Huh? Since When--?

[Ron Hubbard]

I use the Exar XR2206 function generator in a lot of my projects but
now I see-- at least according to Mouser-- that the IC has become
obsolete? Since when? Why? How can such a useful chip become
discontinued? This not right!

Ron

[Michael Black]

It's somewhere about 40 years old. I can remember "new product" type
columns that dealt with it about 1974, but can't remember if it was around
before that. The Intersil 8038 function generator is older than 1974.

About 40 years is pretty long time. I remember decades ago how fast
things came along, and that often meant taking over from some older
device. It seemed at the time that a given IC would have a shorter
lifespan than a given tube, and then later it seemed like a surprise that
some ICs had actually lasted quite a long time.

Some of it is that other things have come along. But also, things have
changed. Back then, it was hard to do a function generator except in
analog, in more recent times there are digital ways of doing it, and
digital has certain advantage.

It's also important to note that ICs were never really introduced for
hobbyists. An IC had to have some potential market, and that meant in
some piece of equipment that would hopefully sell enough that the IC
company would sell many of those ICs. Any time a device found it's way
into hobbyist circles, it was because there was some demand somewhere out
there for the device in the first place.

And so forty years ago, there was some market for an analog function
generator. The XR was especially good since it was cheap, so it wasn't
just in "function generators" (ie a piece of test equipment that generated
signals) but for various instances where some sort of signal was needed.
As long as there was enough large demand for an IC, it stayed in
production. But analog is fussy, and a lot of the secondary uses for a
cheap function generator IC can easily be done with digital, especially
when a piece of equipment already includes a CPU. Even if someone is
manufacturing a function generator, they likely would start in digital.

So all those modems that used the 2206 (I think they were used in some) no
longer need them, since digital is better, besides the period when the
2206 could form a modem went out with about the 300baud modems. I think
the 2206 was used in some of the cheaper analog music synthesizers, but
nowadays most music synthesis is done in digital. The demand is no longer
there.

That said, just because an IC is no longer in productin doesn't mean it
won't be available for some time. Especially not a popular IC that was
around for forty years. There will be stock around, to fulfill repair
requirements, and because so many were made over so many years it won't
all dry up immediately. And once no one is manufacturing with them, a
"reasonable supply" is likely to be more than enough for those who
actually want to use the IC. Or if the IC was popular enough, cheap
enough, common enough, chances are there is an endless supply sitting in
all kinds of parts drawers on all kinds of workbenches, bought because it
was an interesting IC or because someone needed to pad an order to fulfill
a minimum order, or for some specific project that was never gotten around
to.

Michael

[Michael A. Terrell]

What's not right about dropping obsolete parts?

Jameco still has some in stock. They are a good place to find EOL
parts.

<http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_34972_-1>


--
You can't have a sense of humor, if you have no sense.

[George Herold]

Does this have the same pinout as the ICL8038? We've got several
tubes of those in stock... (never to be used)
(I could stick a few in the mail?)

I think digital signal generation and PIC's (etc) were the death of
the old analog function generator chips.

George H.

[Ron Hubbard]

On Jan 12, 4:25 am, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:

> Ron Hubbard wrote:
>
> > I use the Exar XR2206 function generator in a lot of my projects but
> > now I see-- at least according to Mouser-- that the IC has become
> > obsolete? Since when? Why? How can such a useful chip become
> > discontinued? This not right!
>
>    What's not right about dropping obsolete parts?

Well, it'd be kind of like killing off the 555/7555. Think about all
those thousands?-- millions?--- of circuits that use the 555 IC. While
not so ubiquitous, the 2206 is an incredibly useful little IC. I don't
know of any other chip where you get a sine wave past 1 MHz with so
few parts let alone triangle waves. I know there other function
generator chips, but if you need to pack it into a small space--- say,
you were making something really funky like a sonic screwdriver--- the
2206 and its associated parts can easily be put on a very narrow piece
of perfboard; ya can't do that with the 8038 or the other similar
chips.

Ron

[Michael A. Terrell]

Ron Hubbard wrote:
>
> On Jan 12, 4:25 am, "Michael A. Terrell" <mike.terr...@earthlink.net>
> wrote:
> > Ron Hubbard wrote:
> >
> > > I use the Exar XR2206 function generator in a lot of my projects but
> > > now I see-- at least according to Mouser-- that the IC has become
> > > obsolete? Since when? Why? How can such a useful chip become
> > > discontinued? This not right!
> >
> > What's not right about dropping obsolete parts?
>
> Well, it'd be kind of like killing off the 555/7555.

What manufacturer has declared them obsolete? The 558 is obsolete,
but how many people needed four 555 timers in a single package?
Obsolete means that there isn't enough demand to keep making a part.
hell, you can still buy new fenders for a Ford'Model T', made with the
original dies.

> Think about all
> those thousands?-- millions?--- of circuits that use the 555 IC. While
> not so ubiquitous, the 2206 is an incredibly useful little IC. I don't
> know of any other chip where you get a sine wave past 1 MHz with so
> few parts let alone triangle waves. I know there other function
> generator chips, but if you need to pack it into a small space--- say,
> you were making something really funky like a sonic screwdriver--- the
> 2206 and its associated parts can easily be put on a very narrow piece
> of perfboard; ya can't do that with the 8038 or the other similar
> chips.

No one cares, if you are the only person who wants to buy them. What
other function generator chips are still in production? A DDS &
microprocessor is the way it's done now. The AD8950 is smaller than the
XR2206, but it does take some brains to use.

I see that you snipped the link of where you can still buy them, and
the link indicates they still have over 100 in stock.

[Michael Black]

On Thu, 12 Jan 2012, George Herold wrote:

> On Jan 11, 6:09 pm, Ron Hubbard <or...@dslnorthwest.net> wrote:
>> I use the Exar XR2206 function generator in a lot of my projects but
>> now I see-- at least according to Mouser-- that the IC has become
>> obsolete? Since when? Why? How can such a useful chip become
>> discontinued? This not right!
>>
>> Ron
>
> Does this have the same pinout as the ICL8038? We've got several
> tubes of those in stock... (never to be used)
> (I could stick a few in the mail?)
>

No, they are not compatible, indeed, I would argue the 2206 is better than
the 8038, coming a tad later. I may be mixing it up with another XR
function generator, but I thought the 2206 included some sort of amplitude
modulator. It's also cleaner to use.

Michael

[Michael Black]

I would never consider using a 2206 at 1Mhz. It really is stretching the
device, while some other device more suitable for "rf" makes it simple
again.

No, we're saying the whole concept of an analog function generator on an
IC is in the past, not that one device is obsolete and others aren't.

I have no idea what you mean by a "sonic screwdriver", but if you don't
need frequency range, there are lots of other solutions. If you only need
one type of waveform, there are other solutions, especially if it's not a
sinewave you need. Note also that the sinewaves out of those function
generator ICs that modify the triangle wave are always limited, if you
need a clean sinewave there are other and better solutions.

A 555 is still a much more generic part than an IC function generator.
The more specific the part, the more likely it will have a finite
lifespan. Endless RF ICs have come and come, sometimes superceded by later
devices, sometimes it all just disappears. Of course, most of those RF
ICs never saw use in consumer equipment, so their numbers were limited.

Michael

[Ron Hubbard]

Not a Doctor Who fan I take it... A sonic screwdriver in fiction is a
multi-purpose pocket-sized tool that does just about everything but
make coffee. Most people say it can't be done in the real world but
like so many things, most people are wrong.

While it's not much more than a hi-tech toy. my circuit can produce a
whopping 143 dB of 13 kHz ultrasound that *will* turn screws (some of
them anyway), turn keys in locks, spin dinner plates, drive your
neighbor mad, and do other silly but cool tricks. while not exactly
the tool of choice on many occasions, a lot of people
have expressed interest in making one and the XR2206 is a very
critical part to frquency modulate the main ultrasonic beam fro 1 Hz
to 100 Hz.

http://www.physicsforums.com/showthread.php?p=3702452&posted=1#post3702452

> If you only need
> one type of waveform, there are other solutions, especially if it's not a
> sinewave you need

Ahh, but that's why the 2206 is such a beautiful chip: it does produce
nice sine waves with a minimum of support parts and the harmonic
distortion can be reduced if anyone wants to take the trouble of
putting in a small pot instead of a fixed resistor and checking the
output on a 'scope but why bother.

Ron

.
________
"Care for a jelly baby?"

-- the 4th Doctor --

[asdf]

On Thu, 12 Jan 2012 14:27:00 -0500, Michael Black wrote:

> No, they are not compatible, indeed, I would argue the 2206 is better
> than the 8038, coming a tad later. I may be mixing it up with another
> XR function generator, but I thought the 2206 included some sort of
> amplitude modulator. It's also cleaner to use.

Another nice beast was the MAX038 (totally unrelated to the ICL8038)
which would produce saw, square, sine, pulse, triangle waveforms up to 20
MHz. Sadly it was discontinued years ago and never replaced. Today I
believe DDS is the only way to go.

[George Herold]

> http://www.physicsforums.com/showthread.php?p=3702452&posted=1#post37...

>
> > If you only need
> > one type of waveform, there are other solutions, especially if it's not a
> > sinewave you need
>
> Ahh, but that's why the 2206 is such a beautiful chip: it does produce
> nice sine waves with a minimum of support parts and the harmonic
> distortion can be reduced if anyone wants to take the trouble of
> putting in a small pot instead of a fixed resistor and checking the
> output on a 'scope but why bother.
>
> Ron
>
> .
> ________
> "Care for a jelly baby?"
>

> -- the 4th Doctor --- Hide quoted text -
>
> - Show quoted text -

Ron have you checked out the VCO on the CD4046? (The price is right!)
If you coddled it I think you can get a triangle wave output.

George H.

[George Herold]

Thanks Michael, The higher frequency *would* have been useful.

George H.

[Phil Hobbs]

Doctor Who, I presume. A couple of questions:

143 dB compared to what? 143 dB SPL A-weighted? 143 dBm? ;)

At what range? A hearing aid can do that inside the ear--not so
whopping at all, though it would certainly hurt.

Annoying people, that I believe. Tightening screws? Not so much.

Are you related to the other Ron Hubbard (the one with the L in front)?


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

[Phil Hobbs]

One approach is to build a sine wave oscillator, and make the triangle
and square wave from that with a comparator and an op amp. The XR2206
had pretty poor THD performance due to the cheesy diode-shaping trick.
You can do a lot better by using a differential BJT pair to round off
the triangle, with one additional resistor to subtract off a bit of
triangle to get rid of the cusp. We talked about that in
sci.electronics.design a year or two back.

[Ron Hubbard]

On Jan 13, 9:06 am, Phil Hobbs

143 dB at 4" to 6" which is not bad considering it comes from a
handheld battery (2 sub-C cells) powered device that drives a piezo-
transducer less than 1" in diameter. But like I said, just a hi-tech
toy to amaze friends and sometimes annoy neighbors heh heh. ;-)

Ron

_________
"Logic is the science of being wrong with certainty."

-- The Doctor (quoting Ketterling's Law) --

[Ron Hubbard]

> George H.- Hide quoted text -

>
> - Show quoted text -

I wish I could get a sine wave from the 4046 but it has the
advantage-- at least for me anyway-- is that it's VCO can be easily
made to have a variable delay when frequency modulated. Makes a nice
siren if someone needed it or a sound effect generator.

Ron

[Michael Black]

On Mon, 16 Jan 2012, Ron Hubbard wrote:


> I wish I could get a sine wave from the 4046 but it has the
> advantage-- at least for me anyway-- is that it's VCO can be easily
> made to have a variable delay when frequency modulated. Makes a nice
> siren if someone needed it or a sound effect generator.
>

So run the 4046 at a higher frequency, and feed it into a ring counter
that has summing resistors on the output, giving you a sinewave.

Don Lancaster wrote about it in the hobby magazines almost about the time
the 8038 came out, and I think before the 2206 came out. The same area is
ocered in his CMOS Cookbook (and perhaps in the TTL Cookbook, I can't
remember) and in a more limited form in his TV Typewriter Cookbook.


Michael

[George Herold]

Or let it clock a CD4020, with the 'right' resistors on the outputs...
into a summing junction.

That's what I'm doing.

George H.

[George Herold]

> Ron- Hide quoted text -

>
> - Show quoted text -

Phil H. has this tanh converter circuit he posted on his web site.
That should make it at least as good as the exar part... A dual
transistor and an opamp I think.

Then you've got a circuit that will do more than 2MHz.

George H.

[Phil Hobbs]

>>At what range? A hearing aid can do that inside the ear--not so
>>whopping at all, though it would certainly hurt.
>>Annoying people, that I believe. Tightening screws? Not so much.

Annoying, people, that I believe. Tightening screws? You're making that
up.

[Chiron]

He said "turning" screws, not tightening them. I might possibly believe
that the vibrations might loosen screws...



--
I have made mistakes but I have never made the mistake of claiming
that I have never made one.
-- James Gordon Bennett

[Phil Hobbs]

That's why I specified tightening. He claimed that it was a 'sonic
screwdriver', whereas it's just an oscillator driving a resonant piezo.
Probably you want a screwdriver to turn both ways....

[Chiron]

Ah, he didn't specify that this was a *bidirectional* sonic
screwdriver... big difference there, you know? With a bidirectional
sonic screwdriver, sure you'd get tightening as well as loosening.

But yeah, I wouldn't buy that it could tighten screws, even if it was
bidirectional.



--
The absence of labels [in ECL] is probably a good thing.
-- T. Cheatham

[Ron Hubbard]

On Jan 19, 12:47 pm, Phil Hobbs

You want proof of concept, take a speaker box (if you can find one)
with two screws on it. Place on the box a spaker connected to a
frequency generataor and tune up the frequency; at one point-- if the
sound is intense enough (i.e "loud") the screws will start to turn
upwards. And of course, if the screws are at their top/terminal
position to begin with, getting the right freq and the screws will go
down-- this of course is easier as you don't hav gravity to contend
with. :-)

Ron

[Ron Hubbard]

That only works for a specific frequency and doesn't work if the input
frequency is being frequency modulated. Besides, why add more
complications to an already sophisticated circuit that fits in a
barely pocket-sized (9 to 11 in.) device? Who wants a foot-long
screwdriver?

Ron

[Phil Hobbs]

Sure it does. Why wouldn't it?

> Besides, why add more
> complications to an already sophisticated circuit that fits in a
> barely pocket-sized (9 to 11 in.) device? Who wants a foot-long
> screwdriver?

I have several. But yours isn't one.

[Phil Hobbs]

Everybody knows that vibration can loosen screws--that's what lock
washers and torque wrenches are there to prevent.

[George Herold]

On Jan 19, 3:47 pm, Phil Hobbs

> hobbs at electrooptical dot nethttp://electrooptical.net- Hide quoted text -

>
> - Show quoted text -

Hmm not to nit pick... (OK I am nit picking :^) But I as far as I can
remember Dr. Who never used his sonic screwdriver for tightening
screws.

George H.

[George Herold]

On Jan 19, 6:14 pm, Phil Hobbs

Yeah it works on the voltage. (not the frequency.) You have to feed
it a known amplitude triangle wave. (I'm reply to the OP and not to
you Phil... And please correct me if I'm wrong.) The exar does
something similar inside.

George H.

>
> > Besides, why add more
> > complications to an already sophisticated circuit that fits in a
> > barely pocket-sized (9 to 11 in.) device? Who wants a foot-long
> > screwdriver?
>
> I have several.  But yours isn't one.
>
> 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 nethttp://electrooptical.net- Hide quoted text -

[Phil Hobbs]

> Hmm not to nit pick... (OK I am nit picking :^) But I as far as I can
> remember Dr. Who never used his sonic screwdriver for tightening
> screws.
>
> George H.

His maintenance guy had one too. ;)

(I haven't watched a Dr. Who episode since I was a kid. I never watch
TV unless I'm stuck in some hotel without a good book, and even then I
just find some documentary or in a pinch the weather report. TV is both
boring and depressing.)

Cheers

Phil Hobbs

[Chiron]

Must not have had the bidirectional model... just my guess, I've never
even seen a Dr. Who episode.


--
How many Zen Buddhist does it take to change a light bulb?

Two. One to change it and one not to change it.

[fungus]

On Jan 19, 11:47 pm, Ron Hubbard <or...@dslnorthwest.net> wrote:
>
> That only works for a specific frequency and doesn't work if the input
> frequency is being frequency modulated. Besides, why add more
> complications to an already sophisticated circuit that fits in a
> barely pocket-sized (9 to 11 in.) device? Who wants a foot-long
> screwdriver?
>

The original sonic screwdriver was made
with vacuum tubes and had space left over.
Then again, it was much bigger on the inside
than on the outside.

[George Herold]

On Jan 19, 11:22 pm, Phil Hobbs

> Phil Hobbs- Hide quoted text -

>
> - Show quoted text -

Yeah Dr. Who was on some afternoon when I was an undergrad.
A crowd would gather to watch... which made it fun.

All I watch on TV these days is occasional sports, (corrupted by my
Dad, so I’m a Buffalo fan) and nature/ science shows on PBS with the
kids.

I never go anywhere without a book in my possession. With my nose
tucked into some trashy novel long lines become enjoyable.

George H.

[Michael A. Terrell]

Ron Hubbard wrote:
>
> Who wants a foot-long screwdriver?

Anyone who needs the proper hand tools. Some of mine are 36", and I
have a custom flexible stainless steel 1/8" blade that is 42 inches to
reach into equipment to adjust hidden controls. I also have a lot of
1/4" hex extensions and can make any length I need. Have you ever used
a 24 foot long drill bit to run wire? I have.


--
You can't have a sense of humor, if you have no sense.

[Michael A. Terrell]

fungus wrote:
>
> The original sonic screwdriver was made
> with vacuum tubes and had space left over.
> Then again, it was much bigger on the inside
> than on the outside.

Like the empty policies of the current administration.

[Michael A. Terrell]

Ron Hubbard wrote:
>
> 143 dB at 4" to 6" which is not bad considering it comes from a
> handheld battery (2 sub-C cells) powered device that drives a piezo-
> transducer less than 1" in diameter. But like I said, just a hi-tech
> toy to amaze friends and sometimes annoy neighbors heh heh. ;-)

Just more 'grade F' science fiction. :(

[Jim Thompson]

On Thu, 26 Jan 2012 12:49:15 -0500, "Michael A. Terrell"
<mike.t...@earthlink.net> wrote:

>
>Ron Hubbard wrote:
>>
>> Who wants a foot-long screwdriver?
>
>
> Anyone who needs the proper hand tools. Some of mine are 36", and I
>have a custom flexible stainless steel 1/8" blade that is 42 inches to
>reach into equipment to adjust hidden controls. I also have a lot of
>1/4" hex extensions and can make any length I need. Have you ever used
>a 24 foot long drill bit to run wire? I have.

I've got a 6 footer, absolutely necessary to get thru fire-breaks. But
I've never seen a 24 footer ;-)

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

[Jim Thompson]

On Thu, 26 Jan 2012 11:10:14 -0700, Jim Thompson
<To-Email-Use-Th...@On-My-Web-Site.com> wrote:

>On Thu, 26 Jan 2012 12:49:15 -0500, "Michael A. Terrell"
><mike.t...@earthlink.net> wrote:
>
>>
>>Ron Hubbard wrote:
>>>
>>> Who wants a foot-long screwdriver?
>>
>>
>> Anyone who needs the proper hand tools. Some of mine are 36", and I
>>have a custom flexible stainless steel 1/8" blade that is 42 inches to
>>reach into equipment to adjust hidden controls. I also have a lot of
>>1/4" hex extensions and can make any length I need. Have you ever used
>>a 24 foot long drill bit to run wire? I have.
>
>I've got a 6 footer, absolutely necessary to get thru fire-breaks. But
>I've never seen a 24 footer ;-)
>
> ...Jim Thompson

But that reminds me, I've used 20' sections of PVC pipe to thread wire
(and coax and CAT-5) thru my old flat-roofed house... pre-thread the
pipe sections with the wire, then shove the PVC from a roof side vent
under the insulation to a ceiling cut-out... great fun :-(

[Michael A. Terrell]

Jim Thompson wrote:
>
> On Thu, 26 Jan 2012 12:49:15 -0500, "Michael A. Terrell"
> <mike.t...@earthlink.net> wrote:
>
> >
> >Ron Hubbard wrote:
> >>
> >> Who wants a foot-long screwdriver?
> >
> >
> > Anyone who needs the proper hand tools. Some of mine are 36", and I
> >have a custom flexible stainless steel 1/8" blade that is 42 inches to
> >reach into equipment to adjust hidden controls. I also have a lot of
> >1/4" hex extensions and can make any length I need. Have you ever used
> >a 24 foot long drill bit to run wire? I have.
>
> I've got a 6 footer, absolutely necessary to get thru fire-breaks. But
> I've never seen a 24 footer ;-)

A six foot 'Diversibit' and three 6' extensions. We used them when I
was teaching people to install alarm systems in the late '70s. They
were used to get from the basement to the attic in two story houses, or
to drill a straight row of holes in studs to run under a row of windows.

[Michael A. Terrell]

Jim Thompson wrote:
>
> On Thu, 26 Jan 2012 11:10:14 -0700, Jim Thompson
> <To-Email-Use-Th...@On-My-Web-Site.com> wrote:
>
> >On Thu, 26 Jan 2012 12:49:15 -0500, "Michael A. Terrell"
> ><mike.t...@earthlink.net> wrote:
> >
> >>
> >>Ron Hubbard wrote:
> >>>
> >>> Who wants a foot-long screwdriver?
> >>
> >>
> >> Anyone who needs the proper hand tools. Some of mine are 36", and I
> >>have a custom flexible stainless steel 1/8" blade that is 42 inches to
> >>reach into equipment to adjust hidden controls. I also have a lot of
> >>1/4" hex extensions and can make any length I need. Have you ever used
> >>a 24 foot long drill bit to run wire? I have.
> >
> >I've got a 6 footer, absolutely necessary to get thru fire-breaks. But
> >I've never seen a 24 footer ;-)
> >
> > ...Jim Thompson
>
> But that reminds me, I've used 20' sections of PVC pipe to thread wire
> (and coax and CAT-5) thru my old flat-roofed house... pre-thread the
> pipe sections with the wire, then shove the PVC from a roof side vent
> under the insulation to a ceiling cut-out... great fun :-(

Not as much as running wire in a department store, over a drop tile
celing that's 30 feet off the floor. We had to use rolling scaffolding,
and remove some tiles, then the cable was tied to a full roll of Scotch
66 tape, and thrown from hole to hole.

[Jim Thompson]

On Fri, 27 Jan 2012 00:02:21 -0500, "Michael A. Terrell"

<mike.t...@earthlink.net> wrote:

>
>Jim Thompson wrote:
>>
>> On Thu, 26 Jan 2012 11:10:14 -0700, Jim Thompson
>> <To-Email-Use-Th...@On-My-Web-Site.com> wrote:
>>
>> >On Thu, 26 Jan 2012 12:49:15 -0500, "Michael A. Terrell"
>> ><mike.t...@earthlink.net> wrote:
>> >
>> >>
>> >>Ron Hubbard wrote:
>> >>>
>> >>> Who wants a foot-long screwdriver?
>> >>
>> >>
>> >> Anyone who needs the proper hand tools. Some of mine are 36", and I
>> >>have a custom flexible stainless steel 1/8" blade that is 42 inches to
>> >>reach into equipment to adjust hidden controls. I also have a lot of
>> >>1/4" hex extensions and can make any length I need. Have you ever used
>> >>a 24 foot long drill bit to run wire? I have.
>> >
>> >I've got a 6 footer, absolutely necessary to get thru fire-breaks. But
>> >I've never seen a 24 footer ;-)
>> >
>> > ...Jim Thompson
>>
>> But that reminds me, I've used 20' sections of PVC pipe to thread wire
>> (and coax and CAT-5) thru my old flat-roofed house... pre-thread the
>> pipe sections with the wire, then shove the PVC from a roof side vent
>> under the insulation to a ceiling cut-out... great fun :-(
>
>
> Not as much as running wire in a department store, over a drop tile
>celing that's 30 feet off the floor. We had to use rolling scaffolding,
>and remove some tiles, then the cable was tied to a full roll of Scotch
>66 tape, and thrown from hole to hole.

I've done that too :-)

[Michael A. Terrell]

Jim Thompson wrote:

>
> Michael A. Terrell wrote:
> >
> > Not as much as running wire in a department store, over a drop tile
> >celing that's 30 feet off the floor. We had to use rolling scaffolding,
> >and remove some tiles, then the cable was tied to a full roll of Scotch
> >66 tape, and thrown from hole to hole.
>
> I've done that too :-)

While some idiot decides the scaffolding is in their way, and gives it
a shove while you're up in the grid? :(

[fungus]

On Jan 28, 12:14 pm, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:

> Jim Thompson wrote:
>
> > Michael A. Terrell wrote:
>

> > >...30 feet off the floor.  We had to use rolling scaffolding,

>
>   While some idiot decides the scaffolding is in their way,
> and gives it a shove while you're up in the grid? :(
>

We're electronics guys. We know how to hook
up a 7000 volt tickler for people like that...

[Ron Hubbard]

> > hobbs at electrooptical dot nethttp://electrooptical.net-Hide quoted text -

>
> > - Show quoted text -
>
> Hmm not to nit pick... (OK I am nit picking :^) But I as far as I can
> remember Dr. Who never used his sonic screwdriver for tightening
> screws.
>

> George H.- Hide quoted text -

>
> - Show quoted text -

Yeah, the screwdriver can't produce true torque-- it works mostly on a
resonance effect. Or rather, it would in the real world; in the Doctor
Who world it does medical scans, welds wire, cut out locks, and
everything else but make a proper cuppa tea.

Mine works at 13 kHz, a compromise frequency that I can hear but most
people have a problem hearing (I don't care *what* they say about the
upper limit for human hearing being 20 kHz, that's BS) but when
frequency modulated, they can hear the lowr secondary frequency.

Ron

[Bob Masta]

On Mon, 30 Jan 2012 16:05:42 -0800 (PST), Ron Hubbard
<or...@dslnorthwest.net> wrote:


>Yeah, the screwdriver can't produce true torque-- it works mostly on a
>resonance effect. Or rather, it would in the real world; in the Doctor
>Who world it does medical scans, welds wire, cut out locks, and
>everything else but make a proper cuppa tea.
>
>Mine works at 13 kHz, a compromise frequency that I can hear but most
>people have a problem hearing (I don't care *what* they say about the
>upper limit for human hearing being 20 kHz, that's BS) but when
>frequency modulated, they can hear the lowr secondary frequency.

That 20 kHz number is correct, but typically only for young
ears. Age in general, and especially an accumulation of
exposures to loud sound, can reduce it substantially.

About 25 years ago I was working with a hearing researcher,
who was trying to get his experimental setup working to
deliver 12 kHz tone bursts to an anaesthetized guinea pig in
a sound booth. I was standing at the equipment rack outside
the booth (door open) and could easily hear the tones. He
was pretty upset to discover that he couldn't hear the sound
even when he held the transducer near his ear.

Like I said, years ago. Dunno if I could still hear that!

Best regards,


Bob Masta

DAQARTA v6.02
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
Frequency Counter, FREE Signal Generator
Pitch Track, Pitch-to-MIDI
Science with your sound card!

[Michael A. Terrell]

It's faster to just drop a 14" New Britan adjustable wrench on their
head. :)

[Michael A. Terrell]

Bob Masta wrote:
>
> On Mon, 30 Jan 2012 16:05:42 -0800 (PST), Ron Hubbard
> <or...@dslnorthwest.net> wrote:
>
> >Yeah, the screwdriver can't produce true torque-- it works mostly on a
> >resonance effect. Or rather, it would in the real world; in the Doctor
> >Who world it does medical scans, welds wire, cut out locks, and
> >everything else but make a proper cuppa tea.
> >
> >Mine works at 13 kHz, a compromise frequency that I can hear but most
> >people have a problem hearing (I don't care *what* they say about the
> >upper limit for human hearing being 20 kHz, that's BS) but when
> >frequency modulated, they can hear the lowr secondary frequency.
>
> That 20 kHz number is correct, but typically only for young
> ears. Age in general, and especially an accumulation of
> exposures to loud sound, can reduce it substantially.
>
> About 25 years ago I was working with a hearing researcher,
> who was trying to get his experimental setup working to
> deliver 12 kHz tone bursts to an anaesthetized guinea pig in
> a sound booth. I was standing at the equipment rack outside
> the booth (door open) and could easily hear the tones. He
> was pretty upset to discover that he couldn't hear the sound
> even when he held the transducer near his ear.
>
> Like I said, years ago. Dunno if I could still hear that!

I used to have no problem hearing the 15,734.34 Hz horizontal sweep
in cheap TVs and monitors. :(

[k...@att.bizzzzzzzzzzzz]

I could hear them from the sidewalk in front of the house.

I worked with a guy (when I was in college) who said he could hear 30kHz, a
few years before(tested by the Navy). Later in the day we were working in the
same lab so without telling him I connected an oscillator to a speaker and
started playing with it around 25kHz. He could *easily* hear 25kHz and got
really pissed when he found out I was playing with him. It had been driving
him nuts for an hour.

[Ron Hubbard]

On Jan 31, 4:52 pm, "k...@att.bizzzzzzzzzzzz"

> him nuts for an hour.- Hide quoted text -

>
> - Show quoted text -

Some years ago they had this sci-fi show that did some really cool
experiments at the first opening of the show as a teaser-- stuff now a
days that you probably couldn't do becaus of an infinite number of
government regulations. Anyway, one of their best experiments [that
used sound] involved using a frequency generator connected to a
parabolic dish; when the tone got up into the ultrasonic, the
wallpaper at the other end of the room burst into flames! An
ultrasonic canon; so cool...

Ron