Topics

A problem filled FG507


Eric
 

I am working on 2 Tektronix function generators. An FG 507 and a FG 502 both 2 Mhz. The 507 is on the bench currently and I am having a weird issue with the frequency selectors. Everything above 100X it working normally anything below 100X is mostly not working and at 10 I am getting an oscillation of 10 – 12 Mhz depending on what 2 opamps I have installed in the sockets. I have value check the main timing cap and it checks fine. I have also replaced the TI sockets and the Op amps thinking one was damaged and the TI sockets were bad. The power rails going in to the op amps are a little low at 13.5V so I am doing to keep digging I am just wondering if anyone knows what might be causing this? Also below 10 there is no oscillation at all. I have checked the timing resisters and all seem to be in order. There is nothing to make me think that the timing caps are bad but I have not measured them yet.


Tom Lee
 

Hi Eric,

You've got a problem with the capacitance multiplier somewhere (that's where you've been looking, I presume -- U1930 and U1940). That circuit is engaged only at the lower multipliers. The switchover occurs where you're seeing a change in behaviors. The "little low" voltage might be a red herring, but it's easy enough to check: Look at the rails with a scope to verify that the op-amp supplies aren't reading low because of excessive ripple. If they're clean, move on. It's not your problem here (although I'd eventally tweak up the rails to bring them to spec). If it's got bad ripple, fix that and assess what you've got after that.

The high-frequency oscillation suggests that you might not be closing the loop around one of those op-amps (U1930). It might something as simple as oxidized switch contacts (very common). If you want to be fastidious, you could check the range switches carefully with an ohmmeter. If you want to do what I would do, shoot some deoxit into the switch assembly. There's a good chance that the lower ranges will spring back to life.

If that doesn't do the trick, post back with a few more measurements around those op-amps at various multiplier settings.

Good luck!

--Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 1/23/2021 11:38, Eric wrote:
I am working on 2 Tektronix function generators. An FG 507 and a FG 502 both 2 Mhz. The 507 is on the bench currently and I am having a weird issue with the frequency selectors. Everything above 100X it working normally anything below 100X is mostly not working and at 10 I am getting an oscillation of 10 – 12 Mhz depending on what 2 opamps I have installed in the sockets. I have value check the main timing cap and it checks fine. I have also replaced the TI sockets and the Op amps thinking one was damaged and the TI sockets were bad. The power rails going in to the op amps are a little low at 13.5V so I am doing to keep digging I am just wondering if anyone knows what might be causing this? Also below 10 there is no oscillation at all. I have checked the timing resisters and all seem to be in order. There is nothing to make me think that the timing caps are bad but I have not measured them yet.




Jared Cabot
 

If it's those gold PCB mount flat spring contacts used in the cam switches, the Tek approved way of cleaning them is with plain white paper.
You don't want any residue left on them at all or you'll attract dust etc, so I wouldn't use deoxit here.
Flush them with isopropyl alcohol to wash yhem then after removing the cam assembly, carefully(!) slip some plain white paper between the switch leaf and the PCB and depress the leaf with your finger.
Withdraw the paper and the gentle abrasiveness of the paper will clean the contacts.


Tom Lee
 

Yes that is absolutely the "right" procedure, but for a 2MHz instrument it is overkill. Deoxit works very well and does not appear to leave a residue of any significance here. I've used it for dozens of FG50x function gens with no problems at all.

Tom

Sent from an iThing; please excuse the terseness and typos

On Jan 23, 2021, at 21:02, "Jared Cabot via groups.io" <jaredcabot=protonmail.com@groups.io> wrote:

If it's those gold PCB mount flat spring contacts used in the cam switches, the Tek approved way of cleaning them is with plain white paper.
You don't want any residue left on them at all or you'll attract dust etc, so I wouldn't use deoxit here.
Flush them with isopropyl alcohol to wash yhem then after removing the cam assembly, carefully(!) slip some plain white paper between the switch leaf and the PCB and depress the leaf with your finger.
Withdraw the paper and the gentle abrasiveness of the paper will clean the contacts.





Eric
 

Thanks for the kick in the right direction. It did ended up being the switch
contacts. I tried the tek cleaning procedure and that got me to where I was.
I was much more aggressive at cleaning the switches and it seems to have
worked very well. Qtip and iso with some elbow grease. All the ranges are
working even the slowest at 50 Seconds/div on the scope I cant even get a
full cycle on the screen. Any one know why something would need to run this
SLOW? 0.002 Hz?

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Tom Lee
Sent: Sunday, January 24, 2021 12:18 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] A problem filled FG507

Yes that is absolutely the "right" procedure, but for a 2MHz instrument it
is overkill. Deoxit works very well and does not appear to leave a residue
of any significance here. I've used it for dozens of FG50x function gens
with no problems at all.

Tom

Sent from an iThing; please excuse the terseness and typos

On Jan 23, 2021, at 21:02, "Jared Cabot via groups.io"
<jaredcabot=protonmail.com@groups.io> wrote:

If it's those gold PCB mount flat spring contacts used in the cam
switches, the Tek approved way of cleaning them is with plain white paper.
You don't want any residue left on them at all or you'll attract dust etc,
so I wouldn't use deoxit here.
Flush them with isopropyl alcohol to wash yhem then after removing the cam
assembly, carefully(!) slip some plain white paper between the switch leaf
and the PCB and depress the leaf with your finger.
Withdraw the paper and the gentle abrasiveness of the paper will clean the
contacts.





Harvey White
 

.002 Hz....

500 seconds/cycle.

Moving something mechanical?

changing the speed of some chemical reaction controlled by electricity?

function generator for an analog computer?

timer?

Harvey

On 1/25/2021 10:23 AM, Eric wrote:
Thanks for the kick in the right direction. It did ended up being the switch
contacts. I tried the tek cleaning procedure and that got me to where I was.
I was much more aggressive at cleaning the switches and it seems to have
worked very well. Qtip and iso with some elbow grease. All the ranges are
working even the slowest at 50 Seconds/div on the scope I cant even get a
full cycle on the screen. Any one know why something would need to run this
SLOW? 0.002 Hz?

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Tom Lee
Sent: Sunday, January 24, 2021 12:18 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] A problem filled FG507

Yes that is absolutely the "right" procedure, but for a 2MHz instrument it
is overkill. Deoxit works very well and does not appear to leave a residue
of any significance here. I've used it for dozens of FG50x function gens
with no problems at all.

Tom

Sent from an iThing; please excuse the terseness and typos

On Jan 23, 2021, at 21:02, "Jared Cabot via groups.io"
<jaredcabot=protonmail.com@groups.io> wrote:

If it's those gold PCB mount flat spring contacts used in the cam
switches, the Tek approved way of cleaning them is with plain white paper.
You don't want any residue left on them at all or you'll attract dust etc,
so I wouldn't use deoxit here.
Flush them with isopropyl alcohol to wash yhem then after removing the cam
assembly, carefully(!) slip some plain white paper between the switch leaf
and the PCB and depress the leaf with your finger.
Withdraw the paper and the gentle abrasiveness of the paper will clean the
contacts.












Eric
 

That make a lot of sense I was thinking just in an electronics lab. Was not even thinking along the lines of physics, chemistry, or electro mechanical. Make total sense now and I can see how it would be extremely useful. Seems I have been stuck in the HF world a little to long.

Thanks,
Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Harvey White
Sent: Monday, January 25, 2021 11:46 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] A problem filled FG507

.002 Hz....

500 seconds/cycle.

Moving something mechanical?

changing the speed of some chemical reaction controlled by electricity?

function generator for an analog computer?

timer?

Harvey


On 1/25/2021 10:23 AM, Eric wrote:
Thanks for the kick in the right direction. It did ended up being the
switch contacts. I tried the tek cleaning procedure and that got me to where I was.
I was much more aggressive at cleaning the switches and it seems to
have worked very well. Qtip and iso with some elbow grease. All the
ranges are working even the slowest at 50 Seconds/div on the scope I
cant even get a full cycle on the screen. Any one know why something
would need to run this SLOW? 0.002 Hz?

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Tom Lee
Sent: Sunday, January 24, 2021 12:18 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] A problem filled FG507

Yes that is absolutely the "right" procedure, but for a 2MHz
instrument it is overkill. Deoxit works very well and does not appear
to leave a residue of any significance here. I've used it for dozens
of FG50x function gens with no problems at all.

Tom

Sent from an iThing; please excuse the terseness and typos

On Jan 23, 2021, at 21:02, "Jared Cabot via groups.io"
<jaredcabot=protonmail.com@groups.io> wrote:

If it's those gold PCB mount flat spring contacts used in the cam
switches, the Tek approved way of cleaning them is with plain white paper.
You don't want any residue left on them at all or you'll attract dust
etc,
so I wouldn't use deoxit here.
Flush them with isopropyl alcohol to wash yhem then after removing
the cam
assembly, carefully(!) slip some plain white paper between the switch
leaf and the PCB and depress the leaf with your finger.
Withdraw the paper and the gentle abrasiveness of the paper will
clean the
contacts.













Tom Lee
 

Glad that you got it working!

As for why millihertz, speedhounds may chase GHz all day long, but there's also a huge applications space of electromechanical systems. Airframes, battleships, buildings...lots of important structures have resonant modes at subsonic frequencies. HP's first function generator (the 202A, from 1951) maxed out at 1.2kHz. The spec was defined by aerospace customers. Going ultra slow is almost as challenging as going ultra fast.

Cheers,
Tom

Sent from an iThing, so please forgive the typos and brevity

On Jan 25, 2021, at 7:23, "Eric" <ericsp@gmail.com> wrote:

Thanks for the kick in the right direction. It did ended up being the switch
contacts. I tried the tek cleaning procedure and that got me to where I was.
I was much more aggressive at cleaning the switches and it seems to have
worked very well. Qtip and iso with some elbow grease. All the ranges are
working even the slowest at 50 Seconds/div on the scope I cant even get a
full cycle on the screen. Any one know why something would need to run this
SLOW? 0.002 Hz?

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Tom Lee
Sent: Sunday, January 24, 2021 12:18 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] A problem filled FG507

Yes that is absolutely the "right" procedure, but for a 2MHz instrument it
is overkill. Deoxit works very well and does not appear to leave a residue
of any significance here. I've used it for dozens of FG50x function gens
with no problems at all.

Tom

Sent from an iThing; please excuse the terseness and typos

On Jan 23, 2021, at 21:02, "Jared Cabot via groups.io"
<jaredcabot=protonmail.com@groups.io> wrote:

If it's those gold PCB mount flat spring contacts used in the cam
switches, the Tek approved way of cleaning them is with plain white paper.
You don't want any residue left on them at all or you'll attract dust etc,
so I wouldn't use deoxit here.
Flush them with isopropyl alcohol to wash yhem then after removing the cam
assembly, carefully(!) slip some plain white paper between the switch leaf
and the PCB and depress the leaf with your finger.
Withdraw the paper and the gentle abrasiveness of the paper will clean the
contacts.














Jim Ford
 

Yes, ISTR a story at Lockheed decades ago of an aircraft cockpit vibrating at about 8 Hz, below the range of human hearing.  Very hard to fly a plane or do anything useful when you're bouncing around like that!     Jim Ford  Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Tom Lee <tomlee@ee.stanford.edu> Date: 1/25/21 9:45 AM (GMT-08:00) To: TekScopes@groups.io Cc: "<TekScopes@groups.io>" <TekScopes@groups.io> Subject: Re: [TekScopes] A problem filled FG507 Glad that you got it working! As for why millihertz, speedhounds may chase GHz all day long, but there's also a huge applications space of electromechanical systems. Airframes, battleships, buildings...lots of important structures have resonant modes at subsonic frequencies. HP's first function generator (the 202A, from 1951) maxed out at 1.2kHz. The spec was defined by aerospace customers. Going ultra slow is almost as challenging as going ultra fast.Cheers,TomSent from an iThing, so please forgive the typos and brevityOn Jan 25, 2021, at 7:23, "Eric" <ericsp@gmail.com> wrote:> Thanks for the kick in the right direction. It did ended up being the switch> contacts. I tried the tek cleaning procedure and that got me to where I was.> I was much more aggressive at cleaning the switches and it seems to have> worked very well. Qtip and iso with some elbow grease. All the ranges are> working even the slowest at 50 Seconds/div on the scope I cant even get a> full cycle on the screen. Any one know why something would need to run this> SLOW? 0.002 Hz?> > Eric> > -----Original Message-----> From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Tom Lee> Sent: Sunday, January 24, 2021 12:18 AM> To: TekScopes@groups.io> Subject: Re: [TekScopes] A problem filled FG507> > Yes that is absolutely the "right" procedure, but for a 2MHz instrument it> is overkill. Deoxit works very well and does not appear to leave a residue> of any significance here. I've used it for dozens of FG50x function gens> with no problems at all.> > Tom> > Sent from an iThing; please excuse the terseness and typos> > On Jan 23, 2021, at 21:02, "Jared Cabot via groups.io"> <jaredcabot=protonmail.com@groups.io> wrote:> >> If it's those gold PCB mount flat spring contacts used in the cam> switches, the Tek approved way of cleaning them is with plain white paper.>> You don't want any residue left on them at all or you'll attract dust etc,> so I wouldn't use deoxit here.>> Flush them with isopropyl alcohol to wash yhem then after removing the cam> assembly, carefully(!) slip some plain white paper between the switch leaf> and the PCB and depress the leaf with your finger.>> Withdraw the paper and the gentle abrasiveness of the paper will clean the> contacts.>> >> >> >> >> > > > > > > > > > > >


Michael W. Lynch
 

On Mon, Jan 25, 2021 at 12:02 PM, Jim Ford wrote:


an aircraft cockpit vibrating at about 8 Hz, below the range of human
hearing.  Very hard to fly a plane or do anything useful when you're bouncing
around like that!
Very true! One only needs to look at the problem of "pogo oscillation" of liquid fueled rockets to see how important "low frequency" is and how dangerous it can be to both machines and the people who crew them.

The Saturn V had some unexpected and very near catastrophic episodes of this "pogo" vibration. It was (wrongly) thought that the problem was limited to "smaller" boosters and would not be a problem for the Saturn V. Unfortunately Apollo 6 (unmanned), 10 and 13 were subjected to approximately 11-16 Hz pogo, of different intensities. This pogo was reported to have been sufficient to have killed the crew on Apollo 6 (had the flight been manned). Changes were made to the F-1 engines, but pogo still made it nearly impossible for the crew of Apollo 10 to read the instruments and the astronauts were slammed violently out of and back into their seats, in spite of their restraints. Work on F1 pogo was ongoing, less violent (but still dangerous) on Apollo 10 and very slight on Apollo 13. These changes never completely eliminated the F-1 engine problem, however, the team succeeded in reducing the violence of the original oscillation to a manageable level.

Unfortunately, the pogo problems also persisted in the J-2 2nd stage. Apollo 13 J-2 2nd stage had a center engine shutdown because of a violent 34G and 16Hz pogo. Had the computers not shut down the malfunctioning center engine, the loss of the vehicle was inevitable This problem was finally mitigated with changes to the J2 engines on Apollo 14 and subsequent launches.

The Soviet N-1 "moon rocket" launches were all failures because of the same pogo phenomenon. It has been reported that Soviet scientists "fixed" the problem on paper, but their program was cancelled before the "fix" could be proven by a successful launch of the vehicle.

--
Michael Lynch
Dardanelle, AR


Tom Lee
 

Thanks for the terrific history, Michael. I'd seen references to the pogo problem, but without numbers. Seeing values like 34G (!!) and 16Hz brings it to life. Thanks!

After all that, no one would need any more evidence of the importance of studying (and controlling) low-frequency resonances, but I can't resist bringing up the Tacoma Narrows Bridge disaster. The youtube vids are always worth revisiting from time to time.

--Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 1/25/2021 11:22, Michael W. Lynch via groups.io wrote:
On Mon, Jan 25, 2021 at 12:02 PM, Jim Ford wrote:

an aircraft cockpit vibrating at about 8 Hz, below the range of human
hearing.  Very hard to fly a plane or do anything useful when you're bouncing
around like that!
Very true! One only needs to look at the problem of "pogo oscillation" of liquid fueled rockets to see how important "low frequency" is and how dangerous it can be to both machines and the people who crew them.

The Saturn V had some unexpected and very near catastrophic episodes of this "pogo" vibration. It was (wrongly) thought that the problem was limited to "smaller" boosters and would not be a problem for the Saturn V. Unfortunately Apollo 6 (unmanned), 10 and 13 were subjected to approximately 11-16 Hz pogo, of different intensities. This pogo was reported to have been sufficient to have killed the crew on Apollo 6 (had the flight been manned). Changes were made to the F-1 engines, but pogo still made it nearly impossible for the crew of Apollo 10 to read the instruments and the astronauts were slammed violently out of and back into their seats, in spite of their restraints. Work on F1 pogo was ongoing, less violent (but still dangerous) on Apollo 10 and very slight on Apollo 13. These changes never completely eliminated the F-1 engine problem, however, the team succeeded in reducing the violence of the original oscillation to a manageable level.

Unfortunately, the pogo problems also persisted in the J-2 2nd stage. Apollo 13 J-2 2nd stage had a center engine shutdown because of a violent 34G and 16Hz pogo. Had the computers not shut down the malfunctioning center engine, the loss of the vehicle was inevitable This problem was finally mitigated with changes to the J2 engines on Apollo 14 and subsequent launches.

The Soviet N-1 "moon rocket" launches were all failures because of the same pogo phenomenon. It has been reported that Soviet scientists "fixed" the problem on paper, but their program was cancelled before the "fix" could be proven by a successful launch of the vehicle.


Michael W. Lynch
 

Tom,

The AS-508 J-2 Center Engine was reported to have flexed the engine thrust frame of the second stage 5.25 INCHES (p/p) during this event. The flex was localized to the Engine thrust frame, but was still serious enough to cause a shutdown. If anyone has ever looked at these component parts, they are very substantial components (even in the relatively small J-2 engine). The forces are huge and can be deadly.

--
Michael Lynch
Dardanelle, AR


Tom Lee
 

Holy Metal Fatigue, Batman! As an aero-astro friend once said to me after the Challenger disaster, "It's not so much a question of 'why did it fail', but rather 'why did it ever work?'".

-- Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 1/25/2021 11:53, Michael W. Lynch via groups.io wrote:
Tom,

The AS-508 J-2 Center Engine was reported to have flexed the engine thrust frame of the second stage 5.25 INCHES (p/p) during this event. The flex was localized to the Engine thrust frame, but was still serious enough to cause a shutdown. If anyone has ever looked at these component parts, they are very substantial components (even in the relatively small J-2 engine). The forces are huge and can be deadly.


Jim Ford
 

Yeah, I can only imagine the severe vibration issues in rockets and missiles!  Some of my colleagues at Lockheed worked on the SR-71 Blackbird, not that much different from a rocket, and the vibration specs were outrageous.  I worked on the U-2, much more benign.  Thanks for the fascinating history, Michael.   JimSent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: "Michael W. Lynch via groups.io" <mlynch003=yahoo.com@groups.io> Date: 1/25/21 11:22 AM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] A problem filled FG507 On Mon, Jan 25, 2021 at 12:02 PM, Jim Ford wrote:>> an aircraft cockpit vibrating at about 8 Hz, below the range of human> hearing.  Very hard to fly a plane or do anything useful when you're bouncing> around like that!>Very true!  One only needs to look at the problem of "pogo oscillation" of liquid fueled rockets to see how important "low frequency" is and how dangerous it can be to both machines and the people who crew them.The Saturn V had some unexpected and very near catastrophic episodes of this "pogo" vibration.  It was (wrongly) thought that the problem was limited to "smaller" boosters and would not be a problem for the Saturn V.  Unfortunately  Apollo 6 (unmanned), 10 and 13 were subjected to approximately 11-16 Hz pogo, of different intensities.  This pogo was reported to have been sufficient to have killed the crew on Apollo 6 (had the flight been manned).  Changes were made to the F-1 engines, but  pogo still made it nearly impossible for the crew of Apollo 10 to read the instruments and the astronauts were slammed violently out of and back into their seats, in spite of their restraints.    Work on F1 pogo was ongoing, less violent (but still dangerous) on  Apollo 10 and very slight on Apollo 13.   These changes never completely eliminated the F-1 engine problem, however, the team succeeded in reducing the violence of the original oscillation to a manageable level.Unfortunately,  the pogo problems also persisted in the J-2 2nd stage.   Apollo 13 J-2 2nd stage had a center engine shutdown because of a violent 34G and 16Hz pogo.  Had the computers not shut down the malfunctioning center engine, the loss of the vehicle was inevitable  This problem was finally mitigated with changes to the J2 engines on Apollo 14 and subsequent launches.The Soviet N-1 "moon rocket" launches were all failures because of the same pogo phenomenon.  It has been reported that Soviet scientists "fixed" the problem on paper, but their program was cancelled before the "fix" could be proven by a successful launch of the vehicle.-- Michael LynchDardanelle, AR


Jim Ford
 

I ask myself that a lot; how and why did it ever work?!    Jim Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Tom Lee <tomlee@ee.stanford.edu> Date: 1/25/21 11:59 AM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] A problem filled FG507 Holy Metal Fatigue, Batman! As an aero-astro friend once said to me after the Challenger disaster, "It's not so much a question of 'why did it fail', but rather 'why did it ever work?'".-- Tom-- Prof. Thomas H. LeeAllen Ctr., Rm. 205350 Jane Stanford WayStanford UniversityStanford, CA 94305-4070http://www-smirc.stanford.eduOn 1/25/2021 11:53, Michael W. Lynch via groups.io wrote:> Tom,>> The AS-508 J-2 Center Engine was reported to have flexed the engine thrust frame of the second stage 5.25 INCHES (p/p) during this event.  The flex was localized to the Engine thrust frame, but was still serious enough to cause a shutdown.  If anyone has ever looked at these component parts, they are very substantial components (even in the relatively small J-2 engine).  The forces are huge and can be deadly.>


n4buq
 

Why did Walter Cronkite never tell me about this?

Thanks,
Barry - N4BUQ


Holy Metal Fatigue, Batman! As an aero-astro friend once said to me
after the Challenger disaster, "It's not so much a question of 'why did
it fail', but rather 'why did it ever work?'".

-- Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 1/25/2021 11:53, Michael W. Lynch via groups.io wrote:
Tom,

The AS-508 J-2 Center Engine was reported to have flexed the engine thrust
frame of the second stage 5.25 INCHES (p/p) during this event. The flex
was localized to the Engine thrust frame, but was still serious enough to
cause a shutdown. If anyone has ever looked at these component parts,
they are very substantial components (even in the relatively small J-2
engine). The forces are huge and can be deadly.


Michael W. Lynch
 

On Mon, Jan 25, 2021 at 02:14 PM, Jim Ford wrote:


Some of my colleagues at Lockheed worked on the SR-71 Blackbird, not that much
different from a rocket, and the vibration specs were outrageous.  I worked
on the U-2, much more benign
Jim, i would not call the U2 "benign". Anything that Kelly Johnson and the Skunk Works developed was far removed from benign. There is very little in aviation history that has interested me more than the SR71/A12 project. Just goes to show what you can do with a slide rule, a great leader/manager, a lot of brilliant minds and a Black Budget.

--
Michael Lynch
Dardanelle, AR


Jim Ford
 

Just compared to the SR-71, the U-2 environment was benign.  I was at Lockheed at the tail end of an era, 1988 to 1993 in Burbank and 1993 to 1995 in Ontario, California at Lockheed Aircraft Service Co.  It's now all the Lockheed Martin Skunk Works in Palmdale, CA last I knew.   JimSent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: "Michael W. Lynch via groups.io" <mlynch003=yahoo.com@groups.io> Date: 1/25/21 1:43 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] A problem filled FG507 On Mon, Jan 25, 2021 at 02:14 PM, Jim Ford wrote:>> Some of my colleagues at Lockheed worked on the SR-71 Blackbird, not that much> different from a rocket, and the vibration specs were outrageous.  I worked> on the U-2, much more benign>Jim,  i would not call the U2 "benign".  Anything that Kelly Johnson and the Skunk Works developed was far removed from benign.  There is very little in aviation history that has interested me more than the SR71/A12 project.  Just goes to show what you can do with a slide rule, a great leader/manager, a lot of brilliant minds and a Black Budget.     -- Michael LynchDardanelle, AR


Tom Lee
 

The story of the SR-71 is remarkable. Anyone who is interested in engineering (and how to get things done despite management) should study the case.

I once had the privilege of meeting Buck Adams, who flew the very Blackbird that is now in the Udvar-Hazy outpost of the Smithsonian. Great man, great storyteller.

-- Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 1/25/2021 13:43, Michael W. Lynch via groups.io wrote:
On Mon, Jan 25, 2021 at 02:14 PM, Jim Ford wrote:

Some of my colleagues at Lockheed worked on the SR-71 Blackbird, not that much
different from a rocket, and the vibration specs were outrageous.  I worked
on the U-2, much more benign
Jim, i would not call the U2 "benign". Anything that Kelly Johnson and the Skunk Works developed was far removed from benign. There is very little in aviation history that has interested me more than the SR71/A12 project. Just goes to show what you can do with a slide rule, a great leader/manager, a lot of brilliant minds and a Black Budget.


Bill E
 

While off-topic even more, the J58 engines on the SR71 were just amazing. Then there were the F-1 engines on the Saturn V. Things have really gone downhill. Boeing and NASA are still screwing around with their 'new' Orion capsule and launch system, looks just like an old Apollo capsule scaled up. Meanwhile, regardless of what you think of Musk, the Dragon capsule and Falcon rocket are another amazing bit of engineering. And they actually look like they were designed after 1960.