Driver to drive?

[Phil Hobbs]

On 02/16/2018 09:59 AM, Phil Hobbs wrote:

Hi, all,

I need another FFT analyzer.  I really like my HP 35660A, but it only
goes up to 100 kHz (50 kHz for two-channel measurements).  I'd really
like one that goes up to at least 10 MHz, and can do the same sorts of
stuff, especially display noise spectral density in different units on
different scales and perform frequency response testing easily.

There are a bunch of USB-style things, which might be okay as long as
they have Linux software available.

What I really want is a smallish boat anchor with two channels, 14-16
bit resolution, > 50 MS/s sampling, FFT analysis, a nice display, and
that can talk to USB sticks.

So my new-to-me HP 89441A analyzer is due to be here Tuesday. I noticed
that it doesn't have the serial cable--is it a regular straight-through
9-pin cable, or something weird?

Thanks

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
https://hobbs-eo.com

 

[John Larkin]

On Thu, 22 Feb 2018 20:33:40 -0500, krw@notreal.com wrote:

On Fri, 23 Feb 2018 11:47:02 +1100, Sylvia Else
sylvia@not.at.this.address> wrote:

There is a light/vent thing in the shower, so I was thinking it would
be cool if the light were on dim all the time.

https://www.dropbox.com/s/po8e9iku1a2zxt0/P2190702.JPG?raw=1

So I need an LED spotlight that runs at low current; most do. Maybe
the one already there would.

I have some dimmable LED lights in my house, but they can't be dimmed so
very much before they start to flicker.

My hallway is pitch black at night in the absence of artificial
lighting, so I installed a couple of discrete LEDs in bezels

https://www.rapidonline.com/kingbright-rtf5010-led-bezel-clip-prominent-5mm-55-0260

run off a small transformer, full wave rectified, but no smoothing (to
eliminate capacitors). They run all the time. Works and looks fine.

We've had a bunch of LED nightlights running for at least ten years.
They run all the time and work like a champ. I think they were a
couple of bucks each.

LEDs are so good now, you could make a 10-year night light that runs
on batteries.


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[Phil Hobbs]

On 02/23/2018 02:13 PM, Gerhard Hoffmann wrote:

Am 23.02.2018 um 18:11 schrieb Phil Hobbs:
On 02/23/2018 11:15 AM, JM wrote:
On 21/02/2018 01:29, pcdhobbs@gmail.com wrote:
I have written a program that controls that thing over the network
and measures spectra from 0.1 Hz to 1MHz, one FFT per decade, reads
the results, combines them and plots them with gnuplot.

One needs a converter box from coax ethernet to contemporary network,
then one just opens port 5000-something on 192.168.178.111 and simply
reads and writes GPIB-strings. And the coax needs 2 terminations, even
when the "cable" is only 5 inch long.

No need for GPIB cards and semi-supported drivers.

These measurements of voltage regulator noise have been done with it:

https://www.flickr.com/photos/137684711@N07/24070698809/in/album-72157662535945536/


    


Just in case you win it and are interested.

Hi, Gerhard,

I did, and I am. I'll have to gin up a nice low-1/f-noise preamp for
it, but that'll be fun.

Thanks

Phil Hobbs


Note that the software options can easily be unlocked on these (although
they would be of little use for your intended application).

The cell-phone stuff won't help much, but I'm hoping that I can turn on
the AYB (spectrogram and waterfall) option without scrooching it.
(Option AY8, the internal source, would be useful too, but it's probably
a HW option.)

The software one should be no big issue as long as the floppy drive
works reliably.

Mine has most options, but I'm not sure about the waterfall.
What is missing is the source up converter for the RF section.
But for RF I have a real VNA.

That thing has so much parameters to set up that I wrote the program
to control it remotely very soon. I had to use a pre-flight check list
otherwise.

Important options are dual channel, needed for cross correlation,
source for Bode plots etc and memory extension.

My program is in C, under Linux. It probably can be compiled under
Windows, too. You'll need a lot of gain to mask the noise in the 1/f
region. That eats into the dynamic range.

I'll remove the most embarrassing FIXMEs over the weekend, a good
opportunity to clean it up

cheers, Gerhard


Hi, Gerhard,

Thanks, that would be great. We're an all-Linux shop round here, so no
worries there.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
https://hobbs-eo.com

 

[John S]

On 2/16/2018 10:48 AM, John Larkin wrote:

On Fri, 16 Feb 2018 15:05:40 -0000, "Kevin Aylward"
kevinRemovAT@kevinaylward.co.uk> wrote:

"John Larkin" wrote in message
news:vecc8dt14p89hcaeb09rd3mkplt5vergrb@4ax.com...



LM317's like some ESR in their output capacitors. I don't want any
electrolytic or tantalum caps in my new thing, just ceramics, and the
sim sure rings:

https://www.dropbox.com/s/11b3w42nsvpliki/317_nocomp.jpg?raw=1

Urhhhh...... the 1 uohm resister is finger nails down a blackboard for me.

That's there to let me snoop the current. I find it hard to aim the LT
Spice current probe at device pins, so I'll stick in a resistor here
and there to make current snooping easy.

I usually use 1m, but I wanted an accurate sim of regulator ringing
and 1m might have affected that a little.

I suppose I could use 0 ohms... tries it... no, LT Spice will not
probe the current in a 0 ohm resistor. Pity.


For a regular spice engine on regular doubles, numbers can't span more than
12 digits and have it solve correctly. So, 1 uohm means 1 Meg max.

Looks like I should be OK here:

https://en.wikipedia.org/wiki/Double-precision_floating-point_format

In real life, PCB traces can be many milliohms. I have rarely used
them as current shunts.


Don't use smaller than 1m ohm

er... This ain't rocket science.

And alternatively, ... you could put a low value resister in the ic output
prior to the feedback, and use a feedback cap direct from the ic output to
its input. Effectively, if configured correctly, the output resister does
the job of an out of loop esr, but without the dc error.

A current snoop resistor could be on the input side too.

You can use a voltage source set to zero volts to sample current.

 

[Gerhard Hoffmann]

Am 21.02.2018 um 02:29 schrieb pcdhobbs@gmail.com:

I did, and I am. I'll have to gin up a nice low-1/f-noise preamp for it, but that'll be fun.

I'm working on a chopper preamp that should be flat down to at least
100mHz, but it seems that I cannot verify that with the 89441A.

It works with parallel ADG819 analog switches, step up transformers,
more low noise gain with ADA4898s on 500 KHz, synchronous demodulator
back to baseband and some more gain.

A Xilinx Coolrunner II generates the timing from a 100 MHz osc.
It looks like I get 120 pV/rtHz.

The main problem is the ringing of the step up transformer. I re-wired
some Macom and Pulse SMD transformers under the microscope using 50u wire.

That was no fun. 1/2

cheers, Gerhard

 

[Gerhard Hoffmann]

Am 23.02.2018 um 20:15 schrieb Phil Hobbs:

So my new-to-me HP 89441A analyzer is due to be here Tuesday. I noticed
that it doesn't have the serial cable--is it a regular straight-through
9-pin cable, or something weird?

I also had to make the cable myself.
It wasn't much work, and it is known how to do it.

 

[Mike]

In article <p6gudf$78j$1@node2.news.atman.pl>,
Piotr Wyderski <peter.pan@neverland.mil> wrote:

Mike wrote:

The most impressive fail (so far) was one that went *bang* in a
standard-lamp, downstairs, sufficiently enthusiastically to be heard
from upstairs. A loud, solid, THUD.

Fortunately, it contained the healthy isotope* of mercury
(on the contrary, the medical thermometers contained the
wrong one, and hence have recently been banned by the EU).

Fortunately, the "bang" was not from the tube shattering, it was
the case/base only. I didn't crack it open further to investigate,
but suspect it was more than just a transistor (maybe overpressure
in an electrolytic that went short across the mains?).

Never had a CFL or 4/5/6 foot tube break indoors.
--
--------------------------------------+------------------------------------
Mike Brown: mjb[-at-]signal11.org.uk | http://www.signal11.org.uk

 

On Fri, 23 Feb 2018 06:44:58 -0800, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

On Fri, 23 Feb 2018 11:54:48 GMT, Steve Wilson <no@spam.com> wrote:

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/22/2018 02:09 PM, Steve Wilson wrote:
So you're the guy who posts upside-down pdfs!

Here it is, right-side up, OCR'd and reduced from 3,494,831 to 1,652,242
bytes:

https://silvercell.000webhostapp.com/pdfs/dietz.pdf

Please replace the one on your site so people can use it

Thanks!

Cheers

Phil Hobbs

I was browsing your website to try to find where you put your SED pdf
files. I found https://electrooptical.net/SED, but there are no pdf files
there. Can you include a link to that folder somewhere?

I also found quite a few broken links. These have a bad effect in google
searh since google will downgrade your site and put it at the bottom of the
search rank. Broken links also affect user satisfaction since they can't
find interesting files.

He employs hunchbacks.

The work he forces his "employees" to do *creates* hunchbacks.

 

On Fri, 23 Feb 2018 14:15:48 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/16/2018 09:59 AM, Phil Hobbs wrote:
Hi, all,

I need another FFT analyzer.  I really like my HP 35660A, but it only
goes up to 100 kHz (50 kHz for two-channel measurements).  I'd really
like one that goes up to at least 10 MHz, and can do the same sorts of
stuff, especially display noise spectral density in different units on
different scales and perform frequency response testing easily.

There are a bunch of USB-style things, which might be okay as long as
they have Linux software available.

What I really want is a smallish boat anchor with two channels, 14-16
bit resolution, > 50 MS/s sampling, FFT analysis, a nice display, and
that can talk to USB sticks.

So my new-to-me HP 89441A analyzer is due to be here Tuesday. I noticed
that it doesn't have the serial cable--is it a regular straight-through
9-pin cable, or something weird?

The DOCs are online, if you don't have them. It appears to be a
common serial cable (but who knows how many pins are used). There is
also a comment about the EMI suppression ferrite position.

 

On Fri, 23 Feb 2018 11:17:29 -0800, John Larkin
<jjlarkin@highland_snip_technology.com> wrote:

On Thu, 22 Feb 2018 20:33:40 -0500, krw@notreal.com wrote:

On Fri, 23 Feb 2018 11:47:02 +1100, Sylvia Else
sylvia@not.at.this.address> wrote:

There is a light/vent thing in the shower, so I was thinking it would
be cool if the light were on dim all the time.

https://www.dropbox.com/s/po8e9iku1a2zxt0/P2190702.JPG?raw=1

So I need an LED spotlight that runs at low current; most do. Maybe
the one already there would.

I have some dimmable LED lights in my house, but they can't be dimmed so
very much before they start to flicker.

My hallway is pitch black at night in the absence of artificial
lighting, so I installed a couple of discrete LEDs in bezels

https://www.rapidonline.com/kingbright-rtf5010-led-bezel-clip-prominent-5mm-55-0260

run off a small transformer, full wave rectified, but no smoothing (to
eliminate capacitors). They run all the time. Works and looks fine.

We've had a bunch of LED nightlights running for at least ten years.
They run all the time and work like a champ. I think they were a
couple of bucks each.

LEDs are so good now, you could make a 10-year night light that runs
on batteries.

Outlets are even easier. Buying beats making.

 

[Phil Hobbs]

On 02/23/2018 05:52 PM, krw@notreal.com wrote:

On Fri, 23 Feb 2018 06:44:58 -0800, John Larkin
jjlarkin@highlandtechnology.com> wrote:

On Fri, 23 Feb 2018 11:54:48 GMT, Steve Wilson <no@spam.com> wrote:

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/22/2018 02:09 PM, Steve Wilson wrote:
So you're the guy who posts upside-down pdfs!

Here it is, right-side up, OCR'd and reduced from 3,494,831 to 1,652,242
bytes:

https://silvercell.000webhostapp.com/pdfs/dietz.pdf

Please replace the one on your site so people can use it

Thanks!

Cheers

Phil Hobbs

I was browsing your website to try to find where you put your SED pdf
files. I found https://electrooptical.net/SED, but there are no pdf files
there. Can you include a link to that folder somewhere?

I also found quite a few broken links. These have a bad effect in google
searh since google will downgrade your site and put it at the bottom of the
search rank. Broken links also affect user satisfaction since they can't
find interesting files.

He employs hunchbacks.

The work he forces his "employees" to do *creates* hunchbacks.

The HR word for it is "employee development". At IBM I developed a
twitch, round here people develop humps. What's not to like?

Cheers

Phil Hobbs
Burg Frankenstein


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
https://hobbs-eo.com

 

[Steve Wilson]

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/23/2018 11:42 AM, Steve Wilson wrote:
Thanks. DFH found that the OldBooks directory had had its permission
changed, and there was some issue with all the phone number links (which
were the bulk of the failures).

Of the remaining five, four are external links that changed and there's
one missing link to our site.

Some of the pages are nice. You are to be congratulated on your amazing
accomplishments. I don't think I've seen another website like yours.

Thanks! It's been a good ride overall.

Cheers

Phil Hobbs

Good Work!

You may wish to tell google the broken links are fixed. I don't know how
to do that, but maybe you can tell google to rescan your site. Or maybe
there's an option in the Control Panel or whatever google calls the
management page. Otherwise google will fix it itself, but it may take 6
months or so.

I also checked your site in MS Explorer. Works fine, but I wish I could
control the background colors like I can in firefox. The MS Explorer
background is black with white text. This works ok but when you mouse over
a link, the background turns white or light yellow. So you have white text
on a white background which is hard to read.

I hate black background. I change all my programs like LTspice to show a
white background with black text, or some other compatible color that is
readable no matter what.

Were you going to give us a link to your SED pdf folder?

 

[Les Cargill]

bitrex wrote:

On 02/21/2018 10:46 PM, Les Cargill wrote:
bitrex wrote:
On 02/20/2018 08:44 PM, krw@notreal.com wrote:
On Tue, 20 Feb 2018 20:31:56 -0500, bitrex
bitrex@de.lete.earthlink.net> wrote:
snip


But you couldn't buy a BeOS box at Best Buy ( or Bob's Computer Store
before that ).

Unfortunately for most of its history x86 wasn't particularly amenable
to fast virtualization, a sleek new OS sold in stores in the late 1990s
which could also run the majority of legacy DOS and Windows software
with little performance hit could have been a contender.

I wish it had. The RADAR DAW box still runs BeOS. Totally
weapons-grade stuff. SFAIK, it's deterministic to a small
epsilon.

Once OS/2, etc. were gone and Microsoft had the market locked down by
the early 2000s Intel and AMD got crackin' on the hardware
virtualization support like gangbusters, interesting that.

I suspect interest in a separate server product offering drove the
interest in virtualization.

--
Les Cargill

 

[Les Cargill]

tabbypurr@gmail.com wrote:

On Thursday, 22 February 2018 15:50:25 UTC, Les Cargill wrote:
tabbypurr wrote:
On Thursday, 22 February 2018 03:23:59 UTC, Les Cargill wrote:
tabbypurr wrote:

I'm looking at putting together something similar to a Class AB/B
audio amp, but it will be driven outside its linear range into
saturation a lot of the time. That's all well & good but for one
thing: wrapping nfb round saturating outputs doesn't work too
well as it takes time for output devices to unsaturate, and the
nfb effectively overreacts, adding distortion. Keeping distortion
low matters here. What tips would you recommend to keep unwanted
distortion minimised?


thanks, NT


Uhhhh.... headroom?

Maybe you've not read through the thread. That wouldn't do what's
required.


I don't know why keeping it off the rails isn't inherently better than
worrying about how it interacts with the rails to begin with.

Once again the required behaviour is that it rails. An amp that doesn't is no use at all.


NT

Fair enough.

--
Les Cargill

 

[George Herold]

On Thursday, February 22, 2018 at 11:01:27 AM UTC-5, Nick Cat wrote:

On Thursday, 22 February 2018 15:50:25 UTC, Les Cargill wrote:
tabbypurr wrote:
On Thursday, 22 February 2018 03:23:59 UTC, Les Cargill wrote:
tabbypurr wrote:

I'm looking at putting together something similar to a Class AB/B
audio amp, but it will be driven outside its linear range into
saturation a lot of the time. That's all well & good but for one
thing: wrapping nfb round saturating outputs doesn't work too
well as it takes time for output devices to unsaturate, and the
nfb effectively overreacts, adding distortion. Keeping distortion
low matters here. What tips would you recommend to keep unwanted
distortion minimised?


thanks, NT


Uhhhh.... headroom?

Maybe you've not read through the thread. That wouldn't do what's
required.


I don't know why keeping it off the rails isn't inherently better than
worrying about how it interacts with the rails to begin with.

Once again the required behaviour is that it rails. An amp that doesn't is no use at all.

Well just rail some upstream opamp into a load it's happy with.
Distortion here and power later?

George H.

NT

 

[Tim Williams]

"John Larkin" <jjlarkin@highlandtechnology.com> wrote in message
news:50i09d15t0dsu4kqnf8ut93p3u0rr78b7q@4ax.com...

She said the worst part was making it work with Internet Explorer.

Screw 'em!

My compromise: I support IE8 on most of my site, with IE9 (or higher, I
forget) required for certain pages (like the Coilcraft model graphing
calculator). IE isn't worth supporting, even for legacy users; it's just
bad. And there are legacy and new alternatives they should use.

Tim

--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: https://www.seventransistorlabs.com/

 

[Tim Williams]

"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:yZ-dnRfUR8J7Ag3HnZ2dnUU7-XOdnZ2d@supernews.com...

The HR word for it is "employee development". At IBM I developed a
twitch, round here people develop humps. What's not to like?

So "Hump Day" is introducing new employees?

Tim

--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: https://www.seventransistorlabs.com/

 

[Phil Hobbs]

On 02/23/2018 03:17 PM, Gerhard Hoffmann wrote:

Am 21.02.2018 um 02:29 schrieb pcdhobbs@gmail.com:


I did, and I am. I'll have to gin up a nice low-1/f-noise preamp for
it, but that'll be fun.


I'm working on a chopper preamp that should be flat down to at least
100mHz, but it seems that I cannot verify that with the 89441A.

I have a 35665A, whose 1/f is pretty good.

It works with parallel ADG819 analog switches, step up transformers,
more low noise gain with ADA4898s on 500 KHz, synchronous demodulator
back to baseband and some more gain.

A Xilinx Coolrunner II generates the timing from a 100 MHz osc.
It looks like I get 120 pV/rtHz.

At 0.1 Hz? Awesome!

The main problem is the ringing of the step up transformer. I re-wired
some Macom and Pulse SMD transformers under the microscope using 50u wire.

That was no fun.    1/2

I bet. I once spent about three weeks repairing metal-patterned PVDF
pyroelectric films with silver paint for a customer demo, so I feel your
pain.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Long Hair]

Paul in Houston TX wrote:

Tom Del Rosso wrote:
I just twisted a torx bit into a spiral trying to remove a rusted screw,
then used a Dremel to cut a slot across the top and took it out with a
flat screwdriver. The screwdriver didn't bend at all.

None of the bits I ever saw are made of hardened steel like a
single-piece screwdriver. Does anybody make harder bits?

Snap-On and Proto both make good torx bits. $12 per bit.
They don't bend, they just suddenly break.

Anything below T-10 should not even be so tight as to twist off (or
bugger up) even the cheap chinese tips.

Among all the drill driver makers one sees at the home center stores,
there are a few where it is easily recognizable that they are made from
better materials.

 

[whit3rd]

On Friday, February 23, 2018 at 8:48:33 PM UTC-8, Tom Del Rosso wrote:

I just twisted a torx bit into a spiral trying to remove a rusted screw,
then used a Dremel to cut a slot across the top and took it out with a
flat screwdriver. The screwdriver didn't bend at all.

None of the bits I ever saw are made of hardened steel like a
single-piece screwdriver. Does anybody make harder bits?

Flat-blade screwdrivers are formed of wire, with a heat-the-tip-and-smash-it
action, followed by some quench and grinding. So, it's easy (trivial) to
semi=harden the tip.

Phillips, not so easy. But yes, there's hard bits out there (some
are TOO hard, and prone to shatter, many are butter-soft, and
few are easy to identify as good 'uns by the buyer).

In 1/4" hex bits, Apex and Hitachi are good. Probably Vermont American,
if they're still in business.

As for traditional Torx drivers (no replaceable tip) I'm mainly just getting no-name ones
and sets, and half of 'em are serviceable. There's a 35-year-old Stanley that
I like, but who knows if that's still relevant info.