Modern digital oscilloscopes question

[John Larkin]

On Wed, 14 Dec 2011 08:41:32 -0800, Fred Abse
<excretatauris@invalid.invalid> wrote:

On Mon, 12 Dec 2011 14:41:29 -0800, John Larkin wrote:

I'd never go back to an analog scope or a VTVM.

I know it isn't tubes, but whaddabout your 610C?

It does have a needle, so I have to think a little. There's a main
range switch and the "x" multiplier above it. Blast from the past.

ftp://jjlarkin.lmi.net/Keithley_1gig.JPG

But it measures 1e-14 amps, so I put up with it.

John

 

[Phil Hobbs]

On 12/14/2011 7:31 PM, John Larkin wrote:

On Wed, 14 Dec 2011 08:41:32 -0800, Fred Abse
excretatauris@invalid.invalid> wrote:

On Mon, 12 Dec 2011 14:41:29 -0800, John Larkin wrote:

I'd never go back to an analog scope or a VTVM.

I know it isn't tubes, but whaddabout your 610C?

It does have a needle, so I have to think a little. There's a main
range switch and the "x" multiplier above it. Blast from the past.

ftp://jjlarkin.lmi.net/Keithley_1gig.JPG

But it measures 1e-14 amps, so I put up with it.

John

My Model 410 micro-microammeter uses an electrometer tube. It's fun to
use, but you have to wait for an hour for it to warm up. (It was $6
plus $25 shipping, and it works perfectly, if your idea of perfect
coincides with the peculiarities of a 1965 electrometer.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

 

[Jamie]

Phil Hobbs wrote:

On 12/14/2011 7:31 PM, John Larkin wrote:

On Wed, 14 Dec 2011 08:41:32 -0800, Fred Abse
excretatauris@invalid.invalid> wrote:

On Mon, 12 Dec 2011 14:41:29 -0800, John Larkin wrote:

I'd never go back to an analog scope or a VTVM.


I know it isn't tubes, but whaddabout your 610C?


It does have a needle, so I have to think a little. There's a main
range switch and the "x" multiplier above it. Blast from the past.

ftp://jjlarkin.lmi.net/Keithley_1gig.JPG

But it measures 1e-14 amps, so I put up with it.

John


My Model 410 micro-microammeter uses an electrometer tube. It's fun to
use, but you have to wait for an hour for it to warm up. (It was $6
plus $25 shipping, and it works perfectly, if your idea of perfect
coincides with the peculiarities of a 1965 electrometer.)

Cheers

Phil Hobbs

I still have 2 HP RF volt meters I use, good for 1 ghz that are tubes

and has a chopper motor in the back

Jamie

 

[John Larkin]

On Wed, 14 Dec 2011 20:17:20 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 12/14/2011 7:31 PM, John Larkin wrote:
On Wed, 14 Dec 2011 08:41:32 -0800, Fred Abse
excretatauris@invalid.invalid> wrote:

On Mon, 12 Dec 2011 14:41:29 -0800, John Larkin wrote:

I'd never go back to an analog scope or a VTVM.

I know it isn't tubes, but whaddabout your 610C?

It does have a needle, so I have to think a little. There's a main
range switch and the "x" multiplier above it. Blast from the past.

ftp://jjlarkin.lmi.net/Keithley_1gig.JPG

But it measures 1e-14 amps, so I put up with it.

John


My Model 410 micro-microammeter uses an electrometer tube. It's fun to
use, but you have to wait for an hour for it to warm up. (It was $6
plus $25 shipping, and it works perfectly, if your idea of perfect
coincides with the peculiarities of a 1965 electrometer.)

Cheers

Phil Hobbs

The 610 uses a classic RCA small-signal mosfet in the front end. I got
it on ebay for about $150. The manual says to replace the high-ohm
resistors every *six months*. I checked it against various high-val
resistors and it seems within 10% or so on the high ranges, pretty
good considering how many 6-months have probably gone by so far.

John

 

[George Herold]

On Dec 14, 7:25 pm, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 14 Dec 2011 10:11:34 -0800 (PST), George Herold





gher...@teachspin.com> wrote:
On Dec 13, 8:54 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Mon, 12 Dec 2011 19:27:22 -0800 (PST), George Herold

gher...@teachspin.com> wrote:
On Dec 12, 5:41 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Mon, 12 Dec 2011 18:32:21 -0000, "eatmorepies"

jckip...@lineone.net> wrote:
Hello

I worked in a place that gave me access to budget, non memory 20MHz CRT
scopes - I no longer work there. They were perfect for my needs.

Six years on and I find I need an oscilloscope, the market seems to have
changed. Are those cheap digital models any good?

I need reasonable Y sensitivity (5mV/div), up to 5MHz, storage would be
nice, it's not for radio work.

I found things like this...

http://www.rapidonline.com/Tools-Equipment/Uni-T-UTD2000-series-2-Cha...

Decent for the money? Or to be avoided?

John

My regular scope is a Rigol DS1052E. It's great. The going price is
around $340.

I'd never go back to an analog scope or a VTVM.

John- Hide quoted text -

- Show quoted text -

I like my Rigol, but to be honest I use the cheap TEK (1001B?) more
often.

I've got an old analog TEK that I'd like to bring back to life!
Not great speed, but it's got a 1mV/div input range that I used.

DSO's mostly suck at low sensitivity.... JL build's his own input
stages, I assume.

George H.

I have an old Tek AM502 diffamp I use to front-end a digital scope. It
has switchable hi/lo cutoff frequency, lots of offset range, and tons
of CMRR. Gain goes up to 100K.

http://www.bellnw.com/products/5292/index.htm

I think there are some smaller boxes like this around. Somebody
(here?) should make an affordable one; it wouldn't be hard, and the
Tek specs could be improved with modern parts.

John- Hide quoted text -

- Show quoted text -

That's nice, it'd be hard to beat the $500 price. (At least for me.)
100K gain in one box is not a small trick.
I made a DC to 2MHz amp out of opamps, but gain only to 10k.
At 100k gain, I had an oscillator.

George H.

This has gain of 100, 1 GHz bandwidth.

http://www.highlandtechnology.com/DSS/J750DS.shtml

I scribbled it out as a PCB layout training exercize, but it worked,
so we called it a product. We've sold a few.

We make another box that has one input and two outputs, one 10x gain
and one 1000x gain, 100 MHz BW, very clean clipping recovery. It's
used for looking at low-level junk on a laser pulse, stuff just before
and after the main flash.

On a multilayer board, in a box, this stuff usually works. The hard
part on the x1000 zoom amp was testing it. Ground loops and RF pickup
drove us whacko. We wound up using a battery-powered
optical-electrical converter connected right to the input and sending
the test signals optically.

John- Hide quoted text -

- Show quoted text -

Hmm, All the same gain X BW product. I can only do 10**10 an order of
magnitude behind what TEK did ,(about?) 40 years ago?
Does anyone do better than 10**11? (all in one small box.)
Is there some fundamental 'thing' that sets a limit? (RC?)

George H.

 

[George Herold]

On Dec 14, 7:31 pm, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 14 Dec 2011 08:41:32 -0800, Fred Abse

excretatau...@invalid.invalid> wrote:
On Mon, 12 Dec 2011 14:41:29 -0800, John Larkin wrote:

I'd never go back to an analog scope or a VTVM.

I know it isn't tubes, but whaddabout your 610C?

It does have a needle, so I have to think a little. There's a main
range switch and the "x" multiplier above it. Blast from the past.

ftp://jjlarkin.lmi.net/Keithley_1gig.JPG

But it measures 1e-14 amps, so I put up with it.

John

I really like meters with needles. They have the perfect 'human
response time' for tweaking things. And it's a direct connection from
eye to hand, you don't have to process some number. We still buy
them from Hoyt.

George H.

 

[George Herold]

On Dec 14, 8:23 pm, Jamie
<jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:

Phil Hobbs wrote:
On 12/14/2011 7:31 PM, John Larkin wrote:

On Wed, 14 Dec 2011 08:41:32 -0800, Fred Abse
excretatau...@invalid.invalid>  wrote:

On Mon, 12 Dec 2011 14:41:29 -0800, John Larkin wrote:

I'd never go back to an analog scope or a VTVM.

I know it isn't tubes, but whaddabout your 610C?

It does have a needle, so I have to think a little. There's a main
range switch and the "x" multiplier above it. Blast from the past.

ftp://jjlarkin.lmi.net/Keithley_1gig.JPG

But it measures 1e-14 amps, so I put up with it.

John

My Model 410 micro-microammeter uses an electrometer tube.  It's fun to
use, but you have to wait for an hour for it to warm up.  (It was $6
plus $25 shipping, and it works perfectly, if your idea of perfect
coincides with the peculiarities of a 1965 electrometer.)

Cheers

Phil Hobbs

I still have 2 HP RF volt meters I use, good for 1 ghz that are tubes
and has a chopper motor in the back

  Jamie- Hide quoted text -

- Show quoted text -

I used an old HP RF voltmeter in gradual school. The thing spat out
1/2 the line voltage onto the ground line. We had it floating and if
I forgot to turn it off before changing the micorwave plumbing it
would 'nibble' on my fingers to remind me.
Really nice needle though!

George H.

 

[Fred Bartoli]

George Herold a écrit :

On Dec 14, 7:25 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Wed, 14 Dec 2011 10:11:34 -0800 (PST), George Herold





gher...@teachspin.com> wrote:
On Dec 13, 8:54 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Mon, 12 Dec 2011 19:27:22 -0800 (PST), George Herold
gher...@teachspin.com> wrote:
On Dec 12, 5:41 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Mon, 12 Dec 2011 18:32:21 -0000, "eatmorepies"
jckip...@lineone.net> wrote:
Hello
I worked in a place that gave me access to budget, non memory 20MHz CRT
scopes - I no longer work there. They were perfect for my needs.
Six years on and I find I need an oscilloscope, the market seems to have
changed. Are those cheap digital models any good?
I need reasonable Y sensitivity (5mV/div), up to 5MHz, storage would be
nice, it's not for radio work.
I found things like this...
http://www.rapidonline.com/Tools-Equipment/Uni-T-UTD2000-series-2-Cha...
Decent for the money? Or to be avoided?
John
My regular scope is a Rigol DS1052E. It's great. The going price is
around $340.
I'd never go back to an analog scope or a VTVM.
John- Hide quoted text -
- Show quoted text -
I like my Rigol, but to be honest I use the cheap TEK (1001B?) more
often.
I've got an old analog TEK that I'd like to bring back to life!
Not great speed, but it's got a 1mV/div input range that I used.
DSO's mostly suck at low sensitivity.... JL build's his own input
stages, I assume.
George H.
I have an old Tek AM502 diffamp I use to front-end a digital scope. It
has switchable hi/lo cutoff frequency, lots of offset range, and tons
of CMRR. Gain goes up to 100K.
http://www.bellnw.com/products/5292/index.htm
I think there are some smaller boxes like this around. Somebody
(here?) should make an affordable one; it wouldn't be hard, and the
Tek specs could be improved with modern parts.
John- Hide quoted text -
- Show quoted text -
That's nice, it'd be hard to beat the $500 price. (At least for me.)
100K gain in one box is not a small trick.
I made a DC to 2MHz amp out of opamps, but gain only to 10k.
At 100k gain, I had an oscillator.
George H.
This has gain of 100, 1 GHz bandwidth.

http://www.highlandtechnology.com/DSS/J750DS.shtml

I scribbled it out as a PCB layout training exercize, but it worked,
so we called it a product. We've sold a few.

We make another box that has one input and two outputs, one 10x gain
and one 1000x gain, 100 MHz BW, very clean clipping recovery. It's
used for looking at low-level junk on a laser pulse, stuff just before
and after the main flash.

On a multilayer board, in a box, this stuff usually works. The hard
part on the x1000 zoom amp was testing it. Ground loops and RF pickup
drove us whacko. We wound up using a battery-powered
optical-electrical converter connected right to the input and sending
the test signals optically.

John- Hide quoted text -

- Show quoted text -

Hmm, All the same gain X BW product. I can only do 10**10 an order of
magnitude behind what TEK did ,(about?) 40 years ago?
Does anyone do better than 10**11? (all in one small box.)
Is there some fundamental 'thing' that sets a limit? (RC?)

George H.

Did once a 10^11 GBW preamp (100K-1MHz) with a 200pV/rtHz input noise
down to 1.5nV/rtHz at 0.1Hz, has 140dB CMRR and still quite a lot (don't
remember the figures) at 1MHz, a few years ago.
It also show no thermal tail so that you can look at the nV level errors
right after a 10V blast.

Maybe I should sell it too?
Wonder what the market for this could be...



--
Thanks,
Fred.

 

[George Herold]

On Dec 15, 11:08 am, Fred Bartoli <" "> wrote:

George Herold a écrit :





On Dec 14, 7:25 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Wed, 14 Dec 2011 10:11:34 -0800 (PST), George Herold

gher...@teachspin.com> wrote:
On Dec 13, 8:54 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Mon, 12 Dec 2011 19:27:22 -0800 (PST), George Herold
gher...@teachspin.com> wrote:
On Dec 12, 5:41 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Mon, 12 Dec 2011 18:32:21 -0000, "eatmorepies"
jckip...@lineone.net> wrote:
Hello
I worked in a place that gave me access to budget, non memory 20MHz CRT
scopes - I no longer work there. They were perfect for my needs.
Six years on and I find I need an oscilloscope, the market seems to have
changed. Are those cheap digital models any good?
I need reasonable Y sensitivity (5mV/div), up to 5MHz, storage would be
nice, it's not for radio work.
I found things like this...
http://www.rapidonline.com/Tools-Equipment/Uni-T-UTD2000-series-2-Cha...
Decent for the money? Or to be avoided?
John
My regular scope is a Rigol DS1052E. It's great. The going price is
around $340.
I'd never go back to an analog scope or a VTVM.
John- Hide quoted text -
- Show quoted text -
I like my Rigol, but to be honest I use the cheap TEK (1001B?) more
often.
I've got an old analog TEK that I'd like to bring back to life!
Not great speed, but it's got a 1mV/div input range that I used.
DSO's mostly suck at low sensitivity.... JL build's his own input
stages, I assume.
George H.
I have an old Tek AM502 diffamp I use to front-end a digital scope. It
has switchable hi/lo cutoff frequency, lots of offset range, and tons
of CMRR. Gain goes up to 100K.
http://www.bellnw.com/products/5292/index.htm
I think there are some smaller boxes like this around. Somebody
(here?) should make an affordable one; it wouldn't be hard, and the
Tek specs could be improved with modern parts.
John- Hide quoted text -
- Show quoted text -
That's nice, it'd be hard to beat the $500 price. (At least for me.)
100K gain in one box is not a small trick.
I made a DC to 2MHz amp out of opamps, but gain only to 10k.
At 100k gain, I had an oscillator.
George H.
This has gain of 100, 1 GHz bandwidth.

http://www.highlandtechnology.com/DSS/J750DS.shtml

I scribbled it out as a PCB layout training exercize, but it worked,
so we called it a product. We've sold a few.

We make another box that has one input and two outputs, one 10x gain
and one 1000x gain, 100 MHz BW, very clean clipping recovery. It's
used for looking at low-level junk on a laser pulse, stuff just before
and after the main flash.

On a multilayer board, in a box, this stuff usually works. The hard
part on the x1000 zoom amp was testing it. Ground loops and RF pickup
drove us whacko. We wound up using a battery-powered
optical-electrical converter connected right to the input and sending
the test signals optically.

John- Hide quoted text -

- Show quoted text -

Hmm, All the same gain X BW product.  I can only do 10**10 an order of
magnitude behind what TEK did ,(about?) 40 years ago?
Does anyone do better than 10**11? (all in one small box.)
Is there some fundamental 'thing' that sets a limit? (RC?)

George H.

Did once a 10^11 GBW preamp (100K-1MHz) with a 200pV/rtHz input noise
down to 1.5nV/rtHz at 0.1Hz, has 140dB CMRR and still quite a lot (don't
remember the figures) at 1MHz, a few years ago.
It also show no thermal tail so that you can look at the nV level errors
right after a 10V blast.

Maybe I should sell it too?
Wonder what the market for this could be...

--
Thanks,
Fred.- Hide quoted text -

- Show quoted text -

Nice! Paralleled BJT's on the input I assume. What was the current
noise?
Does it go below 100kHz?

I 'cheated' and used opamps. OPA288's at a gain of 10 they have a
wiggle a bit beyond 2MHz, so I that's where I rolled 'em off.
But very nice otherwise.
Well 3nV of voltage noise, so not even close to 0.2nV

George H.

 

[Fred Abse]

On Wed, 14 Dec 2011 19:24:55 -0800, George Herold wrote:

I used an old HP RF voltmeter in gradual school.

Schooling should be a gradual process ;-)

I still use an HP vector voltmeter.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[Fred Abse]

On Wed, 14 Dec 2011 16:31:38 -0800, John Larkin wrote:

On Wed, 14 Dec 2011 08:41:32 -0800, Fred Abse
excretatauris@invalid.invalid> wrote:

On Mon, 12 Dec 2011 14:41:29 -0800, John Larkin wrote:

I'd never go back to an analog scope or a VTVM.

I know it isn't tubes, but whaddabout your 610C?

It does have a needle, so I have to think a little.

A rare ability in this age of "lead people by the hand".

There's a main
range switch and the "x" multiplier above it. Blast from the past.

Give me knobs and switches over menu-driven crap every time ;-)

ftp://jjlarkin.lmi.net/Keithley_1gig.JPG

But it measures 1e-14 amps, so I put up with it.

I intend to keep putting up with mine.


--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[Fred Abse]

On Wed, 14 Dec 2011 19:10:39 -0800, George Herold wrote:

I really like meters with needles.

You, me, both.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[Les Cargill]

Fred Abse wrote:

On Wed, 14 Dec 2011 19:24:55 -0800, George Herold wrote:

I used an old HP RF voltmeter in gradual school.

Schooling should be a gradual process ;-)

http://www.imdb.com/title/tt0084917/quotes

Walt: Daddy what's gradual school?
T. S. Garp: What?
Walt: Gradual school. Mommy say's she teaches at gradual school.
T. S. Garp: Oh Gradual school is where you go to school and you
gradually find out you don't want to go to school anymore.

I still use an HP vector voltmeter.

--
Les Cargill

 

[John Larkin]

On Fri, 16 Dec 2011 12:56:14 -0800, Fred Abse
<excretatauris@invalid.invalid> wrote:

On Wed, 14 Dec 2011 16:31:38 -0800, John Larkin wrote:

On Wed, 14 Dec 2011 08:41:32 -0800, Fred Abse
excretatauris@invalid.invalid> wrote:

On Mon, 12 Dec 2011 14:41:29 -0800, John Larkin wrote:

I'd never go back to an analog scope or a VTVM.

I know it isn't tubes, but whaddabout your 610C?

It does have a needle, so I have to think a little.

A rare ability in this age of "lead people by the hand".

Well, it is hard to read a needle to 5 or 6 decimal places.

John

 

[Les Cargill]

George Herold wrote:

On Dec 16, 10:35 pm, Les Cargill<lcargil...@comcast.com> wrote:
Fred Abse wrote:
On Wed, 14 Dec 2011 19:24:55 -0800, George Herold wrote:

I used an old HP RF voltmeter in gradual school.

Schooling should be a gradual process ;-)

http://www.imdb.com/title/tt0084917/quotes

Walt: Daddy what's gradual school?
T. S. Garp: What?
Walt: Gradual school. Mommy say's she teaches at gradual school.
T. S. Garp: Oh Gradual school is where you go to school and you
gradually find out you don't want to go to school anymore.

I still use an HP vector voltmeter.

--
Les Cargill

Ah thanks, Now I know where I got it from.

It must of 'rang true' when I read it.

George H.

The original novel was from John Irving, who most seem to
have forgot, and is always striking to read. Throw the
original "Forrest Gump" on there, too.

--
Les Cargill

 

[George Herold]

On Dec 16, 3:56 pm, Fred Abse <excretatau...@invalid.invalid> wrote:

On Wed, 14 Dec 2011 19:24:55 -0800, George Herold wrote:
I used an old HP RF voltmeter in gradual school.

Schooling should be a gradual process ;-)

I still use an HP vector voltmeter.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)

Well for me, "It's called gradual school,
becasue you gradually decide you don't want to be in school anymore."

George H.

 

[George Herold]

On Dec 16, 10:35 pm, Les Cargill <lcargil...@comcast.com> wrote:

Fred Abse wrote:
On Wed, 14 Dec 2011 19:24:55 -0800, George Herold wrote:

I used an old HP RF voltmeter in gradual school.

Schooling should be a gradual process ;-)

http://www.imdb.com/title/tt0084917/quotes

Walt: Daddy what's gradual school?
T. S. Garp: What?
Walt: Gradual school. Mommy say's she teaches at gradual school.
T. S. Garp: Oh Gradual school is where you go to school and you
gradually find out you don't want to go to school anymore.

I still use an HP vector voltmeter.

--
Les Cargill

Ah thanks, Now I know where I got it from.

It must of 'rang true' when I read it.

George H.

 

[krw@att.bizzzzzzzzzzzz]

On Fri, 16 Dec 2011 20:22:27 -0800 (PST), George Herold
<gherold@teachspin.com> wrote:

On Dec 16, 3:56 pm, Fred Abse <excretatau...@invalid.invalid> wrote:
On Wed, 14 Dec 2011 19:24:55 -0800, George Herold wrote:
I used an old HP RF voltmeter in gradual school.

Schooling should be a gradual process ;-)

I still use an HP vector voltmeter.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)

Well for me, "It's called gradual school,
becasue you gradually decide you don't want to be in school anymore."

I figured it out before I went that far. Then I went back because I was being
paid to go. I gradually came to the conclusion that I wasn't being paid
enough. ;-)

 

[Fred Abse]

On Fri, 16 Dec 2011 20:39:09 -0800, John Larkin wrote:

On Fri, 16 Dec 2011 12:56:14 -0800, Fred Abse
excretatauris@invalid.invalid> wrote:

On Wed, 14 Dec 2011 16:31:38 -0800, John Larkin wrote:

On Wed, 14 Dec 2011 08:41:32 -0800, Fred Abse
excretatauris@invalid.invalid> wrote:

On Mon, 12 Dec 2011 14:41:29 -0800, John Larkin wrote:

I'd never go back to an analog scope or a VTVM.

I know it isn't tubes, but whaddabout your 610C?

It does have a needle, so I have to think a little.

A rare ability in this age of "lead people by the hand".

Well, it is hard to read a needle to 5 or 6 decimal places.

But how often is that necessary?

I seldom need more than 3

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)