I changed the CRT HV anode wire on TEK o'scope by ...
- removing the silicon glued cover/cap
- desolder old anode lead
- clean silicon
- solder new anode lead
- re-silicon the lead cover/cap

Now ? is there any test i should perform to make sure i did the
job correctly/well ?
Like checking for corona leaks or any other such matters ?

Best method to do these tests

Also i noticed the Aquadag coating on the good CRT is alot more
uneven (bumpy) is there anything that should be done with the
Aquadag ?

Any useful ideas and help appreciated.
robb

"robb" <some@where.on.net> wrote in message
news:13qepm0ch1nti23@corp.supernews.com...
>I changed the CRT HV anode wire on TEK o'scope by ...
> - removing the silicon glued cover/cap
> - desolder old anode lead
> - clean silicon
> - solder new anode lead
> - re-silicon the lead cover/cap
>
> Now ? is there any test i should perform to make sure i did the
> job correctly/well ?
> Like checking for corona leaks or any other such matters ?
>
> Best method to do these tests
>
> Also i noticed the Aquadag coating on the good CRT is alot more
> uneven (bumpy) is there anything that should be done with the
> Aquadag ?
>
> Any useful ideas and help appreciated.
> robb
>

Turn it on in a dark room and look for corona, smell for ozone, listen for
sizzling, and pull the plug if anything bursts into flames

James Sweet wrote:
> "robb" <some@where.on.net> wrote in message
> news:13qepm0ch1nti23@corp.supernews.com...
>> I changed the CRT HV anode wire on TEK o'scope by ...
>> - removing the silicon glued cover/cap
>> - desolder old anode lead
>> - clean silicon
>> - solder new anode lead
>> - re-silicon the lead cover/cap
>>
>> Now ? is there any test i should perform to make sure i did the
>> job correctly/well ?
>> Like checking for corona leaks or any other such matters ?
>>
>> Best method to do these tests
>>
>> Also i noticed the Aquadag coating on the good CRT is alot more
>> uneven (bumpy) is there anything that should be done with the
>> Aquadag ?
>>
>> Any useful ideas and help appreciated.
>> robb
>>
>
> Turn it on in a dark room and look for corona, smell for ozone, listen for
> sizzling, and pull the plug if anything bursts into flames
>
>
Ahhh!!! why deny us the pleasure of a nice bonfire?????
(have a video capable phone ready please!)

"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns9A3A9EC34FF93jyanikkuanet@64.209.0.86...
> "robb" <some@where.on.net> wrote in
> news:13qepm0ch1nti23@corp.supernews.com:
>
> > I changed the CRT HV anode wire on TEK o'scope by ...
> > - removing the silicon glued cover/cap
> > - desolder old anode lead
> > - clean silicon
> > - solder new anode lead
> > - re-silicon the lead cover/cap
> >
> > Now ? is there any test i should perform to make sure i did
the
> > job correctly/well ?
> >
>
> I'd allow a sufficient time for the silicone to cure FULLY.
> Otherwise,it becomes a leakage path.
>
> Better to wait too long than too little.
> Jim Yanik
>

Hello Jim,

Thanks for help.

I created a mock up cap and silicon seal on a piece of glass
just after the repair cap and seal so that i could check in 24
hours to see where the mock up was in the curring cycle.

I was planning to wait 24 hours, check the mock up curring and
then see if i should wait another 24.

Thanks for the help ,
robb

"James Sweet" <jamessweet@hotmail.com> wrote in message
news:lUJpj.2817$FW3.19@trndny03...
>
> "robb" <some@where.on.net> wrote in message
> news:13qepm0ch1nti23@corp.supernews.com...
> >I changed the CRT HV anode wire on TEK o'scope by ...
> > - removing the silicon glued cover/cap
> > - desolder old anode lead
> > - clean silicon
> > - solder new anode lead
> > - re-silicon the lead cover/cap
> >
> > Now ? is there any test i should perform to make sure i did
the
> > job correctly/well ?
> >
>
> Turn it on in a dark room and look for corona, smell for ozone,
listen for
> sizzling, and pull the plug if anything bursts into flames
>
>

Haha....
I may eat my soldering iron if it bursts into flames. (after it
cools down... the soldering iron that is)

thanks, i think,
robb

"Sjouke Burry" <burrynulnulfour@ppllaanneett.nnlll> wrote in
message news:47a770ca$0$25473$ba620dc5@text.nova.planet.nl...
> James Sweet wrote:
> > "robb" <some@where.on.net> wrote in message
> > news:13qepm0ch1nti23@corp.supernews.com...
> >> I changed the CRT HV anode wire on TEK o'scope by ...
> >> - removing the silicon glued cover/cap
> >> - desolder old anode lead
> >> - clean silicon
> >> - solder new anode lead
> >> - re-silicon the lead cover/cap
> >>
> >> Now ? is there any test i should perform to make sure i did
the
> >> job correctly/well ?
> >>
> > Turn it on in a dark room and look for corona, smell for
ozone, listen for
> > sizzling, and pull the plug if anything bursts into flames
> >
> Ahhh!!! why deny us the pleasure of a nice bonfire?????
> (have a video capable phone ready please!)

Ok, so i will start he video camera before i turn it on
the next uTube hit :{
robb
robb

"robb" <some@where.on.net> wrote in message
news:13qepm0ch1nti23@corp.supernews.com...
>I changed the CRT HV anode wire on TEK o'scope by ...
> - removing the silicon glued cover/cap
> - desolder old anode lead
> - clean silicon
> - solder new anode lead
> - re-silicon the lead cover/cap
>
> Now ? is there any test i should perform to make sure i did the
> job correctly/well ?
> Like checking for corona leaks or any other such matters ?
>
> Best method to do these tests
>
> Also i noticed the Aquadag coating on the good CRT is alot more
> uneven (bumpy) is there anything that should be done with the
> Aquadag ?
>
> Any useful ideas and help appreciated.
> robb

An AM radio nearby can give a good indication of corona discharge. You get a
sort of a 'whining' noise. Breathing on the area with a good "HAAAAA" will
also show up any tendency for corona, which takes place more readily when
the air surrounding any potential discharge site, is made moist. With the AM
radio on, wave a screwdriver around the area. Again, this will provoke any
potential sites, and you should hear it. Eveness of the outer 'dag coating
should not be of any consequence.

Arfa

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:itOpj.1346$N53.74@newsfe1-win.ntli.net...
>
> "robb" <some@where.on.net> wrote in message
> news:13qepm0ch1nti23@corp.supernews.com...
> >I changed the CRT HV anode wire on TEK o'scope by ...
> > - removing the silicon glued cover/cap
> > - desolder old anode lead
> > - clean silicon
> > - solder new anode lead
> > - re-silicon the lead cover/cap
>
> An AM radio nearby can give a good indication of corona
discharge. You get a
> sort of a 'whining' noise. Breathing on the area with a good
"HAAAAA" will
> also show up any tendency for corona, which takes place more
readily when
> the air surrounding any potential discharge site, is made
moist.

Hello Arfa,

Thanks for reply.

Breathing with a HAAAAA ? is this going to be one of those the
HAAHAHA, the jokes on me kinda of suggestions ? where my ears
buzz, i see flashes of light and my eyebrow twitches for the rest
of the day.

Sounds suspiciously like one of those suggestions the Senior
engineers give to the new rookies to amuse themselves and the
other senior engineers.


>With the AM
> radio on, wave a screwdriver around the area. Again, this will
provoke any
> potential sites, and you should hear it. Eveness of the outer
'dag coating
> should not be of any consequence.
>
> Arfa

as long as it does not provoke a zap on me then i will give it a
try.

Thanks for the help Arfa,
robb

"robb" <some@where.on.net> wrote in message
news:13qh1nqc1f43u55@corp.supernews.com...
>
> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
> news:itOpj.1346$N53.74@newsfe1-win.ntli.net...
>>
>> "robb" <some@where.on.net> wrote in message
>> news:13qepm0ch1nti23@corp.supernews.com...
>> >I changed the CRT HV anode wire on TEK o'scope by ...
>> > - removing the silicon glued cover/cap
>> > - desolder old anode lead
>> > - clean silicon
>> > - solder new anode lead
>> > - re-silicon the lead cover/cap
>>
>> An AM radio nearby can give a good indication of corona
> discharge. You get a
>> sort of a 'whining' noise. Breathing on the area with a good
> "HAAAAA" will
>> also show up any tendency for corona, which takes place more
> readily when
>> the air surrounding any potential discharge site, is made
> moist.
>
> Hello Arfa,
>
> Thanks for reply.
>
> Breathing with a HAAAAA ? is this going to be one of those the
> HAAHAHA, the jokes on me kinda of suggestions ? where my ears
> buzz, i see flashes of light and my eyebrow twitches for the rest
> of the day.
>
> Sounds suspiciously like one of those suggestions the Senior
> engineers give to the new rookies to amuse themselves and the
> other senior engineers.
>

No, it's quite genuine. You need to "HAAAA" like a giant sigh, rather than
blow like putting out a candle. This shifts a large volume of slow-moving
and moist air into the area. Any spikes on the soldering or poor insulation
on the HV, will discharge much more readily into moist air, than dry air. It
represents no danger to you, as nothing is going to jump that distance,
unless your 'scope tube has a PDA with about a 100kV on it ...


>
>>With the AM
>> radio on, wave a screwdriver around the area. Again, this will
> provoke any
>> potential sites, and you should hear it.

>
> as long as it does not provoke a zap on me then i will give it a
> try.

The metal shaft of a screwdriver with a plastic handle, held in your hand,
will draw a good arc from a high voltage supply, without you feeling a
thing. In the good old days of valve (tube) only TV sets, it was a standard
test to pull an arc from the top caps of the boost rectifier and HOP valves.
Also, from the cap of a DY87 or the wires of an EY86 HV rectifier valve. You
couldn't do it in later sets, because of those new-fangled transistor
things, that would just expire if did anything like that within about 2
yards of them ! Anyway, the point is that if there is anywhere that has a
predisposition to corona discharge, a metal screwdriver blade waved in the
vicinity, will likely help it along. I'm not talking a big long spark
jumping out at you, just some ozone, or maybe a discharge that you can hear.


Trust me ! No dangerous suggestions from this quarter, ever ...

>
> Thanks for the help Arfa,
> robb
>
>

Arfa

Arfa Daily wrote:
<snip>
> Trust me ! No dangerous suggestions from this quarter, ever ...
>
>> Thanks for the help Arfa,
>> robb
>>
>>
Related: Check your car's high tension (spark plug) wires. On a dark
night, away from ambient light; open the hood with engine running.
Leaky HT wires will be readily apparent.

I had an AH Sprite that 'accidentally' introduced me to this technique,
which I've seen published since. I opened the hood for some
reason...blue sparks were dancing all over the engine. I replaced all
the HT leads toute suite....

jak
>
> Arfa
>
>

Silicon cured, CRT installed and tested.

Sorry no fireworks or shooting flames

thanks to Arfa, Jim, James, Sjouke etc...for the help.

Installed the new CRT and watched for all the symptoms and signs
people mentioned in the (sci.electronic.$$$$$) groups

No HV problems. But now the scope needs display adjusting to
suit the new CRT.

Problems:
==========
The display is skewed and the intensity and focus are off.

I was not expecting te new CRT to have hyper-intensity troubles.
That is... from no visible trace to oversaturated CRT brightness
is a very small range of knob motion maybe a 1/4-1/3 of he full
turn .

And the focus is very sensitive, touch sensitive ? was not
before.

And the internal probe calibration signal (.5 V @ 1 kHz) produces
a trace with fuzzy band for peaks ( 20 - 30 mV) or so wide. This
was not the case before maybe more like (5 mV ripple before CRT
swap)

So hopefully i can sort these problems out.

thanks for all the safety advice,
robb



"robb" <some@where.on.net> wrote in message
news:13qepm0ch1nti23@corp.supernews.com...
> I changed the CRT HV anode wire on TEK o'scope by ...
> - removing the silicon glued cover/cap
> - desolder old anode lead
> - clean silicon
> - solder new anode lead
> - re-silicon the lead cover/cap
>
> Now ? is there any test i should perform to make sure i did the
> job correctly/well ?

"robb" <some@where.on.net> wrote in message
news:13qma34qvgsf357@corp.supernews.com...
> Silicon cured, CRT installed and tested.
>
> Sorry no fireworks or shooting flames
>
> thanks to Arfa, Jim, James, Sjouke etc...for the help.
>
> Installed the new CRT and watched for all the symptoms and signs
> people mentioned in the (sci.electronic.$$$$$) groups
>
> No HV problems. But now the scope needs display adjusting to
> suit the new CRT.
>
> Problems:
> ==========
> The display is skewed and the intensity and focus are off.
>
> I was not expecting te new CRT to have hyper-intensity troubles.
> That is... from no visible trace to oversaturated CRT brightness
> is a very small range of knob motion maybe a 1/4-1/3 of he full
> turn .
>
> And the focus is very sensitive, touch sensitive ? was not
> before.
>
> And the internal probe calibration signal (.5 V @ 1 kHz) produces
> a trace with fuzzy band for peaks ( 20 - 30 mV) or so wide. This
> was not the case before maybe more like (5 mV ripple before CRT
> swap)
>
> So hopefully i can sort these problems out.
>

It sounds to me like this replacement CRT might not be quite as 'compatible'
as you had hoped ... Maybe that's part of the reason that the PDA lead
was not long enough to fit in your chassis i.e. to stop such a substitution
taking place. As far as the trace being 'skewed' do you mean that it is not
perfectly horizontal, or that it is trapezoidally distorted ? If the former,
then most decent 'scopes have a trace rotation control somewhere. As far as
the brightness / focus issues go, that is likely to be quite difficult to
resolve, and will probably require changes to be made to the component
values in the resistor chains providing the biasing voltages to the various
electrodes. I would suggest that you will not get too far with that, without
having schematics for both the 'scope that you've put the tube in, and the
one that it came out of, so that you can make comparisons of values and
expected voltages. Just as a matter of interest, are the quoted deflection
sensitivities for both tubes the same ?

Good luck with it - I think you'ree going to need it, but it's nice to see
that a sense of experimentation still exists out there - it's the sort of
thing that I would have been playing with 30 years ago ...


Arfa

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:MvVqj.4991$nG4.2323@newsfe6-win.ntli.net...
>
> "robb" <some@where.on.net> wrote in message
> news:13qma34qvgsf357@corp.supernews.com...
> > Silicon cured, CRT installed and tested.
> > Sorry no fireworks or shooting flames
> >
> > Problems:
> > ==========
> > The display is skewed and the intensity and focus are off.
> > I was not expecting te new CRT to have hyper-intensity
troubles.
> > That is... from no visible trace to oversaturated CRT
brightness
> > is a very small range of knob motion maybe a 1/4-1/3 of he
full
> > turn .
> > And the focus is very sensitive, touch sensitive ? was not
> > before.
>
> It sounds to me like this replacement CRT might not be quite as
'compatible'
> as you had hoped ... Maybe that's part of the reason that
the PDA lead
> was not long enough to fit in your chassis i.e. to stop such a
substitution
> taking place. As far as the trace being 'skewed' do you mean
that it is not
> perfectly horizontal, or that it is trapezoidally distorted ?
If the former,
> then most decent 'scopes have a trace rotation control
somewhere. As far as
> the brightness / focus issues go, that is likely to be quite
difficult to
> resolve, and will probably require changes to be made to the
component
> values in the resistor chains providing the biasing voltages to
the various
> electrodes. I would suggest that you will not get too far with
that, without
> having schematics for both the 'scope that you've put the tube
in, and the
> one that it came out of, so that you can make comparisons of
values and
> expected voltages. Just as a matter of interest, are the quoted
deflection
> sensitivities for both tubes the same ?
>
> Good luck with it - I think you'ree going to need it, but it's
nice to see
> that a sense of experimentation still exists out there - it's
the sort of
> thing that I would have been playing with 30 years ago ...
>

Hello Arfa,
It is a Tek scope.
There are lots of pots for adjusting the CRT params.

The CRT was replaced with its **reverse** compatible replacement
P/N.

That is, typically one replaces the earlier model CRT with the
newer model and i have done the reverse. I replaced the newer
model with the earlier model. Unless it was a "one way
compatibility" then technically it should work.

The HV lead was longer in newer models because of physical change
to the Flyback/HV multiplier transformer and orientation. The
earlier model machines had an HV Jack on an 3" HV lead coming off
the Flyback the newer models have te HV Jack on the Flyback
directly.

So you need just 1" (2.5 cm) more HV lead to make it there.

Hopefully i can cure problems with the adjustments, as I do not
really want to modify the original PCB /schematic values.

Thanks for help and ideas Arfa,
robb

"robb" <some@where.on.net> wrote in message
news:13qoip0fdq0muc3@corp.supernews.com...
>
> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
> news:MvVqj.4991$nG4.2323@newsfe6-win.ntli.net...
>>
>> "robb" <some@where.on.net> wrote in message
>> news:13qma34qvgsf357@corp.supernews.com...
>> > Silicon cured, CRT installed and tested.
>> > Sorry no fireworks or shooting flames
>> >
>> > Problems:
>> > ==========
>> > The display is skewed and the intensity and focus are off.
>> > I was not expecting te new CRT to have hyper-intensity
> troubles.
>> > That is... from no visible trace to oversaturated CRT
> brightness
>> > is a very small range of knob motion maybe a 1/4-1/3 of he
> full
>> > turn .
>> > And the focus is very sensitive, touch sensitive ? was not
>> > before.
>>
>> It sounds to me like this replacement CRT might not be quite as
> 'compatible'
>> as you had hoped ... Maybe that's part of the reason that
> the PDA lead
>> was not long enough to fit in your chassis i.e. to stop such a
> substitution
>> taking place. As far as the trace being 'skewed' do you mean
> that it is not
>> perfectly horizontal, or that it is trapezoidally distorted ?
> If the former,
>> then most decent 'scopes have a trace rotation control
> somewhere. As far as
>> the brightness / focus issues go, that is likely to be quite
> difficult to
>> resolve, and will probably require changes to be made to the
> component
>> values in the resistor chains providing the biasing voltages to
> the various
>> electrodes. I would suggest that you will not get too far with
> that, without
>> having schematics for both the 'scope that you've put the tube
> in, and the
>> one that it came out of, so that you can make comparisons of
> values and
>> expected voltages. Just as a matter of interest, are the quoted
> deflection
>> sensitivities for both tubes the same ?
>>
>> Good luck with it - I think you'ree going to need it, but it's
> nice to see
>> that a sense of experimentation still exists out there - it's
> the sort of
>> thing that I would have been playing with 30 years ago ...
>>
>
> Hello Arfa,
> It is a Tek scope.
> There are lots of pots for adjusting the CRT params.
>
> The CRT was replaced with its **reverse** compatible replacement
> P/N.
>
> That is, typically one replaces the earlier model CRT with the
> newer model and i have done the reverse. I replaced the newer
> model with the earlier model. Unless it was a "one way
> compatibility" then technically it should work.
>
> The HV lead was longer in newer models because of physical change
> to the Flyback/HV multiplier transformer and orientation. The
> earlier model machines had an HV Jack on an 3" HV lead coming off
> the Flyback the newer models have te HV Jack on the Flyback
> directly.
>
> So you need just 1" (2.5 cm) more HV lead to make it there.
>
> Hopefully i can cure problems with the adjustments, as I do not
> really want to modify the original PCB /schematic values.
>
> Thanks for help and ideas Arfa,
> robb
>
Hmmmm. Sometimes, compatible substitution *is* a one-way street. If the
parameters of the two tubes were sufficiently similar, I would not have
expected there to be a huge difference in the external setups, or for the
operation of the user controls to become 'bunched' as you described. There
are a couple of Tek 'scope experts who pop up on here from time to time who
would be much better qualified to advise you on the specifics of your
problems than I, so hopefully one of them will dive in to help you shortly !

Arfa