Date   
Re: 151-5001-00 cross reference?

radioconnection@...
 

Problem was a bad .01uF coupling cap to the buffer stage base. A few pF stray capacitance in the bad part was just enough show a marginal signal on the stage output.

Re: Tek 2465A S/N B019121

Brad Thompson
 

Lawrence Joy via Groups.Io wrote on 5/18/2019 5:15 PM:

<snip>
4) How do you remove Torx head screws that seem deformed? There is a black plastic cover over the A3 and A2A1 assemblies at the rear of the chassis. This cover is held to the rear chassis with two Torx head screws of what seem to be T-10 size. I was able to remove one of the screws, the one by the fan, but the other screw by the CRT back end cover was a bear. My Torx T-10 size driver was too small and my Torx T-15 size driver was way too big. It seemed like I needed the next size up, a T-11.
<snip>

Hello--

Try slipping a small piece of aluminum foil over the T-10's tip and placing the foiled tip
in the Torx's head recess. This works (sometimes).

73--

Brad  AA1IP

Re: [OT] surface mount components

Tony Fleming
 

I can see tweezers style volt/ohm/...meter.

On Sat, May 18, 2019 at 6:04 PM Alberto I2PHD <@I2PHD> wrote:

On 2019-05-19 0:56, Alberto I2PHD wrote:
When working with SMDs, I find this tool very handy :




Made by Mastech, model Nr. MS8911.
Hmmm, it looks like the photo did not get through...

It can be seen here :

http://i2phd.org/public/Twezeer.jpg

--
/*73 Alberto I2PHD*
Keyboard Not Found : Press F1 to continue/




Re: [OT] surface mount components

Tony Fleming
 

I have them also and find them very nice to use!

On Sat, May 18, 2019 at 5:56 PM Alberto I2PHD <@I2PHD> wrote:


When working with SMDs, I find this tool very handy :




Made by Mastech, model Nr. MS8911.

When grabbing an SMD component, it can tell you whether it is a resistor,
a capacitor or an inductor, showing also its
value.
The measure can be performed at 4 different frequencies, and it can even
tell the ESR...
Given that the smaller SMD components do not have on their bodies enough
space to print their value, it is in these
cases a cannot-do-without tool.

Paid about 50 Euro one year ago.

--
/*73 Alberto I2PHD*
Keyboard Not Found : Press F1 to continue/




Re: Odd screw heads in a Tek 497P

Brian Symons
 

Many types of electrical terminals use a screw head that is designed to accept both a Cross or a Flat screwdriver - both versions of Philips & Flat or PoziDriv & Flat exist.
You may not have been aware of it but there is a special screwdriver tip designed just to fit these screws.
These screwdrivers are called various names by different manufacturers such as Xeno by Wiha but there are often referred to as Modulo, Terminal, +/- , PlusMinus, or Plus Minus Screwdrivers or just Philips/Slot or Pozi/Slot.
Although either the correct type of Cross or Flat will fit, they don't fit very well while the special tip fits the screw head perfectly & allows higher torque & less risk of damaging the screw head.

Regards,
Brian.

On 19-May-19 05:25, Larry McDavid wrote:
If you often work on electronic, optical or camera equipment made around the world, you will want three types of cross-head drivers:

Phillips (unfortunately the US standard and a really poor choice)

Pozidriv (used throughout the rest of the world instead of Phillips)

JIS (commonly seen on Japanese electronics and cameras). Pozidriv drivers do not fit these well! Get the correct driver for the screw you use...

I often work on microscopes that have truly tiny screws that are often JIS.

These three types can be easily purchased on Amazon. Wiha makes excellent Phillips and Pozidriv drivers but, alas, not JIS.

I have a friend in The Netherlands and he had to ask me to buy and ship some Phillips drivers to him because he could not buy them there. All the cross-head screws sold there are Pozidriv.

Square drive or Robertson heads are now found in some high-torque wood screws in the US.

Pozidriv heads are found in some wood deck screws; boxes of those screws often include a Pozidriv bit. These bits are usually marked PZ.

There are some interesting combination heads found in electrical equipment. Some combine Pozidriv with flat blade recesses and circuit breaker screws combine flat blade and square drive recesses.

The Wiki article referenced below is a really good one.

Larry


On 5/18/2019 11:27 AM, Chuck Harris wrote:
And yet, it too is a cross shaped, with square sides that won't
cam out. and is incompatible with Phillips...  Just like the pozidriv.

Those I have tried fit the pozidriv screwdrivers just fine.


-Chuck Harris

Carsten Bormann wrote:
On May 18, 2019, at 14:10, Chuck Harris <cfharris@...> wrote:

Asian made screws with a dot between the slots are also
posidrive.
Not really:
https://en.wikipedia.org/wiki/List_of_screw_drives#JIS_B_1012
...

SMD tweezers (Re: [TekScopes] [OT] surface mount components)

Carsten Bormann
 

Made by Mastech, model Nr. MS8911.
I have a cheap Mastech MS8910, which is not very practical (the snake-tongue tips are useless, the legs too rigid, etc).
The inductance tester and the low voltage selections (0.1 V rms so you do not open PN junctions) in the MS8911 sound very interesting, though.

My goto SMD tweezer is the HP4070C, also sometimes sold in yellow as HP990C.
(HP is “HoldPeak”, not “Hewlett Packard” here.)

They have useful SMD testing capabilities (with a little inside push, the tips open wide enough for some quick through-hole testing as well), but also can do continuity beeping and test coin cells as well as diodes, including LEDs and zeners (up to 23+ V). No inductance testing and no ESR, though.
The battery cell testing mode is interesting, because you get to choose between a non-trivial load (hundreds of Ω, “10 mA”) in the forward (plus) direction, but essentially no load (~ 1 MΩ) in the backward (minus) direction; sometimes quite useful for in-circuit voltage testing (“does this voltage take a load?”) as well.

Quite good ergonomics, too, even though I’d still like the tips to be even more pointy.
Even comes with cheap test leads that you can plug into 4mm holes in the tips, you can put in your own more pointy leads or grabbers for better in-circuit and through-hole testing.
Annoying lack of a way to switch it off, it will auto-switch off after a couple of minutes and some useless beeping. 2 AAA batteries (that last an eternity), so no expensive and quickly depleted coin cells.

At < $20 shipped, they are cheap enough to have a HP4070C (or a HP990C) at every desk or station. Come with a reasonable hard case for carrying around.
Don’t fall for the (slightly cheaper) 990B or lower, the C versions have 6000 counts and are quite accurate for a tweezer.

Grüße, Carsten

Re: Odd screw heads in a Tek 497P

tom jobe <tomjobe@...>
 

Thank you everyone,
For this informative discussion about the different kinds of screw heads and the proper tools for each.
The Wikipedia article summarized the subject very well, complete with photos to show us the many types of screw heads and related tools.
tom jobe...

On 5/19/2019 1:05 AM, Brian Symons wrote:
Many types of electrical terminals use a screw head that is designed to accept both a Cross or a Flat screwdriver - both versions of Philips & Flat or PoziDriv & Flat exist.
You may not have been aware of it but there is a special screwdriver tip designed just to fit these screws.
These screwdrivers are called various names by different manufacturers such as Xeno by Wiha but there are often referred to as Modulo, Terminal, +/- , PlusMinus, or Plus Minus Screwdrivers or just Philips/Slot or Pozi/Slot.
Although either the correct type of Cross or Flat will fit, they don't fit very well while the special tip fits the screw head perfectly & allows higher torque & less risk of damaging the screw head.

Regards,
Brian.

On 19-May-19 05:25, Larry McDavid wrote:
If you often work on electronic, optical or camera equipment made around the world, you will want three types of cross-head drivers:

Phillips (unfortunately the US standard and a really poor choice)

Pozidriv (used throughout the rest of the world instead of Phillips)

JIS (commonly seen on Japanese electronics and cameras). Pozidriv drivers do not fit these well! Get the correct driver for the screw you use...

I often work on microscopes that have truly tiny screws that are often JIS.

These three types can be easily purchased on Amazon. Wiha makes excellent Phillips and Pozidriv drivers but, alas, not JIS.

I have a friend in The Netherlands and he had to ask me to buy and ship some Phillips drivers to him because he could not buy them there. All the cross-head screws sold there are Pozidriv.

Square drive or Robertson heads are now found in some high-torque wood screws in the US.

Pozidriv heads are found in some wood deck screws; boxes of those screws often include a Pozidriv bit. These bits are usually marked PZ.

There are some interesting combination heads found in electrical equipment. Some combine Pozidriv with flat blade recesses and circuit breaker screws combine flat blade and square drive recesses.

The Wiki article referenced below is a really good one.

Larry


On 5/18/2019 11:27 AM, Chuck Harris wrote:
And yet, it too is a cross shaped, with square sides that won't
cam out. and is incompatible with Phillips...  Just like the pozidriv.

Those I have tried fit the pozidriv screwdrivers just fine.


-Chuck Harris

Carsten Bormann wrote:
On May 18, 2019, at 14:10, Chuck Harris <cfharris@...> wrote:

Asian made screws with a dot between the slots are also
posidrive.
Not really:
https://en.wikipedia.org/wiki/List_of_screw_drives#JIS_B_1012
...

Photo Storage Space Solution, was IMPORTANT: Photos are eating up our storage

 

Thank you for your suggestions on what we should do to slow down our use of storage space on Groups.io.



After consulting with Michael Dunn I have changed the maximum size limit allowed for photos from 4096 x 4096 to 2048 x 2048.

Please note that groups.io indicates they will resize photos larger than this new size so that they don’t exceed 2048x2048.



It is still necessary to keep the size of your photos to the minimum necessary to make your point.



I will be monitoring the amount of storage we use to be sure we stay well under the limits Groups.io allows us.

If storage space becomes an issue in the future it may be necessary compress large photos.



Dennis Tillman W7PF

Re: Odd screw heads in a Tek 497P

radioconnection@...
 

My set of drivers arrived today. Amazing how well things go when using the right tools. Not a cheap set, but well worth the bucks.

Tek 497P lithium battery

radioconnection@...
 

I see a lithium battery on a processor board in my 497P. Battery is reading about 2.665 volts. Anyone know what a good replacement is, and will I lose calibration data if I replace the battery? Will the unit self calibrate if the battery dies?

Also, all of the SMD electrolytics look like black tantalum caps--there are encapsulated in black material. No sign of the aluminum can variety. Are these generally stable and reliable?

Pete

Re: Photo Storage Space Solution, was IMPORTANT: Photos are eating up our storage

EJP
 

Pour encourager les autres, I resized 8 photos in my AF501 trigger album to 600x800. Image size went from 1.2M to < 64K. Times eight. Rather worth it I thought.

EJP

Re: Tek 497P lithium battery

John Miles
 

You'll lose any saved traces and memory presets when you disconnect the battery, but no calibration data is stored in NVRAM on these units. The battery is actually a primary cell that's not recharged by the analyzer, so any convenient 3V battery is fine as a replacement. A CR2032 or similar battery holder can be epoxied to the PCB.

No problem with the black tantalums. They can be left in place unless/until they cause trouble. You may sometimes see the blue epoxy-dipped tantalum caps fail shorted, but there aren't many of those and it generally isn't worth replacing them pre-emptively.

-- john, KE5FX

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
radioconnection@...
Sent: Sunday, May 19, 2019 9:08 PM
To: TekScopes@groups.io
Subject: [TekScopes] Tek 497P lithium battery

I see a lithium battery on a processor board in my 497P. Battery is reading
about 2.665 volts. Anyone know what a good replacement is, and will I lose
calibration data if I replace the battery? Will the unit self calibrate if the
battery dies?

Also, all of the SMD electrolytics look like black tantalum caps--there are
encapsulated in black material. No sign of the aluminum can variety. Are these
generally stable and reliable?

Pete

Changing the battery of a 2465B

Alberto I2PHD
 

I have a 2465B 'scope that I bought second hand about 20 years ago. It has always worked flawlessly, no signs of the dreaded 04 error at power on.
Considering that maybe the previous owner did use it for a number of years before selling it to me, I am fearing that the battery that holds the calibration data is near to the end of its life....

So, my question is... is there a recommended procedure to change the battery with a fresh one without losing the calibration data ?
I don't have the zillion test equipment that Tektronix deems as necessary to perform a new calibration, and sending it to someplace in the States to have it calibrated would cost me for shipping alone an amount similar to the actual price of the instrument...

Thanks for any suggestions...


--
/*73 Alberto I2PHD*
Keyboard Not Found : Press F1 to continue/

Re: [OT] surface mount components

David Kuhn
 

Hello Alberto,

I never thought of this use for smart tweezers. Good suggestion! When I
checked out the MS8911 on Amazon, it doesn't look like it does ESR for that
price. I've had two $300 ESR tweezers and both of them failed and fell
apart. They were a high-end brand but fell apart. I did buy a cheap
(~$25) Mastech MS8910 TWEEZER that does everything but ESR. It does seem
to work very well (sans ESR), but it very nice for $25.

I have a couple of other gauges (Agilent 4263B/16089C and the $20 Component
tester project). The expensive Agilent is about the hardest and worst
device to test ESR; it is on the repair bench for one reason: it looks so
cool. It does work it, but the results vary wildly depending on the setup,
and it is hard to use on an occasional basis; I don't find it trust
worthy. The older smart tweezers (that failed) seemed very good, but the
best ESR device I have/had is the $20 (with plex case) component tester
project that you can purchase on ebay or amazon, probably for less than
$20.

I see there are smart tweezers out there with ESR for about $200 on Amazon
and EBAY. I may have to check out BangGood and AlieExpress for a better
price.

Dave

Anyway, again, for component placement on a previously un-soldered board,
or for cleaned pads, the Mastech tweezers is a very good idea.

On Sat, May 18, 2019 at 6:56 PM Alberto I2PHD <@I2PHD> wrote:


When working with SMDs, I find this tool very handy :




Made by Mastech, model Nr. MS8911.

When grabbing an SMD component, it can tell you whether it is a resistor,
a capacitor or an inductor, showing also its
value.
The measure can be performed at 4 different frequencies, and it can even
tell the ESR...
Given that the smaller SMD components do not have on their bodies enough
space to print their value, it is in these
cases a cannot-do-without tool.

Paid about 50 Euro one year ago.

--
/*73 Alberto I2PHD*
Keyboard Not Found : Press F1 to continue/




Re: Changing the battery of a 2465B

Paul Amaranth
 

If your NVRAM is still viable, dump the contents using a prom programmer and
then put the data into a new one before installing it.

It's not too hard to cobble up a suitable device using an arduino.

When you take out the old one, put in a good quality socket.

Paul

On Mon, May 20, 2019 at 01:10:46PM +0200, Alberto I2PHD wrote:
I have a 2465B 'scope that I bought second hand about 20 years ago. It has
always worked flawlessly, no signs of the dreaded 04 error at power on.
Considering that maybe the previous owner did use it for a number of years
before selling it to me, I am fearing that the battery that holds the
calibration data is near to the end of its life....

So, my question is... is there a recommended procedure to change the battery
with a fresh one without losing the calibration data ?
I don't have the zillion test equipment that Tektronix deems as necessary to
perform a new calibration, and sending it to someplace in the States to have
it calibrated would cost me for shipping alone an amount similar to the
actual price of the instrument...

Thanks for any suggestions...


--
/*73 Alberto I2PHD*
Keyboard Not Found : Press F1 to continue/





!DSPAM:5ce28b4e161396325818081!
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix & Windows

Re: SMD tweezers (Re: [TekScopes] [OT] surface mount components)

Hawker
 

That 0.1V or less excitation is very important. I used to have a BK 886 with 0.05V excitation. It could usually accurately read caps in circuit.
I now have a BK880, which is supposed to be more accurate. However it only has a 0.3V minimum excitation voltage and does not read as accurate in circuit as the 886.
What is also important if you want to measure capacitance less than about 470pf (and large inductors) is 100KHz sample frequency. That Mastertech only goes to 10KHz so it isn't going to be as accurate fro smaller value caps or large inductors. I don't know if 0.1V is low enough, but clearly better than the BK 880's 0.3V, which isn't low enough.

Re: Changing the battery of a 2465B

Chuck Harris
 

I presume that your 2465B is from before serial number B050000, and
has a battery and cmos ram setup, rather than the later Dallas NVRAM.

If that is so, it is trivial to replace the battery without losing
your calibration data... not that the data is all that valuable on
a scope so long out of calibration.

What you do is remove the A5 controller board, being sure not to
short the connections on the bottom of the board to any metal surface,
and set it down on a wooden board... [less static on wood, than on plastic,
and you sure don't want to use metal...]

Using a set of micrograbber clip leads, connect the minus lead of a 3V
battery to any convenient ground on the A5 board, and the Plus lead
to either of the cathodes of D2770, or D2371. You can solder a wire,
if you are afraid of your micrograbber clips, I don't as I think that
is a more dangerous act, than using a micrograbber clip. Just be sure
that your clips have a good J hook on their metal part.

Unsolder the battery, and install a new battery. Remove the micrograbber
clips.

Don't use a power supply for the 3V, just use a pair of AA cells, or
any lithium cell. Your soldering iron tip will be grounded (if it isn't,
you should throw it away), and may your calibration constants, by shorting
the battery to ground through the power supply... while you unsolder it.

And that is all.

The replacement battery is made by Eagle-Pitcher, and is readily available.

-Chuck Harris

Alberto I2PHD wrote:

I have a 2465B 'scope that I bought second hand about 20 years ago. It has always
worked flawlessly, no signs of the dreaded 04 error at power on.
Considering that maybe the previous owner did use it for a number of years before
selling it to me, I am fearing that the battery that holds the calibration data is
near to the end of its life....

So, my question is... is there a recommended procedure to change the battery with a
fresh one without losing the calibration data ?
I don't have the zillion test equipment that Tektronix deems as necessary to perform
a new calibration, and sending it to someplace in the States to have it calibrated
would cost me for shipping alone an amount similar to the actual price of the
instrument...

Thanks for any suggestions...

Re: Changing the battery of a 2465B

 

Chuck - Does the same hold true for a 2445? One of mine is giving me a battery error. Also, can you provide more information on the Eagle-Pitcher replacement battery? I couldn't find anything suitable cross-referencing the Tek part number so I bought a AA size Lithium battery, planning to use an AA battery holder with it, but if there is a correct battery I would rather go with that.

TIA, Lee

Re: Changing the battery of a 2465B

Alberto I2PHD
 

On 2019-05-20 15:20, Chuck Harris wrote:
I presume that your 2465B is from before serial number B050000, and
has a battery and cmos ram setup, rather than the later Dallas NVRAM.
Yes, the SN is B012133.
Other than telling me that it was made in Beaverton, Ohio, I don't how to interpret that number... year of production ? Special features ?
If that is so, it is trivial to replace the battery without losing
your calibration data... not that the data is all that valuable on
a scope so long out of calibration.
This brings to another question... when the 04 error is displayed ? When the checksum of the RAM is invalid, or when the instrument is actually out of the specifications ?
And in this latter case, how can the firmware tell that ?
Don't use a power supply for the 3V, just use a pair of AA cells, or
any lithium cell. Your soldering iron tip will be grounded (if it isn't,
you should throw it away), and may your calibration constants, by shorting
the battery to ground through the power supply... while you unsolder it.
Yes, I will use a couple of AAA cells for that, and a Weller soldering iron.
The replacement battery is made by Eagle-Pitcher, and is readily available.
Well, I have never opened the instrument, and I thought, apparently wrongly, that a CR2032 cell could do.
They are sold around here at the supermarket, a 6-pack for 3 Euro. Is that cell sold by Eagle-Pitcher different from a CR2032 ?

Thanks for your suggestions.


--
/*73 Alberto I2PHD*
Keyboard Not Found : Press F1 to continue/

1502 TDR repair

Paul Amaranth
 

After getting the HV issues sorted out I had another problem
putting my 1502 back together. When pulling the cabinet off
the power feedthrough on the cabinet disintegrated. I ended
up with 3 pins and a handful of shredded rubber.

I could not find the part called out in the 1502 manual and,
in any event, it was probably a Tek special part and NLA
anyway. A search yielded nothing that would fit in the space.

I had some Flexane-80 castable urethane left over from another
project so I used an IEC connector as a form, plugged the pins
into it and used another IEC cord to space them properly and
built up a cardboard form around it to get a flange. Didn't
turn out as pretty as I would have liked (the rubber had too
high a viscosity to flow in completely and left some voids),
but it fit, it works and allowed the cabinet to go back on.

If you do this, don't forget to use a mold release or you'll never
get the feedthrough out of the socket. Also note that the ground
pin is slightly longer than the other two.

I think you could probably use one of the silicone rubber molding
compounds as well.

Finally I can get that one off my bench!

Paul
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix & Windows