MessageView 421F schematic

[John Fields]

On Sun, 27 Jul 2003 12:42:16 -0500, John Fields
<jfields@austininstruments.com> wrote:

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?

---
Oops... 60Hz = 3600 cycles per minute, = 7200 strokes per minute...

--
John Fields

 

[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 Raytheon. 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.



OK, you want pictures? Here they are :

whole thing : http://jelinux.pico-systems.com/images/da64clos.png

opened up and connected :
http://jelinux.pico-systems.com/images/da64all.png

Looking into resistor array :
http://jelinux.pico-systems.com/images/da64in.png

showing Cooling fan : http://jelinux.pico-systems.com/images/da64fan.png
<http://jelinux.pico-systems.com/images/da64all.png>

Coax adaptors in storage :
http://jelinux.pico-systems.com/images/da64adap.png
<http://jelinux.pico-systems.com/images/da64all.png>

<http://jelinux.pico-systems.com/images/da64all.png>

If anyone knows anything about this model, especially specs, that would be
greatly appreciated.

Thanks,

Jon

 

[Mike Harrison]

On Mon, 28 Jul 2003 18:17:35 -0400, Boris Mohar <borism@sympatico.ca> wrote:

On Mon, 28 Jul 2003 22:01:13 +0100, Mike Harrison <mike@whitewing.co.uk
wrote:

Just took apart my Metcal MX2 PSU out of curiosity, and found a little pushbutton switch inside,
which is operated by a small grubscrew in the side of the case - anyone know what it's for...?
I don't have the original manual so I don't know if there's any mention of it in there....

Metcal irons are RF driven. That may be an interlock switch.
Nope - it works with the switch in either position. It also doesn't appear to alter the action of

the trip function.

 

[Clint Sharp]

In message <u6gcivs692ib92ng5p01575r3am696df05@4ax.com>, Mike Harrison
<mike@whitewing.co.uk> writes

Just took apart my Metcal MX2 PSU out of curiosity, and found a
little pushbutton switch inside,
which is operated by a small grubscrew in the side of the case -
anyone know what it's for...?
I don't have the original manual so I don't know if there's any
mention of it in there....

Metcal irons are RF driven. That may be an interlock switch.
Nope - it works with the switch in either position. It also doesn't
appear to alter the action of
the trip function.

Just a guess, maybe if it's RF driven, it's to change the frequency to

alleviate interference?
--
Clint

 

[Matthieu Benoit]

May I relay your request,
Please could you send me more information about your DATAIO programmer ;
Do you have any documentation for it ?
Does it need a software on floppy as the datai/o Unisite? How it looks
like ? Can you make a picture of it? etc..
Please contribute freely to this resource page
http://matthieu.benoit.free.fr/126.htm
Also Note that DataI/O offers a very bad support , they do not either
know how to support their own programmers that they
state to figure that they are no longer supported.
DataI/O as swallowed SMS Germany ; As you I have an SMS Sprint Expert
that works fine on demo mode but for which
no software can work (too old programmer : 1991)..
Best Regards,,

MB.

PS You may find at good price a second hand 3900 datai/o Unit at the
address below but the shop is closed until the end of August:
Electronique Diffusion
137 avenue Paul Vaillant Couturier, 94250 Gentilly , France
Tel +33-1 47 35 19 30
Fax +33-1 49 85 91 78
They have a large stock of second hand measurement equipmennts, their
catalogue may be downloaded at:

http://www.electronique-diffusion.fr/Gentilly/Gentilly.html

Ho0gA a écrit :

My son accidentally erased my system disk 2/3. My current system is
5.50. If someone can send me corresponding disk image or later system
release disks, it would be nice.

thanx in advance.

Hooga (NOSPAMhooga@bigfoot.com)

 

[jolphil]

Kalman Rubinson <kr4@nyu.edu> wrote in message news:<10gjiv83g1i1ftimvl37rsvhik85bhaor5@4ax.com>...

Can't provide you with the solution requested but I have found that
such variations are much less of a problem with high quality external
amps and speakers. Some of what we object to with the louder signals
is the distortion imposed by those dinky TV amp/speakers,

Kal


On Thu, 31 Jul 2003 20:36:15 -0400, Vlad <Vlad@bla.Bla.com> wrote:

I am looking for a piece of equipment to regulate the audio level of
my audio output TV set.
Cable or satellite, they all have the same problem. We change channel
and the audio level varies some times more than 6 dB . The worse
offender is CNN ( a channel that I would preferred to be 6 dB lower)
Ideally it should be an assembly that included two amplifiers the
automatic gain control and two decent speakers. Ideally the units
should have a remote control (one more for the collection) to control
the power, the volume and some settings for the 'automatic gain
control}
Most TV sets today have little speakers most of the times on the side
of the set that decrease the intelligibility and provide poor
response.

Does this device exists or do I have to make one?

Vlad

Hi,
Yes it is possible and even some TV"s feature this ..My Panasonic has
this feature..You have to look at the specs to find it..
Sometime cable companies will adjust the overall sound level on a
channel to reduce cross talk and co-channel interferrence..Air
channels I reason will sometimes lower the audio level of the show so
you have to turn up the volume..Then blast you with the
commercial..(just my guess)
As to a vague description of how it can be done is to use a resistive
voltage
divider but the lower leg is a FET ..There as you vary the gate
voltage, the ratio is changed due to the changing drain
resistance..This is a less elagant way to do it but you get the idea..
Good Luck,
JP

 

[Mark (UK)]

Hiya!

Stick the output thru a VCR, and watch the VCR output. The AGC will
control the volume.

Alternatively, use an audio compressor.

Yours, Mark.

Vlad wrote:

I am looking for a piece of equipment to regulate the audio level of
my audio output TV set.
Cable or satellite, they all have the same problem. We change channel
and the audio level varies some times more than 6 dB . The worse
offender is CNN ( a channel that I would preferred to be 6 dB lower)
Ideally it should be an assembly that included two amplifiers the
automatic gain control and two decent speakers. Ideally the units
should have a remote control (one more for the collection) to control
the power, the volume and some settings for the 'automatic gain
control}
Most TV sets today have little speakers most of the times on the side
of the set that decrease the intelligibility and provide poor
response.

Does this device exists or do I have to make one?

Vlad

 

[Boris Mohar]

On 2 Aug 2003 04:30:18 -0700, ks_raman@rediffmail.com (ksr) wrote:

I am very interested to know how an electric nailer works.
Are portable cordless electric nailers available anywhere?

They were installing windows in my house and I asked how many finishing
nails can his cordless nailer drive. "Couple of thousand" I was told
which seemed like a lot unit it was pointed out that the nailer ran on
combustible gas cartridge. I do not know if it even had a battery for the
ignition. Might have been a piezo.

--

Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs http://www3.sympatico.ca/borism/
Aurora, Ontario

 

[Rich Andrews]

Robert Baer <robertbaer@earthlink.net> wrote in
news:3F215BC9.556406FB@earthlink.net:

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.....

Recording conversations is OK so long as one party knows that the
conversation is being recorded.

r


--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"

 

[Rich Andrews]

"Gordon Hanka" <DontSpamMe-grhanka@comcast.net> wrote in
news:6FydnZIptbjstHijXTWcqw@comcast.com:

Back in the 1980's I used to trim circuit board leads before soldering,
with a combination cutter/crimper that would cut the lead wires to about
2mm and simultaneously smash the 2mm lead flat, so it couldn't pull back
through the board. These tools came in both hand and pneumeatic
versions. This was much better than bending/trimming the leads.

Now I can't find a tool like this. Can anyone give me a lead? Thanks.

Gordon

I hated equipement that had crimped component leads! Everytime I worked on a
pices of equipment that crimped the leads, I wanted to take the guy that did
that out back and introduce him to Mr. Crowbar.

Do you know what I really think of an idea like that? PBPBPBPB!


r


--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"

 

[John Crighton]

On Mon, 07 Jul 2003 01:10:12 GMT, "Steve" <zarco@sonic.net> wrote:

Hi Gang,
Picked up one of these scopes, and there are a number of smoked
resistors that are so fried, I can't tell what they are. Need a copy of the
schematic (jpg format if possible), or if someone can tell me the values of;

R24, 7, 16, and 3

Thanks!
Steve W6SSP
p.s.-did a google search, and there are places that sell schemos, but no
freebies


Hello Steve,

you are in luck,

R24 500 ohms
R7 5.6K
R16 15K
R3 100 ohm

I found the circuit here and had a quick look.
http://www.thevalvepage.com/servdata/servdata.htm

Good luck with the restoration/overhaul. I remember
playing with one of these old Telequipment CROs
years ago. I can't remember which model. It was a
tall upright model with push button switches.
I was looking at very slow events. What impressed
me was the excellent triggering and the two or three
seconds per cm on the slowest time base range.
Nice to use.

Regards.
John Crighton
Sydney

 

[Fred Abse]

On Sun, 10 Aug 2003 03:15:55 +0100, William G. Moody wrote:

I have a traffic light, and I would like to try and get the lights to
flash off and on.

Can you tell me which intersection, so that I can stay away?



--
Then there's duct tape ...
(Garrison Keillor)
nofr@sbhevre.pbzchyvax.pb.hx

 

[Fred Abse]

On Sun, 10 Aug 2003 14:14:47 +0100, Rich Andrews wrote:

I have a stange distortion on a 465 that I picked up recently. At first
glance I thought there was a power supply issue or a vertical amp
problem, but now I think it is the CRT. Can anyone confirm my
suspicions? I posted pics of the display on
alt.binaries.schematics.electronic.

First photo looks like some (horribly distorted) timebase waveform is
getting into the Y amps. There are a couple of test points, IIRC, on the
Y preamp PCB, giving the balanced output after channel switching. Connect
another 'scope set to differential (CH1 minus CH2) across these, you'll
see what is going to the main verical amplifier, and that will
incriminate or absolve the preamps. Test points are (I think), in the
middle, towards the back.

Second photo looks like a normal "A and B mixed" display.


--
Then there's duct tape ...
(Garrison Keillor)
nofr@sbhevre.pbzchyvax.pb.hx

 

[Fred Abse]

On Sun, 10 Aug 2003 14:14:47 +0100, Rich Andrews wrote:

I have a stange distortion on a 465 that I picked up recently. At first
glance I thought there was a power supply issue or a vertical amp
problem, but now I think it is the CRT. Can anyone confirm my
suspicions? I posted pics of the display on
alt.binaries.schematics.electronic.

On a second look at photo #1, you might have magnetic field interference,
though, personally I doubt it, the screening in one of those is just too
good. Make sure there are no possible sources of this (other instruments,
electric fan, etc) near.

I doubt very much it's the CRT. That sort doesn't have distributed plates
where you could get part of one plate moved with respect to the others.
Also the "re-entrant" horizontal scan points to timebase interference.

--
Then there's duct tape ...
(Garrison Keillor)
nofr@sbhevre.pbzchyvax.pb.hx

 

[Rich Andrews]

Fred Abse <excretatauris@cerebrumconfus.it> wrote in
newsan.2003.08.10.13.51.18.18815.1041@cerebrumconfus.it:

On Sun, 10 Aug 2003 14:14:47 +0100, Rich Andrews wrote:

I have a stange distortion on a 465 that I picked up recently. At first
glance I thought there was a power supply issue or a vertical amp
problem, but now I think it is the CRT. Can anyone confirm my
suspicions? I posted pics of the display on
alt.binaries.schematics.electronic.

First photo looks like some (horribly distorted) timebase waveform is
getting into the Y amps. There are a couple of test points, IIRC, on the
Y preamp PCB, giving the balanced output after channel switching. Connect
another 'scope set to differential (CH1 minus CH2) across these, you'll
see what is going to the main verical amplifier, and that will
incriminate or absolve the preamps. Test points are (I think), in the
middle, towards the back.

Second photo looks like a normal "A and B mixed" display.

The distortion is in very specific areas of the display and seems to be
mostly in the upper left quadrant. I thought there was a shadow mask similar
to a TV CRT on those CRT's....then again maybe not. In any case, running the
trace off the top or bottom and cranking up the intensity to where the whole
face glows dimly reveals a area which is brighter than normal that more or
less corresponds to the distorted area.

The tube must have been dropped really hard to knock the mask loose if it
exists.

r



--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"

 

[Fred Abse]

On Sun, 10 Aug 2003 18:50:38 +0100, Rich Andrews wrote:

The distortion is in very specific areas of the display and seems to be
mostly in the upper left quadrant. I thought there was a shadow mask
similar to a TV CRT on those CRT's....then again maybe not.

No, there isn't. There is a PDA mesh a bit back from the faceplate but
that probably won't be ferromagnetic.

In any
case, running the trace off the top or bottom and cranking up the
intensity to where the whole face glows dimly reveals a area which is
brighter than normal that more or less corresponds to the distorted
area.

That probably doesn't mean much, since we already know there's a velocity
irrregularity at the LHS. BTW, I wouldn't recommend doing that too often
:-(

What you need to do is switch off the timebase (set to X-Y) and with a
(not too bright) single spot, move the spot over the screen area with the
position controls, one at a time to see if you can trace out straight
lines. If you still get funnies, try and see whether it appears to be
interaction between axes, since the X and Y amps are still in circuit.
Then it's time to get another 'scope and see what is happening at the
plates.

It would be very unlikely for the CRT shield to have become magnetized,
since it's made of mumetal, which is as near to non-retentive as you can
get in a high permeability alloy. Expensive, too, it's mostly nickel.

Have you checked the power supplies for voltage and ripple within
tolerance? It could be tired decoupling capacitors.

Does the instrument look to have been dropped?



--
Then there's duct tape ...
(Garrison Keillor)
nofr@sbhevre.pbzchyvax.pb.hx

 

[Jim Yanik]

Rich Andrews <n0-spam@yah0o.com> wrote in
news:Xns93D382A7AF80Dmc2500183316chgoill@216.168.3.44:

Fred Abse <excretatauris@cerebrumconfus.it> wrote in
newsan.2003.08.10.13.51.18.18815.1041@cerebrumconfus.it:

On Sun, 10 Aug 2003 14:14:47 +0100, Rich Andrews wrote:

I have a stange distortion on a 465 that I picked up recently. At
first glance I thought there was a power supply issue or a vertical
amp problem, but now I think it is the CRT. Can anyone confirm my
suspicions? I posted pics of the display on
alt.binaries.schematics.electronic.

First photo looks like some (horribly distorted) timebase waveform is
getting into the Y amps. There are a couple of test points, IIRC, on
the Y preamp PCB, giving the balanced output after channel switching.
Connect another 'scope set to differential (CH1 minus CH2) across
these, you'll see what is going to the main verical amplifier, and
that will incriminate or absolve the preamps. Test points are (I
think), in the middle, towards the back.

Second photo looks like a normal "A and B mixed" display.



The distortion is in very specific areas of the display and seems to
be mostly in the upper left quadrant. I thought there was a shadow
mask similar to a TV CRT on those CRT's....then again maybe not. In
any case, running the trace off the top or bottom and cranking up the
intensity to where the whole face glows dimly reveals a area which is
brighter than normal that more or less corresponds to the distorted
area.

The tube must have been dropped really hard to knock the mask loose if
it exists.

r

To check CRT geometry,put in some sinewave signal of 1 cycle per
division,amplitude enough to reach from top to bottom of graticule.Move
position controls and watch for distortion of sine wave.
The usual manner is to use time marks from a calibration generator,which
most people do not have.It's possible for hard shocks to distort the mesh
lens at the end of the electron gun structure,or to fracture the glass EG
rods,and have glass chips make 'hot' or dark spots on the phosphor.

--
Jim Yanik,NRA member
remove null to contact me

 

[Rich Andrews]

Fred Abse <excretatauris@cerebrumconfus.it> wrote in
newsan.2003.08.10.19.18.21.445679.2142@cerebrumconfus.it:

On Sun, 10 Aug 2003 18:50:38 +0100, Rich Andrews wrote:

The distortion is in very specific areas of the display and seems to be
mostly in the upper left quadrant. I thought there was a shadow mask
similar to a TV CRT on those CRT's....then again maybe not.

No, there isn't. There is a PDA mesh a bit back from the faceplate but
that probably won't be ferromagnetic.


In any
case, running the trace off the top or bottom and cranking up the
intensity to where the whole face glows dimly reveals a area which is
brighter than normal that more or less corresponds to the distorted
area.

That probably doesn't mean much, since we already know there's a velocity
irrregularity at the LHS. BTW, I wouldn't recommend doing that too often
:-(

Agreed, but I felt it was a quick and dirty test to rule out the vertical and
horiz amps. What if I reversed the deflection plate leads. If there is a
problem with one amp, then would not the problem will move to the other side
of the display?

If I took a dc battery and a pot, would that not totally rule out the
electronics?

What you need to do is switch off the timebase (set to X-Y) and with a
(not too bright) single spot, move the spot over the screen area with the
position controls, one at a time to see if you can trace out straight
lines. If you still get funnies, try and see whether it appears to be
interaction between axes, since the X and Y amps are still in circuit.
Then it's time to get another 'scope and see what is happening at the
plates.

Did that and using the hor. pos. pot to trace out a line yields a a very
bumpy line at the areas where distortion occurs.

It would be very unlikely for the CRT shield to have become magnetized,
since it's made of mumetal, which is as near to non-retentive as you can
get in a high permeability alloy. Expensive, too, it's mostly nickel.

Have you checked the power supplies for voltage and ripple within
tolerance? It could be tired decoupling capacitors.

It has been a while since I worked on a scope, the last one being a 555. Now
there is a formidable monster! Decoupling caps were an issue then and it
seems they still can be. To be honest, no. I need to get a manual.

I had thought that if PS ripple were an issue, any abberation would occur at
the same vertical axis. A trace at the bottom 1/4 of the screen is
relatively pure.

Does the instrument look to have been dropped?

Actually, no. It looks straight and dent free. Now if someone had changed
the tube out and resurrected a dropped 475, I couldn't say.

Aren't unusual problems kinda fun? It certainly makes one drop back to
basics.

r


--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"

 

[bg]

I've had similiar looking problems on my 465 when filter caps went bad.
Don't remember offhand which caps, but I do recall they were near they HV
section , blue and perhaps 200 volt or better. The bottom JPG looks like you
have both time bases switched in, that could be normal. You probably need a
second scope to look at your sweep signal.
bg
Rich Andrews wrote in message ...

I have a stange distortion on a 465 that I picked up recently. At first
glance I thought there was a power supply issue or a vertical amp problem,
but now I think it is the CRT. Can anyone confirm my suspicions? I
posted
pics of the display on alt.binaries.schematics.electronic.


r


--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"

 

[Rich Andrews]

"bg" <bg@nospam.com> wrote in news:bh71e9$o55$1@terabinaries.xmission.com:

I've had similiar looking problems on my 465 when filter caps went bad.
Don't remember offhand which caps, but I do recall they were near they
HV section , blue and perhaps 200 volt or better. The bottom JPG looks
like you have both time bases switched in, that could be normal. You
probably need a second scope to look at your sweep signal.

The bottom signal is clear and straight. When you move the trace up on the
screen to the top 1/3, it is distorted.

r

bg
Rich Andrews wrote in message ...
I have a stange distortion on a 465 that I picked up recently. At first
glance I thought there was a power supply issue or a vertical amp
problem, but now I think it is the CRT. Can anyone confirm my
suspicions? I
posted
pics of the display on alt.binaries.schematics.electronic.


r


--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"

--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"