Date   

Re: FW: [TekScopes] Another interesting Tektronix web site

teamlarryohio
 

Been far too long, but the ones I used were the same type generally as the fan mounts. Otoh, McMaster has a huge variety of hardware bits.
G'luck!
-ls-


Re: Email adresses of group exposed

Carsten Bormann
 

On 2021-06-20, at 16:05, Jean-Paul <notjonpaul@xi.nteco.mcom> wrote:

As Scott McNealy said in 1999, "You have zero privacy anyway. Get over it.”
One of the reasons for shunning political statements on a technical mailing list is that otherwise one would need to respond to parroted inane platitudes like the above.

Please limit yourself to the topics that this mailing list is about.
Thank you.

On to the subject of this thread (which is about running this group, so it is not entirely off-topic):
Trying to protect mail addresses against spammers is utterly futile (you wouldn’t believe the technical level to which spammers have now advanced, even if many of them are still rather stupid).

Spam is a quantitative problem, so quantitative mitigations do help, and making it too easy to scavenge mail addresses can increase the footprint of the problem.
So I think if there are controls on group.io that reduce the exposure of member email addresses, these should be activated.
Not making the article searchable by search engines is counter-productive though.
Asking users not to include email addresses of replied to posters in their replies, which are put there automatically by their mail readers, is highly futile (see top line of this posting :-).

So, indeed, your email address has now been scavenged, you might want to get over it; but maybe we can still reduce the quantitative hit somewhat.

Grüße, Carsten


Re: Type CA module in a 545

David Kuhn
 

Hello again Jeff,

" calibration process on the plug-in?"

I just did the resistance test on both the high gain modules and the weak
one. Everything looked the same except the filament resistance. Pin 15 to
ground is supposed to be ~65 ohms. On the good module is ~74 ohms. On
the weak one, it is 100 ohms.

So I guess I am looking at some old/bad tubes. I have to pull out the tube
tester and get it working.

Dave

On Sat, Jun 19, 2021 at 8:32 PM Jeff Dutky <jeff.dutky@gmail.com> wrote:

Pardon me if this is a stupid question, but have you performed the
calibration process on the plug-in?

There are steps in the cal process that specifically address the gain
(step #8) and there are front panel controls (recessed pots adjustable with
a screw driver) to trim the gain on both channels.

-- Jeff Dutky






Re: Type CA module in a 545

David Kuhn
 

Not fully. With the exception of some trim caps that can not be reached
without and extender (I'm not sure how they adjusted those), the only pot
inside in the Vertical Position/Range pot. The front panel, recessed gain
pots, are at MAX.

Swapping 12AUT's around, and 10volt square wave can almost see 9volts.

As far as the scope chassis, I was thinking may have been marginal, I have
another CA module. With it's gain pot, I make a 10Volt PP SW look about
13volts. So the range is there in the scope.

I have tested some resistors to see if they are dropping too much, but
haven't found any too far out.

I guess I need to insert the working CA module and make voltage measurement
readings (although on the weak one they line up with what is shown on the
schematic), and then record scoped PP values at each stage, then do the
same in the weak module. I am guessing I have some weak tubes in there,
but not the 12AUT (finger burners - lol). It's just that both channels are
identically weak. So I was thinking towards that wonky multiplexer circuit.

I will review the cal procedure again, but I don't know what it can tell me
to adjust to get the gain back.

Dave

On Sat, Jun 19, 2021 at 8:32 PM Jeff Dutky <jeff.dutky@gmail.com> wrote:

Pardon me if this is a stupid question, but have you performed the
calibration process on the plug-in?

There are steps in the cal process that specifically address the gain
(step #8) and there are front panel controls (recessed pots adjustable with
a screw driver) to trim the gain on both channels.

-- Jeff Dutky






Re: 7854 printed manuals and their revisions

 

On Thu, Apr 15, 2021 at 04:46 PM, Martin Hodge wrote:


you made it apparent that there may be other versions available
The latest and probably the last revision is APRIL 1990.

/Håkan


Re: 475A Problem

Renée
 

48V is low.....the other issue I noted on my 475 is when the main caps allow too much ripple...the tants start to go due to Peak voltages exceed ratings.
Renée

On 6/20/21 10:47 AM, Jeff Dutky wrote:
The 50 V rail plays the same role on the 475/A as the 55 V rail on the 465. No idea why they are different, but here we are. 46 V is well out of spec for the 50 V rail, even 48 V is suspiciously low. I second Mark’s suggestion to check the rectifier and caps. Once that’s fixed I would verify all the power rails, voltages and ripple currents. If the electrolytic on the 50 V rail have gone dry there may be others that need replacement as well.

— Jeff Dutky




Re: 475A Problem

 

The 50 V rail plays the same role on the 475/A as the 55 V rail on the 465. No idea why they are different, but here we are. 46 V is well out of spec for the 50 V rail, even 48 V is suspiciously low. I second Mark’s suggestion to check the rectifier and caps. Once that’s fixed I would verify all the power rails, voltages and ripple currents. If the electrolytic on the 50 V rail have gone dry there may be others that need replacement as well.

— Jeff Dutky


Re: 7854 printed manuals and their revisions

GeorgeP
 

I have
First printing APR 1980
Revised FEB 1986

After change 6-11-86
There are:
10-17-86 (for all sn) Electrical parts list changes
10-29-86 (effective at sn B095440) Electrical parts list changes
12-08-86 (effective at sn B095459) Remove TP31 and TP38 on A23
02-17-87 (effective at sn B105497) Electrical parts list changes

george


Re: Email adresses of group exposed

Jean-Paul
 

the full emails show in any quoted text, and other forums i join do not have that flaw.

Jon


Re: FW: [TekScopes] Another interesting Tektronix web site

Dave Wise
 

Thanks for the suggestion, Renee, I might be able to use a stack of them. I’m aiming for something anyone anywhere can get cheaply anytime. That should cover the 3 other people in the world who still use a Type D or H ☺

Dave Wise

From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Renée via groups.io
Sent: Sunday, June 20, 2021 10:31 AM
To: TekScopes@groups.io
Subject: Re: FW: [TekScopes] Another interesting Tektronix web site

by your description try Grommet and bushings at Mouser..they come in
various sizes...it is what I have used for isolation.
Renée

On 6/20/21 10:10 AM, Mike Dinolfo wrote:
Don't know if they have shock mounts that will work for you, but I
recently came across shock mount-type items at mcmaster.com. Try
https://www.mcmaster.com/bumper-cushions/<https://www.mcmaster.com/bumper-cushions>

I'm not the first to suggest Mcmaster.com; other Tekscopes group members
have previously suggested Mcmaster as a source for bumpers, hardware,
raw materials, tools, etc. Good outfit to deal with (but I don't know
if they will ship outside of the US).

Mike Dinolfo N4MWP

On 6/20/21 11:30 AM, Dave Wise wrote:
Closeup photos available off-list.

I don’t know how to cast something hollow. Anyway, my goal is to
come up with something cheap and easy. Can you suggest phrases to
search for? “Shock mount” and “vibration isolator” mostly pick up
mike stands and heavy automotive/HVAC stuff.

The shape is a hollow ball with a flange at each end and a hole
through the axis. You squeeze the flanges through the mounting holes
in the chassis. With 348-007 (used in Type D and H from the 1950s,
now deteriorating) you finish up with screw-washers-nut through the
hole to prevent a big shock from tearing the cushion apart. 348-0087
(used in Type 1A6 and 1A7 from the 1960s and may outlive me) is a
different material, stiffer, and instead of a screw, it is secured
with a plug at each end. I think 348-0087 would fit in a D or H.

If I had access to the PISL (Purchased Item Source List microfilm
“window cards”), I could determine who Tek bought them from - if they
bought them - but they’re surely gone now anyway.

Dave Wise

From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
Harvey White via groups.io
Sent: Saturday, June 19, 2021 7:38 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Another interesting Tektronix web site

Could you make a mold and cast some sort of rubber?

Harvey


On 6/19/2021 10:10 PM, Dave Wise wrote:
I performed this procedure on one of the chassis cushion mounts in
my Type D plugin. (Tek P/N 348-0007-00. 348-0087-00 might work too.)

No effect.

Must be a different rubber.

Unless someone has another idea, I will look at cushions made for RC
helicopter camera mounts.
This one caught my eye:

https://www.amazon.com/HONBAY-Vibration-Rubber-Fright-Controller/dp/B073LPTHCL/ref=pd_di_sccai_4/130-3441475-1604467<https://www.amazon.com/HONBAY-Vibration-Rubber-Fright-Controller/dp/B073LPTHCL/ref=pd_di_sccai_4/130-3441475-1604467>

HONBAY 24pcs RC Anti Vibration Rubber Balls for Fright Controller
Gimbal

On closer look, it's far from ideal. The parts are 13mm overall
height, 8mm overall diameter, 6mm hole diameter, approximately 7mm
chassis spacing.
The mounting holes in Type D are themselves 8mm diameter (5/16") so
the cushions will slip free unless the chassis and subchassis are
modified, perhaps by gluing down washers with 6mm ID.
Also the Type D chassis are spaced on approximately 10mm centers,
not 7mm, so glue the washer on the bottom side of the upper and the
top side of the lower.

I'll report results in a month or so.















Re: FW: [TekScopes] Another interesting Tektronix web site

Dave Wise
 

Thanks for the link, Mike. You made me look. The “Flanged Compression Springs” are similar to the original shape, but the smallest part is too big and heavy: 5/8-inch long with a 1-inch flange and 33 pounds per inch spring rate. The original is more like 3/8” long, 1/2” flange, and a couple pounds per inch rate. That’s more like you might see in e.g. an optical disk transport, that doesn’t seem to be M-C’s market.

I’m still looking at RC-copter camera mount balls. There seem to be about a half-dozen sizes, but it’s hard to get dimensions - sellers can’t comprehend using them for anything but their intended purpose. “Tektronix? What kind of quadcopter is that?” <facepalm>

Dave Wise

From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Mike Dinolfo via groups.io
Sent: Sunday, June 20, 2021 10:11 AM
To: TekScopes@groups.io
Subject: Re: FW: [TekScopes] Another interesting Tektronix web site

Don't know if they have shock mounts that will work for you, but I
recently came across shock mount-type items at mcmaster.com. Try
https://www.mcmaster.com/bumper-cushions/<https://www.mcmaster.com/bumper-cushions>

I'm not the first to suggest Mcmaster.com; other Tekscopes group members
have previously suggested Mcmaster as a source for bumpers, hardware,
raw materials, tools, etc. Good outfit to deal with (but I don't know
if they will ship outside of the US).

Mike Dinolfo N4MWP

On 6/20/21 11:30 AM, Dave Wise wrote:
Closeup photos available off-list.

I don’t know how to cast something hollow. Anyway, my goal is to come up with something cheap and easy. Can you suggest phrases to search for? “Shock mount” and “vibration isolator” mostly pick up mike stands and heavy automotive/HVAC stuff.

The shape is a hollow ball with a flange at each end and a hole through the axis. You squeeze the flanges through the mounting holes in the chassis. With 348-007 (used in Type D and H from the 1950s, now deteriorating) you finish up with screw-washers-nut through the hole to prevent a big shock from tearing the cushion apart. 348-0087 (used in Type 1A6 and 1A7 from the 1960s and may outlive me) is a different material, stiffer, and instead of a screw, it is secured with a plug at each end. I think 348-0087 would fit in a D or H.

If I had access to the PISL (Purchased Item Source List microfilm “window cards”), I could determine who Tek bought them from - if they bought them - but they’re surely gone now anyway.

Dave Wise

From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Harvey White via groups.io
Sent: Saturday, June 19, 2021 7:38 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Another interesting Tektronix web site

Could you make a mold and cast some sort of rubber?

Harvey


On 6/19/2021 10:10 PM, Dave Wise wrote:
I performed this procedure on one of the chassis cushion mounts in my Type D plugin. (Tek P/N 348-0007-00. 348-0087-00 might work too.)

No effect.

Must be a different rubber.

Unless someone has another idea, I will look at cushions made for RC helicopter camera mounts.
This one caught my eye:

https://www.amazon.com/HONBAY-Vibration-Rubber-Fright-Controller/dp/B073LPTHCL/ref=pd_di_sccai_4/130-3441475-1604467<https://www.amazon.com/HONBAY-Vibration-Rubber-Fright-Controller/dp/B073LPTHCL/ref=pd_di_sccai_4/130-3441475-1604467>
HONBAY 24pcs RC Anti Vibration Rubber Balls for Fright Controller Gimbal

On closer look, it's far from ideal. The parts are 13mm overall height, 8mm overall diameter, 6mm hole diameter, approximately 7mm chassis spacing.
The mounting holes in Type D are themselves 8mm diameter (5/16") so the cushions will slip free unless the chassis and subchassis are modified, perhaps by gluing down washers with 6mm ID.
Also the Type D chassis are spaced on approximately 10mm centers, not 7mm, so glue the washer on the bottom side of the upper and the top side of the lower.

I'll report results in a month or so.











Re: FW: [TekScopes] Another interesting Tektronix web site

Renée
 

by your description try Grommet and bushings at Mouser..they come in various sizes...it is what I have used for isolation.
Renée

On 6/20/21 10:10 AM, Mike Dinolfo wrote:
Don't know if they have shock mounts that will work for you, but I
recently came across shock mount-type items at mcmaster.com.  Try
https://www.mcmaster.com/bumper-cushions/

I'm not the first to suggest Mcmaster.com; other Tekscopes group members
have previously suggested Mcmaster as a source for bumpers, hardware,
raw materials, tools, etc.  Good outfit to deal with (but I don't know
if they will ship outside of the US).

Mike Dinolfo N4MWP

On 6/20/21 11:30 AM, Dave Wise wrote:
Closeup photos available off-list.

I don’t know how to cast something hollow.  Anyway, my goal is to come up with something cheap and easy.  Can you suggest phrases to search for?  “Shock mount” and “vibration isolator” mostly pick up mike stands and heavy automotive/HVAC stuff.

The shape is a hollow ball with a flange at each end and a hole through the axis.  You squeeze the flanges through the mounting holes in the chassis.  With 348-007 (used in Type D and H from the 1950s, now deteriorating) you finish up with screw-washers-nut through the hole to prevent a big shock from tearing the cushion apart.  348-0087 (used in Type 1A6 and 1A7 from the 1960s and may outlive me) is a different material, stiffer, and instead of a screw, it is secured with a plug at each end.  I think 348-0087 would fit in a D or H.

If I had access to the PISL (Purchased Item Source List microfilm “window cards”), I could determine who Tek bought them from - if they bought them - but they’re surely gone now anyway.

Dave Wise

From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Harvey White via groups.io
Sent: Saturday, June 19, 2021 7:38 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Another interesting Tektronix web site

Could you make a mold and cast some sort of rubber?

Harvey


On 6/19/2021 10:10 PM, Dave Wise wrote:
I performed this procedure on one of the chassis cushion mounts in my Type D plugin. (Tek P/N 348-0007-00. 348-0087-00 might work too.)

No effect.

Must be a different rubber.

Unless someone has another idea, I will look at cushions made for RC helicopter camera mounts.
This one caught my eye:

https://www.amazon.com/HONBAY-Vibration-Rubber-Fright-Controller/dp/B073LPTHCL/ref=pd_di_sccai_4/130-3441475-1604467
HONBAY 24pcs RC Anti Vibration Rubber Balls for Fright Controller Gimbal

On closer look, it's far from ideal. The parts are 13mm overall height, 8mm overall diameter, 6mm hole diameter, approximately 7mm chassis spacing.
The mounting holes in Type D are themselves 8mm diameter (5/16") so the cushions will slip free unless the chassis and subchassis are modified, perhaps by gluing down washers with 6mm ID.
Also the Type D chassis are spaced on approximately 10mm centers, not 7mm, so glue the washer on the bottom side of the upper and the top side of the lower.

I'll report results in a month or so.














Re: 475A Problem

Mark Vincent
 

Dick,

Check VR1416. Mine was open and I replaced it with a BZX85B9V1. The filter cans can also be going bad. Mine now has new high temperature long life ones in it. The output filter, 4,7mfd, of the 50V supply may also be bad. You can put something like 22mfd 100V as a replacement. The additional filtering will not hurt. The drifting voltage as it warms meas something is temperature sensitive. You can check R1416. Mine was dark brown in the body and I replaced the original 1/2 W with a 2W 1% type of 5600 ohms that tested at a few ohms below the original 5620 ohms. Also make sure to set the 50V adjust to 50V output after you find any problems and replace any parts.

Mark


Re: FW: [TekScopes] Another interesting Tektronix web site

Dave Wise
 

I went through the catalog and didn’t see anything like these.

The McMaster shock mounts I’m familiar with are the right size and stiffness to replace the Tek 500-series fan mounts. The Type D/H subchassis cushions are much softer (hollow ball) and are flexible snap-in flange mount instead of stud or screw.

What part numbers did you use for your amps?

From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of teamlarryohio via groups.io
Sent: Sunday, June 20, 2021 10:03 AM
To: TekScopes@groups.io
Subject: Re: FW: [TekScopes] Another interesting Tektronix web site

Dave, has anyone suggested McMaster? That's where I found the shock mounts Ampeg used in several of their guiter / bass amps.
-ls-


Re: FW: [TekScopes] Another interesting Tektronix web site

 

Don't know if they have shock mounts that will work for you, but I
recently came across shock mount-type items at mcmaster.com.  Try
https://www.mcmaster.com/bumper-cushions/

I'm not the first to suggest Mcmaster.com; other Tekscopes group members
have previously suggested Mcmaster as a source for bumpers, hardware,
raw materials, tools, etc.  Good outfit to deal with (but I don't know
if they will ship outside of the US).

Mike Dinolfo N4MWP

On 6/20/21 11:30 AM, Dave Wise wrote:
Closeup photos available off-list.

I don’t know how to cast something hollow.  Anyway, my goal is to come up with something cheap and easy.  Can you suggest phrases to search for?  “Shock mount” and “vibration isolator” mostly pick up mike stands and heavy automotive/HVAC stuff.

The shape is a hollow ball with a flange at each end and a hole through the axis.  You squeeze the flanges through the mounting holes in the chassis.  With 348-007 (used in Type D and H from the 1950s, now deteriorating) you finish up with screw-washers-nut through the hole to prevent a big shock from tearing the cushion apart.  348-0087 (used in Type 1A6 and 1A7 from the 1960s and may outlive me) is a different material, stiffer, and instead of a screw, it is secured with a plug at each end.  I think 348-0087 would fit in a D or H.

If I had access to the PISL (Purchased Item Source List microfilm “window cards”), I could determine who Tek bought them from - if they bought them - but they’re surely gone now anyway.

Dave Wise

From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Harvey White via groups.io
Sent: Saturday, June 19, 2021 7:38 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Another interesting Tektronix web site

Could you make a mold and cast some sort of rubber?

Harvey


On 6/19/2021 10:10 PM, Dave Wise wrote:
I performed this procedure on one of the chassis cushion mounts in my Type D plugin. (Tek P/N 348-0007-00. 348-0087-00 might work too.)

No effect.

Must be a different rubber.

Unless someone has another idea, I will look at cushions made for RC helicopter camera mounts.
This one caught my eye:

https://www.amazon.com/HONBAY-Vibration-Rubber-Fright-Controller/dp/B073LPTHCL/ref=pd_di_sccai_4/130-3441475-1604467
HONBAY 24pcs RC Anti Vibration Rubber Balls for Fright Controller Gimbal

On closer look, it's far from ideal. The parts are 13mm overall height, 8mm overall diameter, 6mm hole diameter, approximately 7mm chassis spacing.
The mounting holes in Type D are themselves 8mm diameter (5/16") so the cushions will slip free unless the chassis and subchassis are modified, perhaps by gluing down washers with 6mm ID.
Also the Type D chassis are spaced on approximately 10mm centers, not 7mm, so glue the washer on the bottom side of the upper and the top side of the lower.

I'll report results in a month or so.










Re: FW: [TekScopes] Another interesting Tektronix web site

teamlarryohio
 

Dave, has anyone suggested McMaster? That's where I found the shock mounts Ampeg used in several of their guiter / bass amps.
-ls-


Re: 475A Problem

Dick
 

The "Low Line" light does come on, but goes out when the
problem seems to go away.

I saw a +50vdc line in the Power Supply, which measures
+46.2vdc, which rises to +48.4vdc when the problem seems
to go away.

Dick, W1KSZ
________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Dave Peterson via groups.io <davidpinsf=yahoo.com@groups.io>
Sent: Sunday, June 20, 2021 9:32 AM
To: TekScopes@groups.io <TekScopes@groups.io>
Subject: Re: [TekScopes] 475A Problem

Looks like your "Low Line" light is on, meaning your +55v supply is low. The +55v drives all the low voltage regulators, so that needs to be fixed first. See the power supply calibration procedure in the service manual.

I would guess you have a problem with a rectifier or power supply cap (or both).

I'm more of a 465 guy, so I may very well be off in the 475A details. Is it +55v in 475A as well guys?

Dave


On Sunday, June 20, 2021, 9:26:46 AM PDT, Dick <w1ksz@outlook.com> wrote:

I have a 475A, ex-IBM with DMM Option. It recently developed a problem.
You can see a picture of what it looks like in the Photo's section, under
475A problem.

If you let it run for 10 minutes or so, the problem seems to get better, but not
completely gone.

Probing the DC Voltages while the problem is there shows the -8vdc line has
dropped to -2.1vdc, and the +5vdc line has dropped to +1.0vdc. When the
problem seems to go away, those voltages come back up to normal.

Anyone have any ideas what to look at ?

Thanks for any help,

Dick, W1KSZ


Re: 475A Problem

Dave Peterson
 

Looks like your "Low Line" light is on, meaning your +55v supply is low. The +55v drives all the low voltage regulators, so that needs to be fixed first. See the power supply calibration procedure in the service manual.

I would guess you have a problem with a rectifier or power supply cap (or both).

I'm more of a 465 guy, so I may very well be off in the 475A details. Is it +55v in 475A as well guys?

Dave

On Sunday, June 20, 2021, 9:26:46 AM PDT, Dick <w1ksz@outlook.com> wrote:

I have a 475A, ex-IBM with DMM Option. It recently developed a problem.
You can see a picture of what it looks like in the Photo's section, under
475A problem.

If you let it run for 10 minutes or so, the problem seems to get better, but not
completely gone.

Probing the DC Voltages while the problem is there shows the -8vdc line has
dropped to -2.1vdc, and the +5vdc line has dropped to +1.0vdc. When the
problem seems to go away, those voltages come back up to normal.

Anyone have any ideas what to look at ?

Thanks for any help,

Dick, W1KSZ


475A Problem

Dick
 

I have a 475A, ex-IBM with DMM Option. It recently developed a problem.
You can see a picture of what it looks like in the Photo's section, under
475A problem.

If you let it run for 10 minutes or so, the problem seems to get better, but not
completely gone.

Probing the DC Voltages while the problem is there shows the -8vdc line has
dropped to -2.1vdc, and the +5vdc line has dropped to +1.0vdc. When the
problem seems to go away, those voltages come back up to normal.

Anyone have any ideas what to look at ?

Thanks for any help,

Dick, W1KSZ


Added album 475A Problem #photo-notice

TekScopes@groups.io Notification <noreply@...>
 

Dick <w1ksz@...> added the album 475A Problem

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