Re: letter series plugins
Bob Pease -
It was interesting that all of the news reports and obituaries stated that Bob died due to the accident. The only reference to a heart attack ever seen was from a comment made by his wife that he "...may have had a stroke or heart attack," Anybody see other reports of this or was witness to the accident?
Greg
|
I think I'm going to paste this note inside my 2465, just in
case I forget how to get it off.
I think I'll print it in red, maybe 30pt type :-)
Paul
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On Mon, Aug 05, 2019 at 09:30:10AM -0400, Chuck Harris wrote: OMG!!!
I surely hope you haven't followed any of these suggestions!
It is easy, loosen the nut, do not let the screw turn,
level the nut with the screw slot, tap it with a tiny
hammer, and it will fall off.
The screw is not threaded into the impeller. It is purely
there to pull the collet into a taper that is inside of the
impeller. The nut does the pulling.
DO NOT ALLOW THE SCREW TO TURN!!!
DO NOT yank, pull, or pry on the impeller.
-Chuck Harris
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix & Windows
|
It is a plastic collet, in a plastic taper. The two practically
weld together after being under tension for many, many years.
The screw is molded into the plastic collet, and turning the screw
relative to the impeller will break the screw free of the collet,
such that it will never be able to pull the collet tight again.
Don't turn the screw!
Move the nut to the end of the screw, and tap it with a light
hammer. That hit will push the collet out of the taper, and it will
release. Don't pull up on the impeller when you tap the screw, just
let it hammer against the motor's endplay washer. You aren't hitting
it hard enough to do any damage....Right???
Once you have the collet off of the shaft, you should send a drop of
light machine oil running down the shaft, and into the bearing.
And, on the other end, use your desoldering station, and slurp the
solder from the center hole of the circuit board (inline with the
shaft), and oil that end too. Just a single drop on each side.
-Chuck Harris
n4buq wrote:
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Show quoted text
Searching for Tektronix "impeller" vs. "fan", I finally found a picture of the collet:
That makes sense to me now. Still unsure how turning the screw damages the collet (presuming the fingers stick to the tapered ID of the impeller and a twisting motion breaks them) but I'm guessing I'll find out soon enough.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Barry" <n4buq@...>
To: [email protected]
Sent: Monday, August 5, 2019 9:12:01 AM
Subject: Re: [TekScopes] 2445 LVPS Issues
Okay, Chuck. I presumed it was a collet but wasn't sure how to release it.
Unfortunately, I did turn the screw some in a CCW direction and then back
again so it sounds like I may have damaged the collet. Ugh! Too tempting
and the manual doesn't give any caveats regarding that (only states not to
remove the nut which I can't really see what that would hurt either but,
perhaps, because it might bind on the slotted burrs and cause the screw to
turn). If I can get the impeller off, I'll see what kind of damage I may
have caused. The impellers are still available but I'm guessing the collet
isn't.
Thanks again,
Barry - N4BUQ
----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: [email protected]
Sent: Monday, August 5, 2019 8:25:19 AM
Subject: Re: [TekScopes] 2445 LVPS Issues
It is easy:
Put a screwdriver in the slot of the screw, and use a wrench to
turn the nut against the screw (DON't LET THE SCREW TURN!!!)
Back off the nut until it is flush with the slot, and give the
nut a light tap with a hammer. It will move into the squirrel
cage a little bit, and then the squirrel cage can be pulled off.
If you let the screw turn relative to the squirrel cage, it will
destroy the delicate plastic collet... you don't want to do that!
-Chuck Harris
n4buq wrote:
Got everything removed except the fan. Any hints/tricks to getting that
off? Loosened the nut but the fan blade won't budge and I don't want to
pull any harder unless it is recommended. I have a feeling that's some
kind of collet and perhaps pressure on the slotted screw would release it
but just don't know.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Barry" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
And there, on page 6-25, is the complete process spelled out very
neatly.
Just didn't expect that.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "n4buq" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
I didn't realize the SM would go into detail on board removal. I will
read
up on it there.
Thanks for the tip on the incorrect silkscreen too.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Tom Gardner" <tggzzz@...>
To: [email protected]
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
The service manual is quite specific on how to remove the various
boards.
It
isn't difficult, if follow instructions.
The manual is available at the usual places, e.g. tekwiki.
Be aware that on some of the 24x5* series the manual and silk screen
show
two
caps swapped. So when recapping, remove and replace a single capacitor
before
moving on to the next; don't remove them all and then start replacing
them.
On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise
coming
from inside the scope after which I started smelling a burning odor.
I
had a few pieces of gear powered up at the time but quickly could
tell
the
smell was coming from the 2445.
I took off the case and top cover and pretty sure the smell is coming
from
the LVPS board(s) but am a bit stumped at how to get those two boards
out.
I'm pretty sure the top ribbon cable needs to come off but don't
quite
see how to get the large plastic cover off of the area where the main
filter caps are.
Looking at some of the smaller caps, they appear to be leaning due to
(I'm
guessing) bulging at the circuit board end but not sure exactly what
overheated (or, possibly, made that thumping noise).
Are there instructions somewhere that outline how to remove those
boards?
If not, could someone provide a couple of hints to get me started?
Thanks,
Barry - N4BUQ
|
Re: letter series plugins
Thanks for your info! I also love old stuff and I have couple older scopes - if one call them that. Simpson Handiscope - it is working! Sencore P5 148 with service manual, but non working for now. I'm gonna try to make it to work, as soon as I have some time. Tony On Mon, Aug 5, 2019 at 4:21 AM ulf_r_k via Groups.Io <ulf_r_k= [email protected]> wrote: I am old enough to have studied vacuum tube physics
and grew up during the 500-era. About a year ago
the university decided to scrap the very large inventory
of obsolete equipment left in a storage building for
maybe 30 years. Amongst the instruments were a bunch
of Tek 54x's. One of them, a 545A was in pristine
condition with absolutely no plack on the knobs
and with the "Tektronix Inc, Checked Tube" labels
white with no sign of use. Unfortunately, there was
a sinus curve on the CRT... with no signal present
on the inputs. So I "vandalised" the instrument by
replacing the electrolythic caps with modern ones
and it performs as good as new. I also grabbed
some 10 plug-ins, mostly letter types including
one "Type N" and two Type 1A7A but apart from those
and two "Type M" nothing exotic.
The blue P2 phosphor is nice to look at but the 4cm
of vertical height makes the 4-channel type M
not very useable. As has been written by others,
the 545 is an example of craftmanship that will
never reoccurr (quoting the late Jim Williams in the EDN article
"There is no place like home").
The 545 resides in my museum like others keep vintage cars.
Ulf KylenfallSM6GXV
|
Thanks for the info!
toggle quoted message
Show quoted text
On Mon, Aug 5, 2019 at 10:19 AM n4buq <n4buq@...> wrote: Searching for Tektronix "impeller" vs. "fan", I finally found a picture of
the collet:
That makes sense to me now. Still unsure how turning the screw damages
the collet (presuming the fingers stick to the tapered ID of the impeller
and a twisting motion breaks them) but I'm guessing I'll find out soon
enough.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Barry" <n4buq@...>
To: [email protected]
Sent: Monday, August 5, 2019 9:12:01 AM
Subject: Re: [TekScopes] 2445 LVPS Issues
Okay, Chuck. I presumed it was a collet but wasn't sure how to release it.
Unfortunately, I did turn the screw some in a CCW direction and then back
again so it sounds like I may have damaged the collet. Ugh! Too tempting
and the manual doesn't give any caveats regarding that (only states not to
remove the nut which I can't really see what that would hurt either but,
perhaps, because it might bind on the slotted burrs and cause the screw to
turn). If I can get the impeller off, I'll see what kind of damage I may
have caused. The impellers are still available but I'm guessing the collet
isn't.
Thanks again,
Barry - N4BUQ
----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: [email protected]
Sent: Monday, August 5, 2019 8:25:19 AM
Subject: Re: [TekScopes] 2445 LVPS Issues
It is easy:
Put a screwdriver in the slot of the screw, and use a wrench to
turn the nut against the screw (DON't LET THE SCREW TURN!!!)
Back off the nut until it is flush with the slot, and give the
nut a light tap with a hammer. It will move into the squirrel
cage a little bit, and then the squirrel cage can be pulled off.
If you let the screw turn relative to the squirrel cage, it will
destroy the delicate plastic collet... you don't want to do that!
-Chuck Harris
n4buq wrote:
Got everything removed except the fan. Any hints/tricks to getting that
off? Loosened the nut but the fan blade won't budge and I don't
want to
pull any harder unless it is recommended. I have a feeling that's
some
kind of collet and perhaps pressure on the slotted screw would
release it
but just don't know.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Barry" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
And there, on page 6-25, is the complete process spelled out very
neatly.
Just didn't expect that.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "n4buq" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
I didn't realize the SM would go into detail on board removal. I
will
read
up on it there.
Thanks for the tip on the incorrect silkscreen too.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Tom Gardner" <tggzzz@...>
To: [email protected]
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
The service manual is quite specific on how to remove the various
boards.
It
isn't difficult, if follow instructions.
The manual is available at the usual places, e.g. tekwiki.
Be aware that on some of the 24x5* series the manual and silk
screen
show
two
caps swapped. So when recapping, remove and replace a single
capacitor
before
moving on to the next; don't remove them all and then start
replacing
them.
On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump
noise
coming
from inside the scope after which I started smelling a burning
odor.
I
had a few pieces of gear powered up at the time but quickly could
tell
the
smell was coming from the 2445.
I took off the case and top cover and pretty sure the smell is
coming
from
the LVPS board(s) but am a bit stumped at how to get those two
boards
out.
I'm pretty sure the top ribbon cable needs to come off but don't
quite
see how to get the large plastic cover off of the area where the
main
filter caps are.
Looking at some of the smaller caps, they appear to be leaning
due to
(I'm
guessing) bulging at the circuit board end but not sure exactly
what
overheated (or, possibly, made that thumping noise).
Are there instructions somewhere that outline how to remove those
boards?
If not, could someone provide a couple of hints to get me
started?
Thanks,
Barry - N4BUQ
|
Searching for Tektronix "impeller" vs. "fan", I finally found a picture of the collet:
That makes sense to me now. Still unsure how turning the screw damages the collet (presuming the fingers stick to the tapered ID of the impeller and a twisting motion breaks them) but I'm guessing I'll find out soon enough.
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "Barry" <n4buq@...>
To: [email protected]
Sent: Monday, August 5, 2019 9:12:01 AM
Subject: Re: [TekScopes] 2445 LVPS Issues
Okay, Chuck. I presumed it was a collet but wasn't sure how to release it.
Unfortunately, I did turn the screw some in a CCW direction and then back
again so it sounds like I may have damaged the collet. Ugh! Too tempting
and the manual doesn't give any caveats regarding that (only states not to
remove the nut which I can't really see what that would hurt either but,
perhaps, because it might bind on the slotted burrs and cause the screw to
turn). If I can get the impeller off, I'll see what kind of damage I may
have caused. The impellers are still available but I'm guessing the collet
isn't.
Thanks again,
Barry - N4BUQ
----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: [email protected]
Sent: Monday, August 5, 2019 8:25:19 AM
Subject: Re: [TekScopes] 2445 LVPS Issues
It is easy:
Put a screwdriver in the slot of the screw, and use a wrench to
turn the nut against the screw (DON't LET THE SCREW TURN!!!)
Back off the nut until it is flush with the slot, and give the
nut a light tap with a hammer. It will move into the squirrel
cage a little bit, and then the squirrel cage can be pulled off.
If you let the screw turn relative to the squirrel cage, it will
destroy the delicate plastic collet... you don't want to do that!
-Chuck Harris
n4buq wrote:
Got everything removed except the fan. Any hints/tricks to getting that
off? Loosened the nut but the fan blade won't budge and I don't want to
pull any harder unless it is recommended. I have a feeling that's some
kind of collet and perhaps pressure on the slotted screw would release it
but just don't know.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Barry" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
And there, on page 6-25, is the complete process spelled out very
neatly.
Just didn't expect that.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "n4buq" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
I didn't realize the SM would go into detail on board removal. I will
read
up on it there.
Thanks for the tip on the incorrect silkscreen too.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Tom Gardner" <tggzzz@...>
To: [email protected]
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
The service manual is quite specific on how to remove the various
boards.
It
isn't difficult, if follow instructions.
The manual is available at the usual places, e.g. tekwiki.
Be aware that on some of the 24x5* series the manual and silk screen
show
two
caps swapped. So when recapping, remove and replace a single capacitor
before
moving on to the next; don't remove them all and then start replacing
them.
On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise
coming
from inside the scope after which I started smelling a burning odor.
I
had a few pieces of gear powered up at the time but quickly could
tell
the
smell was coming from the 2445.
I took off the case and top cover and pretty sure the smell is coming
from
the LVPS board(s) but am a bit stumped at how to get those two boards
out.
I'm pretty sure the top ribbon cable needs to come off but don't
quite
see how to get the large plastic cover off of the area where the main
filter caps are.
Looking at some of the smaller caps, they appear to be leaning due to
(I'm
guessing) bulging at the circuit board end but not sure exactly what
overheated (or, possibly, made that thumping noise).
Are there instructions somewhere that outline how to remove those
boards?
If not, could someone provide a couple of hints to get me started?
Thanks,
Barry - N4BUQ
|
Test the fan by itself and ru it for 30 minutes and see if it stays just
worm. If it gets hot, you will need to replace it. Also, how freely it
spins? Is it like new or slight resistance?
Gooooooood luck!
Tony
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Show quoted text
On Sun, Aug 4, 2019 at 11:14 PM n4buq <n4buq@...> wrote: The fan was working - at least I'm pretty sure it was. Something in the
PS began to smell of smoke so I'm pulling it to perform needed repair and
maintenance work (mostly capacitor replacements).
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Tony Fleming" <czecht@...>
To: [email protected]
Sent: Sunday, August 4, 2019 10:17:23 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
I did not remove mine, when fixing mine. It was little dusty so I used a
brush. It works, so I don't fix what isn't broken.... ha ha ha
BUT my memory isn't that good to remember if it is glued or some set-screw
- sorry.
Is your fan working?
On Sun, Aug 4, 2019 at 9:32 PM n4buq <n4buq@...> wrote:
I've already pulled on it harder than I was really comfortable doing;
however, the instructions state to use "firm pressure" to pull the fan
blade off.
I'm wondering if the slotted screw is intended to be used to push against
the motor shaft and push the fan blade off. If that were the case,
though,
I'd think that would be in the instructions so I'm thinking that's not
a
proper approach.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Tony Fleming" <czecht@...>
To: [email protected]
Sent: Sunday, August 4, 2019 7:44:33 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
They are VERY FRAGILE! Do not apply much pressure or it just brakes.
I don't know how to remove it without braking it, sorry!
On Sun, Aug 4, 2019 at 7:13 PM n4buq <n4buq@...> wrote:
Got everything removed except the fan. Any hints/tricks to getting that
off? Loosened the nut but the fan blade won't budge and I don't
want
to
pull any harder unless it is recommended. I have a feeling that's
some
kind of collet and perhaps pressure on the slotted screw would
release
it
but just don't know.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Barry" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
And there, on page 6-25, is the complete process spelled out very
neatly.
Just didn't expect that.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "n4buq" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
I didn't realize the SM would go into detail on board
removal. I
will
read
up on it there.
Thanks for the tip on the incorrect silkscreen too.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Tom Gardner" <tggzzz@...>
To: [email protected]
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
The service manual is quite specific on how to remove the
various
boards.
It
isn't difficult, if follow instructions.
The manual is available at the usual places, e.g. tekwiki.
Be aware that on some of the 24x5* series the manual and silk
screen
show
two
caps swapped. So when recapping, remove and replace a single
capacitor
before
moving on to the next; don't remove them all and then start
replacing
them.
On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of
thump
noise
coming
from inside the scope after which I started smelling a
burning
odor. I
had a few pieces of gear powered up at the time but quickly
could
tell
the
smell was coming from the 2445.
I took off the case and top cover and pretty sure the
smell is
coming
from
the LVPS board(s) but am a bit stumped at how to get those
two
boards
out.
I'm pretty sure the top ribbon cable needs to come off but
don't
quite
see how to get the large plastic cover off of the area
where
the
main
filter caps are.
Looking at some of the smaller caps, they appear to be
leaning
due
to
(I'm
guessing) bulging at the circuit board end but not sure
exactly
what
overheated (or, possibly, made that thumping noise).
Are there instructions somewhere that outline how to remove
those
boards?
If not, could someone provide a couple of hints to get me
started?
Thanks,
Barry - N4BUQ
|
Re: letter series plugins
Yes. I had read all that I could find of Jim¡¯s and Bob¡¯s pubications at that point (I was a practicing engineer at the time and subscribed to the trade journals that published their columns). I have since collected as many of those publications as I can find, including the first three ¡°Analog Circuit Design¡± books published by Newnes.
I had the pleasure of speaking with Bob at some point and after that conversation he sent me an autographed copy of his book.
Jim Williams¡¯ Linear Technology application note number 47 is required reading for anyone doing analog measurements. His two books on analog circuit design are also required reading, as is Bob¡¯s book on troubleshooting analog circuits.
I was stunned to hear of Jim¡¯s passing and then doubly stunned to hear of Bob¡¯s passing as he drove away from Jim¡¯s funeral. As Chuck wrote, it was a bad week.
For those who are interested, pretty much sll of their published work is available online.
DaveD
Sent from a small flat thingy
toggle quoted message
Show quoted text
On Aug 5, 2019, at 09:35, Chuck Harris <cfharris@...> wrote:
He was driving when he died of a heart attack,
no doubt brought on by grief. He rolled to a
stop with no impact. In other words, he was
in control of the car to the very end.
It was a pretty rough week for all of us in the
analog electronics world.
-Chuck Harris
John Griessen wrote:
On 8/5/19 12:30 AM, Greg Muir via Groups.Io wrote:
Bob managed to lose his life from an auto accident in his old VW Beetle while on
his way back from Jim Williams funeral. I thought he died driving it slowly and rolled to a stop with no impact...
|
Okay, Chuck. I presumed it was a collet but wasn't sure how to release it. Unfortunately, I did turn the screw some in a CCW direction and then back again so it sounds like I may have damaged the collet. Ugh! Too tempting and the manual doesn't give any caveats regarding that (only states not to remove the nut which I can't really see what that would hurt either but, perhaps, because it might bind on the slotted burrs and cause the screw to turn). If I can get the impeller off, I'll see what kind of damage I may have caused. The impellers are still available but I'm guessing the collet isn't.
Thanks again,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "Chuck Harris" <cfharris@...>
To: [email protected]
Sent: Monday, August 5, 2019 8:25:19 AM
Subject: Re: [TekScopes] 2445 LVPS Issues
It is easy:
Put a screwdriver in the slot of the screw, and use a wrench to
turn the nut against the screw (DON't LET THE SCREW TURN!!!)
Back off the nut until it is flush with the slot, and give the
nut a light tap with a hammer. It will move into the squirrel
cage a little bit, and then the squirrel cage can be pulled off.
If you let the screw turn relative to the squirrel cage, it will
destroy the delicate plastic collet... you don't want to do that!
-Chuck Harris
n4buq wrote:
Got everything removed except the fan. Any hints/tricks to getting that
off? Loosened the nut but the fan blade won't budge and I don't want to
pull any harder unless it is recommended. I have a feeling that's some
kind of collet and perhaps pressure on the slotted screw would release it
but just don't know.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Barry" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
And there, on page 6-25, is the complete process spelled out very neatly.
Just didn't expect that.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "n4buq" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
I didn't realize the SM would go into detail on board removal. I will
read
up on it there.
Thanks for the tip on the incorrect silkscreen too.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Tom Gardner" <tggzzz@...>
To: [email protected]
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
The service manual is quite specific on how to remove the various
boards.
It
isn't difficult, if follow instructions.
The manual is available at the usual places, e.g. tekwiki.
Be aware that on some of the 24x5* series the manual and silk screen
show
two
caps swapped. So when recapping, remove and replace a single capacitor
before
moving on to the next; don't remove them all and then start replacing
them.
On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise
coming
from inside the scope after which I started smelling a burning odor. I
had a few pieces of gear powered up at the time but quickly could tell
the
smell was coming from the 2445.
I took off the case and top cover and pretty sure the smell is coming
from
the LVPS board(s) but am a bit stumped at how to get those two boards
out.
I'm pretty sure the top ribbon cable needs to come off but don't quite
see how to get the large plastic cover off of the area where the main
filter caps are.
Looking at some of the smaller caps, they appear to be leaning due to
(I'm
guessing) bulging at the circuit board end but not sure exactly what
overheated (or, possibly, made that thumping noise).
Are there instructions somewhere that outline how to remove those
boards?
If not, could someone provide a couple of hints to get me started?
Thanks,
Barry - N4BUQ
|
Re: letter series plugins
On Mon, Aug 5, 2019 at 08:35 AM, Chuck Harris wrote:
He was driving when he died of a heart attack,
no doubt brought on by grief. He rolled to a
stop with no impact. In other words, he was
in control of the car to the very end.
It was a pretty rough week for all of us in the
analog electronics world.
-Chuck Harris
Chuck I appreciate these little insights that you and others provide to the lives and careers of these giants of analog circuits. One thing that I always enjoyed was looking at these two gentleman's workbenches. They both seemed to always be working in a perpetual pile of rubbish and thousands of components. I say this with the greatest respect and admiration, since they seem to bring order out of the chaos of their work area. I find that my work area looks more like this every day, so maybe there is hope for me? Thanks for sharing with those of us who are less experienced and knowledgeable. -- Michael Lynch Dardanelle, AR
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Re: letter series plugins
Indeed! They can be friendly in the
winter. But a $19 milk shed heater, and
a 2465 scope is quite a bit more cost effective,
is fast enough to do most work, and heats better
too!
-Chuck Harris
Michael A. Terrell wrote:
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A vacuum tube Tektronix scope was no problem in the winter, at a TV station
in Alaska. It might even get the control room to 40F, if it and both
transmitters were on! I would turn on the studio's Halogen lights to warm
up, when it was below freezing in the control room. There wasn't enough
waste heat left from the return water to the old boilers to keep us warm.
That was 45 years ago, and the scope was sufficient to repair the
electronics in the Analog Monochrome days.I also had four Tektronix RM529
waveform monitors that were Hybrids to help provide heat. :)
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Re: letter series plugins
Hi Tom,
I get what you are saying. I really do.
I also know that there are very few things today that would
warrant using such a power hungry, bench space hungry old
scope in real engineering today. The real world of money
paying engineering has passed them by in numerous ways.
It doesn't mean that there aren't a few old codgers (regardless
of their biological age) that own these scopes, and try to shoe
horn big problems into their limited capabilities...
I still like them, but I don't use them anymore. They lack the
capabilities necessary to do meaningful work in virtually every
aspect of engineering today. Honestly, they do.
It is down to aesthetics, and I would never argue for or against
such points.
-Chuck Harris
fiftythreebuick wrote:
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Hi Chuck-
Actually, if working with RF anywhere in the lower HF range or MF (such as AM bcst) or any number of analog circuits, the old 500 series mainframes provide plenty of bandwidth.
And the controls are laid out in a very logical manner, the controls are big enough to grasp without having to be careful not to hit something you don't mean to touch. The display is razor sharp. And maybe it's just that Greg and I are old, but I'm right with him on hearing the fan spin up, the time delay relay pull in and that delightful smell of vacuum tube electronics. When the old scope has enough capability for the job at hand, there is such an extreme "pleasure of operation" factor involved for some of us.
I solved the heat issue in my old shop decades ago by adding a small window unit air conditioner to run when I was using either my 555 (particularly if I needed two of them at once!) or my Collins 30L-1. The extra cooling from the window unit did the trick and was a very equitable trade for the opportunity to use those instruments in comfort.
My new shop has plenty of capacity in its own dedicated central air conditioner so there's no problem there.
I think it's just a matter of what you like. I have a 7104 and a 7934 sitting within arm's reach and they get used regularly, but when it's up to the job, the 555 is my first choice! :-)
Hope you have a good night!
Tom
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Re: letter series plugins
He was driving when he died of a heart attack,
no doubt brought on by grief. He rolled to a
stop with no impact. In other words, he was
in control of the car to the very end.
It was a pretty rough week for all of us in the
analog electronics world.
-Chuck Harris
John Griessen wrote:
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On 8/5/19 12:30 AM, Greg Muir via Groups.Io wrote:
Bob managed to lose his life from an auto accident in his old VW Beetle while on
his way back from Jim Williams funeral. I thought he died driving it slowly and rolled to a stop with no impact...
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OMG!!!
I surely hope you haven't followed any of these suggestions!
It is easy, loosen the nut, do not let the screw turn,
level the nut with the screw slot, tap it with a tiny
hammer, and it will fall off.
The screw is not threaded into the impeller. It is purely
there to pull the collet into a taper that is inside of the
impeller. The nut does the pulling.
DO NOT ALLOW THE SCREW TO TURN!!!
DO NOT yank, pull, or pry on the impeller.
-Chuck Harris
Bob Albert via Groups.Io wrote:
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If you can do it, perhaps gripping the fan motor shaft with a big pliers and wobbling the blade may help. Wobble it back and forth numerous times but never with much force.
I have a problem with the main tuning knob on my TS-940S. I can't undo the set screw. It seems to be bunged up and so far nothing has budged it. Luckily I have no need to remove it but still...
Bob
On Sunday, August 4, 2019, 09:14:38 PM PDT, n4buq <n4buq@...> wrote:
The fan was working - at least I'm pretty sure it was. Something in the PS began to smell of smoke so I'm pulling it to perform needed repair and maintenance work (mostly capacitor replacements).
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Tony Fleming" <czecht@...>
To: [email protected]
Sent: Sunday, August 4, 2019 10:17:23 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
I did not remove mine, when fixing mine. It was little dusty so I used a
brush. It works, so I don't fix what isn't broken.... ha ha ha
BUT my memory isn't that good to remember if it is glued or some set-screw
- sorry.
Is your fan working?
On Sun, Aug 4, 2019 at 9:32 PM n4buq <n4buq@...> wrote:
I've already pulled on it harder than I was really comfortable doing;
however, the instructions state to use "firm pressure" to pull the fan
blade off.
I'm wondering if the slotted screw is intended to be used to push against
the motor shaft and push the fan blade off. If that were the case, though,
I'd think that would be in the instructions so I'm thinking that's not a
proper approach.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Tony Fleming" <czecht@...>
To: [email protected]
Sent: Sunday, August 4, 2019 7:44:33 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
They are VERY FRAGILE! Do not apply much pressure or it just brakes.
I don't know how to remove it without braking it, sorry!
On Sun, Aug 4, 2019 at 7:13 PM n4buq <n4buq@...> wrote:
Got everything removed except the fan. Any hints/tricks to getting that
off? Loosened the nut but the fan blade won't budge and I don't want
to
pull any harder unless it is recommended. I have a feeling that's some
kind of collet and perhaps pressure on the slotted screw would release
it
but just don't know.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Barry" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
And there, on page 6-25, is the complete process spelled out very
neatly.
Just didn't expect that.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "n4buq" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
I didn't realize the SM would go into detail on board removal. I
will
read
up on it there.
Thanks for the tip on the incorrect silkscreen too.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Tom Gardner" <tggzzz@...>
To: [email protected]
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
The service manual is quite specific on how to remove the various
boards.
It
isn't difficult, if follow instructions.
The manual is available at the usual places, e.g. tekwiki.
Be aware that on some of the 24x5* series the manual and silk
screen
show
two
caps swapped. So when recapping, remove and replace a single
capacitor
before
moving on to the next; don't remove them all and then start
replacing
them.
On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump
noise
coming
from inside the scope after which I started smelling a burning
odor. I
had a few pieces of gear powered up at the time but quickly
could
tell
the
smell was coming from the 2445.
I took off the case and top cover and pretty sure the smell is
coming
from
the LVPS board(s) but am a bit stumped at how to get those two
boards
out.
I'm pretty sure the top ribbon cable needs to come off but
don't
quite
see how to get the large plastic cover off of the area where
the
main
filter caps are.
Looking at some of the smaller caps, they appear to be leaning
due
to
(I'm
guessing) bulging at the circuit board end but not sure exactly
what
overheated (or, possibly, made that thumping noise).
Are there instructions somewhere that outline how to remove
those
boards?
If not, could someone provide a couple of hints to get me
started?
Thanks,
Barry - N4BUQ
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Re: letter series plugins
A vacuum tube Tektronix scope was no problem in the winter, at a TV station
in Alaska. It might even get the control room to 40F, if it and both
transmitters were on! I would turn on the studio's Halogen lights to warm
up, when it was below freezing in the control room. There wasn't enough
waste heat left from the return water to the old boilers to keep us warm.
That was 45 years ago, and the scope was sufficient to repair the
electronics in the Analog Monochrome days.I also had four Tektronix RM529
waveform monitors that were Hybrids to help provide heat. :)
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Show quoted text
On Sun, Aug 4, 2019 at 3:41 PM Chuck Harris <cfharris@...> wrote: Au Contraire? Mais non, certainement pas!
Even Jim Williams was vexed by the 50MHz limit imposed by
his favorites, the 547, and 556....but for opamp, and low
performance switching supply work, they were adequate, as
long as you didn't consider the environmental aspects of
using such a scope (by environmental, I use the traditional
usage, as in: the environment in the lab...).
I grew up as an engineer in the waning days of the 545B, 547
and 585A. I have used all of them for serious electronics work,
as they were what we could get, and I was damn glad to have them
at the time. Still, I simply don't know of anyone that does
serious work with 500 series scopes anymore. The limitations
are too severe. They can't even keep up with a modern USB port.
1MHz switching supplies have spikes that they cannot even come
close to seeing. Just because your scope can't see them, doesn't
mean they won't burn out your transistors and diodes.
Disregarding the low bandwidth, the heat they produce is enough
to eliminate them from serious consideration. I not so fondly
remember my lab in graduate school over taxing the building's air
conditioner with all of the HP and Tektronix gear we needed for
our research. It was intolerable to have the lab get over 110F
in the summer; doors open, huge floor standing fans blowing papers
everywhere. It was so hot that the thermal overload switches in
the scopes were tripped.
Nostalgia is great, especially if you remember only the good
stuff. Thinking fondly of using a scope in the '70s, and using
it for serious electronics work today are not the same thing.
I pull out my 547, 545B, and 585A from time to time to play with,
but when work needs to be done, they are parked in their corral.
My 7854 does most of my heavy lifting, scope wise.
-Chuck Harris
Greg Muir via Groups.Io wrote:
Chuck Harris wrote: ¡°With the exception of the late, great, Jim Williams of Linear Technology fame, big tube scopes, haven't been used for serious
electronics work in 30 years.¡±
Au Contraire. There are still a few Jim Williams types out there who
enjoy the use of a stable and reliable product that may have grown gray
hair but is still a viable instrument.
Yes, the trend nowadays is to have the fastest, biggest and best of
everything in the engineering world but it is not necessary for every
application. I am fully aware that the academic institutions must prepare
their students to hit the ground running when launched into their
professions thereby being able to use state-of-the-art test instruments
instead of archaic hardware. And I agree it is nice to be lazy, punch
softkeys or click on a mouse to get what you want instantaneously but to
come into the lab on a cold winters day with a steaming cup of coffee, hit
the switch on that big fire breathing dragon, hear the fan wind up and
smell the odor of pure legacy for me is rather pleasing. But if I need
speed and easy accuracy I can always reach over and turn on that little
solid-state rice box and continue on.
We¡¯ve been obviously witness to the loss of older hardware through the
advancements of technology and I have no objections about it happening.
But there is that certain amount of tradition in some of us (me ¨C 70 years
old, design engineering for 50 of them, raised on tube-type equipment and
still going strong) that harks back to those few people who were brave
enough to start in their garages endlessly working to serve the engineering
profession by manufacturing the best and most technically advanced products
of their time.
Some day my 519, 547 and 581 will be relinquished either to a collector
or the scrap heap but in the meantime I will still get usefulness out of
them.
Greg
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It is easy:
Put a screwdriver in the slot of the screw, and use a wrench to
turn the nut against the screw (DON't LET THE SCREW TURN!!!)
Back off the nut until it is flush with the slot, and give the
nut a light tap with a hammer. It will move into the squirrel
cage a little bit, and then the squirrel cage can be pulled off.
If you let the screw turn relative to the squirrel cage, it will
destroy the delicate plastic collet... you don't want to do that!
-Chuck Harris
n4buq wrote:
toggle quoted message
Show quoted text
Got everything removed except the fan. Any hints/tricks to getting that off? Loosened the nut but the fan blade won't budge and I don't want to pull any harder unless it is recommended. I have a feeling that's some kind of collet and perhaps pressure on the slotted screw would release it but just don't know.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Barry" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
And there, on page 6-25, is the complete process spelled out very neatly.
Just didn't expect that.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "n4buq" <n4buq@...>
To: [email protected]
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
I didn't realize the SM would go into detail on board removal. I will read
up on it there.
Thanks for the tip on the incorrect silkscreen too.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Tom Gardner" <tggzzz@...>
To: [email protected]
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues
The service manual is quite specific on how to remove the various boards.
It
isn't difficult, if follow instructions.
The manual is available at the usual places, e.g. tekwiki.
Be aware that on some of the 24x5* series the manual and silk screen show
two
caps swapped. So when recapping, remove and replace a single capacitor
before
moving on to the next; don't remove them all and then start replacing
them.
On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise
coming
from inside the scope after which I started smelling a burning odor. I
had a few pieces of gear powered up at the time but quickly could tell
the
smell was coming from the 2445.
I took off the case and top cover and pretty sure the smell is coming
from
the LVPS board(s) but am a bit stumped at how to get those two boards
out.
I'm pretty sure the top ribbon cable needs to come off but don't quite
see how to get the large plastic cover off of the area where the main
filter caps are.
Looking at some of the smaller caps, they appear to be leaning due to
(I'm
guessing) bulging at the circuit board end but not sure exactly what
overheated (or, possibly, made that thumping noise).
Are there instructions somewhere that outline how to remove those
boards?
If not, could someone provide a couple of hints to get me started?
Thanks,
Barry - N4BUQ
|
Re: letter series plugins
On 8/5/19 12:30 AM, Greg Muir via Groups.Io wrote: Bob managed to lose his life from an auto accident in his old VW Beetle while on his way back from Jim Williams funeral. I thought he died driving it slowly and rolled to a stop with no impact...
|
Re: letter series plugins
Absolutely, I agree!
I really enjoy the aesthetics of the 545B, 547, and 585A.
I keep a few around just so I can look at them. But I will
not go out of my way to find work for them to do. I am way
too busy for that. For real work I use a 7854, or, if I need
some deep storage capability, a more modern digital scope.
There was only one case where I found a 545B was the superior
scope to use, and that was a poorly designed system that dumped
lots of digital noise down the power cord. The 545B had greatly
superior rejection of power line noise than did a 2465, or
a 2236. Proper filtering and grounding of the offending system,
had the greatest affect of all.
-Chuck Harris
Jamie Ostrowski wrote:
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Certainly nothing wrong with enjoying the aesthetics of the old 500 series
scopes. By all measures, the modern sportbike motorcycles outperform the
cruiser Harley Davidsons in acceleration and handling, yet the Harleys
still remain incredibly popular.
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Re: letter series plugins
The 453 and 454 are both quite viable for use today, and usually not expensive. Some versions are all solid state (except for the CRT, of course!) and others have tube HV rectifiers and two Nuvistors in the pre-amp section. Someone mentioned Tektronix scopes in TV shops. In my time in that craft (1966-75), the only way a typical TV shop got a Tektronix scope was by good luck or some devious means like Vietnam war veterans obtaining a "souvenir" from a friend in base supply for a couple bottles of Chevis Regal. They and others, like HP, were just too expensive until around 1970 when older ones began to become available. TV repair people made do with Sencore, Eico, B&K, and Really Crummy Apparatus scopes, with a few Heathkits as well. In 1974, General Electric closed it's plants in Utica, and 500 series scopes became plentiful and affordable.
Bruce Gentry, KA2IVY, Syracuse, New York
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On 8/4/19 11:52 PM, Mlynch001 wrote: I am quite late to the party when it comes to old scopes. Have a couple of old Heathkit Tube scopes, but no TEKTRONIX tube scopes. I do have several slightly later transistorized scopes, and though probably almost as antique, they still meet my needs. I have a 465B, 475A, T922, T935, 5113 (2), 7623A and 7633. My prized obsolete piece is a Type 576 Curve Tracer, this is one piece of equipment that has no equal in modern electronics. I have also managed to collect a few pieces of digital Tektronix equipment, and find these equally useful in some situations. However, I find the older equipment to be superior in construction and craftsmanship, as well as infinitely more repairable. I am learning electronics as hobby, mostly by self taught observation and study, so these wonderful old Tektronix scopes fit my needs to a tee.
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Re: letter series plugins
I am old enough to have studied vacuum tube physics
and grew up during the 500-era. About a year ago
the university decided to scrap the very large inventory
of obsolete equipment left in a storage building for
maybe 30 years. Amongst the instruments were a bunch
of Tek 54x's. One of them, a 545A was in pristine
condition with absolutely no plack on the knobs
and with the "Tektronix Inc, Checked Tube" labels
white with no sign of use. Unfortunately, there was
a sinus curve on the CRT... with no signal present
on the inputs. So I "vandalised" the instrument by
replacing the electrolythic caps with modern ones
and it performs as good as new. I also grabbed
some 10 plug-ins, mostly letter types including
one "Type N" and two Type 1A7A but apart from those
and two "Type M" nothing exotic.
The blue P2 phosphor is nice to look at but the 4cm
of vertical height makes the 4-channel type M
not very useable. As has been written by others,
the 545 is an example of craftmanship that will
never reoccurr (quoting the late Jim Williams in the EDN article
"There is no place like home").
The 545 resides in my museum like others keep vintage cars.
Ulf KylenfallSM6GXV
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Mlynch001
Michael A. Terrell