Driver to drive?

On Saturday, February 24, 2018 at 10:12:24 AM UTC-5, John Robertson wrote:

On 2018/02/23 7:42 PM, 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?


Get good quality bits and your problem goes away. If you buy off Amazon
or eBay then you get 3rd world quality, not 1st world.

Try some Hazet tools some time as an example of 1st world quality. Be
sure you get them from a factory authorized distributor or you are
likely to just buy counterfeit.

https://www.hazet.de/produktkatalog/index.php?language=en

There is a reason why some brands of tools cost more than others...

John :-#)#

Makes no difference what brand when the screw is rusted. You need to use penetrating lubricant.

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

 

[John Robertson]

On 2018/02/24 9:53 AM, bloggs.fredbloggs.fred@gmail.com wrote:

On Saturday, February 24, 2018 at 10:12:24 AM UTC-5, John Robertson wrote:
On 2018/02/23 7:42 PM, 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?


Get good quality bits and your problem goes away. If you buy off Amazon
or eBay then you get 3rd world quality, not 1st world.

Try some Hazet tools some time as an example of 1st world quality. Be
sure you get them from a factory authorized distributor or you are
likely to just buy counterfeit.

https://www.hazet.de/produktkatalog/index.php?language=en

There is a reason why some brands of tools cost more than others...

John :-#)#

Makes no difference what brand when the screw is rusted. You need to use penetrating lubricant.

Oh no! You don't want to open THAT can of worms again, do you?

ATF|Acetone mix seems best based on research done years ago. However ATF
formulas have changed so something else (not WD-40!) may work better.
Original article:

http://www.flippers.com/pdfs/Machinist's Workshop penetrating oils
April_May 2007-rust.pdf

Another article on penetrating oils based on above:

http://www.flippers.com/pdfs/Penetrating Oil Showdown-rust.pdf

Discussion runs on about how the photo in the original article shows
Power Steering Fluid (PSF) instead or Automatic Transmission Fluid (ATF)
so it may indeed be that you want a 50:50 mix of PSF|Acetone. To be
honest I've never tried either as we haven't run into any rusted screws
that needed penetrating fluids in the past few years. It would be fun to
retry that with fresh bolts and nuts and enough of them so you get a
reasonable average for each penetrating fluid.

The research IS needed.

But who has the time? Not I!

John :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

 

[mpm]

On Saturday, February 24, 2018 at 10:45:05 AM UTC-5, k...@notreal.com wrote:
> Something that actually does what it promises?

Solidly in the FWIW category...

In my "perfect little world", there are ONLY pan-head Phillips screws!

Every three months or so, I have to have a little "talk" with production about not using multiple different fasteners where they're not needed. I found one build last week that required three different tools to open the top cover - and there was nothing special about it. (other than being a one-off custom).

In other words: Laziness and inattentiveness.

Anyway: Also want to give a quick shout-out to www.boltdepot.com
I also have a borderline fetish for good quality, hard-to-find, fender washers.

You either appreciate that, or you're not yet initiated.

 

[George Herold]

On Friday, February 23, 2018 at 11:48:33 PM UTC-5, 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?

--

I twisted up a harbor freight 'security' torx bit in
a relatively new product. I blamed it on the hole down
the center. I've got some old sears craftsman and vermont
american bits that are good. I don't know about newer ones.

George H.

 

[JM]

On 23/02/2018 17:11, Phil Hobbs wrote:

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.

You'll be able to do that.

(Option AY8, the internal source, would be useful too, but it's probably
a HW option.)

Oh, you got an 89431A as well as a 89410A? You'll soon be welding a
couple of 42H racks on top of each other to save on floor space.

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

Cheers

Phil Hobbs

 

[Phil Hobbs]

On 02/24/2018 06:23 PM, JM wrote:

On 23/02/2018 17:11, Phil Hobbs wrote:
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.

You'll be able to do that.

(Option AY8, the internal source, would be useful too, but it's probably
a HW option.)


Oh, you got an 89431A as well as a 89410A? You'll soon be welding a
couple of 42H racks on top of each other to save on floor space.

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

Cheers

Phil Hobbs

I got the complete 89441A 2.65 GHz gizmo. I'll move my spare Tek11801C
out of the rack to make space.

You can fit a lot in a 7-foot EIA rack.

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]

Fox's Mercantile wrote:

"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

"I'm not a Brewster, I'm the son of a sea cook!" -Mortimer

 

[Phil Hobbs]

On 02/24/2018 06:29 PM, Phil Hobbs wrote:

On 02/24/2018 06:23 PM, JM wrote:
On 23/02/2018 17:11, Phil Hobbs wrote:
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.

You'll be able to do that.

(Option AY8, the internal source, would be useful too, but it's probably
a HW option.)


Oh, you got an 89431A as well as a 89410A? You'll soon be welding a
couple of 42H racks on top of each other to save on floor space.

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

Cheers

Phil Hobbs


I got the complete 89441A 2.65 GHz gizmo.  I'll move my spare Tek11801C
out of the rack to make space.

You can fit a lot in a 7-foot EIA rack.

Speaking of which, I could use a shorter four-post instrument rack with
adjustable rails, but they never seem to come up on eBay--just the
flimsy audio and gigundo server racks.

Any sourcing suggestions? I bought my present HP one from long-lost SED
regular ecnerwal in about 2009.

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]

Phil Hobbs wrote:

Any sourcing suggestions? I bought my present HP one from long-lost SED
regular ecnerwal in about 2009.

Hunt up an old Tek rolling cart. They have two vertical pillars which
are std 19" wide opening. Good heavy duty cart with 600Lb smooth rool
casters. Most come with shelves and drawers too (which can be re-sold
if not desired).

 

[Phil Hobbs]

On 02/24/2018 08:09 PM, Long Hair wrote:

Phil Hobbs wrote:


Any sourcing suggestions? I bought my present HP one from long-lost SED
regular ecnerwal in about 2009.


Hunt up an old Tek rolling cart. They have two vertical pillars which
are std 19" wide opening. Good heavy duty cart with 600Lb smooth rool
casters. Most come with shelves and drawers too (which can be re-sold
if not desired).

I'm from back then too, so I remember them fondly. (Well, the 7000
series, not the 5XX tube monsters.)

You couldn't fit a stack of 19" rack equipment on a 7000-series cart,
because it's too narrow. I haven't used the ginormo tube-scope carts,
but in general tippable carts are way too short and unstable. It's hard
to see how you could get more than one or (at most) two large
instruments on those before the tipping motion became dicey.

I've got instruments on Ikea kitchen carts, which are fine, but I need a
second real rack.

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]

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote in
news:arudnYqcBfI1jQ_HnZ2dnUU7-aPNnZ2d@supernews.com:

On 02/24/2018 08:09 PM, Long Hair wrote:
Phil Hobbs wrote:


Any sourcing suggestions? I bought my present HP one from long-lost
SED regular ecnerwal in about 2009.


Hunt up an old Tek rolling cart. They have two vertical pillars
which
are std 19" wide opening. Good heavy duty cart with 600Lb smooth
rool casters. Most come with shelves and drawers too (which can be
re-sold if not desired).

I'm from back then too, so I remember them fondly. (Well, the 7000
series, not the 5XX tube monsters.)

You couldn't fit a stack of 19" rack equipment on a 7000-series cart,
because it's too narrow. I haven't used the ginormo tube-scope carts,
but in general tippable carts are way too short and unstable. It's
hard to see how you could get more than one or (at most) two large
instruments on those before the tipping motion became dicey.

I've got instruments on Ikea kitchen carts, which are fine, but I need
a second real rack.

Cheers

Phil Hobbs

These were not "tipping carts". These monsters could mount a friggin
shuttle cockpit console. ;-)

The K420 series. I have a couple that have five foot tall pillars on
them. The casters are to die for in mobility terms.

https://www.ebay.com/itm/Tektronix-K420-Instrument-Workstation-
Cart/332365981238

 

I still don't see why you don't just take some diodes and whatever and clip the input at slightly higher than the max input and clipped output.

Why ?

 

On Sunday, 25 February 2018 07:37:00 UTC, jurb...@gmail.com wrote:

I still don't see why you don't just take some diodes and whatever and clip the input at slightly higher than the max input and clipped output.

Why ?

It's possible. But the clipping point would drift with temp, and the clipping be a bit nonlinear. I'd much prefer the clipping to occur in the output stage so it gets as near the rails as possible and so it's more psu variation tolerant.


NT

 

>"It's possible. But the clipping point would drift with temp, and the clipping be a bit nonlinear. I'd much prefer the clipping to occur in the output stage so it gets as near the rails as possible and so it's more psu variation tolerant. "

That's why I said HIGHER, the output stage still clips.

The application is still puzzling. If I was rolling in money I ight offer you the hundred bucks for a provisional patent (might be more now) so you could reveal it you cryptic fucker.

You have posed more of a question than stated. Why does the output have to clip ? It must have something to do with the load.

So you got people half the time thinking about your problem and half the time trying to figure out WTF ?

Well, it beats watching reruns of old sitcoms nobody would watch the first time around...

 

On Sunday, 25 February 2018 09:13:04 UTC, jurb...@gmail.com wrote:

I still don't see why you don't just take some diodes and whatever and clip the input at slightly higher than the max input and clipped output.

"It's possible. But the clipping point would drift with temp, and the clipping be a bit nonlinear. I'd much prefer the clipping to occur in the output stage so it gets as near the rails as possible and so it's more psu variation tolerant. "

That's why I said HIGHER, the output stage still clips.

I guess I'm not clear what scheme you're proposing. I can see problems with any input controlled clipping unless it were very adaptive.

The application is still puzzling. If I was rolling in money I ight offer you the hundred bucks for a provisional patent (might be more now) so you could reveal it you cryptic fucker.

You have posed more of a question than stated. Why does the output have to clip ? It must have something to do with the load.

So you got people half the time thinking about your problem and half the time trying to figure out WTF ?

Well, it beats watching reruns of old sitcoms nobody would watch the first time around...

I can't disclose the app on this one, I'll just have to remain a cryptic fcker.


NT

 

Floor space is a bit of an issue, because we've got a lot of good stuff:

https://electrooptical.net/Lab_Tour/

https://electrooptical.net/Equipment

So I really need a shorter version of the big HP rack in the photos.

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

 

[JM]

On 23/02/2018 20:17, 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.

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

I designed a CSEM receiver 20 or so years ago with sub 100pV noise
(0.01-15Hz BW and 120dB overall gain) with a similar architecture.
These worked with Ag-AgCl field sensors with a source resistance of
about 5 ohms.

I'd expect modern CSEM receivers to have improved on that - a google or
patent search might give you some ideas?

 

[Winfield Hill]

JM wrote...

On 23/02/2018 20:17, 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.

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.

I designed a CSEM receiver 20 or so years ago with sub 100pV noise
(0.01-15Hz BW and 120dB overall gain) with a similar architecture.
These worked with Ag-AgCl field sensors with a source resistance of
about 5 ohms.

Just as a reminder, Paul and I made a simple 65 pV/rt-Hz preamp,
all the how-to details reported in AoE III, pages 505 to 508.


--
Thanks,
- Win

 

[legg]

On Fri, 23 Feb 2018 11:11:27 -0800, John Larkin
<jjlarkin@highland_snip_technology.com> wrote:

On Fri, 23 Feb 2018 01:14:45 -0500, legg <legg@nospam.magma.ca> wrote:

On Thu, 22 Feb 2018 07:11:41 -0800, John Larkin
jjlarkin@highlandtechnology.com> wrote:

On Sun, 18 Feb 2018 13:12:50 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/18/2018 08:14 AM, Chris Jones wrote:
On 17/02/2018 07:18, bloggs.fredbloggs.fred@gmail.com wrote:
On Friday, February 16, 2018 at 12:51:24 PM UTC-5, John Larkin wrote:
On Fri, 16 Feb 2018 08:57:05 -0800 (PST),
bloggs.fredbloggs.fred@gmail.com wrote:

On Thursday, February 15, 2018 at 8:32:35 PM UTC-5, John Larkin wrote:
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

But this fixes it:

https://www.dropbox.com/s/9q80heyfbwh5frp/317_comp.jpg?raw=1

This ain't rocket science, but I haven't seen it done before.

317 needs no such ESR compensation.

The data sheet says it does.

The ringing looks suspiciously like excitation of the SRF of an
output capacitor.

The frequency is low, and is different on the rising and falling edges
of the load current pulse. It's the chip pseudo-inductance resonating,
not the cap's ESL. If the ringing were local to the caps, my damping
on ADJ wouldn't fix that.

Cap series L makes a different waveform than paralleled inductance.


Did your model give it any ESL? And your solution merely reduces the
shunt resistance by a factor of 20x which probably has more to do
with damping than anything else.

With a big cap from ADJ to ground, it rings badly, too. It has to be
the *right* capacitor to damp the ringing.

I tried this with two different LM317 models; the ringing is somewhat
different (the LT317 is better), but the damping idea is the same.

It's amazing that LT ever made a 317. I think they did that early on,
when they needed some revenue. They want $4 for it! I'm paying less
than a tenth of that for TI.

I doubt you're going to see this energetic resonance on anything other
than the LT part.


I doubted it too, but found out the hard way when:
my 337's all oscillated, and
the 317s rang so badly that the oscillation ripple on the positive rails
was even bigger than on the negative rails.

The 317s wouldn't oscillate by themselves, but they would ring like a
bell even after I cured the 337's of oscillation.

I had to scratch off a lot of solder mask and tack on many tantalums to
cure my boards. Quite embarassing.


Check out the Erroll Dietz article I posted upthread.

He used three values of Cadj, 0, 10u, and 1000u. He didn't try
anything like 22nF. I'm sort of surprised that nobody seems to have
tried that, or at least publicized it.

As I recall, from the time when I was actually checking transient
response and output noise of commercial linear prototypes, the kudos
for getting a 10n cap to do the job that a 10uF part was illustrated
to do (or not to do) in the literature, wasn't worth mentioning.

If it was, it was as the prelude to the inevitable 'Why not just leave
it out? Nobody's going to do that anyways.'

Tantalum caps were not even a consideration.....but the product still
worked over the temperature range.

With the harnessing involved, critical decoupling was always at the
load, so my measurements on the output terminals were just 'nice to
know' ~ required for a test spec or sales blurb.

Power supplys were, and are still, just not sexy.

RL

Some of my boards are half power supply. Many steps from +48 to +1 to
-12. Nuisance.

Well, if they are all linear regulators, then that will ensure a
roughly equal distribution of heat dissipation......

RL

 

[Long Hair]

pcdhobbs@gmail.com wrote:

Floor space is a bit of an issue, because we've got a lot of good stuff:

https://electrooptical.net/Lab_Tour/

https://electrooptical.net/Equipment

So I really need a shorter version of the big HP rack in the photos.

Cheers

Phil Hobbs

Are you planning on using the rack as a mobile device?

Because they are almost always fitted with small diameter hard casters.

Those Tek carts, BTW can have heavy items fitted right down next to
the floor. It ain't no scope cart. New ones sell for $1500. That is
all we use in our labs. The last one had four in it, right before the
boss moved.