wallet at all times and now I beg for 20
bucks, Hmm. Sad part is I make about 4 times the money. In any event
I've not received to much feedback on the "Self Test OK" message the
seller had posted. Any comments? I'm too much of a skeptic when it

comes

to eBay purchases. It's just a convenient place to purchase such goods.
Any feedback would be appreciated as to possible pitfalls regarding

this

device. I like to prep for issues rather then build myself up for
failure. What do they say...it's better to be pleasantly surprised then
let down.

Thanks,

Jeff

On 12/29/2012 5:40 PM, J. L. Trantham wrote:

According to the manual, there are only two 'adjustments' that can

be made

on a 3457A, Input Offset Amplifier adjustment and AC Converter

Frequency

Response, both needed only if there is a 'HARDWARE ERR' failure

message

after 'TEST' is selected and then only if it is a specific

'AUXERR' or

16 or
256 is seen. Otherwise, all the calibrations are done from the

front panel

with specific inputs from the front panel.

The CALNUM? is incremented by 'several digits' with a 'complete
calibration', one for each calibration point entered, per the manual.
Interestingly, when I sent my two 3458A's to Agilent for

calibration, the

CALNUM incremented by only 1. However, when I calibrated one of them
before
sending it to Agilent, (since I lost the data in the DALLAS CALRAM
chip that
I was removing) the CALNUM went from 1 to something like 34 or
something. I
don't recall. It seems that if you have the appropriate software to
run the
complete calibration protocol, it only increments by '1' instead

of by all

the data points entered. Such software exists for the 3457A but I have
never seen it available 'on theBay'. I suspect Agilent would have that
software and equipment to do that calibration and, thus, an Agilent
calibration may only increment the CALNUM? by 1.

When getting an Agilent calibration of the 3458A, you get 'As
Received' and
'As Completed' data. Very helpful to me in that the only two points my
'House CAL' of the one 3458A failed were the two 'midrange' AC Voltage
values. All else 'PASSED'.

I agree with Dave. If it's HP/Agilent, I prefer Agilent to do the

CAL. If

it's Solartron, I prefer AMETEK (Solartron), etc.

I believe that having some 'basic' professionally calibrated

instruments

(DMM's, Noise Sources, Power Sensors, Frequency Standards (unless you
have a
GPSDO, CS Standard, etc.) etc.), that you can then use as 'transfer
standards' to do your own 'in house' calibration of other

instruments, is

very important if you want to set up a reliable workshop.

Of course, you will also need a 'stable' source of the various

signals

that
you will use to be 'measured' by the various 'DUT's', such as

resistance,

voltage, current, frequency, etc. The 3458A is relatively easy to
calibrate, requiring only 10.000000 VDC, 10000.000 ohms, and some AC
voltage
at various frequencies, IIRC. I have never CAL'd a 3457A but the

3478A

is a
multi-step process.

This whole thing can become very 'addictive'. Be careful.

Joe

-----Original Message-----
From: hp_agilent_equipment@...

<mailto:hp_agilent_equipment%40yahoogroups.com>

<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...

<mailto:hp_agilent_equipment%40yahoogroups.com>

<mailto:hp_agilent_equipment%40yahoogroups.com>] On Behalf Of

David Kirkby

Sent: Saturday, December 29, 2012 5:53 PM
To: hp_agilent_equipment@...

<mailto:hp_agilent_equipment%40yahoogroups.com>

<mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: Re: [hp_agilent_equipment] 3457a on the way

On 29 December 2012 20:01, Jeff Machesky <jeff@...

<mailto:jeff%40codebest.com>

<mailto:jeff%40codebest.com>
<mailto:jeff%40codebest.com> > wrote:

Thanks Dave, I actually have watched those videos. Bit drawn out

like

most of his videos..but still good. Too much detail is not

always a bad

thing.

I thought the bit showing the noise on the DVM was a bit silly when it
was connected to a DC power supply.

As for the 3457A, if it works I plan on getting it calibrated by

Agilent

within the year. From what I understand it's about a $200 US

investment.

The meter was last calibrated in '98, so I'll be curious to see how
accurate it is when I get it.

I think the calibration service you chose might dictate whether you
get data about the condition when sent.

When I send mine in for cal, I'd like to know what was out and by how
much. But I'm not going to pay extra for a calibration service that
provides that. As far as I'm concerned, if Agilent calibrate it, then
it is OK. For me personally, it makes no difference whatsoever if it
has ISO, NIST or whatever calibration. But I'd prefer Agilent to
someone else.

I have calibration certificate here for an Agilent VNA calibration
kit. It was done by a calibration house in the USA. But from what I
can gather from reading the documentation, the equipment to calibrate
them is not available commerically. So it makes me wonder how a lab
can calibrate a cal kit, when the equipment to do it can't be bought.

I suspect there is a fairly cosy realationship between some test
equipment dealers and calibration facilities.

I plan on purchasing some
voltage references from the well known site as a basic test of the
3457A. I may even calibrate it based on those references if it's

way out

and later getting it NIST traceable calibrated.

I don't know if there are pots in there you can adjust with a trimmer,
or if it is all done electronically. You might find it is impossible
to calibrate yourself.

I never had any reason to look inside mine.

Dave

------------------------------------

Yahoo! Groups Links

Did HP (or Tek, or anyone for that matter) make any oscilloscopes that
were
basically analog scopes, but with the ability to digitize what is seen on
the display (at some lesser resolution than what you might be able to see
on the actual display, presumably)? As I understand it - which may
admittedly be incorrect - some of the older spectrum analyzers are sort of
like this.

So, this hypothetical oscilloscope type would basically have the analog
display "in parallel" with an ADC, such that you could look at the screen
and see the waveform displayed like an analog scope, or use the ADC to see
a digital approximation. (Presumably the digital stuff could also be used
to capture and store one-shot things like a regular digital oscilloscope.)
This would be opposed to a purely digital oscilloscope where the ADC and
memory is always between the signal and the display.

The reason for doing this, of course, would be that the analog display
would be "higher resolution" than the ability of the ADC, but the digital
stuff would enable automation and storage ability. This would stop being
important once digital was high-enough resolution to look more or less
indistinguishable to humans.

Did such "hybrid" oscilloscopes ever exist? If so, what are some model
numbers?

Thanks for your time - sorry if that was a bit lengthy.

Did HP (or Tek, or anyone for that matter) make any oscilloscopes that were
basically analog scopes, but with the ability to digitize what is seen on
the display (at some lesser resolution than what you might be able to see
on the actual display, presumably)? As I understand it - which may
admittedly be incorrect - some of the older spectrum analyzers are sort of
like this.

So, this hypothetical oscilloscope type would basically have the analog
display "in parallel" with an ADC, such that you could look at the screen
and see the waveform displayed like an analog scope, or use the ADC to see
a digital approximation. (Presumably the digital stuff could also be used
to capture and store one-shot things like a regular digital oscilloscope.)
This would be opposed to a purely digital oscilloscope where the ADC and
memory is always between the signal and the display.

The reason for doing this, of course, would be that the analog display
would be "higher resolution" than the ability of the ADC, but the digital
stuff would enable automation and storage ability. This would stop being
important once digital was high-enough resolution to look more or less
indistinguishable to humans.

Did such "hybrid" oscilloscopes ever exist? If so, what are some model
numbers?

Thanks for your time - sorry if that was a bit lengthy.


[Non-text portions of this message have been removed]

In order to use a HP 8757A SNA as a display, the noise figure meter 8970B

My datecode is only 2725 yelding E36 error. Bad luck!
To display firmware release enter 99.9 SP on the 8970B.
If someone could provide me with related ROM dump, would be great!

At the risk of shameless self-promotion, I've placed a GPIB-to-USB adapter on the E-place for sale/auction. I hope I've chosen a reasonable price range.

If you want to have a look, it's item 150972490568.

Keep the peace(es).

-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies --
kyrrin (at) bluefeathertech do/t c=o=m
"Quid Malmborg in Plano..."

--------------------------------------------------------------------------------

No virus found in this message.
Checked by AVG - www.avg.com <>
Version: 10.0.1430 / Virus Database: 2637/5497 - Release Date: 12/30/12

Another important consideration will be the onboard battery BT501.

See if you can determine its age.

Also, according to my manual (dated Feb 1988 ed 3) on page 6-26,
along with the list of the many updates applied to new revs,
they list a new battery and new resistors to replace the old one.

The original unit appears to have used a 2.9V model and has been
replaced by a 3.4V battery. If you plan on sending it in for cal,
you would probably want to put in a fresh battery.

You probably don't want to pay Agilent to do it for you and you don't
want to lose the new cal constants a week after calibration.

Hopefully that mod has been done already and all you will have to do
is source the replacement. You will probably need a second battery to
keep the NVRAM powered while you replace the old one.

Todd

--- In hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>, Jeff Machesky <jeff@...> wrote:

Wow, lots of replies all of a sudden. I'm already prepping the wife for
the $200 + price tag of calibration. Funny how when I was single I

would

have about $800 in cash in my wallet at all times and now I beg for 20
bucks, Hmm. Sad part is I make about 4 times the money. In any event
I've not received to much feedback on the "Self Test OK" message the
seller had posted. Any comments? I'm too much of a skeptic when it

comes

to eBay purchases. It's just a convenient place to purchase such goods.
Any feedback would be appreciated as to possible pitfalls regarding

this

device. I like to prep for issues rather then build myself up for
failure. What do they say...it's better to be pleasantly surprised then
let down.

Thanks,

Jeff

On 12/29/2012 5:40 PM, J. L. Trantham wrote:

According to the manual, there are only two 'adjustments' that can

be made

on a 3457A, Input Offset Amplifier adjustment and AC Converter

Frequency

Response, both needed only if there is a 'HARDWARE ERR' failure

message

after 'TEST' is selected and then only if it is a specific

'AUXERR' or

16 or
256 is seen. Otherwise, all the calibrations are done from the

front panel

with specific inputs from the front panel.

The CALNUM? is incremented by 'several digits' with a 'complete
calibration', one for each calibration point entered, per the manual.
Interestingly, when I sent my two 3458A's to Agilent for

calibration, the

CALNUM incremented by only 1. However, when I calibrated one of them
before
sending it to Agilent, (since I lost the data in the DALLAS CALRAM
chip that
I was removing) the CALNUM went from 1 to something like 34 or
something. I
don't recall. It seems that if you have the appropriate software to
run the
complete calibration protocol, it only increments by '1' instead

of by all

the data points entered. Such software exists for the 3457A but I have
never seen it available 'on theBay'. I suspect Agilent would have that
software and equipment to do that calibration and, thus, an Agilent
calibration may only increment the CALNUM? by 1.

When getting an Agilent calibration of the 3458A, you get 'As
Received' and
'As Completed' data. Very helpful to me in that the only two points my
'House CAL' of the one 3458A failed were the two 'midrange' AC Voltage
values. All else 'PASSED'.

I agree with Dave. If it's HP/Agilent, I prefer Agilent to do the

CAL. If

it's Solartron, I prefer AMETEK (Solartron), etc.

I believe that having some 'basic' professionally calibrated

instruments

(DMM's, Noise Sources, Power Sensors, Frequency Standards (unless you
have a
GPSDO, CS Standard, etc.) etc.), that you can then use as 'transfer
standards' to do your own 'in house' calibration of other

instruments, is

very important if you want to set up a reliable workshop.

Of course, you will also need a 'stable' source of the various

signals

that
you will use to be 'measured' by the various 'DUT's', such as

resistance,

voltage, current, frequency, etc. The 3458A is relatively easy to
calibrate, requiring only 10.000000 VDC, 10000.000 ohms, and some AC
voltage
at various frequencies, IIRC. I have never CAL'd a 3457A but the

3478A

is a
multi-step process.

This whole thing can become very 'addictive'. Be careful.

Joe

-----Original Message-----
From: hp_agilent_equipment@...

<mailto:hp_agilent_equipment%40yahoogroups.com>

<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...

<mailto:hp_agilent_equipment%40yahoogroups.com>

<mailto:hp_agilent_equipment%40yahoogroups.com>] On Behalf Of

David Kirkby

Sent: Saturday, December 29, 2012 5:53 PM
To: hp_agilent_equipment@...

<mailto:hp_agilent_equipment%40yahoogroups.com>

<mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: Re: [hp_agilent_equipment] 3457a on the way

On 29 December 2012 20:01, Jeff Machesky <jeff@...
<mailto:jeff%40codebest.com>
<mailto:jeff%40codebest.com> > wrote:

Thanks Dave, I actually have watched those videos. Bit drawn out

like

most of his videos..but still good. Too much detail is not

always a bad

thing.

I thought the bit showing the noise on the DVM was a bit silly when it
was connected to a DC power supply.

As for the 3457A, if it works I plan on getting it calibrated by

Agilent

within the year. From what I understand it's about a $200 US

investment.

The meter was last calibrated in '98, so I'll be curious to see how
accurate it is when I get it.

I think the calibration service you chose might dictate whether you
get data about the condition when sent.

When I send mine in for cal, I'd like to know what was out and by how
much. But I'm not going to pay extra for a calibration service that
provides that. As far as I'm concerned, if Agilent calibrate it, then
it is OK. For me personally, it makes no difference whatsoever if it
has ISO, NIST or whatever calibration. But I'd prefer Agilent to
someone else.

I have calibration certificate here for an Agilent VNA calibration
kit. It was done by a calibration house in the USA. But from what I
can gather from reading the documentation, the equipment to calibrate
them is not available commerically. So it makes me wonder how a lab
can calibrate a cal kit, when the equipment to do it can't be bought.

I suspect there is a fairly cosy realationship between some test
equipment dealers and calibration facilities.

I plan on purchasing some
voltage references from the well known site as a basic test of the
3457A. I may even calibrate it based on those references if it's

way out

and later getting it NIST traceable calibrated.

I don't know if there are pots in there you can adjust with a trimmer,
or if it is all done electronically. You might find it is impossible
to calibrate yourself.

I never had any reason to look inside mine.

Dave

There was one on Ebay. I bought it. It has a shunt impedance of 50 ohms and a series impedance of zero ohms....Looks just like a 11048C to me...I don't understand.

Dan in Chandler, AZ
==================================================

--- In hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>, "martin_u_fischer" <martin.u.fischer@...> wrote:

Hello Steve,

even using resistors of utmost precision you would neither obtain a

600 ohms input resistance (= load resistance for the TG) nor a 50 ohms output resistance (= source resistance for the 50 ohms load).

You may verify this fact by terminating the output into 50 ohms and

measuring the resulting input resistance (which will be 575 ohms). Terminating the input into 600 ohms (= source resistance of the TG) will yield a source resistance of approx. 47.916666 ohms for the load.

Regards
Martin