Topics

Little ceramic trimmer caps that always break... A fix.


Stephen
 

On Wed, Aug 19, 2020 at 04:54 AM, Carsten Bormann wrote:

(Earlier in my life, I experienced the eyesight of my father deteriorate over
a span of a decade. Something I wouldn't wish my worst enemies, if I had any
to wish something bad onto.)
My father has ARMD (81yo), so I should be careful too.

Let me just say that your posts are highly enjoyable on so many levels.
Any nits don’t distract from that.
I concur!


Carsten Bormann
 

On 2020-08-19, at 17:35, Chuck Harris <cfharris@...> wrote:

my brain fills
in whatever word it can think of that fits the space.
I think that is a problem fundamentally every proofreader has.
Confirmation bias in the small.

My retina specialist says not to worry, it will only
get worse... especially if he tries to fix it.
(Earlier in my life, I experienced the eyesight of my father deteriorate over a span of a decade. Something I wouldn't wish my worst enemies, if I had any to wish something bad onto.)

I know you want perfection out of each of us, but I for
one, am not up to it anymore.
Please don’t take my comments as personal criticism.
They were directed to the list (or I would have sent them personally to you).
And, yes, I do like some attention to detail; perfection is not a very useful goal for informal messages like these...

I do this gig for fun, and it is becoming less and less
fun as the nits get picked.
Let me just say that your posts are highly enjoyable on so many levels.
Any nits don’t distract from that.
(Too bad that telling more about your tractors would be off-topic on this list.)

Grüße, Carsten


Chuck Harris
 

Well, the key to good proofreading is to be able to see
the mistakes. And since my retina was damaged by my
vitreous humor pulling away... a present I got for my
53rd birthday..., I can't do that very well anymore.

I see a tiny magnified spot right at the center of vision
on my right (dominant) eye, that darts around as I read,
or inspect things.... So, when I read, I cannot always
tell the difference between a "n" and an "h", or an "i"
and an "l", or an "o" and a "b" or "d", g", ... without
serious study.

It's worse, of course the smaller the print. And, my brain,
and good vocabulary isn't helping me much, as my brain fills
in whatever word it can think of that fits the space.

My retina specialist says not to worry, it will only
get worse... especially if he tries to fix it.

I know you want perfection out of each of us, but I for
one, am not up to it anymore.

I do this gig for fun, and it is becoming less and less
fun as the nits get picked.

I think I'll go play with my tractors...

-Chuck Harris

Carsten Bormann wrote:

On 2020-08-19, at 14:58, Chuck Harris <cfharris@...> wrote:

FG504 can become FG540, Chuck can become CHuck…
WElcome to the clbu.

As was pointed out, it is useful to get model numbers, part numbers, measurements etc. right, so as Barry reminded us, proofreading is king for those.

(And wrt to the measurements, if someone gives a timebase setting in nanosiemens per division, I cringe, but maybe it’s normal that a lot of people simply don’t know how to type measurements and any correction will be seen as nitpicking, so there is no learning either.)

Grüße, Carsten





Carsten Bormann
 

On 2020-08-19, at 14:58, Chuck Harris <cfharris@...> wrote:

FG504 can become FG540, Chuck can become CHuck…
WElcome to the clbu.

As was pointed out, it is useful to get model numbers, part numbers, measurements etc. right, so as Barry reminded us, proofreading is king for those.

(And wrt to the measurements, if someone gives a timebase setting in nanosiemens per division, I cringe, but maybe it’s normal that a lot of people simply don’t know how to type measurements and any correction will be seen as nitpicking, so there is no learning either.)

Grüße, Carsten


Chuck Harris
 

Perhaps, but Dennis is a geezer too, and there is nothing
we have said that he doesn't already know all too well.

I'm done.

-Chuck Harris

pdxareaid wrote:

we are going to get slapped for this geezer fest, but now in my late sixties i exhibit all of the above annoyances when typing with
one addition. i am basically a touch typist but developed some bad habits over the years (coding does that) and tend to look at the keyboard when composing. i find i
will use a word like "composed" or "composing" correctly in my mind but in reading what i typed, i will find "compose".
lately on the fly grammar checking has been flagging some of these.
as far as dexterity, i have the same problem with the guitar. the fingers are not working like they used to.
We're all like old electrolytic caps. If we don't blow our tops, someday we'll eventually leak out. Regular use does stave off
an early demise.
DID vs DIDN'T: yes the sign bit gets a bit sticky at times too.
i have no problem with the shift key, however, as is plainly obvious in this posting :-)




Chuck Harris
 

No, it's age.

We have the benefit of self introspection, and a memory that
can remind of us of how things were, and how they aren't anymore.

My heart and lungs are good, but I cannot run a 4 minute mile
anymore.

For a while, you can brush these things off as just little nothings,
but at a certain point, for me, it became clear that changes were
afoot.

-Chuck Harris

Stephen wrote:

I’m mid 50’s and I just realized I missed a word on my last post. I meant “when he DIDN’T find it”, but wrote “when he DID find it”... See? It’s not only age, it’s also that we’re trying to do things faster and faster, in order to keep up with a world that constantly demands speed and responsiveness.




pdxareaid
 

we are going to get slapped for this geezer fest, but now in my late sixties i exhibit all of the above annoyances when typing with
one addition. i am basically a touch typist but developed some bad habits over the years (coding does that) and tend to look at the keyboard when composing. i find i
will use a word like "composed" or "composing" correctly in my mind but in reading what i typed, i will find "compose".
lately on the fly grammar checking has been flagging some of these.
as far as dexterity, i have the same problem with the guitar. the fingers are not working like they used to.
We're all like old electrolytic caps. If we don't blow our tops, someday we'll eventually leak out. Regular use does stave off
an early demise.
DID vs DIDN'T: yes the sign bit gets a bit sticky at times too.
i have no problem with the shift key, however, as is plainly obvious in this posting :-)


Stephen
 

I’m mid 50’s and I just realized I missed a word on my last post. I meant “when he DIDN’T find it”, but wrote “when he DID find it”... See? It’s not only age, it’s also that we’re trying to do things faster and faster, in order to keep up with a world that constantly demands speed and responsiveness.


Michael W. Lynch
 

On Wed, Aug 19, 2020 at 07:58 AM, Chuck Harris wrote:


I am getting older. I can't see as well as I once did, I cant type
as well as I once did... And I don't like it.
Chuck,

You always have a way to make me laugh, learn, or in this case; to feel better. I'm glad to hear that I am not alone.

--
Michael Lynch
Dardanelle, AR


Dave Wise
 

We're all aging, one day per day. I swap keystrokes and beat the shift all the time.

Five years from now someone will search for "FG504" and if not for pedantry, they would miss your helpful note.

Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Chuck Harris via groups.io <cfharris=erols.com@groups.io>
Sent: Wednesday, August 19, 2020 6:21 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break... A fix.

I am mid sixties as well, but to further my stress
is a little dementia thing that runs down my mother's
side of the family...

I have always edited myself, but lately there is way
too (just typed as "oot") much red on the page.

Anyway, I wanted this to be a little helpful note for
folks suffering from the trimmer capacitor plague.

I apologize for turning it into an exposition on my
degrading capabilities...

-Chuck Harris

n4buq wrote:
Mid-sixties here and having some of the same issues. I work with a lot of various systems and am constantly crossing up numbers and letters (or conflating one system's numbers with another, etc.). Very annoying. I have had to resort to carefully rereading what I've typed to pick out the nits (just like I did for this one). It is indeed frustrating if not downright embarrasing at times.

Thanks,
Barry - N4BUQ
<snip>


Paul Amaranth
 

I could type 40 wpm on a manual typewriter all day with very few mistakes.
I suppose that dates me.

Now I can't type a line without a couple of typos. My theory is that as
the cost of a mistake decreases we just get lazy. Making a typo in
an editing program has essentially zero cost (other than finding and
fixing it). Add in spell check and you don't even have to remember
spelling (I'll ignore auto-correct).

Age has nothing to do with it. That's my take and I'm sticking with it :-)

Thanks for your service notes Chuck. Whenever I see one I file it away.
They're always full of useful information.

Paul

On Wed, Aug 19, 2020 at 09:09:42AM -0400, n4buq wrote:
Mid-sixties here and having some of the same issues. I work with a lot of various systems and am constantly crossing up numbers and letters (or conflating one system's numbers with another, etc.). Very annoying. I have had to resort to carefully rereading what I've typed to pick out the nits (just like I did for this one). It is indeed frustrating if not downright embarrasing at times.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: TekScopes@groups.io
Sent: Wednesday, August 19, 2020 7:58:25 AM
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break... A fix.

It is becoming a touchy subject for me. All my life I have
been a very fast touch typist. I spent a lot of time writing
programs, and later writing documentation, and could always
type quickly and effortlessly...

But in my 60's, I am noticing coordination problems in my typing,
I "slur" my shift control, and swap adjacent letters.

FG504 can become FG540, Chuck can become CHuck...

I even do a little weird thing where small common words, like
"the" come out backwards "eht", and other words always gain an
extra letter, such as "ratio" always getting typed "ration".

I always find it amusing when I type a long treatise on some subject
or other, and the only comments that get made are about a misplaced
comma, or a typo.

I am getting older. I can't see as well as I once did, I cant type
as well as I once did... And I don't like it.

I am working through a couple of FG504's. If I can help, just ask.

-Chuck Harris


Colin Herbert via groups.io wrote:
No, the typo doesn't matter in so far as that is what it was. I was just
curious because I am trying to get a FG504 working correctly and not doing
too well at the moment. I didn't mean to insult you or anything like that;
please forgive me if that's what it came over as.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck
Harris
Sent: 19 August 2020 13:22
To: TekScopes@groups.io
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break... A
fix.

Honestly, does it really matter that I mistyped FG504?

I am talking about ceramic trimmers that exist in
hundreds of Tektronix instrument models.

-Chuck Harris

Colin Herbert via groups.io wrote:
Do you mean an FG504? I can't find any FG540 on TekWiki.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck
Harris
Sent: 19 August 2020 05:15
To: TekScopes
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break...
A fix.

Just to clear up some confusion:

This note is about subminiature ceramic disk type
trimmer capacitors. Tektronix equipment from the
1980's onward is littered with these little timebombs.

It is a "modernization" of the old style ceramic
trimmers that had a silver plated half circle on
the lid that was soldered to the adjusting screw.

In this case, the silver plating is inside of the
trimmer, and the ceramic disk is held on by very
temperamental magic. The moving ceramic disk sticks
to its ceramic base, and the magic disappears.

-Chuck Harris

Chuck Harris wrote:
Hi All,

Just a note. As happens to all of us, one of those
little ceramic trimmers in an FG540 was broken. The
screw turned and turned, but the ceramic disk on top
didn't. It was frozen solid.

Bother...

I didn't have a spare, so I removed the trimmer, and
found the ceramic disk frozen solid to the ceramic
base... no trimming going on here!

First, I put the capacitor into some IPA to soak for
a bit. There was more than enough stinky flux on
the cap, so I think the flux was gluing the cap stuck.

After it soaked for a while, I was able to turn the
disk with my fingers... don't use tools, it will break!

I put it in for some more soaking, and twisting, until
it was good and clean.

Next, I took a small dot of cyanoacrylate glue, and
spread it around the screw. A small dot, not a flood.
[If you can't control your glue bottle, put some CA glue
on a piece of plastic, and use a toothpick to bring a dot
to your trimmer.]

Then finally, I gave a rag a squirt of "Kicker", a CA
glue accelerator, and put the rag near the trimmer... The
kicker's fumes are enough to harden the glue almost
instantly. If you don't have any kicker, just let it set
a while, it will harden from the moisture in the air.

I gave the screw a twist, and all was back to normal.

-Chuck Harris




















!DSPAM:5f3d24a4225522099113515!
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix/Linux - We don't do windows


Chuck Harris
 

I am mid sixties as well, but to further my stress
is a little dementia thing that runs down my mother's
side of the family...

I have always edited myself, but lately there is way
too (just typed as "oot") much red on the page.

Anyway, I wanted this to be a little helpful note for
folks suffering from the trimmer capacitor plague.

I apologize for turning it into an exposition on my
degrading capabilities...

-Chuck Harris

n4buq wrote:

Mid-sixties here and having some of the same issues. I work with a lot of various systems and am constantly crossing up numbers and letters (or conflating one system's numbers with another, etc.). Very annoying. I have had to resort to carefully rereading what I've typed to pick out the nits (just like I did for this one). It is indeed frustrating if not downright embarrasing at times.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: TekScopes@groups.io
Sent: Wednesday, August 19, 2020 7:58:25 AM
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break... A fix.

It is becoming a touchy subject for me. All my life I have
been a very fast touch typist. I spent a lot of time writing
programs, and later writing documentation, and could always
type quickly and effortlessly...

But in my 60's, I am noticing coordination problems in my typing,
I "slur" my shift control, and swap adjacent letters.

FG504 can become FG540, Chuck can become CHuck...

I even do a little weird thing where small common words, like
"the" come out backwards "eht", and other words always gain an
extra letter, such as "ratio" always getting typed "ration".

I always find it amusing when I type a long treatise on some subject
or other, and the only comments that get made are about a misplaced
comma, or a typo.

I am getting older. I can't see as well as I once did, I cant type
as well as I once did... And I don't like it.

I am working through a couple of FG504's. If I can help, just ask.

-Chuck Harris


Colin Herbert via groups.io wrote:
No, the typo doesn't matter in so far as that is what it was. I was just
curious because I am trying to get a FG504 working correctly and not doing
too well at the moment. I didn't mean to insult you or anything like that;
please forgive me if that's what it came over as.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck
Harris
Sent: 19 August 2020 13:22
To: TekScopes@groups.io
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break... A
fix.

Honestly, does it really matter that I mistyped FG504?

I am talking about ceramic trimmers that exist in
hundreds of Tektronix instrument models.

-Chuck Harris

Colin Herbert via groups.io wrote:
Do you mean an FG504? I can't find any FG540 on TekWiki.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck
Harris
Sent: 19 August 2020 05:15
To: TekScopes
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break...
A fix.

Just to clear up some confusion:

This note is about subminiature ceramic disk type
trimmer capacitors. Tektronix equipment from the
1980's onward is littered with these little timebombs.

It is a "modernization" of the old style ceramic
trimmers that had a silver plated half circle on
the lid that was soldered to the adjusting screw.

In this case, the silver plating is inside of the
trimmer, and the ceramic disk is held on by very
temperamental magic. The moving ceramic disk sticks
to its ceramic base, and the magic disappears.

-Chuck Harris

Chuck Harris wrote:
Hi All,

Just a note. As happens to all of us, one of those
little ceramic trimmers in an FG540 was broken. The
screw turned and turned, but the ceramic disk on top
didn't. It was frozen solid.

Bother...

I didn't have a spare, so I removed the trimmer, and
found the ceramic disk frozen solid to the ceramic
base... no trimming going on here!

First, I put the capacitor into some IPA to soak for
a bit. There was more than enough stinky flux on
the cap, so I think the flux was gluing the cap stuck.

After it soaked for a while, I was able to turn the
disk with my fingers... don't use tools, it will break!

I put it in for some more soaking, and twisting, until
it was good and clean.

Next, I took a small dot of cyanoacrylate glue, and
spread it around the screw. A small dot, not a flood.
[If you can't control your glue bottle, put some CA glue
on a piece of plastic, and use a toothpick to bring a dot
to your trimmer.]

Then finally, I gave a rag a squirt of "Kicker", a CA
glue accelerator, and put the rag near the trimmer... The
kicker's fumes are enough to harden the glue almost
instantly. If you don't have any kicker, just let it set
a while, it will harden from the moisture in the air.

I gave the screw a twist, and all was back to normal.

-Chuck Harris




















n4buq
 

Mid-sixties here and having some of the same issues. I work with a lot of various systems and am constantly crossing up numbers and letters (or conflating one system's numbers with another, etc.). Very annoying. I have had to resort to carefully rereading what I've typed to pick out the nits (just like I did for this one). It is indeed frustrating if not downright embarrasing at times.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: TekScopes@groups.io
Sent: Wednesday, August 19, 2020 7:58:25 AM
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break... A fix.

It is becoming a touchy subject for me. All my life I have
been a very fast touch typist. I spent a lot of time writing
programs, and later writing documentation, and could always
type quickly and effortlessly...

But in my 60's, I am noticing coordination problems in my typing,
I "slur" my shift control, and swap adjacent letters.

FG504 can become FG540, Chuck can become CHuck...

I even do a little weird thing where small common words, like
"the" come out backwards "eht", and other words always gain an
extra letter, such as "ratio" always getting typed "ration".

I always find it amusing when I type a long treatise on some subject
or other, and the only comments that get made are about a misplaced
comma, or a typo.

I am getting older. I can't see as well as I once did, I cant type
as well as I once did... And I don't like it.

I am working through a couple of FG504's. If I can help, just ask.

-Chuck Harris


Colin Herbert via groups.io wrote:
No, the typo doesn't matter in so far as that is what it was. I was just
curious because I am trying to get a FG504 working correctly and not doing
too well at the moment. I didn't mean to insult you or anything like that;
please forgive me if that's what it came over as.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck
Harris
Sent: 19 August 2020 13:22
To: TekScopes@groups.io
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break... A
fix.

Honestly, does it really matter that I mistyped FG504?

I am talking about ceramic trimmers that exist in
hundreds of Tektronix instrument models.

-Chuck Harris

Colin Herbert via groups.io wrote:
Do you mean an FG504? I can't find any FG540 on TekWiki.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck
Harris
Sent: 19 August 2020 05:15
To: TekScopes
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break...
A fix.

Just to clear up some confusion:

This note is about subminiature ceramic disk type
trimmer capacitors. Tektronix equipment from the
1980's onward is littered with these little timebombs.

It is a "modernization" of the old style ceramic
trimmers that had a silver plated half circle on
the lid that was soldered to the adjusting screw.

In this case, the silver plating is inside of the
trimmer, and the ceramic disk is held on by very
temperamental magic. The moving ceramic disk sticks
to its ceramic base, and the magic disappears.

-Chuck Harris

Chuck Harris wrote:
Hi All,

Just a note. As happens to all of us, one of those
little ceramic trimmers in an FG540 was broken. The
screw turned and turned, but the ceramic disk on top
didn't. It was frozen solid.

Bother...

I didn't have a spare, so I removed the trimmer, and
found the ceramic disk frozen solid to the ceramic
base... no trimming going on here!

First, I put the capacitor into some IPA to soak for
a bit. There was more than enough stinky flux on
the cap, so I think the flux was gluing the cap stuck.

After it soaked for a while, I was able to turn the
disk with my fingers... don't use tools, it will break!

I put it in for some more soaking, and twisting, until
it was good and clean.

Next, I took a small dot of cyanoacrylate glue, and
spread it around the screw. A small dot, not a flood.
[If you can't control your glue bottle, put some CA glue
on a piece of plastic, and use a toothpick to bring a dot
to your trimmer.]

Then finally, I gave a rag a squirt of "Kicker", a CA
glue accelerator, and put the rag near the trimmer... The
kicker's fumes are enough to harden the glue almost
instantly. If you don't have any kicker, just let it set
a while, it will harden from the moisture in the air.

I gave the screw a twist, and all was back to normal.

-Chuck Harris


















Chuck Harris
 

It is becoming a touchy subject for me. All my life I have
been a very fast touch typist. I spent a lot of time writing
programs, and later writing documentation, and could always
type quickly and effortlessly...

But in my 60's, I am noticing coordination problems in my typing,
I "slur" my shift control, and swap adjacent letters.

FG504 can become FG540, Chuck can become CHuck...

I even do a little weird thing where small common words, like
"the" come out backwards "eht", and other words always gain an
extra letter, such as "ratio" always getting typed "ration".

I always find it amusing when I type a long treatise on some subject
or other, and the only comments that get made are about a misplaced
comma, or a typo.

I am getting older. I can't see as well as I once did, I cant type
as well as I once did... And I don't like it.

I am working through a couple of FG504's. If I can help, just ask.

-Chuck Harris


Colin Herbert via groups.io wrote:

No, the typo doesn't matter in so far as that is what it was. I was just curious because I am trying to get a FG504 working correctly and not doing too well at the moment. I didn't mean to insult you or anything like that; please forgive me if that's what it came over as.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck Harris
Sent: 19 August 2020 13:22
To: TekScopes@groups.io
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break... A fix.

Honestly, does it really matter that I mistyped FG504?

I am talking about ceramic trimmers that exist in
hundreds of Tektronix instrument models.

-Chuck Harris

Colin Herbert via groups.io wrote:
Do you mean an FG504? I can't find any FG540 on TekWiki.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck Harris
Sent: 19 August 2020 05:15
To: TekScopes
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break... A fix.

Just to clear up some confusion:

This note is about subminiature ceramic disk type
trimmer capacitors. Tektronix equipment from the
1980's onward is littered with these little timebombs.

It is a "modernization" of the old style ceramic
trimmers that had a silver plated half circle on
the lid that was soldered to the adjusting screw.

In this case, the silver plating is inside of the
trimmer, and the ceramic disk is held on by very
temperamental magic. The moving ceramic disk sticks
to its ceramic base, and the magic disappears.

-Chuck Harris

Chuck Harris wrote:
Hi All,

Just a note. As happens to all of us, one of those
little ceramic trimmers in an FG540 was broken. The
screw turned and turned, but the ceramic disk on top
didn't. It was frozen solid.

Bother...

I didn't have a spare, so I removed the trimmer, and
found the ceramic disk frozen solid to the ceramic
base... no trimming going on here!

First, I put the capacitor into some IPA to soak for
a bit. There was more than enough stinky flux on
the cap, so I think the flux was gluing the cap stuck.

After it soaked for a while, I was able to turn the
disk with my fingers... don't use tools, it will break!

I put it in for some more soaking, and twisting, until
it was good and clean.

Next, I took a small dot of cyanoacrylate glue, and
spread it around the screw. A small dot, not a flood.
[If you can't control your glue bottle, put some CA glue
on a piece of plastic, and use a toothpick to bring a dot
to your trimmer.]

Then finally, I gave a rag a squirt of "Kicker", a CA
glue accelerator, and put the rag near the trimmer... The
kicker's fumes are enough to harden the glue almost
instantly. If you don't have any kicker, just let it set
a while, it will harden from the moisture in the air.

I gave the screw a twist, and all was back to normal.

-Chuck Harris
















Stephen
 

On Wed, Aug 19, 2020 at 01:22 AM, Chuck Harris wrote:


Honestly, does it really matter that I mistyped FG504?
I make typos all the time. Especially with multi spellcheck in different languages. It writes whatever it wants... If I don’t double check...

Don’t worry, it’s okay. I understood you were talking about the FG504.
But maybe Colin did believe an actual FG540 existed and was confused when he did find it. Mistakes happen.


Colin Herbert
 

No, the typo doesn't matter in so far as that is what it was. I was just curious because I am trying to get a FG504 working correctly and not doing too well at the moment. I didn't mean to insult you or anything like that; please forgive me if that's what it came over as.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck Harris
Sent: 19 August 2020 13:22
To: TekScopes@groups.io
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break... A fix.

Honestly, does it really matter that I mistyped FG504?

I am talking about ceramic trimmers that exist in
hundreds of Tektronix instrument models.

-Chuck Harris

Colin Herbert via groups.io wrote:
Do you mean an FG504? I can't find any FG540 on TekWiki.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck Harris
Sent: 19 August 2020 05:15
To: TekScopes
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break... A fix.

Just to clear up some confusion:

This note is about subminiature ceramic disk type
trimmer capacitors. Tektronix equipment from the
1980's onward is littered with these little timebombs.

It is a "modernization" of the old style ceramic
trimmers that had a silver plated half circle on
the lid that was soldered to the adjusting screw.

In this case, the silver plating is inside of the
trimmer, and the ceramic disk is held on by very
temperamental magic. The moving ceramic disk sticks
to its ceramic base, and the magic disappears.

-Chuck Harris

Chuck Harris wrote:
Hi All,

Just a note. As happens to all of us, one of those
little ceramic trimmers in an FG540 was broken. The
screw turned and turned, but the ceramic disk on top
didn't. It was frozen solid.

Bother...

I didn't have a spare, so I removed the trimmer, and
found the ceramic disk frozen solid to the ceramic
base... no trimming going on here!

First, I put the capacitor into some IPA to soak for
a bit. There was more than enough stinky flux on
the cap, so I think the flux was gluing the cap stuck.

After it soaked for a while, I was able to turn the
disk with my fingers... don't use tools, it will break!

I put it in for some more soaking, and twisting, until
it was good and clean.

Next, I took a small dot of cyanoacrylate glue, and
spread it around the screw. A small dot, not a flood.
[If you can't control your glue bottle, put some CA glue
on a piece of plastic, and use a toothpick to bring a dot
to your trimmer.]

Then finally, I gave a rag a squirt of "Kicker", a CA
glue accelerator, and put the rag near the trimmer... The
kicker's fumes are enough to harden the glue almost
instantly. If you don't have any kicker, just let it set
a while, it will harden from the moisture in the air.

I gave the screw a twist, and all was back to normal.

-Chuck Harris










Chuck Harris
 

Honestly, does it really matter that I mistyped FG504?

I am talking about ceramic trimmers that exist in
hundreds of Tektronix instrument models.

-Chuck Harris

Colin Herbert via groups.io wrote:

Do you mean an FG504? I can't find any FG540 on TekWiki.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck Harris
Sent: 19 August 2020 05:15
To: TekScopes
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break... A fix.

Just to clear up some confusion:

This note is about subminiature ceramic disk type
trimmer capacitors. Tektronix equipment from the
1980's onward is littered with these little timebombs.

It is a "modernization" of the old style ceramic
trimmers that had a silver plated half circle on
the lid that was soldered to the adjusting screw.

In this case, the silver plating is inside of the
trimmer, and the ceramic disk is held on by very
temperamental magic. The moving ceramic disk sticks
to its ceramic base, and the magic disappears.

-Chuck Harris

Chuck Harris wrote:
Hi All,

Just a note. As happens to all of us, one of those
little ceramic trimmers in an FG540 was broken. The
screw turned and turned, but the ceramic disk on top
didn't. It was frozen solid.

Bother...

I didn't have a spare, so I removed the trimmer, and
found the ceramic disk frozen solid to the ceramic
base... no trimming going on here!

First, I put the capacitor into some IPA to soak for
a bit. There was more than enough stinky flux on
the cap, so I think the flux was gluing the cap stuck.

After it soaked for a while, I was able to turn the
disk with my fingers... don't use tools, it will break!

I put it in for some more soaking, and twisting, until
it was good and clean.

Next, I took a small dot of cyanoacrylate glue, and
spread it around the screw. A small dot, not a flood.
[If you can't control your glue bottle, put some CA glue
on a piece of plastic, and use a toothpick to bring a dot
to your trimmer.]

Then finally, I gave a rag a squirt of "Kicker", a CA
glue accelerator, and put the rag near the trimmer... The
kicker's fumes are enough to harden the glue almost
instantly. If you don't have any kicker, just let it set
a while, it will harden from the moisture in the air.

I gave the screw a twist, and all was back to normal.

-Chuck Harris










Colin Herbert
 

Do you mean an FG504? I can't find any FG540 on TekWiki.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck Harris
Sent: 19 August 2020 05:15
To: TekScopes
Subject: Re: [TekScopes] Little ceramic trimmer caps that always break... A fix.

Just to clear up some confusion:

This note is about subminiature ceramic disk type
trimmer capacitors. Tektronix equipment from the
1980's onward is littered with these little timebombs.

It is a "modernization" of the old style ceramic
trimmers that had a silver plated half circle on
the lid that was soldered to the adjusting screw.

In this case, the silver plating is inside of the
trimmer, and the ceramic disk is held on by very
temperamental magic. The moving ceramic disk sticks
to its ceramic base, and the magic disappears.

-Chuck Harris

Chuck Harris wrote:
Hi All,

Just a note. As happens to all of us, one of those
little ceramic trimmers in an FG540 was broken. The
screw turned and turned, but the ceramic disk on top
didn't. It was frozen solid.

Bother...

I didn't have a spare, so I removed the trimmer, and
found the ceramic disk frozen solid to the ceramic
base... no trimming going on here!

First, I put the capacitor into some IPA to soak for
a bit. There was more than enough stinky flux on
the cap, so I think the flux was gluing the cap stuck.

After it soaked for a while, I was able to turn the
disk with my fingers... don't use tools, it will break!

I put it in for some more soaking, and twisting, until
it was good and clean.

Next, I took a small dot of cyanoacrylate glue, and
spread it around the screw. A small dot, not a flood.
[If you can't control your glue bottle, put some CA glue
on a piece of plastic, and use a toothpick to bring a dot
to your trimmer.]

Then finally, I gave a rag a squirt of "Kicker", a CA
glue accelerator, and put the rag near the trimmer... The
kicker's fumes are enough to harden the glue almost
instantly. If you don't have any kicker, just let it set
a while, it will harden from the moisture in the air.

I gave the screw a twist, and all was back to normal.

-Chuck Harris




Chuck Harris
 

Just to clear up some confusion:

This note is about subminiature ceramic disk type
trimmer capacitors. Tektronix equipment from the
1980's onward is littered with these little timebombs.

It is a "modernization" of the old style ceramic
trimmers that had a silver plated half circle on
the lid that was soldered to the adjusting screw.

In this case, the silver plating is inside of the
trimmer, and the ceramic disk is held on by very
temperamental magic. The moving ceramic disk sticks
to its ceramic base, and the magic disappears.

-Chuck Harris

Chuck Harris wrote:

Hi All,

Just a note. As happens to all of us, one of those
little ceramic trimmers in an FG540 was broken. The
screw turned and turned, but the ceramic disk on top
didn't. It was frozen solid.

Bother...

I didn't have a spare, so I removed the trimmer, and
found the ceramic disk frozen solid to the ceramic
base... no trimming going on here!

First, I put the capacitor into some IPA to soak for
a bit. There was more than enough stinky flux on
the cap, so I think the flux was gluing the cap stuck.

After it soaked for a while, I was able to turn the
disk with my fingers... don't use tools, it will break!

I put it in for some more soaking, and twisting, until
it was good and clean.

Next, I took a small dot of cyanoacrylate glue, and
spread it around the screw. A small dot, not a flood.
[If you can't control your glue bottle, put some CA glue
on a piece of plastic, and use a toothpick to bring a dot
to your trimmer.]

Then finally, I gave a rag a squirt of "Kicker", a CA
glue accelerator, and put the rag near the trimmer... The
kicker's fumes are enough to harden the glue almost
instantly. If you don't have any kicker, just let it set
a while, it will harden from the moisture in the air.

I gave the screw a twist, and all was back to normal.

-Chuck Harris




Chuck Harris
 

Hi John,

This is normal stuff when you calibrate an instrument for the
first time in decades.

These little subminiature trimmer caps break all the time. Every
time I try to turn one for the first time, my jaw clenches up,
and I give it a gentle turn. Either the ceramic part breaks free
and the cap turns, or the screw breaks free of the ceramic disk.

It is fixed, and the generator impedance is now adjusted. I am
about half way through the calibration adjustments...

All is good. I just like to put out repair notes as my local
reality reminds me of them.

-Chuck Harris

John Ferguson via groups.io wrote:

Wow, Chuck, it was worse than I thought, but it sounds like you have prevailed.

john