Date   

Re: Smoke damage 7704A

Bill (Doc) Courtright
 

Watching. I had a similar experience. Gear in closet but lots of smoke and water damage to all most all my 5K and 7K PI's.Luckily the 7K mainframes were not in the building. Instead my primary 5403 was soaked when the drop ceiling fell from the water.   After a year or so of setting in a warm house I carefully powered it up and with some control and switch cleaning has been fine. Lucky I guess. Cannot say how well calibrated it is but my limited references indicated that it was good enough.   So good luck. I will never get around  to going over the many PI's that I have as severe Arthritis has set in and working small controls is near impossible.   Bill

-----Original Message-----
From: Thomas Voshell <tvoshell@cableone.net>
To: TekScopes@groups.io
Sent: Wed, Jul 14, 2021 3:18 pm
Subject: [TekScopes] Smoke damage 7704A

I have a 7704A that was damaged in a house fire.  The scope was in a closet upstairs and everything outside of the closet was either melted or burned.  There is significant smoke residue on the outside of the covers and possibly some overspray from fire hoses.  I have not yet taken the covers off; no knobs frame plastics are melted on mainframe or plug-ins which look externally smoked up. (7a18, 7a26, 7b50, 7b51). I believe powering it up would be foolhardy as carbon conducts. My inclination is to completely disassemble the frame and wash with water the electronics and allow to air dry.  Due to age I am worried about old plastic flat cable connectors and the acquisition to display unit connector.  The CRT connector and the HVPS also worry me.

Does anyone have any suggestions/comments/insights/experience WRT this situation?

Thanks,
TomV


Re: What was the first oscilloscope to have cursors?

Brad Thompson
 

ken chalfant wrote on 7/14/2021 2:34 PM:

That’s it - (567/6R1)!
Hello--

Did you mean "what was the first oscilloscope to have cursers"?

My vote would go to the Fairchild/Dumont 766H....

73--

Brad  AA1IP


Re: explosion mystery on my 7104

Gary Robert Bosworth
 

Any cap that smoked must be replaced. Capacitors are supposed to take a
gulp of current and build up a fixed charge. If they conduct continuous
current, they are resistive and can eventually heat up and cause a fire.

On Wed, Jul 14, 2021, 11:32 n4buq <n4buq@knology.net> wrote:

Hi Keith,

After that cap smoked, the scope worked okay with the blown cap in it. I
did replace both line caps along with the electrolytics. Hopefully it's
cured for as long as I'll be using it.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Keith" <coolblueglow@gmail.com>
To: TekScopes@groups.io
Sent: Wednesday, July 14, 2021 12:28:43 PM
Subject: Re: [TekScopes] explosion mystery on my 7104

Hi Barry,

Curiously, my 2445b just blew the same part. unlike you, I got the smoke
and
the magnificent sonics and everything. Did you replace yours? My scope
seems
to be working fine without it, but of course this is an illusion, right?
:-)

Weird that both our 2445 series would blow their tops at around the same
time. Mine has about 20k hours on it.

Cheers,

Keith
coolblueglow










Smoke damage 7704A

Thomas Voshell
 

I have a 7704A that was damaged in a house fire. The scope was in a closet upstairs and everything outside of the closet was either melted or burned. There is significant smoke residue on the outside of the covers and possibly some overspray from fire hoses. I have not yet taken the covers off; no knobs frame plastics are melted on mainframe or plug-ins which look externally smoked up. (7a18, 7a26, 7b50, 7b51). I believe powering it up would be foolhardy as carbon conducts. My inclination is to completely disassemble the frame and wash with water the electronics and allow to air dry. Due to age I am worried about old plastic flat cable connectors and the acquisition to display unit connector. The CRT connector and the HVPS also worry me.

Does anyone have any suggestions/comments/insights/experience WRT this situation?

Thanks,
TomV


Re: 2445b shelf vents for bottom air intakes - should I?

satbeginner
 

Depending on the devices placed below the shelf holding the 2445, it even might be worse to have holes.

The holes in the bottom of the scope are there to let in air at ambient temperature, so if there is another warm device below it, the 2445 might suck in warmer air than expected, so the holes in the shelf could have an adverse effect.

That's why in telecom technology rack mount devices must be designed to have front to back cooling only, and not bottom upward cooling, to avoid one big chimney.

Just my 2 cents,

Leo


Re: What was the first oscilloscope to have cursors?

ken chalfant
 

That’s it - (567/6R1)!

I missed the previous mention.

Thanks very much.

Regards,

Ken

On 14Jul, 2021, at 11:47 AM, David Holland <david.w.holland@gmail.com> wrote:

The 567/6R1 combo previously mentioned?

https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fw140.com%2Ftekwiki%2Fwiki%2F567&;data=04%7C01%7C%7Cebb1536f9e7246d6731c08d946ef79a0%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637618816619250166%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=GbmEzJt9jWuC24Vzvbmeg4ouhf9IJRW%2FgzPgBSqC1V8%3D&amp;reserved=0

David


On Wed, Jul 14, 2021 at 1:28 PM ken chalfant <kpchalfant@msn.com <mailto:kpchalfant@msn.com>> wrote:

Greetings,

I can’t prove it even looking back at my really old Tektronix catalogs -
but, when I was in HS back in the late 1960’s a professor at the local
college, what was then the Cragmor Campus in Colorado Springs, part of CU
Boulder, would let me come up to their lab and mess around with test
equipment.

They had a Tek scope that was as big (maybe bigger) than a Tek 556. It
had a large plug-in on the right hand side that, as I recall, allowed for
time measurements. It may have even been able to do amplitude. If my
memory serves me it would allow the user to place intensified dots on the
trace and it displayed the value on Nixie tubes within the plug-in.

Does anybody else remember a scope like this?

Ken


On 14Jul, 2021, at 1:09 AM, cmjones01 <chris@stumpie.com> wrote:

On Tue, Jul 13, 2021 at 8:05 PM nj902 <wb0emu@arrl.net> wrote:

Cursors as in highlighted dots (or bars) that can be moved along the
trace with a corresponding method of determining time and voltage..

A second part of the question (if the answer is different) - which was
the first Tektronix scope to have cursors.

Cursor voltage measurement on a Tek scope would have been possible in
1974, certainly. With a 7D12/M2 plugin the timebase delay settings can
be used to highlight a portion of trace for voltage measurement, and
any delayed timebase with a calibrated delay will effectively do
cursor time measurement. If you want on-screen digital readout of
delta-delayed time that comes in 1976 with the 7B85. So in the 7000
series scopes, I'd say that manually-controlled digital cursor
measurements of time and voltage were possible together for the first
time in 1976.

Chris











Re: explosion mystery on my 7104

n4buq
 

Hi Keith,

After that cap smoked, the scope worked okay with the blown cap in it. I did replace both line caps along with the electrolytics. Hopefully it's cured for as long as I'll be using it.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Keith" <coolblueglow@gmail.com>
To: TekScopes@groups.io
Sent: Wednesday, July 14, 2021 12:28:43 PM
Subject: Re: [TekScopes] explosion mystery on my 7104

Hi Barry,

Curiously, my 2445b just blew the same part. unlike you, I got the smoke and
the magnificent sonics and everything. Did you replace yours? My scope seems
to be working fine without it, but of course this is an illusion, right? :-)

Weird that both our 2445 series would blow their tops at around the same
time. Mine has about 20k hours on it.

Cheers,

Keith
coolblueglow






Re: 2445b shelf vents for bottom air intakes - should I?

Michael W. Lynch
 

RIFA Caps

--
Michael Lynch
Dardanelle, AR


Re: 2445b shelf vents for bottom air intakes - should I?

Tom Gardner
 

When my delayed action smoke generator fired, it destroyed a series
resistor, a 1cm diameter patch of prepreg, and deposited pots of
carbon on the PCB and the exhaust fan.

At the very least you should inspect the area to see if you need to
remove a carbon deposit. Replacing all the RIFAs and the Al
electrolytic isn't difficult, but replace one at a time since there is
a discrepancy on some 24x5x.

On 14/07/2021, Keith <coolblueglow@gmail.com> wrote:
Thanks Jose,

Yes, that's the one I was worrying about. I'm going to cut the holes and add
a small fan too.

Curiously, I just put the 2445b up on the finished shelf and fired it up.
(no holes yet)

A few minutes after I fired it up, she made a terrible sound and magic smoke
came out.

I believe it was simply the Line RF filter module failing, which I've heard
others describe here on the forum. Apparently, it gives this rather
magnificent and stinky display of failure - and the scope keeps on working,
though without (I presume) RF filtering on the AC line in.

Just a good reminder that these devices are not getting any younger, and
neither am I!

Cheers

Keith
coolblueglow






Re: What was the first oscilloscope to have cursors?

Dave Voorhis
 

On 14 Jul 2021, at 18:28, ken chalfant <kpchalfant@msn.com> wrote:


Greetings,

I can’t prove it even looking back at my really old Tektronix catalogs - but, when I was in HS back in the late 1960’s a professor at the local college, what was then the Cragmor Campus in Colorado Springs, part of CU Boulder, would let me come up to their lab and mess around with test equipment.

They had a Tek scope that was as big (maybe bigger) than a Tek 556. It had a large plug-in on the right hand side that, as I recall, allowed for time measurements. It may have even been able to do amplitude. If my memory serves me it would allow the user to place intensified dots on the trace and it displayed the value on Nixie tubes within the plug-in.

Does anybody else remember a scope like this?
Mentioned earlier in this thread, it’s probably a 6R1 plugin for the 567 oscilloscope.

In other words, one of these? https://w140.com/tekwiki/wiki/6R1

In one of these? https://w140.com/tekwiki/wiki/567


Re: What was the first oscilloscope to have cursors?

David Holland
 

The 567/6R1 combo previously mentioned?

https://w140.com/tekwiki/wiki/567

David

On Wed, Jul 14, 2021 at 1:28 PM ken chalfant <kpchalfant@msn.com> wrote:

Greetings,

I can’t prove it even looking back at my really old Tektronix catalogs -
but, when I was in HS back in the late 1960’s a professor at the local
college, what was then the Cragmor Campus in Colorado Springs, part of CU
Boulder, would let me come up to their lab and mess around with test
equipment.

They had a Tek scope that was as big (maybe bigger) than a Tek 556. It
had a large plug-in on the right hand side that, as I recall, allowed for
time measurements. It may have even been able to do amplitude. If my
memory serves me it would allow the user to place intensified dots on the
trace and it displayed the value on Nixie tubes within the plug-in.

Does anybody else remember a scope like this?

Ken


On 14Jul, 2021, at 1:09 AM, cmjones01 <chris@stumpie.com> wrote:

On Tue, Jul 13, 2021 at 8:05 PM nj902 <wb0emu@arrl.net> wrote:

Cursors as in highlighted dots (or bars) that can be moved along the
trace with a corresponding method of determining time and voltage..

A second part of the question (if the answer is different) - which was
the first Tektronix scope to have cursors.

Cursor voltage measurement on a Tek scope would have been possible in
1974, certainly. With a 7D12/M2 plugin the timebase delay settings can
be used to highlight a portion of trace for voltage measurement, and
any delayed timebase with a calibrated delay will effectively do
cursor time measurement. If you want on-screen digital readout of
delta-delayed time that comes in 1976 with the 7B85. So in the 7000
series scopes, I'd say that manually-controlled digital cursor
measurements of time and voltage were possible together for the first
time in 1976.

Chris










Re: 2445b shelf vents for bottom air intakes - should I?

Alex
 

As long as the scope has its 4 bottom legs intact and the bottom of the scope is separated by that amount from the shelf I'd say its enough. I use my 2465B sitting on top of my 2247A and the exhaust air from the 2465B does not seem to be restricted in the least. Its not like you are going to have a huge amount of airflow at those spots anyhow. I would think the design of those four bottom legs took into account that the scope could be ran while sitting flat on them on a solid surface. I am usually at 27-29 deg C ambient, unless I run the AC, but your mileage may vary.

Furthermore very knowledgeable persons extremely familiar with Tek designs have mentioned in this forum and others many many times that U800 as it is factory mounted is NOT heat sensitive as long as you have a normal airflow inside the scope, and certainly no huge dust accumulation. That is the reason why Tek never installed the planned heatsink after they ran some operational tests and found out it was not needed. I for one just left U800 alone and it works just fine.


Re: explosion mystery on my 7104

Keith
 

Hi Barry,

Curiously, my 2445b just blew the same part. unlike you, I got the smoke and the magnificent sonics and everything. Did you replace yours? My scope seems to be working fine without it, but of course this is an illusion, right? :-)

Weird that both our 2445 series would blow their tops at around the same time. Mine has about 20k hours on it.

Cheers,

Keith
coolblueglow


Re: What was the first oscilloscope to have cursors?

ken chalfant
 

Greetings,

I can’t prove it even looking back at my really old Tektronix catalogs - but, when I was in HS back in the late 1960’s a professor at the local college, what was then the Cragmor Campus in Colorado Springs, part of CU Boulder, would let me come up to their lab and mess around with test equipment.

They had a Tek scope that was as big (maybe bigger) than a Tek 556. It had a large plug-in on the right hand side that, as I recall, allowed for time measurements. It may have even been able to do amplitude. If my memory serves me it would allow the user to place intensified dots on the trace and it displayed the value on Nixie tubes within the plug-in.

Does anybody else remember a scope like this?

Ken

On 14Jul, 2021, at 1:09 AM, cmjones01 <chris@stumpie.com> wrote:

On Tue, Jul 13, 2021 at 8:05 PM nj902 <wb0emu@arrl.net> wrote:

Cursors as in highlighted dots (or bars) that can be moved along the trace with a corresponding method of determining time and voltage..

A second part of the question (if the answer is different) - which was the first Tektronix scope to have cursors.
Cursor voltage measurement on a Tek scope would have been possible in
1974, certainly. With a 7D12/M2 plugin the timebase delay settings can
be used to highlight a portion of trace for voltage measurement, and
any delayed timebase with a calibrated delay will effectively do
cursor time measurement. If you want on-screen digital readout of
delta-delayed time that comes in 1976 with the 7B85. So in the 7000
series scopes, I'd say that manually-controlled digital cursor
measurements of time and voltage were possible together for the first
time in 1976.

Chris





Re: 2445b shelf vents for bottom air intakes - should I?

Keith
 

Thanks Jose,

Yes, that's the one I was worrying about. I'm going to cut the holes and add a small fan too.

Curiously, I just put the 2445b up on the finished shelf and fired it up. (no holes yet)

A few minutes after I fired it up, she made a terrible sound and magic smoke came out.

I believe it was simply the Line RF filter module failing, which I've heard others describe here on the forum. Apparently, it gives this rather magnificent and stinky display of failure - and the scope keeps on working, though without (I presume) RF filtering on the AC line in.

Just a good reminder that these devices are not getting any younger, and neither am I!

Cheers

Keith
coolblueglow


Re: A high-priced Tektronix RM504

stevenhorii
 

Yes - proving the authenticity of “NASA” property tags can be a challenge
given the wide availability of printers that can print on foil tags.
However, compared to tags printed using conventional printing techniques,
microscopic examination can show the pixilated edges of letters from
digital printers.

Also, a NASA property tag does not usually increase the value by much to
collectors unless that tag is on a flight item or a piece of equipment that
can be documented by NASA records or photographs showing the equipment in
use. You can find “owned by NASA” stuff all over eBay - from security
cameras to test equipment. Some value for non-flight hardware is high if it
was something specifically made for NASA and has the contract number on it
to prove it.

Steve Horii



On Wed, Jul 14, 2021 at 12:51 Roy Thistle <roy.thistle@mail.utoronto.ca>
wrote:

On Tue, Jul 13, 2021 at 09:19 PM, stevenhorii wrote:


and generally provide
reasonable estimates of selling prices.
Then this RM504 is an exception to the rule.
By the way... how does one verify the authenticity of the "Blue and silver
sticker" on the front?

--
Roy Thistle






Re: A high-priced Tektronix RM504

Roy Thistle
 

On Tue, Jul 13, 2021 at 09:19 PM, stevenhorii wrote:


and generally provide
reasonable estimates of selling prices.
Then this RM504 is an exception to the rule.
By the way... how does one verify the authenticity of the "Blue and silver sticker" on the front?

--
Roy Thistle


Re: 2445b shelf vents for bottom air intakes - should I?

Jose Luu
 

Hi Keith

The failure prone U800 IC is underneath, I remember that its failure is heat related.
Make sure it is well taken care of.
I did put a small 20mm fan inside the case to blow some air on it.

Best
José


Looking for XY monitor with storage tube.

Mattis Lind
 

Not really a scope but almost. I am looking for a XY display with storage tube. Tek 603 or perhaps 611.

Anyone that has one to sell?


Re: What was the first oscilloscope to have cursors?

cmjones01
 

On Tue, Jul 13, 2021 at 8:05 PM nj902 <wb0emu@arrl.net> wrote:

Cursors as in highlighted dots (or bars) that can be moved along the trace with a corresponding method of determining time and voltage..

A second part of the question (if the answer is different) - which was the first Tektronix scope to have cursors.
Cursor voltage measurement on a Tek scope would have been possible in
1974, certainly. With a 7D12/M2 plugin the timebase delay settings can
be used to highlight a portion of trace for voltage measurement, and
any delayed timebase with a calibrated delay will effectively do
cursor time measurement. If you want on-screen digital readout of
delta-delayed time that comes in 1976 with the 7B85. So in the 7000
series scopes, I'd say that manually-controlled digital cursor
measurements of time and voltage were possible together for the first
time in 1976.

Chris

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