Date   
Re: Set screw size

EB4APL
 

Well, if they used different thread standards at that time they probably
used Whitworth for the UK plant.
I don't think they used different threads, parts like knobs, couplings
and everything threaded probably came from a common origin, the same as
the electronic parts.
If they used different threads they would need to use UNC standards for
the US factory, Whitworth for the Guernsey plant and Metric for the
Holland plant.
Also the mechanical parts would be different, either inch or metric based.
But the manuals are common for the products manufactured in either
factory, and at the beginning they list the serial number ranges
assigned to each factory and there are no listed differences for any
part, screws in particular.

Regards,
Ignacio EB4APL


El 16/01/2016 a las 16:13, HankC @HankC [TekScopes] escribió:

Don't forget, some scopes were built at Tek's UK plant, so some
setscrews may be metric.
HankC, Boston WA1HOS

[Non-text portions of this message have been removed]


------------------------------------------------------------------------
Posted by: HankC <@HankC>
------------------------------------------------------------------------


---
El software de antivirus Avast ha analizado este correo electrónico en busca de virus.
https://www.avast.com/antivirus

Test Equipment

Carl Hallberg
 

Hi group,
I hit send by accident.
I need the room, so I have some test gear to sell and some to give away. I don't want to ship it. Partial list below. Contact me off group. I live in Chicago Land / Northwest Indiana area.

Tek 546 free. Never tried to plug it in.
Tek 556 Front panel great shape. One TD I used already, lost the other. No CRT or tubes. Slid out of van unto road. Free.
Tek 214 Works, was basket case. Missing knob and batteries. I made circuit board shunt regulator in place of batteries;use external bat. Offer.
Tek 7834 Repaired Pwr Supply, used NOS TIPL753 transistors and 1N4937 diodes. CRT near end of life. Case beat up. Offer. Maybe another one.
3 - HP 5328A One has Channel C @ 500MHz. All work, HPIB chip missing in one. Offer.
Tek TD1085/u Military version of 7B53, but no readout. Offer.

There are other things, but would discuss.

Carl
@n9ess

Test Equipment

Carl Hallberg
 

Re: Set screw size

David DiGiacomo
 

On Sat, Jan 16, 2016 at 8:13 AM, HankC <@HankC> wrote:

Don't forget, some scopes were built at Tek's UK plant, so some setscrews may be metric.


This is not correct... all parts were identical between US and UK
built scopes... otherwise it would have been a service nightmare.

Re: Don't fix if it ain't broke or preventative maintenance

Dwayne Verhey <yg@...>
 

Siggi,-

It sounds like the balance of probability is that at the time the 400
series scopes were introduced, 20MHz was a typical scope BW, so it
wasn't necessary to mention it; but by the time the 2400 series was
introduced there were enough 100 and 200MHz scopes around that Tek's
techs figured they better clarify things for people like me.

On 15/01/2016 10:37 PM, Sigurður Ásgeirsson siggi@... [TekScopes]
wrote:

Hey Dwayne,

In the service manual for the 2400-series scopes it clearly specified to
use 20MHz bandwidth for PSU ripple measurement. I also believe it's a
de-facto standard for this, as noise is a monotonic function of bandwidth.
That being said I checked the service manual for my 485, which just lists
acceptable ripple without further spec.

Siggi
On Fri, Jan 15, 2016 at 21:52 Dwayne Verhey yg@... [TekScopes] <
TekScopes@...> wrote:

Re: Set screw size

 

Don't forget, some scopes were built at Tek's UK plant, so some setscrews may be metric.
 HankC, Boston WA1HOS

[Non-text portions of this message have been removed]

Re: Don't fix if it ain't broke or preventative maintenance

Marian B
 

The average HP 3400A has a -3 dB bandwidth of about 5 Hz to 20...25 MHz.
I guess that in fact the 3400A set the 20 MHz bandwidth standard for
this kind of measurement. Maybe even Tek themselves used 3400A's?

(The 10 MHz spec of the 3400A is a +- 5 % bandwidth i.e. +- 0.5 dB)

Cheers, Marian

On 16.01.2016 04:37, Sigurður Ásgeirsson siggi@... [TekScopes] wrote:


Hey Dwayne,

In the service manual for the 2400-series scopes it clearly specified to
use 20MHz bandwidth for PSU ripple measurement. I also believe it's a
de-facto standard for this, as noise is a monotonic function of bandwidth.
That being said I checked the service manual for my 485, which just lists
acceptable ripple without further spec.

Siggi
On Fri, Jan 15, 2016 at 21:52 Dwayne Verhey yg@... [TekScopes] <
TekScopes@...> wrote:



Siguour,-

I'm curious where you get the 20MHz specification. The manual calls for
a scope with "Bandwidth, DC to 100 mega-hertz; minimum deflection
factor, five millivolts/division; accuracy, within 3%, and the example
given is the Tektronix 454A Oscilloscope with two P6054 probes (which
Google says are 150MHz and 250MHz, respectively).

I'm not saying you are wrong, the test scope is also to be used for
other things like the high-speed timing adjustment. I just don't see
anything in the manual about 20 MHz (mind you, these manuals often
assume some basic level of prior knowledge and experience, which I don't
have).

I certainly get your point about the persistence of a digital scope
compared to the old analogue. Even with the intensity cranked up to
maximum, the 475 trace is pretty faint at the fastest time base settings
using the delayed sweep function. Even though the 475 is rated at 200MHz
bandwidth and the Rigol is rated equivalent to 150MHz (mine is upgraded
to the DS1152E-EDU spec), It's a darn sight easier to catch and study a
transient or high-speed waveform displayed on the digital scope!

That said, at slower time base settings, I really like the "feel" of the
475 analogue display compared to the Rigol. The variations in intensity
and the smoothness of the curves highlight the pixellation of the
Rigol's display. Now if only it was in colour...

On 15/01/2016 8:45 PM, Sigurður Ásgeirsson siggi@... [TekScopes]
wrote:




The noise and ripple is typically specified at 20MHz bandwidth. Also
beware that it's specified as seen on an analog scope of the time.
Digital scopes may show higher noise and ripple, as depending on
settings
such as memory depth. Effectively they can be set to more persistence
than
the phosphor of the old-style analog scope.



modeled some new things with solvespace and FreeCAD (was: 351-0449-00 PCB Holder )

John Griessen
 

On 01/15/2016 07:25 PM, Sigurður Ásgeirsson siggi@... [TekScopes] wrote:
Hey Chris,

I modelled the thing in FreeCad and uploaded to ShapeWays <
http://shpws.me/Lp5e
<https://www.shapeways.com/product/CGNES54EY/fg504-bracket>> to see how
that works.
I haven't test-printed the thing - will do that on Monday, so absolutely no
guarantee that this is fit for any purpose ATM. The outline dimensions on
ShapeWays seem to fit my broken one here, so that's something.
It seems ShapeWays wants $2.88/pc for a "White strong and flexible nylon"
version of this, plus shipping (this is zero markup, cause monetary profit
is not what we do here).
I also modeled some new things with solvespace and FreeCAD and have just launched it
as an open hardware project on kickstarter.com:
https://www.kickstarter.com/projects/1652064221/hexrad-a-modular-enclosure-system-for-outdoor-radi

It's an outdoor radio node enclosure system of stackable modules for when your design grows
in volume as a prototype, then slims down some, then gets a custom enclosure later...
or, if you're a hobbyist it just grows and grows and you get more of them for the nest project...

I do intend to make profit on it. So I can evolve it further and sell it to willing buyers
at a reasonable price to pay for my lab where I design things. Then there are many field biologists
that need a full hardware/software system for solar powered instrumentation in the wilds.

John Griessen
--
Ecosensory

Re: Yet Another 454A Question--150 VDC Supply, and still a sweep problem (And a 454 manual)

 

With the scope off, what is the resistance across R1085? If it is near 0, suspect a collector to emitter short on Q1086.

One trick I use is to measure the resistance across each resistor in the non-working circuit. If the measured value is more than the value of the resistor, you have a clue.

2 volts ripple on the unregulated 150 volt supply does not sound too high. Also, the DC voltage should be up around 160 volts.

----- Original Message -----
From: Matthew Cottrell mcottrell@... [TekScopes]
To: TekScopes@...
Sent: Friday, January 15, 2016 10:26 PM
Subject: [TekScopes] Yet Another 454A Question--150 VDC Supply, and still a sweep problem (And a 454 manual)



Sorry to be a pest here, but I still have not fixed my 454A horizontal
amp problem. However, I am noting that the 150 VDC supply has about 2
volts of ripple--that seems high. Does anyone have any idea what the
specification would be? Given the values of the filter components, I
would imagine a lot less.

As for the horizontal amp problem, waveform # 23 appears to be OK, but
waveform #17 is essentially non-existent (very low amplitude). The DC
voltage across R1085 is essentially zero ( well, about 30 mV). This
whole amplifier section is a mystery to me--should have paid more
attention in electronics classes way back when. If it were tubes, I
could probably figure it out. Does anybody have a clue? I know that
there are potential resistor drift problems, but I hesitate to start
desoldering resistors at random to check their value.

I have swapped several transistors between the right and left halves of
the horizontal amp, with no change.

If there is a Tektronix 454A guru out there who might be able to fix
this thing, I would be happy to know about them. I love this scope, for
the sharp trace and the (otherwise) repairability, but this horizontal
amplifier circuitry is kicking my butt.

Thanks--and don't forget that I have a 454 (NOT 454A) manual available
for the cot of shipping.

Regards--

Matthew

2782 calibration

Brian Yee
 

Hi, looking for some advice on running the calibration software for the
2782/2784 spectrum
analyzers. I have the calibration software installed, but it seems real
picky about what is
connected to it, it needs specific a GPIB card (PCII/PCIIa) and signal
sources, power meters, etc.
I got all that connected and talking, but ran into some issues with the DUT
identifying
itself (cal software says "dut name does not match dut connected to
system").

I'm looking for anyone who has run the cal software before who can give me
guidance
on setup and operation. The service manual doesn't seem to be of any help.

BTW, these are nice instruments, but I think Tek went the wrong direction
when it comes
to calibration and maintenance of these instruments. HP put in self-cal
routines, and
all you need to do is move a jumper and apply the proper stimulus, much
more field-maintainable.

Brian

Re: Don't fix if it ain't broke or preventative maintenance

Siggi
 

Hey Dwayne,

In the service manual for the 2400-series scopes it clearly specified to
use 20MHz bandwidth for PSU ripple measurement. I also believe it's a
de-facto standard for this, as noise is a monotonic function of bandwidth.
That being said I checked the service manual for my 485, which just lists
acceptable ripple without further spec.

Siggi
On Fri, Jan 15, 2016 at 21:52 Dwayne Verhey yg@... [TekScopes] <
TekScopes@...> wrote:



Siguour,-

I'm curious where you get the 20MHz specification. The manual calls for
a scope with "Bandwidth, DC to 100 mega-hertz; minimum deflection
factor, five millivolts/division; accuracy, within 3%, and the example
given is the Tektronix 454A Oscilloscope with two P6054 probes (which
Google says are 150MHz and 250MHz, respectively).

I'm not saying you are wrong, the test scope is also to be used for
other things like the high-speed timing adjustment. I just don't see
anything in the manual about 20 MHz (mind you, these manuals often
assume some basic level of prior knowledge and experience, which I don't
have).

I certainly get your point about the persistence of a digital scope
compared to the old analogue. Even with the intensity cranked up to
maximum, the 475 trace is pretty faint at the fastest time base settings
using the delayed sweep function. Even though the 475 is rated at 200MHz
bandwidth and the Rigol is rated equivalent to 150MHz (mine is upgraded
to the DS1152E-EDU spec), It's a darn sight easier to catch and study a
transient or high-speed waveform displayed on the digital scope!

That said, at slower time base settings, I really like the "feel" of the
475 analogue display compared to the Rigol. The variations in intensity
and the smoothness of the curves highlight the pixellation of the
Rigol's display. Now if only it was in colour...

On 15/01/2016 8:45 PM, Sigurður Ásgeirsson siggi@... [TekScopes]
wrote:




The noise and ripple is typically specified at 20MHz bandwidth. Also
beware that it's specified as seen on an analog scope of the time.
Digital scopes may show higher noise and ripple, as depending on settings
such as memory depth. Effectively they can be set to more persistence
than
the phosphor of the old-style analog scope.




[Non-text portions of this message have been removed]

Yet Another 454A Question--150 VDC Supply, and still a sweep problem (And a 454 manual)

Matthew Cottrell
 

Sorry to be a pest here, but I still have not fixed my 454A horizontal amp problem. However, I am noting that the 150 VDC supply has about 2 volts of ripple--that seems high. Does anyone have any idea what the specification would be? Given the values of the filter components, I would imagine a lot less.

As for the horizontal amp problem, waveform # 23 appears to be OK, but waveform #17 is essentially non-existent (very low amplitude). The DC voltage across R1085 is essentially zero ( well, about 30 mV). This whole amplifier section is a mystery to me--should have paid more attention in electronics classes way back when. If it were tubes, I could probably figure it out. Does anybody have a clue? I know that there are potential resistor drift problems, but I hesitate to start desoldering resistors at random to check their value.

I have swapped several transistors between the right and left halves of the horizontal amp, with no change.

If there is a Tektronix 454A guru out there who might be able to fix this thing, I would be happy to know about them. I love this scope, for the sharp trace and the (otherwise) repairability, but this horizontal amplifier circuitry is kicking my butt.

Thanks--and don't forget that I have a 454 (NOT 454A) manual available for the cot of shipping.

Regards--

Matthew

Re: Set screw size

Dwayne Verhey <yg@...>
 

Tom,-

Yes, those are the ones. The set screw I measured had a major diameter of .105" -- visibly smaller than my .112" screws, and the tap started grabbing immediately.

I bumped up the OD to .410 (original was ~ .380"), but that was for extra strength as I wasn't planning for longer screws at the time, so they still hang out a couple of threads. I cut the slot a bit shy and finished to depth with a hand-file to radius the corners, as that is exactly where it cracked. Afterwards I realized that those slots don't really need to go across both sides of the bore -- the nylon flex piece only sits in one side. Oh well, it's easier to file this way...

On 15/01/2016 9:23 PM, Tom Jobe tomjobe@... [TekScopes] wrote:

Hi YG,
I would guess you are talking about the three piece flex couplers with
the center nylon flex piece for 1/8" shafts, as they are the only shaft
connector parts that usually crack.
I just checked some of the broken aluminum coupler parts I have and a
4-40 tap fits them perfectly.
The solid aluminum couplers never break in my experience, and they have
4-40 threads as well.
The 4-40 set screws I checked had major diameters of .110" to .112" just
as a reference.
As far as I know, Tektronix only used standard 4-40 and 5-40 threads on
the small knobs and shafts.
tom jobe...
PS if you have the three piece flex style couplers, consider increasing
the out side diameter of your new aluminum pieces a bit, at least so the
set screws are fully in the material instead of hanging out in the
breeze. You could also radius the sharp corners of your end mill so the
cracks might not want to propagate out of those sharp corners like they
do on the original Tektronix coupler parts.

Re: Don't fix if it ain't broke or preventative maintenance

Dwayne Verhey <yg@...>
 

Siguour,-

I'm curious where you get the 20MHz specification. The manual calls for
a scope with "Bandwidth, DC to 100 mega-hertz; minimum deflection factor, five millivolts/division; accuracy, within 3%, and the example
given is the Tektronix 454A Oscilloscope with two P6054 probes (which
Google says are 150MHz and 250MHz, respectively).

I'm not saying you are wrong, the test scope is also to be used for
other things like the high-speed timing adjustment. I just don't see
anything in the manual about 20 MHz (mind you, these manuals often
assume some basic level of prior knowledge and experience, which I don't
have).

I certainly get your point about the persistence of a digital scope
compared to the old analogue. Even with the intensity cranked up to
maximum, the 475 trace is pretty faint at the fastest time base settings
using the delayed sweep function. Even though the 475 is rated at 200MHz
bandwidth and the Rigol is rated equivalent to 150MHz (mine is upgraded
to the DS1152E-EDU spec), It's a darn sight easier to catch and study a
transient or high-speed waveform displayed on the digital scope!

That said, at slower time base settings, I really like the "feel" of the
475 analogue display compared to the Rigol. The variations in intensity
and the smoothness of the curves highlight the pixellation of the
Rigol's display. Now if only it was in colour...


On 15/01/2016 8:45 PM, Sigurður Ásgeirsson siggi@... [TekScopes]
wrote:


The noise and ripple is typically specified at 20MHz bandwidth. Also
beware that it's specified as seen on an analog scope of the time.
Digital scopes may show higher noise and ripple, as depending on settings
such as memory depth. Effectively they can be set to more persistence than
the phosphor of the old-style analog scope.


Re: Set screw size

Tom Jobe <tomjobe@...>
 

Hi YG,
I would guess you are talking about the three piece flex couplers with
the center nylon flex piece for 1/8" shafts, as they are the only shaft
connector parts that usually crack.
I just checked some of the broken aluminum coupler parts I have and a
4-40 tap fits them perfectly.
The solid aluminum couplers never break in my experience, and they have
4-40 threads as well.
The 4-40 set screws I checked had major diameters of .110" to .112" just
as a reference.
As far as I know, Tektronix only used standard 4-40 and 5-40 threads on
the small knobs and shafts.
tom jobe...
PS if you have the three piece flex style couplers, consider increasing
the out side diameter of your new aluminum pieces a bit, at least so the
set screws are fully in the material instead of hanging out in the
breeze. You could also radius the sharp corners of your end mill so the
cracks might not want to propagate out of those sharp corners like they
do on the original Tektronix coupler parts.

On 1/15/2016 4:53 PM, yg@... [TekScopes] wrote:

Before buttoning up my 475 earlier today, I investigated the odd feel
of the #1 vertical position knob, and found that one of the aluminium
sleeves of the shaft coupler was cracked. In fact, it broke in two
when I started to loosen the set screws.

Ok, no problem, I have a lathe and can whip out a replacement in less
time than it would take to look up the part number in the manual. But
when I went to drill and tap the set screws, I realized they were
actually smaller than the #4-40 stipulated in the parts diagram. A
quick check confirmed that the major diameter was about 5 thou
undersized and the thread pitch was a touch off 40tpi too. In fact,
it's pretty much bang-on 0.6mm metric pitch (although the diameter is
not a standard metric size). I'd say it was closest to a Bodmer
thread, except it seems to be 60° flank angle.

There's only 4 or 5 threads, so it's close enough to fit in a #4-40
hole, but it's a sloppy fit, quite likely to strip out the aluminium
when tightened. Does anyone know what the actual thread is, or why Tek
didn't/wouldn't use a standard #4-40?

I made mine #4-40 for now, but the shortest set screws I have are a
bit longer and get pretty close to the components on the adjacent board.





Re: 351-0449-00 PCB Holder - PG508 & FG504

Siggi
 

I tried putting a pair of those brackets into a shopping basket to see what
the shipping's like.
In the US it's pretty reasonable:

Order Summary
Items (2) $5.76
Shipping $4.99

Tax 0% $0.00
Total: $10.75

However it'll cost me around USD $11 or so to get a minimum order to the
frozen tundra of Canada. That's on the order of 2 billion CAD at the
current exchange rate, I believe.

On Fri, 15 Jan 2016 at 20:25 Sigurður Ásgeirsson <siggi@...> wrote:

Hey Chris,

I modelled the thing in FreeCad and uploaded to ShapeWays <
http://shpws.me/Lp5e
<https://www.shapeways.com/product/CGNES54EY/fg504-bracket>> to see how
that works.
I haven't test-printed the thing - will do that on Monday, so absolutely
no guarantee that this is fit for any purpose ATM. The outline dimensions
on ShapeWays seem to fit my broken one here, so that's something.
It seems ShapeWays wants $2.88/pc for a "White strong and flexible nylon"
version of this, plus shipping (this is zero markup, cause monetary profit
is not what we do here).
If it's fit for a purpose, that sounds pretty reasonable to me?

Siggi

On Mon, 11 Jan 2016 at 15:44 cmbath@... [TekScopes] <
TekScopes@...> wrote:



Hi Siggi,


Let me know if you are interested in making an additional 4 of these if
you get around to it.


Happy to reimburse you.



Chris


[Non-text portions of this message have been removed]



[Non-text portions of this message have been removed]

Re: Don't fix if it ain't broke or preventative maintenance

Siggi
 

On Fri, 15 Jan 2016 at 10:58 Dwayne Verhey yg@... [TekScopes] <
TekScopes@...> wrote:



Paul and David,-

How much does frequency of the ripple matter?

The noise and ripple is typically specified at 20MHz bandwidth. Also
beware that it's specified as seen on an analog scope of the time.
Digital scopes may show higher noise and ripple, as depending on settings
such as memory depth. Effectively they can be set to more persistence than
the phosphor of the old-style analog scope.

Re: 351-0449-00 PCB Holder - PG508 & FG504

Siggi
 

Hey Chris,

I modelled the thing in FreeCad and uploaded to ShapeWays <
http://shpws.me/Lp5e
<https://www.shapeways.com/product/CGNES54EY/fg504-bracket>> to see how
that works.
I haven't test-printed the thing - will do that on Monday, so absolutely no
guarantee that this is fit for any purpose ATM. The outline dimensions on
ShapeWays seem to fit my broken one here, so that's something.
It seems ShapeWays wants $2.88/pc for a "White strong and flexible nylon"
version of this, plus shipping (this is zero markup, cause monetary profit
is not what we do here).
If it's fit for a purpose, that sounds pretty reasonable to me?

Siggi

On Mon, 11 Jan 2016 at 15:44 cmbath@... [TekScopes] <
TekScopes@...> wrote:



Hi Siggi,


Let me know if you are interested in making an additional 4 of these if
you get around to it.


Happy to reimburse you.



Chris






[Non-text portions of this message have been removed]

Set screw size

yg@...
 

Before buttoning up my 475 earlier today, I investigated the odd feel of the #1 vertical position knob, and found that one of the aluminium sleeves of the shaft coupler was cracked. In fact, it broke in two when I started to loosen the set screws.

Ok, no problem, I have a lathe and can whip out a replacement in less time than it would take to look up the part number in the manual. But when I went to drill and tap the set screws, I realized they were actually smaller than the #4-40 stipulated in the parts diagram. A quick check confirmed that the major diameter was about 5 thou undersized and the thread pitch was a touch off 40tpi too. In fact, it's pretty much bang-on 0.6mm metric pitch (although the diameter is not a standard metric size). I'd say it was closest to a Bodmer thread, except it seems to be 60° flank angle.

There's only 4 or 5 threads, so it's close enough to fit in a #4-40 hole, but it's a sloppy fit, quite likely to strip out the aluminium when tightened. Does anyone know what the actual thread is, or why Tek didn't/wouldn't use a standard #4-40?

I made mine #4-40 for now, but the shortest set screws I have are a bit longer and get pretty close to the components on the adjacent board.

Re: Is this a broken cal.fixture?

Leo Potjewijd
 

The plugin wasn't broken, but it seems the Yahoo webinterface is: those links looked a lot different when I typed them (the seond one wasn't even there)...