OT: Tek 465

[Mark Zacharias]

Just bought a Tek 2246 on the 'Bay. This means the 465 will probably need to
be sold, assuming the new one is OK and all.

I would entertain serious offers from the good folks who know me here on the
Group (USA only, please) prior to putting it up on eBay.

Probably about 175.00 plus freight.

Yes, this is the same 'scope Mr. Yanik helped me with recently. Replaced a
bad bridge rectifier.

Everything works great, bright sharp trace, no burns. Physical condition
very good, nothing bent or broken, minor scuffs around the case but not
involving the face. I have several versions of the manuals etc on PDF.

Any questions please ask.

Thanks.


Mark Z.

--
"I can't die until the government finds a safe place to bury my liver."

 

[Jeffrey Angus]

On 8/27/2011 7:07 AM, Mark Zacharias wrote:

Just bought a Tek 2246 on the 'Bay. This means the 465 will probably
need to be sold, assuming the new one is OK and all.

Watch out Mark, the policy gestapo will come gunning for you. ;-)

Chris wrote:
[...]will be more than happy to pay a fair price / fair market value

This group does NOT have in its name one of the following:
forsale marketplace ads biz
thus it is NOT the proper group for this.

The charter for this group:

Jeff



--
"Everything from Crackers to Coffins"

 

[Jim Yanik]

"Mark Zacharias" <mark_zacharias@labolgcbs.net> wrote in
news:4e58de02$0$2960$a8266bb1@newsreader.readnews.com:

Just bought a Tek 2246 on the 'Bay. This means the 465 will probably
need to be sold, assuming the new one is OK and all.

I would entertain serious offers from the good folks who know me here
on the Group (USA only, please) prior to putting it up on eBay.

Probably about 175.00 plus freight.

Yes, this is the same 'scope Mr. Yanik helped me with recently.
Replaced a bad bridge rectifier.

Everything works great, bright sharp trace, no burns. Physical
condition very good, nothing bent or broken, minor scuffs around the
case but not involving the face. I have several versions of the
manuals etc on PDF.

Any questions please ask.

Thanks.


Mark Z.

I guess I better download a 2246 manual soon...... :-}

I've worked on them,but I'm not fond of them.
I don't know much about the microprocessor controls/digital section.

--
Jim Yanik
jyanik
at
localnet
dot com

 

[Jeffrey Angus]

On 8/27/2011 9:35 AM, Jim Yanik wrote:

I guess I better download a 2246 manual soon...... :-}

*grins* You don't think Mark's going to break that right away do you?

Jeff

--
"Everything from Crackers to Coffins"

 

[Jamie]

Mark Zacharias wrote:

Just bought a Tek 2246 on the 'Bay. This means the 465 will probably
need to be sold, assuming the new one is OK and all.

I would entertain serious offers from the good folks who know me here on
the Group (USA only, please) prior to putting it up on eBay.

Probably about 175.00 plus freight.

Yes, this is the same 'scope Mr. Yanik helped me with recently. Replaced
a bad bridge rectifier.

Everything works great, bright sharp trace, no burns. Physical condition
very good, nothing bent or broken, minor scuffs around the case but not
involving the face. I have several versions of the manuals etc on PDF.

Any questions please ask.

Thanks.


Mark Z.

That's funny, I also have a 465 sitting collecting dust because it once

shorted the bridge rectifier and later on in its life, it did it again.

So I put it aside and started to use my other, better one..

Jamie

 

[Mark Zacharias]

"Jeffrey Angus" <grendelair@aim.com> wrote in message
news:j3ap0v$bi0$1@dont-email.me...

On 8/27/2011 7:07 AM, Mark Zacharias wrote:
Just bought a Tek 2246 on the 'Bay. This means the 465 will probably
need to be sold, assuming the new one is OK and all.

Watch out Mark, the policy gestapo will come gunning for you. ;-)

Chris wrote:
[...]will be more than happy to pay a fair price / fair market value

This group does NOT have in its name one of the following:
forsale marketplace ads biz
thus it is NOT the proper group for this.

The charter for this group:

Jeff



--
"Everything from Crackers to Coffins"

I thought about someone maybe getting all worked up about posting something
for sale here, but I figured the guys who know me wouldn't care and anyone
else, well, you get the idea...

As far as the 2246 breaking, that's why I'm keeping my B&K 100mHz, as a
backup.

Tek is the Harley Davidson of oscilloscopes, after all.

Mark Z.

 

[Mark Zacharias]

"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns9F4E6BE3C4F38jyaniklocalnetcom@216.168.3.44...

"Mark Zacharias" <mark_zacharias@labolgcbs.net> wrote in
news:4e58de02$0$2960$a8266bb1@newsreader.readnews.com:

Just bought a Tek 2246 on the 'Bay. This means the 465 will probably
need to be sold, assuming the new one is OK and all.

I would entertain serious offers from the good folks who know me here
on the Group (USA only, please) prior to putting it up on eBay.

Probably about 175.00 plus freight.

Yes, this is the same 'scope Mr. Yanik helped me with recently.
Replaced a bad bridge rectifier.

Everything works great, bright sharp trace, no burns. Physical
condition very good, nothing bent or broken, minor scuffs around the
case but not involving the face. I have several versions of the
manuals etc on PDF.

Any questions please ask.

Thanks.


Mark Z.


I guess I better download a 2246 manual soon...... :-}

I've worked on them,but I'm not fond of them.
I don't know much about the microprocessor controls/digital section.

--
Jim Yanik
jyanik
at
localnet
dot com

I've looked for a service / maintenance manual on BAMA etc, all I can find
is an operators manual...

I see lots of 2465 carcasses on eBay, but not really any 2246's. I hope this
means they tend to be more reliable...

Mark Z.

 

[Jim Yanik]

"Mark Zacharias" <mark_zacharias@labolgcbs.net> wrote in
news:4e59b1db$0$2867$a8266bb1@newsreader.readnews.com:

"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns9F4E6BE3C4F38jyaniklocalnetcom@216.168.3.44...
"Mark Zacharias" <mark_zacharias@labolgcbs.net> wrote in
news:4e58de02$0$2960$a8266bb1@newsreader.readnews.com:

Just bought a Tek 2246 on the 'Bay. This means the 465 will probably
need to be sold, assuming the new one is OK and all.

I would entertain serious offers from the good folks who know me
here on the Group (USA only, please) prior to putting it up on eBay.

Probably about 175.00 plus freight.

Yes, this is the same 'scope Mr. Yanik helped me with recently.
Replaced a bad bridge rectifier.

Everything works great, bright sharp trace, no burns. Physical
condition very good, nothing bent or broken, minor scuffs around the
case but not involving the face. I have several versions of the
manuals etc on PDF.

Any questions please ask.

Thanks.


Mark Z.


I guess I better download a 2246 manual soon...... :-}

I've worked on them,but I'm not fond of them.
I don't know much about the microprocessor controls/digital section.

--
Jim Yanik
jyanik
at
localnet
dot com


I've looked for a service / maintenance manual on BAMA etc, all I can
find is an operators manual...

I see lots of 2465 carcasses on eBay, but not really any 2246's. I
hope this means they tend to be more reliable...

Mark Z.

While at TEK,I found a lot of channel amp/switch ICs failing,all TEK-made
unobtainium ICs. 2245/46/47 series scopes were NOT easy to troubleshoot.
That is why I prefer the 2213/2215/2235 series,hardly any Tek-made ICs,and
I think you could kludge up a surface mount board to sub for the one TEK-
made IC,if necessary.

Plus,most of the 2246 circuitry is on the main board,and VERY hard to get
to. The power supply is buried in the middle of the scope,you have to
remove the top board to access it. It's a switcher PS,of course.

But the TDS series scopes are even worse for DIY repairs;
no schematics at all.

TEK -really- blew it when they sold off the TEK-IC/hybrid manufacturing
unit,and I tried to warn them beforehand. Damn beancounters.....

I'm not sure if the sales engineers ever passed on my comments about
selling the IC/hybrid unit.Probably not,TEK managers had a way of chilling
dissent,they never wanted to hear opposition to their "bright ideas";
Shitty managers.
Now they're owned by Danaher. B-)

Oh,and TEK is moving scope production to China. (or has already)

scope serial numbers may start with a "C" for Chinese made stuff,"T" was
for Taiwan-made stuff,and "H" for Heenvereen.


--
Jim Yanik
jyanik
at
localnet
dot com

 

[Jim Yanik]

"Mark Zacharias" <mark_zacharias@labolgcbs.net> wrote in
news:4e59a0f2$0$2742$a8266bb1@newsreader.readnews.com:

I thought about someone maybe getting all worked up about posting
something for sale here, but I figured the guys who know me wouldn't
care and anyone else, well, you get the idea...

IMO,if a regular is selling an -occasional- item,no problem posted it
here,just put FS: in the header.

As far as the 2246 breaking, that's why I'm keeping my B&K 100mHz, as
a backup.

Good idea.

Tek is the Harley Davidson of oscilloscopes, after all.

Mark Z.

No,TEK -USED to be- the Harley Davidson of scopes.

--
Jim Yanik
jyanik
at
localnet
dot com

 

[Jeff Liebermann]

On Sat, 27 Aug 2011 22:11:45 -0500, "Mark Zacharias"
<mark_zacharias@labolgcbs.net> wrote:

I see lots of 2465 carcasses on eBay, but not really any 2246's. I hope this
means they tend to be more reliable...

Dream on. I have two 2246A scopes and one 2247A. The 2247A is
working an on the shelf:
<http://802.11junk.com/jeffl/pics/home/slides/lab.html>
One 2246A is in my "to be repaired one of these daze" pile:
<http://802.11junk.com/jeffl/crud/scopes-to-be-fixed.jpg>
The "to be repaired" 2246A has a large carbonized hole in the PCB
where a power transistor used to live. Repairing the board is
problematic. Actually, just extracting the board was a near
nightmare, which may help explain why I abandoned the repair.

I obtained a service manual with the scopes, and no, you can't have
it. There some CD's and prints of the 2246A manual for sale on eBay
for $7 to $15.

My other 2246A is either lost, stolen, loaned, or buried somewhere.
Last time I tried it, I had to bang on the case to revive an
intermittent in the vertical amps somewhere.



--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Mark Zacharias]

"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:mfej57p4dtbm6h5ptbosfs98pk5ifeot5d@4ax.com...

On Sat, 27 Aug 2011 22:11:45 -0500, "Mark Zacharias"
mark_zacharias@labolgcbs.net> wrote:

I see lots of 2465 carcasses on eBay, but not really any 2246's. I hope
this
means they tend to be more reliable...

Dream on. I have two 2246A scopes and one 2247A. The 2247A is
working an on the shelf:
http://802.11junk.com/jeffl/pics/home/slides/lab.html
One 2246A is in my "to be repaired one of these daze" pile:
http://802.11junk.com/jeffl/crud/scopes-to-be-fixed.jpg
The "to be repaired" 2246A has a large carbonized hole in the PCB
where a power transistor used to live. Repairing the board is
problematic. Actually, just extracting the board was a near
nightmare, which may help explain why I abandoned the repair.

I obtained a service manual with the scopes, and no, you can't have
it. There some CD's and prints of the 2246A manual for sale on eBay
for $7 to $15.

My other 2246A is either lost, stolen, loaned, or buried somewhere.
Last time I tried it, I had to bang on the case to revive an
intermittent in the vertical amps somewhere.



--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Disappointing on the reliability front. Ah, well. It's only money, and as I
say, I'm keeping the B&I 100mHz as my primary backup, and this doesn't count
a couple miscellaneous 15 and 20 meg Kenwoods and BE&Kiss I have laying
around.

Never used a scope with cursor readout - I'm going to have a learning curve
on this one. I suspect it will mostly be used as a plain analog scope
though, in 35 years mainly working audio I don't think I've ever "needed" a
crt readout.

I did not have any illusions about being able to fix the 2246 when (not if)
the time comes. I was probably lucky to get the 465 going.

Mark Z.

 

[Mark Zacharias]

"Mark Zacharias" <mark_zacharias@labolgcbs.net> wrote in message
news:4e5a3058$0$2925$a8266bb1@newsreader.readnews.com...

"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:mfej57p4dtbm6h5ptbosfs98pk5ifeot5d@4ax.com...
On Sat, 27 Aug 2011 22:11:45 -0500, "Mark Zacharias"
mark_zacharias@labolgcbs.net> wrote:

I see lots of 2465 carcasses on eBay, but not really any 2246's. I hope
this
means they tend to be more reliable...

Dream on. I have two 2246A scopes and one 2247A. The 2247A is
working an on the shelf:
http://802.11junk.com/jeffl/pics/home/slides/lab.html
One 2246A is in my "to be repaired one of these daze" pile:
http://802.11junk.com/jeffl/crud/scopes-to-be-fixed.jpg
The "to be repaired" 2246A has a large carbonized hole in the PCB
where a power transistor used to live. Repairing the board is
problematic. Actually, just extracting the board was a near
nightmare, which may help explain why I abandoned the repair.

I obtained a service manual with the scopes, and no, you can't have
it. There some CD's and prints of the 2246A manual for sale on eBay
for $7 to $15.

My other 2246A is either lost, stolen, loaned, or buried somewhere.
Last time I tried it, I had to bang on the case to revive an
intermittent in the vertical amps somewhere.



--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Damn spell checkers. Let me try again.

Disappointing on the reliability front. Ah, well. It's only money, and as I
say, I'm keeping the B&K 100mHz as my primary backup, and this doesn't count
a couple miscellaneous 15 and 20 meg Kenwoods and B&Ks I have laying
around.

Never used a scope with cursor readout - I'm going to have a learning curve
on this one. I suspect it will mostly be used as a plain analog scope
though, in 35 years mainly working audio I don't think I've ever "needed" a
crt readout.

I did not have any illusions about being able to fix the 2246 when (not if)
the time comes. I was probably lucky to get the 465 going.

Mark Z.

 

[Jeffrey Angus]

On 8/28/2011 7:15 AM, Mark Zacharias wrote:

Disappointing on the reliability front.

I just happen to have a 1948-49 Tek 511A sitting in
the shop. Thing works just fine. Of course, this is
a classic example of "They don't make 'em like they
used to."

Jeff

--
"Everything from Crackers to Coffins"

 

[Jim Yanik]

Jeff Liebermann <jeffl@cruzio.com> wrote in
news:mfej57p4dtbm6h5ptbosfs98pk5ifeot5d@4ax.com:

On Sat, 27 Aug 2011 22:11:45 -0500, "Mark Zacharias"
mark_zacharias@labolgcbs.net> wrote:

I see lots of 2465 carcasses on eBay, but not really any 2246's. I
hope this means they tend to be more reliable...

Dream on. I have two 2246A scopes and one 2247A. The 2247A is
working an on the shelf:
http://802.11junk.com/jeffl/pics/home/slides/lab.html
One 2246A is in my "to be repaired one of these daze" pile:
http://802.11junk.com/jeffl/crud/scopes-to-be-fixed.jpg
The "to be repaired" 2246A has a large carbonized hole in the PCB
where a power transistor used to live. Repairing the board is
problematic. Actually, just extracting the board was a near
nightmare, which may help explain why I abandoned the repair.

While at TEK,on 1720/1730 PS boards,I used to Dremel out the carbonized
area,fill in the hole with epoxy,and then lay new runs and set eyelets.
I used cellophane tape over the hole when putting in the epoxy,less finish
grinding to make it flat.

I obtained a service manual with the scopes, and no, you can't have
it. There some CD's and prints of the 2246A manual for sale on eBay
for $7 to $15.

My other 2246A is either lost, stolen, loaned, or buried somewhere.
Last time I tried it, I had to bang on the case to revive an
intermittent in the vertical amps somewhere.

yes,2245/6/7 scopes are a PITA to work on.

--
Jim Yanik
jyanik
at
localnet
dot com

 

[Jeff Liebermann]

On Sun, 28 Aug 2011 09:50:24 -0500, Jim Yanik <jyanik@abuse.gov>
wrote:

While at TEK,on 1720/1730 PS boards,I used to Dremel out the carbonized
area,fill in the hole with epoxy,and then lay new runs and set eyelets.
I used cellophane tape over the hole when putting in the epoxy,less finish
grinding to make it flat.

I've done that a few times in the past with mixed results. I have a
rather pricy power supply waiting for my attention, with a similar
hole. Works ok for low impedance circuitry, but I wouldn't use it for
hi-v or high impedance. I also use the Scotch tape trick, but also
add some fiberglass matting. I've also found that Bondo works better
than epoxy because it doesn't shrink when it hardens.

yes,2245/6/7 scopes are a PITA to work on.

The scopes that I and several friends have were purchased from a
former large corporation, that cound them uneconomical to repair.
There was a pile of them, which we purchased for peanuts. They were
happy to see them go.

Did you notice the TAS 465 scope in the pile to be fixed?
<http://802.11junk.com/jeffl/crud/scopes-to-be-fixed.jpg>
It lights up, runs, but the beam and alpha are stuck on the left side
of the screen. Vertical seems to be working but it's difficult to
tell with the beam off the screen. Obviously, a horizontal amp
problem. Yet, I've been inside 3 times and have not been able to find
an obvious culprit. However, I just found a schematic and manual, so
I'll probably try again. It has one big advantage... it's light
weight.

One of the T922 scopes on top of the pile works. Which one, I forgot.
The other has a blown flyback xformer. I haven't found a substitute
yet.

The two on the bottom of the pile are both HP 1740A 100MHz scopes.
Both have power supply problems, which are probably bad electrolytics.
I'm too lazy to fix them.

There are also at least 4 more assorted scopes around the house, and 3
more in the office, some of which work.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Jeff Liebermann]

On Sun, 28 Aug 2011 07:15:36 -0500, "Mark Zacharias"
<mark_zacharias@labolgcbs.net> wrote:

Never used a scope with cursor readout - I'm going to have a learning curve
on this one.

It's easy, but I hardly ever use the cursor for repair work. If the
waveform looks "reasonable", that's usually good enough. If I were
back to doing design, I might find it useful. What I find handy on
the 2246A/2247A is the ability to store and recall setups. I have a
few stored for various things I tend to do repeatedly, which saves me
some knob twiddling.

Suggestion: Open the box and blow out the dust and crud. Test
equipment tends to live longer when the air path isn't clogged.

I suspect it will mostly be used as a plain analog scope
though, in 35 years mainly working audio I don't think I've ever "needed" a
crt readout.

I suggest you look into a DSO (digital storage oscilloscope)
<http://www.rigolna.com/products/digital-oscilloscopes/>
or USB scopes. This is one that I borrowed, liked, but haven't
bought:
<http://www.syscompdesign.com/CGR101.html>
At 2Mhz max, it's good enough for audio except when you want to
measure near the noise floor. With only 10 bits, that's problematic.

I did not have any illusions about being able to fix the 2246 when (not if)
the time comes. I was probably lucky to get the 465 going.

Nothing wrong with believing in luck. Just don't try to rely on it.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Jim Yanik]

Jeff Liebermann <jeffl@cruzio.com> wrote in
news:18vk575npasgvjnhv61ab56hm4tgm8afr2@4ax.com:

On Sun, 28 Aug 2011 09:50:24 -0500, Jim Yanik <jyanik@abuse.gov
wrote:

While at TEK,on 1720/1730 PS boards,I used to Dremel out the
carbonized area,fill in the hole with epoxy,and then lay new runs and
set eyelets. I used cellophane tape over the hole when putting in the
epoxy,less finish grinding to make it flat.

I've done that a few times in the past with mixed results. I have a
rather pricy power supply waiting for my attention, with a similar
hole. Works ok for low impedance circuitry, but I wouldn't use it for
hi-v or high impedance. I also use the Scotch tape trick, but also
add some fiberglass matting. I've also found that Bondo works better
than epoxy because it doesn't shrink when it hardens.

My carbonized hole was the HV osc xstr,a TIP31C.
I never had any problem with epoxy shrinkage. I used a clear epoxy from
Hysol.
Now I would use my RAKA boat-building epoxy with fumed silica filler.great
stuff.

yes,2245/6/7 scopes are a PITA to work on.

The scopes that I and several friends have were purchased from a
former large corporation, that cound them uneconomical to repair.
There was a pile of them, which we purchased for peanuts. They were
happy to see them go.

Did you notice the TAS 465 scope in the pile to be fixed?
http://802.11junk.com/jeffl/crud/scopes-to-be-fixed.jpg

Missed that. Never worked on one.

It lights up, runs, but the beam and alpha are stuck on the left side
of the screen. Vertical seems to be working but it's difficult to
tell with the beam off the screen. Obviously, a horizontal amp
problem.

could also be a sweep problem;sweep triggered,but sweep gen not ramping.
might just be a CRT deflection pin lead fell off. I've seen them get
loose,and get shaken off in moving the scope.

Yet, I've been inside 3 times and have not been able to find
an obvious culprit. However, I just found a schematic and manual, so
I'll probably try again. It has one big advantage... it's light
weight.

One of the T922 scopes on top of the pile works. Which one, I forgot.
The other has a blown flyback xformer. I haven't found a substitute
yet.

I always liked the T922/32/35/442. Not the T912.

The two on the bottom of the pile are both HP 1740A 100MHz scopes.
Both have power supply problems, which are probably bad electrolytics.
I'm too lazy to fix them.

There are also at least 4 more assorted scopes around the house, and 3
more in the office, some of which work.

WOW,most people only have one or two scopes.....

are you fixing them for friends,or the occasional sale?

--
Jim Yanik
jyanik
at
localnet
dot com

 

[Jeff Liebermann]

On Sun, 28 Aug 2011 18:34:22 -0500, Jim Yanik <jyanik@abuse.gov>
wrote:

My carbonized hole was the HV osc xstr,a TIP31C.

The TIP31c is good for 100VDC. That's right on the border where I
would worry about any remaining carbonized epoxy causing a conduction
path. Good to know it worked.

I never had any problem with epoxy shrinkage. I used a clear epoxy from
Hysol.
Now I would use my RAKA boat-building epoxy with fumed silica filler.great
stuff.

Silica filler, as in sand? Well, that will give it considerable
hardness and strength. However, I don't think that will be necessary
to repair a PCB. I was dealing with a rather large hole, about 3/4"
in diameter. I wanted to make sure than any applied pressure would
not crack the epoxy. So, I added fiberglass matt reinforcing.

Did you notice the TAS 465 scope in the pile to be fixed?
http://802.11junk.com/jeffl/crud/scopes-to-be-fixed.jpg

Missed that. Never worked on one.

They look fairly nice inside and seem easy to work. Unfortunately,
there are plenty of proprietary parts.

It lights up, runs, but the beam and alpha are stuck on the left side
of the screen. Vertical seems to be working but it's difficult to
tell with the beam off the screen. Obviously, a horizontal amp
problem.

could also be a sweep problem;sweep triggered,but sweep gen not ramping.
might just be a CRT deflection pin lead fell off. I've seen them get
loose,and get shaken off in moving the scope.

I checked all the loose connection possibilities. All the scope
deflections leads have voltage. I don't think it's a trigger problem
because the various text labels that should show up on the screen, are
also stuck on the left side. I can see them sorta move when I
randomly push buttons, so I know they're functional, just not
displaying. I'll figure it out eventually. Project for tonite is yet
another blown power supply in an IFR-1500 service monitor. Great
monitor, disgusting power supply design.

One of the T922 scopes on top of the pile works. Which one, I forgot.
The other has a blown flyback xformer. I haven't found a substitute
yet.

I always liked the T922/32/35/442. Not the T912.

Yep. Not a bad scope, but the 922 is only good for 15Mhz. In these
daze of 100MHz scopes, it's kinda limiting.

The two on the bottom of the pile are both HP 1740A 100MHz scopes.
Both have power supply problems, which are probably bad electrolytics.
I'm too lazy to fix them.

There are also at least 4 more assorted scopes around the house, and 3
more in the office, some of which work.

WOW,most people only have one or two scopes.....

I forgot to mention 6ea Tek 5110 scopes with 5A18 vertical plug-ins.
They're rack mounted into various ham radio repeaters, hi-fi racks,
and at radio sites. I got tired of dragging a scope with me every
time I needed to do some repairs. So, I just added one into every
rack where I thought it might be useful. Works great, except that all
the other techs steal my scope probes.

are you fixing them for friends,or the occasional sale?

I have friends and I have customers. The difference is that the
customers pay me. Otherwise, they're the same.

Some of the better scopes were intended for me to use. Literally,
every scope required some form of repair or rework. I tend to buy
broken things, and fix them. (Don't ask me why I have 6 chain saws).
I plan to sell them eventually, but have not had the time or incentive
to fix any of them[1]. Diving into the shop, I see a Tek 2205, HP
182C, and Tek 213 scope/DVM, all of which are in need of something. I
didn't know I had that many scopes. Time to find some friends, err...
customers, and get rid of them. Otherwise, I'll just repupose my shop
as a museum.

[1] That may happen soon, as the computah repair biz is really slow.
What I usually do is take a few days off, and diagnose everything and
order parts. About 2 weeks later, when the parts arrive late, I do
assembly line repair on everything possible. I've done this several
times in the past and it works quite well for me. The problem is
finding the uninterrupted time.

Incidentally, I just found a box of Tek repair parts, dating back to
the 1970's era. Nuvistors, tubes, semiconductors, etc. There's an
inventory list, but the boxes have probably been pillaged. Any
interest?
<http://802.11junk.com/jeffl/crud/Tek-Parts.jpg>
There are 4 similar, but smaller plastic boxes stuffed with parts.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Jim Yanik]

Jeff Liebermann <jeffl@cruzio.com> wrote in
news:4pnl57568hr7j9pumqdvcn5k35gcos1mvc@4ax.com:

On Sun, 28 Aug 2011 18:34:22 -0500, Jim Yanik <jyanik@abuse.gov
wrote:

My carbonized hole was the HV osc xstr,a TIP31C.

The TIP31c is good for 100VDC. That's right on the border where I
would worry about any remaining carbonized epoxy causing a conduction
path. Good to know it worked.

the TIP-31C supply rail was 40v unreg;the reason why it burned up is the
+5v rail main filter cap ESR shot up,and the switcher drove it back up to
5v and all the other supplies went way higher;the +40 went to over 60vDC.
then the HV-osc xstr over dissipated,and burned up the PCB.

I never had any problem with epoxy shrinkage. I used a clear epoxy
from Hysol.
Now I would use my RAKA boat-building epoxy with fumed silica
filler.great stuff.

Silica filler, as in sand?

no,it's a white superfine powder used in epoxy mixes,for "filling the
weave" after fiberglassing your boat.It makes the epoxy thicker,and hard as
a rock. Nothing like sand (and a lot cleaner!).
Go to Systemthree.com,and read(free download!) their Epoxy Book,it's VERY
informative about using epoxies and fillers. I use wood flour,fumed
silica,phenolic microballoons,and chopped plastic fibers for
fillers,depending on the application. chopped glass fiber is also
available,but I've never used it.

I began using this stuff when I briefly returned to large model
rocketry;you need strong body tubes and fin attachments with the higher
power rocket motors now available.Fun,but an expensive hobby.

Well, that will give it considerable
hardness and strength. However, I don't think that will be necessary
to repair a PCB. I was dealing with a rather large hole, about 3/4"
in diameter. I wanted to make sure than any applied pressure would
not crack the epoxy. So, I added fiberglass matt reinforcing.

the holes I filled were about 0.5" in diameter or less.

Did you notice the TAS 465 scope in the pile to be fixed?
http://802.11junk.com/jeffl/crud/scopes-to-be-fixed.jpg

Missed that. Never worked on one.

They look fairly nice inside and seem easy to work. Unfortunately,
there are plenty of proprietary parts.

It lights up, runs, but the beam and alpha are stuck on the left
side of the screen. Vertical seems to be working but it's difficult
to tell with the beam off the screen. Obviously, a horizontal amp
problem.

could also be a sweep problem;sweep triggered,but sweep gen not
ramping. might just be a CRT deflection pin lead fell off. I've seen
them get loose,and get shaken off in moving the scope.

I checked all the loose connection possibilities. All the scope
deflections leads have voltage. I don't think it's a trigger problem
because the various text labels that should show up on the screen, are
also stuck on the left side. I can see them sorta move when I
randomly push buttons, so I know they're functional, just not
displaying. I'll figure it out eventually. Project for tonite is yet
another blown power supply in an IFR-1500 service monitor. Great
monitor, disgusting power supply design.

One of the T922 scopes on top of the pile works. Which one, I
forgot. The other has a blown flyback xformer. I haven't found a
substitute yet.

I always liked the T922/32/35/442. Not the T912.

Yep. Not a bad scope, but the 922 is only good for 15Mhz. In these
daze of 100MHz scopes, it's kinda limiting.

Nice thing is that they don't use -any- TEK-made ICs.
but they still have those low-pressure cam switch contacts,I'm surprised
any are still working. the plastic degrades and the little gold finger
contact falls off the spring part.No replacements available,either,AFAIK.

The two on the bottom of the pile are both HP 1740A 100MHz scopes.
Both have power supply problems, which are probably bad
electrolytics. I'm too lazy to fix them.

There are also at least 4 more assorted scopes around the house, and
3 more in the office, some of which work.

WOW,most people only have one or two scopes.....

I forgot to mention 6ea Tek 5110 scopes with 5A18 vertical plug-ins.
They're rack mounted into various ham radio repeaters, hi-fi racks,
and at radio sites. I got tired of dragging a scope with me every
time I needed to do some repairs. So, I just added one into every
rack where I thought it might be useful. Works great, except that all
the other techs steal my scope probes.

are you fixing them for friends,or the occasional sale?

I have friends and I have customers. The difference is that the
customers pay me. Otherwise, they're the same.

Some of the better scopes were intended for me to use. Literally,
every scope required some form of repair or rework. I tend to buy
broken things, and fix them. (Don't ask me why I have 6 chain saws).
I plan to sell them eventually, but have not had the time or incentive
to fix any of them[1]. Diving into the shop, I see a Tek 2205, HP
182C, and Tek 213 scope/DVM, all of which are in need of something. I
didn't know I had that many scopes. Time to find some friends, err...
customers, and get rid of them. Otherwise, I'll just repupose my shop
as a museum.

213 and all 200 series scopes are prone to having the plastic locator pins
in the case halves break or pull out under shock,and then the PCBs shift
around,and the pins spread open the female connectors,the little leaf
springs fall out and short things out.It's still a nice little scope,only
1 MHZ BW,but has the nifty on-screen DMM. TEK field service people used to
use(and abuse) them.

[1] That may happen soon, as the computah repair biz is really slow.
What I usually do is take a few days off, and diagnose everything and
order parts. About 2 weeks later, when the parts arrive late, I do
assembly line repair on everything possible. I've done this several
times in the past and it works quite well for me. The problem is
finding the uninterrupted time.

Incidentally, I just found a box of Tek repair parts, dating back to
the 1970's era. Nuvistors, tubes, semiconductors, etc. There's an
inventory list, but the boxes have probably been pillaged. Any
interest?

No,but thanks anyways.

http://802.11junk.com/jeffl/crud/Tek-Parts.jpg
There are 4 similar, but smaller plastic boxes stuffed with parts.

--
Jim Yanik
jyanik
at
localnet
dot com

 

[bg]

Incidentally, I just found a box of Tek repair parts, dating back to
the 1970's era. Nuvistors, tubes, semiconductors, etc. There's an
inventory list, but the boxes have probably been pillaged. Any
interest?
http://802.11junk.com/jeffl/crud/Tek-Parts.jpg
There are 4 similar, but smaller plastic boxes stuffed with parts.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

I've got a 465 that needs both of the dual FET buffer chips that are in the
verticle front end (right after the attenuators). I've heard that the 2n5911
is similiar but I'd have to buy hundreds of them which is way beyond what a
used parts scope would cost. Do you have any for sale?
bg