MessageView 421F schematic

[Mike Feher]

Ron -

It sounds like even if a signal generator existed that met your original
specifications it alone would not be able to accomplish what you are after.
Being able to generate the strong fields that you require is going to take a
lot more power than signal generators are capable of. Another problem will
be to convert the RF energy into a magnetic field. A typical electromagnet
is not going to work at high frequencies due to the magnets inductance,
which will make it even more difficult to feed them just from a generator.
Your project does sound interesting, however, you will need to look into the
realism of being able to create your fields with available signal sources
and components. Regards - Mike

--



Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-901-9193



"EMScan81" <emscan81@aol.com> wrote in message
news:20030714221919.18594.00000288@mb-m20.aol.com...

Ron,

OK, you really want to know what I want to do? OK, well, I want to use a
four
coil cross with a two phase A/C signal through them to create a circularly
polarized signal. I'll be using another field, a static magnetic field,
at
right angles to the circular field. I'm doing at home research in
spintronics,
which concerns electrons and their spin. In spintronics the electron as a
magnetic dipole is spun around like a compass needle would if you put a
magnet
over it on a string and twisted the string around. That's why the
circular
field needs to be more than a simple RF signal--the "near field" needs to
be
strong--I'm using coils, not antennas. I'm trying to ionize a material
this
way as well, because there are some Lorentz force effects that occur with
the
static magnetic field's existence. It's better for me to have a higher
frequency because that will help ionize the target material that I'm
studying
(a ceramic magnet) and increase the chances of observing this Lorentz
force
interaction. Well, there you go.

Thanks!
Ed

PS--I guess I don't really need the low frequency ability. It would have
been
nice to map the field--trouble shoot it if you will--but I could probably
come
up with other ways of doing that.

 

[ctsbillc]

There are function generator kits around which will do the low end stuff up
to 10 MHz or so. There is even an Exar chip for a few $ which will do it
with few external components. I think the number is XR038.

Mike is quite correct on the difficulties with driving electromagnets, you
have to know what you are doing. Up to a few kHz you may use a ferrite core
and get half a Tesla flux density. Lower that this, iron cores may give you
up to two Tesla. Properly shape your pole pieces to get a good field across
the gap. Or maybe wind a big Helmholtz coil for a lower but more linear
field.

Best regards,

Bill C

"Mike Feher" <n4fs@monmouth.com> wrote in message
news:7y0Ra.33055$QD2.7294587@news4.srv.hcvlny.cv.net...

Ron -

It sounds like even if a signal generator existed that met your original
specifications it alone would not be able to accomplish what you are
after.
Being able to generate the strong fields that you require is going to take
a
lot more power than signal generators are capable of. Another problem will
be to convert the RF energy into a magnetic field. A typical electromagnet
is not going to work at high frequencies due to the magnets inductance,
which will make it even more difficult to feed them just from a generator.
Your project does sound interesting, however, you will need to look into
the
realism of being able to create your fields with available signal sources
and components. Regards - Mike

--



Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-901-9193



"EMScan81" <emscan81@aol.com> wrote in message
news:20030714221919.18594.00000288@mb-m20.aol.com...
Ron,

OK, you really want to know what I want to do? OK, well, I want to use
a
four
coil cross with a two phase A/C signal through them to create a
circularly
polarized signal. I'll be using another field, a static magnetic field,
at
right angles to the circular field. I'm doing at home research in
spintronics,
which concerns electrons and their spin. In spintronics the electron as
a
magnetic dipole is spun around like a compass needle would if you put a
magnet
over it on a string and twisted the string around. That's why the
circular
field needs to be more than a simple RF signal--the "near field" needs
to
be
strong--I'm using coils, not antennas. I'm trying to ionize a material
this
way as well, because there are some Lorentz force effects that occur
with
the
static magnetic field's existence. It's better for me to have a higher
frequency because that will help ionize the target material that I'm
studying
(a ceramic magnet) and increase the chances of observing this Lorentz
force
interaction. Well, there you go.

Thanks!
Ed

PS--I guess I don't really need the low frequency ability. It would
have
been
nice to map the field--trouble shoot it if you will--but I could
probably
come
up with other ways of doing that.

 

[EMScan81]

Thanks for all this help!!

Ed

 

[Metrology]

Hank,

Give GIDEP a shot... http://gidep.org
{Government-Industry Data Exchange Program}

Free site (must subscribe though) of US armed forces tech data..


Search the database by model or FSN #

Results:
The acronym "TM" is a tech manual, "CP" Cal procedure etc...


Good luck
PJ







"Henry Kolesnik" <wd5jfr@oklahoma.net> wrote in message news:<vgotgltbuspt43@corp.supernews.com>...

Anyone have a manual or schematic on this HF sig. gen? I can't find
anything except my queries.
tnx
hank wd5jfr

 

[Metrology]

Sharp,

The most common problem is the power supply.. Due to the heat and
poor fan design I'd recommend replacing the large Electrolytic caps..

Dielectric Absorption is basicly a cap drying out..

Dont be fooled, most will pass a basic cap checker test... Only an
advanced cap checker will catch the true problem....!

Good Luck...
pj






"Sharp" <dj_pulpo@hotmail.com> wrote in message news:<bddcjq$lhv$1@nsnmpen2-gest.nuria.telefonica-data.net>...

I have a tektronix 492 spectrum analyzer and I have a problem with the
display;

The analyzer seems to work ok but the video is compresed in a little square
on the screen.

I thing that is a problem in the deflection amps board or in the video
procesor board, but I don't have the service manual or any kind of
schematics...

Anybody can help me??

Thanks!

 

[Michael A. Terrell]

ctsbillc wrote:

Analysis requires expertise, also, its not the sort of thing you can do
without experience, and usually an engineering degree.

Best Regards,

Bill C

What a load of bullshit! Yes, you need to know what you are doing. Its
the same when using any piece of test equipment. On the other hand, if
you think you need "an engineering degree" to understand the instrument,
your are a low grade moron. There are a whole of a lot of S/As on
benches used by production, test and service techs. Last place I worked
the ratio was over 10 to 1 for production & test vs design, and it was
an engineering to order company. A true production plant would probably
have even more.

--


Michael A. Terrell
Central Florida

 

[Michael A. Terrell]

Walter Harley wrote:

"Winfield Hill" <whill@picovolt.com> wrote in message
news:bejimt014io@drn.newsguy.com...
Walter wrote...
[...]
In my own power supplies, I've usually put a switch on the output, so
that
I can leave the supply powered up and simply switch the output on and
off.
But the bench supplies I've bought never seem to have that feature,
which
has always puzzled me.

Such a switch can get you into trouble, if it applies an instantaneous
supply-voltage step to a circuit. The dV/dt slew rate can be very high.

Hmm, good point. Of course, that could happen in the as-manufactured
circuit too - some of my circuits get powered by batteries, turned on by a
switch, so there's going to be as much dV/dt as the internal impedance of
the battery permits. If the circuit dies on the power supply, it might be
telling me something.

I guess what I really want is a switch that either cuts the output to zero
or ramps it back up to the preset voltage over the course of, say, 100msec.
I do want it to go all the way to zero, though, so that when I'm fooling
around with the circuit I don't inadvertently reverse-bias a tantalum cap or
whatever. Alternately, I want the max current to be limited to < 5mA or
so - which amounts to the same thing.

It always makes me uncomfortable to turn on a circuit under test by means of
turning on the AC to the bench power supply. I wonder whether the supply's
current limiting circuitry will be able to kick in in time, whether the
voltages will stabilize right away, and so forth. I guess I've never
actually had a problem with it, though; not sure why.

-w

We just put all the power supplies into a switched outlet strip, and
turned them on at the same time for both board and module level testing
on the production floor. That way you didn't forget to kill one output
and damage a new $8000 circuit board that was fresh from assembly.
--


Michael A. Terrell
Central Florida

 

[Michael A. Terrell]

ctsbillc wrote:

There are function generator kits around which will do the low end stuff up
to 10 MHz or so. There is even an Exar chip for a few $ which will do it
with few external components. I think the number is XR038.

Mike is quite correct on the difficulties with driving electromagnets, you
have to know what you are doing. Up to a few kHz you may use a ferrite core
and get half a Tesla flux density. Lower that this, iron cores may give you
up to two Tesla. Properly shape your pole pieces to get a good field across
the gap. Or maybe wind a big Helmholtz coil for a lower but more linear
field.

Best regards,

Bill C

The Exar is a 8038. It is an old design, so I would recommend using
a newer design from Maxim, the MAX 038. You can get the PDF datasheet
and a sample chip from: http://www.maximic.com
--


Michael A. Terrell
Central Florida

 

[Michael A. Terrell]

Jean Sicard wrote:

I am looking for the following switches for the Collins 479S-6 test set:
DC51-01 and DC51-64. I need about 50 of them. They are near impossible to
find. Also looking for maintenance manual. Any help would be greatly
appreciated.

Thanks
Jean

Post a picture to news:alt.binaries.schematics.electronic so people can
see what they look like, then tell people here what the name of the
tread is on A.B.S.E.
--


Michael A. Terrell
Central Florida

 

[gothika]

570 is pretty high resolution, most of the one's I'v eused in the past
were in the range of 320 to 440 lines and produced fairly good images.
(consider that minidv camcorders are usually in the 500-550 range on
the recorder.)
As for output. Gigahz the higher the better and the highest wattage
you can get.
I just purchased an elcheapo wireless off of ebay(50 bucks.) that was
just 200mw at 900mghz.
The resolution is 440 lines and is sensitive in the low infrared as
well.
It does manage to transmit a fairly clear signal through a brick wall
at about 90 ft. But that's just about as far as it'll go without snow.
The color is fairly good considering it's 1/3 inch ccd.
I'll be tweaking it up a bit to see if I can get a bit more range out
of it, but considering the price It's limitations are bearable.
I plan to use it strickley for security, you sound as if you want
something in the broadcast quality range.
What are your bugetary limits? I could scout around the web at various
companies I do business with and see if they have what you need.
P.S. stay away from X10, it's rinky dink junk that defective out of
the box about half the time. The specs are overblown to the point of
actually falsehoods as well.
On 12 Jul 2003 04:48:28 -0700, seymoria@yahoo.com (amer) wrote:

Hello everyone.

I need your advice for purchasing a small wireless video camera with a
built-in transmitter. Main features I am looking for are :

1- VERY high resolution, (comparable to modern Sony camcorders).
2- Transmitter which can operate out of its "line-of-sight" also.
3- Transmitter which can pass signal thru walls. (not mandatory)
4- Moderately long range (e.g. 300 meters).
5- Video to be recorded on a suitable device for later playback on TV.
6- Long battery life (~6 hours)

I have been browsing the internet but cant select the right model as I
dont know much about electronics. Currently I have found one with '570
lines of horizontal resolution'. Is this comparable to a normal
camcorder? The website is :

http://www.nctc.com/~dfluehe/

What frequency, MHz or GHz, transmitter would be right for me? They
start from 500 Mz and go upto 2.4 Ghz. Some, mentioned as for 'CCTV'
equipment, go right upto 10 and 24 GHz also!

How can I record the video for later playback on a normal home-TV?
What type of
device can I employ? Also what instrument would receive signal from
the transmitter? Do I need to purchase an antenna or an amplifier
also?

Thanks very much for any help you can provide.

Regards,
Amer

 

[gothika]

What you actually need is an SEG(special effects generator.)
There are low end "switcher" style segs made though most are composite
video which I don't think is what you want.
Try going onto ebay in the professional video catagory and looking for
an SEG or video switcher.
You'll just use the video wipe or crossfade(lapse) settings and set
the duration for whatever time you want.
It'd be to complex and expensive to make.
You can get a small one on ebay for from 90 to 200 bucks.
On Sun, 6 Jul 2003 14:48:42 -0400, "Steve Lefevre"
<lefevre.10@osu.edu> wrote:

Hey folks -

I'm trying to get my hands on (which probably means 'make') a video mixer,
like a DJ mixer.

I want to have it so I can use the video outs on two laptops, have one
laptop playing a DVD, which goes through the mixer to the projection screen,
and meanwhile I'm getting the next DVD scene ready. When it's at the right
point, I slide the slider over and now laptop 2 is on the projection screen.

Can this be a simple project? I'm a self taught computer geek, but I don't
have very much electrical knowledge.

Steve

 

[gothika]

It'd help if you gave us the model and make of the camcorder.
Most 8mm have a video/audio out right on the side.(2 rca out jacks.)
At least all my Sony's, RCA's, Hitachi's and Panasonics do.
Your's may be under a rubberized cover that'll just pull out or off.
Then you just need a stereo rca cable.

On Wed, 25 Jun 2003 00:25:35 -0400, "Matt A. Clement"
<buckeyes1997@yahoo.com> wrote:

im going to start poking around in the camera for a video signal that can be
taken outside for a direct hookup to transfer video from older 8mm
camcorders.

has anyone done this and or is it going to be possible? the camera has a
vcr mode where it plays it back in the viewfinder so there must be a video
signal somewhere right?

what does a video signal look like on an o-scope....ive never really played
with video signals.

 

[Robert Baer]

Jeff Wisnia wrote:

This one happened with on one else looking, thank goodness...

SWMBO complained that her car's key fob door unlocker/horn blower gizmo
was getting "weak". ('98 Oldsmobile) I snapped it open, noted the
battery number and picked up a replacement at Rat Shack the next day.

I popped the new battery in and gave it a try....................."Nada"

I took it back into my workshop, checked that the battery was oriented
the same way the old one, and then started examining the little circuit
board with a loupe, hoping to discover a cracked joint. Nothing visibly
wrong there, so I peeled off the rubber keypad and found some not
unexpected greenish goop inside.*

I said to myself, "So that's what's wrong!" and cleaned the crud off
with alcohol.

Took it back outside again. Still nothing!

Back inside once more, opened it up hoping for a miracle, whereupon my
eye fell on some tiny "black on black" raised lettering on the inside of
the little devil's back cover reading, "After changing battery, place
near car and press Lock and Unlock buttons for 7 seconds".

Followed the instructions, and at the count of seven the car's horn
blipped once and all was well in River City again.

RTFI !!!

Now, I wonder what the hell that did? Could it have been programming the
car's receiver/decoder to match the xmitter? If so, it sure doesn't seem
a very secure system, does it?

_________________________________________________________________________

*The oily stuff I often find under the rubber keypads of our TV remotes
and similar gadgets when they start getting antsy about responding to
the keypresses. I was told years ago that it's oil from peoples fingers
which migrates right through the silicone (??) rubber, but I'm inclined
to think it's plasticisers coming out of the material. Anyway, wiping it
off with alcohol always seems to make them work like new again. Anybody
know more about this subject?

Jeff

--
Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"Success is getting what you like; Happiness is liking what you get."

I have seen the same problem, and think you are correct that the glop
is plasticisers.

 

[Jon Elson]

A E wrote:

Jon Elson wrote:



Hello, all,

I have just picked up an ancient US Army Signal Corps dummy load,
model DA-64A/UP, made in about 1958 by Ratheon. It is a massive
unit, with 12 100 W resistors in it, and forced air cooling. It has
some massive coaxial connectors on it that are unfamiliar to me.
It is 50 Ohms, though. I was wondering if anyone had the specs on this,
with respect to average and peak RF power, and frequency range.

Thanks in advance,

Jon



Pictures? I'd like to see those connectors. They could be GR-874.



Well, I'll get pix soon. No, these are not like GR-874 connectors at all.

They are large (1.5 - 2.5" diameter, with convoluted ceramic inserts,
and threaded clamping rings. They look like thay are made for very large
voltages at frequencies below 50 MHz, maybe. There are 4 adaptors in
one of the end covers, and a coax extender in the other. Some of the
connector
part numbers are :
CBRS UG-34/U
S276-1306P1
CBIB UG180A/U
CBRS UG-222/U

The whole thing is in a cylindrical can 12" diam x 20" long, with removable
caps on each end. the caps have really big O rings to hermetically seal the
thing, which is why a 45-year old power cord looks like new. (The power
cord is to run the cooling blower.)

Jon

 

[amer]

Hi friend.
Thanks for posting a helpful response.

Yes, you are correct, I want a long range thing that can work out of
line of sight and pass thru walls also. Range = 100 meters at least.

Maybe I would need an amplifier-transmitter-receiver- set for this
camera? My budgetary limits depend on how much i get for my money.
Roughly, its upto 500 $.

My requirements may fall out of the unlicensed transmitter range, and
may be FMTV is the only option for me?

Thanks a lot.
Amer


gothika <gothika@earthlink.net> wrote in message news:<eismhvgdmsvcrm406hdk31sqd064e2ak47@4ax.com>...

570 is pretty high resolution, most of the one's I'v eused in the past
were in the range of 320 to 440 lines and produced fairly good images.
(consider that minidv camcorders are usually in the 500-550 range on
the recorder.)
As for output. Gigahz the higher the better and the highest wattage
you can get.
I just purchased an elcheapo wireless off of ebay(50 bucks.) that was
just 200mw at 900mghz.
The resolution is 440 lines and is sensitive in the low infrared as
well.
It does manage to transmit a fairly clear signal through a brick wall
at about 90 ft. But that's just about as far as it'll go without snow.
The color is fairly good considering it's 1/3 inch ccd.
I'll be tweaking it up a bit to see if I can get a bit more range out
of it, but considering the price It's limitations are bearable.
I plan to use it strickley for security, you sound as if you want
something in the broadcast quality range.
What are your bugetary limits? I could scout around the web at various
companies I do business with and see if they have what you need.
P.S. stay away from X10, it's rinky dink junk that defective out of
the box about half the time. The specs are overblown to the point of
actually falsehoods as well.
On 12 Jul 2003 04:48:28 -0700, seymoria@yahoo.com (amer) wrote:

 

[Robert Baer]

Andreas Nilsson wrote:

Hello,

I want to record a telephone call, and also have the possibility to feed
the telephone from an own audio source through a connector, rather than
just speaking into the handset.

So, what I need is an adapter with a telephone handset connector in one
end, and two audio connectors (3,5 mm or whatever) in the other end -
one out (that I can connect to a recording device) and one in (that I
can feed with my audio signal).

I have seen a lot of adapters connecting to the telephone handset
connector giving an audio-out connector; but I need something where I
can also provide the signal that is sent to the phone (and to the person
I am talking to).

Thanks in advance.

Since you speak about the handset, be advised that one used to put a
handset into a pair of muffs that was a part of a 110 baud or 300 baud
modem - it was a way of getting around the direct connection
restrictions that Ma Bell had at the time (1980s).
There was a speaker (or similar) on one end used to generate sound,
and a microphone on the other end to pickup sound.
So much time has elapsed since those daze, it would be a challenge to
find one of those old modems.
OTOH, many phones still have a transformer inside for "sidetone"
coupling of the two signals.
So one can use a coil pickup for listening to conversations; some
experimentation is in order to find the most sensitive position for
pickup.
It might be possible to use the same coil for transmitting signals to
the phone; i have not tried that.
These are the two possible ways to allow what you have in mind.
Just do not record conversations; there are some fairly stiff federal
regulations.....

 

[ctsbillc]

Well, never had one apart, but it has got to be a slug of soft iron which
gets pulled into a magnetic circuit with a coil of wire wrapped around it.
The coil will be connected to the mains, and provide magnetic attraction at
twice mains frequency.

A spring will set its return location.

Bill C

"Camilo Andres Gil Cardona" <camilogil@100cia.zzn.com> wrote in message
news:c54ff370.0307262022.127c7418@posting.google.com...

Hi everybody! i want and need to know how works an electric engraver,
or to be more objetive, i need to know its internal system, what
generate de mechanical vibration... any answer or link with that topic
will be appreciated!
Here is a link with the device to you make an idea what device i'm
talking about
http://www.mytoolstore.com/dremel/misctols.html

 

[Richard Crowley]

"Camilo Andres Gil Cardona" wrote ...

Hi everybody! i want and need to know how works an electric engraver,
or to be more objetive, i need to know its internal system, what
generate de mechanical vibration...

It is just a big, heavy-duty "buzzer".
The moving armature is connected to the shaft that holds the "engraving"
tip.
The line mains current directly moves it up and down.

 

[John Fields]

On Sun, 27 Jul 2003 09:34:43 -0400, "ctsbillc" <nospamctsbillc@ieee.org>
wrote:

Well, never had one apart, but it has got to be a slug of soft iron which
gets pulled into a magnetic circuit with a coil of wire wrapped around it.
The coil will be connected to the mains, and provide magnetic attraction at
twice mains frequency.

---
_Has_ to be?

Where do you live that has 3600Hz mains?

--
John Fields

 

[John Fields]

On Sun, 27 Jul 2003 08:13:17 -0700, "Richard Crowley"
<rcrowley7@xprt.net> wrote:

"Camilo Andres Gil Cardona" wrote ...
Hi everybody! i want and need to know how works an electric engraver,
or to be more objetive, i need to know its internal system, what
generate de mechanical vibration...

It is just a big, heavy-duty "buzzer".
The moving armature is connected to the shaft that holds the "engraving"
tip.
The line mains current directly moves it up and down.

--
John Fields