开云体育

Thanks for the ideas.

Tge trackbis just lifted, there is no break. It's flexible, held together
by the conformal coating, and there's continuity. So, I want to glue it
down. I don't think it would be possible to get epoxy under there, as I
don't think it will wick. However CA glue will. What do you think of that?

On Fri, 3 May 2019, 15:56 Brendan via Groups.Io <the_infinite_penguin=
[email protected] wrote:

On Fri, May 3, 2019 at 06:29 AM, cheater cheater wrote:

I have a piece of equipment where a trace was lifted. The part is still
attached and I would like to glue it down. The part is a socket for a
cable, and the plug is difficult to insert and remove. I will have to
solder the other pin which is the ground plane, and broke off, so the

glue

has to survive that. I'll also need to add some structural solder on

the

sides. Is cyanoacrylate a good idea here? Anything better than that?

Thanks.

This is what I use. It is actually a pcb over coat epoxy but it seems to
stand up well to heat.

I have a piece of equipment where a trace was lifted. The part is still
attached and I would like to glue it down. The part is a socket for a
cable, and the plug is difficult to insert and remove. I will have to
solder the other pin which is the ground plane, and broke off, so the glue
has to survive that. I'll also need to add some structural solder? on the
sides. Is cyanoacrylate a good idea here? Anything better than that?
Thanks.

I have a piece of equipment where a trace was lifted. The part is still
attached and I would like to glue it down. The part is a socket for a
cable, and the plug is difficult to insert and remove. I will have to
solder the other pin which is the ground plane, and broke off, so the glue
has to survive that. I'll also need to add some structural solder on the
sides. Is cyanoacrylate a good idea here? Anything better than that?
Thanks.

Your idea is correct, the large belt driven compressors are the best
and places like Harbor Freight has them brand new for a reasonable price.
Don't forget the water filtration and drain the water from the tank.
You could make a "self draining" or "automatic" condensation purge
with an Arduino or ESP32/ESP8266 and few more parts to open valve.
But a reminder once a month should give you time to check the system
and drain the water from the tank.


On Thu, May 2, 2019 at 10:24 AM David Kuhn <Daveyk021@...> wrote:

" Because they don't have a "quiet" air compressor. "

That's the biggest problem. In the garage, I built a compressor dog

house

with six inch walls with insulation on all side. Even the access
door is

6" thick with insulation. It worked great, but the air compressor
got

used hard. Well know the saying "out of sight, out of mind"?
That's the problem. It never got maintenance. Now, I just let it
be noisy in the garage as needed. I don't use it that much, so I
just go out and turn it on as-needed rather than let it be
automatic. I would like to have a

huge

tall tank that hold a lot of air; but they can be expensive. I need
to

go

to some auctions and find a six foot tall belt driven compressor
that can run only every so often and let it on automatic.


On Wed, May 1, 2019 at 9:59 PM Harvey White <madyn@...>
wrote:

On Wed, 1 May 2019 14:53:04 +0200, you wrote:

I hear conflicting reports on what one should do. What's your take?
Are there different types where you should or shouldn't?

Compressed air isn't. There's not enough room in the an.

Druckluft 67 (aka Dust Off 67) from Kontakt / CRC says not to
shake the can "or otherwise the fluid might come out", but is it
always the case with all types? What is that fluid for, anyways?

The fluid evaporates, produces gas, and that's what your
"compressed air" happens to be.

I read reviews of some cheaper compressed air products on amazon
and they complained about the quality. What can go wrong with
compressed air?

Liquid for one, which you don't want, and then again, what's the
liquid that's evaporating to give you this "air"?

Two things people brought up were one brand produced very weak
pressure, and another produced flammable rather than inert gas.

Depends on what's evaporating. Butane would work, so would freon,
so would a lot of other things, includin propane.

Druckluft 67 touts as being oil free. Are there other things that
might go wrong?

er..... what's in that liquid?

Why would someone use canned compressed air rather than an air

compressor?

Because they don't have an air compressor. Because they don't
know the difference. Because they don't have a "quiet" air compressor.
Because they don't have the driers and particle filters to clean
up the output air from the compressor (which may or may not have
oil in it from the air pump).

Harvey

Thanks.

Sorry for asking this question: What is " levelling head kit" ?
I think it has something to do with calibration....

On Thu, May 2, 2019 at 5:25 PM Craig Sawyers <
c.sawyers@...>
wrote:

And you can get a levelling head kit (no housing) for the SG504 from me

...

David

I have one of your kits and have had for quite a while. Just waiting to
find an SG504 without head
that is less than stupid money ;-)

Craig

On Thu, 2 May 2019 10:07:39 -0500, you wrote:

After reading your email Harvey I went to see what is available and I
agree, it would be nice to have it also.

Yep, I have about 10-15 scopes, variously, and a number of V and H
plugins to deal with. Those are good things to have. A good set of
extenders is also nice to have, although you can do some work without
them.

If you're working with the TM500/TM5000 series, then a good set of
extender boards is really nice to have.

I need to slow down, I would spend myself into a hole in the ground!
For some reason I do not go just 10%, I must go 100% and run out of time

to

play with it all!

Slow down a bit, plan what you want, then go over that with an idea of
what you need....

Then try to get it.

Hamfests can be good.

I'll donate my stuff to a club when I'm gone, hope someone will have fun
with some of my stuff one day!

Always good to spread the wealth that way.

Harvey

On Wed, May 1, 2019 at 9:12 PM Harvey White <madyn@...>

wrote:

On Wed, 1 May 2019 21:02:32 -0500, you wrote:

Great information, and thank you for that.
The option 22 are some probes - but I do not know what probes they

were.

If you know, or anyone else, let me know please.
Do you have, or do you know where I can get the software for the

P6407/GPIB

Word Recog?
I also would like to know how to use it - I can't find much on the

Internet

about it.
But someone is sending me the P6407, it should be here by end of next

week.

There's a digital trigger option with a word recognizer, that allows
you to trigger on a digital pattern. That's what the P6407 is used
for. The GPIB option would simply allow you to set that pattern, if
at all, and whatever trigger qualities you need.

Attach the leads to digital signals, set the pattern you want for a
trigger, and the scope should trigger on that one. Never really used
it on my 2430A, but got the trigger generator anyway. Turns out to be
more useful to have a logic analyzer for what I was doing, and I do.

This was a foray into the logic analyzer domain of products to allow
the scope different characteristics.

You use this for digital only and a logic analyzer is better. You use
a digital trigger to look at an analog waveform, and you need either
this scope or we need a logic analyzer with a scope plugin (or
triggering of the scope from the LA.

Harvey

You have a great day!
Tony

On Wed, May 1, 2019 at 6:27 PM Ken Winterling <wa2lbi@...>

wrote:

Tony,

FYI, Tektronix produced a number of 2465 model "packages" that

included

certain options. I have 2465DVS and it has a DMM.

*Model Includes options*
2465 CTS 9, 10, 22
2465 DMS 1, 9, 10, 22
2465 DVS 1, 5, 9, 10, 22
2465A CT 9, 10, 22
2465A DM 1, 9, 10, 22
2465A DV 1, 5, 9, 10, 22
2465B CT 9, 10, 22
2465B DM 1, 9, 10, 22
2465B DV 1, 5, 9, 10, 22



Ken
WA2LBI





On Wed, May 1, 2019 at 7:03 PM Tony Fleming <czecht@...>

wrote:

My scope is 2465 DMS and it has DMM also - not an add-on.
Someone said that mine is 2465 CTS (but I think all CRT scopes can

be

called that).
As per catalog Tektronix put out, I could not find my model either!
But there are many catalogs that are incomplete, I think.
If your scope works, the manual for 2465B should be the same.
Also, look at the back of your scope and find a silver tape that

has

options printed on it with small holes punched out, if you have

that

option.
That is how mine has options 1, 9, 10 and GPIB port.
See if on the back is any other "model number".

I'm looking for the software that would communicate with my

computer -

does

anyone have the software and or manual for it?
Also, I have a port for P6407 - I also need as much help with that

and

software that, I assume, it will need.

Tony

On Wed, May 1, 2019 at 5:45 PM Dave Daniel <kc0wjn@...>

wrote:

All,

I have a Trektronix 2465B that has the DMM option physically

present.

Looking at the TekWki web page for the 2465B, I see photos that

show

this 'scope branded as "2465BVD". My 'scope is branded as

"2465B".

The DVM does not appear to have been an add-on.

Can anyone explain how a 2465B with the DMM option would not be

branded

as a 2465BDV?

Thanks

DaveD

On Thu, 2 May 2019 10:03:24 -0500, you wrote:

WOW what a nice reply Harvey! Thank you very much! You swiped me off my
feet with all the details!

Well, step back from the leaves and look at the branch, then step back
and look at the tree, then the forest. Easy to get lost when you're
trying to count leaves in a national park...

OK, I knew I was over my head, but now I think I'll start at -100th floor
and work up from there.

Get a feel for it. Some things are good for scope functional
evaluation, some things are needed to calibrate and standardize
scopes.

What are you building this lab for? Not only why, but what do you
want to do? Immediate answers not needed (and they're for you, not
me). But the answers for these questions show you different
directions for equipment.

Digital electronics require a very different set of instrumentation
(with overlaps always) than RF measurement, or Audio, or general
purpose repair, or television, etc.

Always ask questions, sometimes even if you know the answer. Always
something to be learned.

Don't worry about how much you know, or don't know. Nobody knows
everything, or is expected to...

Me? I do a lot of general purpose work, but a lot of design in
digital, power supplies, graphics displays, etc. That tends to make
me look at relatively high bandwidth analog (500 Mhz to 1 Ghz if
needed), I use logic analyzers and a fair amount of power supplies as
needed. Signal generators and meters are also useful.

RF stuff? Not that much. So that's how my lab works.

Harvey

I'l read this later and try to go from there.
All of you TEK guys are GREAT! Thank you all!

On Thu, May 2, 2019 at 12:03 AM Harvey White <madyn@...>

wrote:

On Wed, 1 May 2019 22:00:36 -0500, you wrote:

Thanks for a fast reply Harvey!
I'm not a professional, just a hobbyist and I love to fix anything I

get

my

hands on.

Well, I've been in electronics for a while, and even earned money
doing it, so I guess I qualify as a professional of sorts.

When I see how people dump everything, before thinking to fix it, it

makes

me sick how wasteful we become.

Some of this stuff is not possible to repair without tools and parts
not available to most...

If I could fix stuff for free I would, that is how much I love to give
anything a second, third... chance to do its work.
Helping handicapped and old/poor people brings me more joy, when I see
their eyes sparkling again!
So not for now I don't need a perfect scope, but a working one that

gets

me

there. My plans are to teach anyone some basic electronics and

encourage

them to have a hobby.....

A good Tektronix scope will be a joy, *if* they can appreciate it.

I once brought a 7000 series scope into a classrom with a 7CT1N (curve
tracer) plugin so I could demonstrate transistor curves.

One of the students looked at it and said "old tech".

He's right, but his view is a trifle narrow....

For now the scope does something, that is much more than when I

received

it, so now I like to play and learn, since my modern scope is nothing

like

2465 DMS.

likely not.

But I always wanted Tek scope so I have one and it needs a checkup and

or

a

way to make it work well.

Well, the basic checks are useful for functionality. IIRC, there are
some functional checks in the service manual.

You can check the sweep at least by looking at the relative numbers of
cycles going from one range to another. You won't get exact, but
you'll see if 20 us/div is about right.

Ditto for the vertical section.

I found on eBay *Tektronix PG506 - * but they are mostly a PLUG-IN

style.

Can I run it without a housing?

No.

It's made to go into a TM500 style housing. It's a power supply unit
with individual (and somewhat odd) voltages available to each
plugin...

Generally comes in 1,3, 4, and 6 module sizes. The 5 unit is made to
be portable. There may be a 2 unit size, but I'm not sure.

TM 501, TM503, TM504, TM515 (portable), and TM506. The TM5000 series
is similar, somewhat larger, with the units being microprocessor based
and remote controllable.

Most of the TM500 units fit into the TM5000 frame, but no TM5000 unit
will fit into a TM500 frame.

When I look over the pictures for *Tektronix PG506 *it seems to me that

the

power supply is in the base unit..... but I don't know anything about

it.

You're right, that's where it is intended to go. There are some older
(perhaps tube) models of test generator, though.

Starting with say, a 20 Mhz oscillator, divide by 10, then 2 to get a
1 us period waveform. Divide by 5 then 2 to get a 2 Mhz waveform (500
ns period), divide by 2 to get a 100 ns period waveform, etc. With
the right frequencies and TTL divider chips, you can get yourself a
timing generator.

The 1-2-5 for voltage is harder, though.

I have skills and even 3D printer, so I can make something to cover the
back end, where I can make a power supply connect....

First just find the TM500 style plugin unit. Check out the TM500
series of plugins (DC 5xx, DM 5xx, PG5xx, etc. They may be a good
addition to your lab, within reason. They're not wonderful, but they
are decently made.

I'll keep your email and start looking for a complete *Tektronix PG506,

*it

can be a great addition to my tools here.

Read the description first, and don't spend tons of money on it.

What you'd be getting is the amplitude part of a calibration
generator, that puts out voltages in the 1-2-5 sequence that Tektronix
uses. It's very convenient and was intended to help calibrate their
vertical plugins and vertical channels.

The more scopes you have, the more you may need this, but think about
it first. There's a lot you can do to work around not having one.

Harvey, you are great help and the rest of the guys here are also very
helpful, I'm glad to belong to Tektronix group!

It's a good group.

You make me smile more and more!

Keep asking questions. There's no perfect setup, and a number of
workarounds.

Harvey

Tony


On Wed, May 1, 2019 at 9:34 PM Harvey White <madyn@...>

wrote:

On Wed, 1 May 2019 21:10:39 -0500, you wrote:

Since I'm new to Tektronix 2465 DMS with DMM, what "signal

standardizer"

model number would I need?

DC voltage standard (PG506 will work, set it on DC for the DMM).

works

for the scope too.

Does anyone have one and what should I look for in a used unit?

good cosmetics, good reports on the seller, and an idea of what you'd
have to replace if things were bad.

Are they mostly good or is there some parts that make them less

reliable?

Ebay and local and you takes your chances....

Where do you buy your parts and who is reliable to buy from for

Tektronix?

Major distributors (Mouser, Digikey, Arrow, etc) for standard parts.

Sphere and Qservice are most reliable, buying another with a

different

problem is often quite useful.

I do have Aktakom Function Signal Generator, 50MHz - 2 channels. Is

that

good enough?

For waveforms, maybe. (linearity).

How do you measure the voltages, and the frequencies (vertical and
horizontal calibration)?

Function generator may not be enough, depending on how serious you
want to get.

Harvey

Thank you guys, you have helped me a lot!
Tony

On Wed, May 1, 2019 at 9:03 PM Harvey White <madyn@...

wrote:

On Wed, 1 May 2019 18:13:05 -0400, you wrote:

With four 7000 series scopes in my lab, I've been patiently

waiting

for

a 067-0587-00,01, or 02 signal standardizer for about a year now

and I

finally grabbed one today. They've been going for pretty big

money

(worth

more than the scope itself) but I managed to snag it for $77

(with

shipping) off of eBay.

My one concern of course is that it works and doesn't need some

form of

rehabilitation.

I will soon find out.

Most of mine worked. The digital circuitry, as I remember it, is
relatively simple. Just checked the listing. Looks clean from

here.

Good luck.

Harvey

On Wed, May 1, 2019 at 11:13 AM Harvey White <

madyn@...>

wrote:

On Tue, 30 Apr 2019 12:47:26 -0700, you wrote:

Hi All,

I need one, good working scope to get started on repairing the

other 30

or so scopes around here. I have a multitude of Tek 7000

frames

to

choose

from but I think the 7904 (or 7904A) is a good place to start.

Once

that's

working + cal'ed I can at least troubleshoot and maybe repair

the

others.

Where can I get one professionally calibrated in the greater

Detroit

area? I can drive a fair distance, but I'm scared to ship.

I've

had

two

7934's, a 7834, and a 7704A crushed in separate shipping

mishaps.

Can't help you there, I'm in the southeast. However...

Also...which plug ins are recommended to cal for building my

golden

scope? I have a collection...

The typical plugins for a 7904 (and that's a good choice, IMHO)

are

at

least one if not two 7A26, and a 7B92A (which I happen to

like).

If

you want the flexibility of two sweep plugins, the 7B80 and

7B85

will

do. If you have a 7103/4 and a 7B10 and 7B15, you could use

them

but

the sweep is not calibrated at the highest frequencies, but

those

could be moved over to the 7103/4 when needed.

For things you'd want:

067-0587-01 signal standardizer. The 01 is intended for 500

mhz

scopes, the 00 is for lower bandwidth, and the 02 is for the

1GHz

bandwidth scopes. Needed to keep the mainframes all agreeing

with

each other as well as provides some nice linearity and gain

signals.

You could use the 00, but it wouldn't allow you to check out

the

frequency response to the limit of the scope's bandwidth for

higher

bandwidth scopes.

PG506/TG501 SG503/SG504 TM500 plugins that provide calibration
signals for vertical and timebase checking, as well as

frequency

response. Those will do any scope. The signal standardizer is
specifically for 7000 series mainframes.

You could also go with a CG501 (TM500) or a CG5001 (TM5000)

module

with the appropriate frame. Note that the CG series may need a
specific head to supply the right signals. Those heads may be
difficult to find.

My favorite (depending) setup in a 7904 is a 7A26 (or 7A24 if I

need

more bandwidth and can tolerate a 50 ohm input plugin), a 7D12

with

an

M2 (sampling) module, a 7D15 counter, and a 7B92A sweep.

Harvey

On Thu, 2 May 2019 13:26:17 -0400, you wrote:

Thanks for the reply Harvey. I have a Mouser order in so I'm just going
to replace all of the HV components and hope the transformer didn't get
toasted. One of those HV caps has a suspicious appearance around
one of the leads.

I actually had one that had a bad CRT, bad horizontal board, and a few
problems in the pulse generator (I think it was the 1503). Not sure
what the 1502's problem was, but I actually got one with a good TD.

It may have had the bad HV board.

Harvey

The 6.2M resistor has drifted up to 7.5M in the intensity path, so
replacing that might help a bit too.

Paul

On Wed, May 01, 2019 at 10:58:37AM -0400, Harvey White wrote:

On Tue, 30 Apr 2019 20:44:20 -0400, you wrote:

After accidentally leaving my 1502 on overnight I came back to find
it dead. I eventually traced it down to a HV problem.

This circuit is so simple it's ludicrous but I'm hampered by having
lost my HV probe. In any event, the output across the HV transformer
is a square wave of about 50V; it's supposed to be 500V. If I
disconnect C4328 (connected directly to the transformer), I see the
expected 500V across the transformer. The HV diodes appear to be OK,
but something is loading it down. I've disconnected the CRT and
controls with no change, so it has to be on the board.

I repaired my 1502's high voltage section. I saw capacitors that had
cracked, and the diodes weren't all that happy either. IIRC,
microwave oven diodes work. I just tested and replaced all the bad
capacitors.

I don't see any unusually low ohm readings either.

Any ideas for tracking down the failed component or should I just
shotgun the multiplier and replace everything? One cap is 0.033
at 600V and the other 3 are 0.027 at 1200V.

It's been noted that sometimes HV capacitors are OK at lower voltages
and leaky at higher ones.

!DSPAM:5ccb6d29156751858445706!

Your idea is correct, the large belt driven compressors are the best and
places like Harbor Freight has them brand new for a reasonable price.
Don't forget the water filtration and drain the water from the tank. You
could make a "self draining" or "automatic" condensation purge with an
Arduino or ESP32/ESP8266 and few more parts to open valve.
But a reminder once a month should give you time to check the system and
drain the water from the tank.


On Thu, May 2, 2019 at 10:24 AM David Kuhn <Daveyk021@...> wrote:

" Because they don't have a "quiet" air compressor.? "

That's the biggest problem.? In the garage, I built a compressor dog

house

with six inch walls with insulation on all side.? Even the access door is

6" thick with insulation.? It worked great, but the air compressor got

used hard.? Well know the saying "out of sight, out of mind"?? That's the
problem.? It never got maintenance.? Now, I just let it be noisy in the
garage as needed.? I don't use it that much, so I just go out and turn it
on as-needed rather than let it be automatic.? I would like to have a

huge

tall tank that hold a lot of air; but they can be expensive.? I need to

go

to some auctions and find a six foot tall belt driven compressor that can
run only every so often and let it on automatic.


On Wed, May 1, 2019 at 9:59 PM Harvey White <madyn@...>
wrote:

On Wed, 1 May 2019 14:53:04 +0200, you wrote:

I hear conflicting reports on what one should do. What's your take?
Are there different types where you should or shouldn't?

Compressed air isn't.? There's not enough room in the an.

Druckluft 67 (aka Dust Off 67) from Kontakt / CRC says not to shake
the can "or otherwise the fluid might come out", but is it always the
case with all types? What is that fluid for, anyways?

The fluid evaporates, produces gas, and that's what your "compressed
air" happens to be.

I read reviews of some cheaper compressed air products on amazon and
they complained about the quality. What can go wrong with compressed
air?

Liquid for one, which you don't want, and then again, what's the
liquid that's evaporating to give you this "air"?

Two things people brought up were one brand produced very weak
pressure, and another produced flammable rather than inert gas.

Depends on what's evaporating.? Butane would work, so would freon, so
would a lot of other things, includin propane.

Druckluft 67 touts as being oil free. Are there other things that
might go wrong?

er..... what's in that liquid?

Why would someone use canned compressed air rather than an air

compressor?

Because they don't have an air compressor.? Because they don't know
the difference.? Because they don't have a "quiet" air compressor.
Because they don't have the driers and particle filters to clean up
the output air from the compressor (which may or may not have oil in
it from the air pump).

Harvey

Thanks.

" Your idea is correct, the large belt driven compressors are the best and
places like Harbor Freight has them brand new for a reasonable price. "

Yea, I have been tempted a few times to use the 25% off coupon to get one,
but I usually do not hear good things about there electrical tools.

There is an elderly lady down the block that we are friends with. Her
husband (dead 20+ years now) has one of those six foot belt driver
compressors near their garage door; I think it is hard wired. She might
use it once a year. When I turned it on, it was amazingly not deafening.
It looks like it was built very well. I can't get her to give it or sell
it to me - lol. I kind of pine for it. It is very old, but still works
great and I am sure built better than anything harbor freight has. Anyway,
I'm not sure I should offer much because of its age and I might be better
off with a new one. They probably all need the pressure/electric switch
changed every few years and I am not sure where to get that part. My
original one in the dog house, probably 29 years old now and still looking
nice, needs that pressure switch. I could never find the MFG parts list
and you wouldn't get one from them after all these years. I haven't found
generic ones either. Maybe there is generic kits to re-plumb old air
compressors? I'll have to look.

Sorry, this is off topic, but I feel every electronics repair lab should
have compress air. Heck where I worked, before GE moved everything, and
our jobs overseas, I used a nice high pressure air line. I could wash
boards off with Simple green and then ISO and blow dry them do dry that I
could power them up right away without letting them dry overnight. The air
sound drove other around me nuts, but you do what you have to do. At one
point, maintenance was going to change my compressed air plumbing to the
nitrogen line (we had a huge nitrogen tank outside) for the drying of
boards, then our closing was announce and no one gave a shite about
anything for the next year and a half 8-(. So nitrogen would be better for
drying and dusting board than compressed air, but I would not want to foot
that bill.

Dave

Dave

On Thu, May 2, 2019 at 11:48 AM Tony Fleming <czecht@...> wrote:

Your idea is correct, the large belt driven compressors are the best and
places like Harbor Freight has them brand new for a reasonable price.
Don't forget the water filtration and drain the water from the tank. You
could make a "self draining" or "automatic" condensation purge with an
Arduino or ESP32/ESP8266 and few more parts to open valve.
But a reminder once a month should give you time to check the system and
drain the water from the tank.


On Thu, May 2, 2019 at 10:24 AM David Kuhn <Daveyk021@...> wrote:

" Because they don't have a "quiet" air compressor. "

That's the biggest problem. In the garage, I built a compressor dog

house

with six inch walls with insulation on all side. Even the access door

is

6" thick with insulation. It worked great, but the air compressor got

used hard. Well know the saying "out of sight, out of mind"? That's

the

problem. It never got maintenance. Now, I just let it be noisy in the
garage as needed. I don't use it that much, so I just go out and turn

it

on as-needed rather than let it be automatic. I would like to have a

huge

tall tank that hold a lot of air; but they can be expensive. I need to

go

to some auctions and find a six foot tall belt driven compressor that

can

run only every so often and let it on automatic.


On Wed, May 1, 2019 at 9:59 PM Harvey White <madyn@...>
wrote:

On Wed, 1 May 2019 14:53:04 +0200, you wrote:

I hear conflicting reports on what one should do. What's your take?
Are there different types where you should or shouldn't?

Compressed air isn't. There's not enough room in the an.

Druckluft 67 (aka Dust Off 67) from Kontakt / CRC says not to shake
the can "or otherwise the fluid might come out", but is it always

the

case with all types? What is that fluid for, anyways?

The fluid evaporates, produces gas, and that's what your "compressed
air" happens to be.

I read reviews of some cheaper compressed air products on amazon and
they complained about the quality. What can go wrong with compressed
air?

Liquid for one, which you don't want, and then again, what's the
liquid that's evaporating to give you this "air"?

Two things people brought up were one brand produced very weak
pressure, and another produced flammable rather than inert gas.

Depends on what's evaporating. Butane would work, so would freon, so
would a lot of other things, includin propane.

Druckluft 67 touts as being oil free. Are there other things that
might go wrong?

er..... what's in that liquid?

Why would someone use canned compressed air rather than an air

compressor?

Because they don't have an air compressor. Because they don't know
the difference. Because they don't have a "quiet" air compressor.
Because they don't have the driers and particle filters to clean up
the output air from the compressor (which may or may not have oil in
it from the air pump).

Harvey

Thanks.

A small positive contribution: The SG504 does indeed not level without a