Date   
Re: Ceramic strip soldering tek video

RalphJ
 

Good morning, aficionados of Tektronix Oscilloscopes;

Back in the 1960s and 1970s when I was actively working with the 500 series of Tektronix oscilloscopes, one admonition found in the operation and service manual was to use "two percent silver bearing solder" when working on the ceramic terminal strips.

The most common solder alloy used generally for electronics was the 60%-40% Sn-Pb (Tin-Lead) alloy form with a melting point of 370 degrees F. The "eutectic" alloy of 63%-37% Sn-Pb did have a lower melting point of 363 degrees F. which was a advantage, yes, but it also did not have a "plastic" state while it cooled, so it did not develop a poor solder connection if the parts were moved while the solder joint was cooling. This "eutectic" quality was helpful.

I need to divert for a moment to make a comment about the degradation of the English language used in electronics in recent years. The lack of attention to how words are used in electronics is impressive. If we do not take the time to learn the language of the discipline and how to write so that you can describe the work that you have done, then your work may just die with you and be lost, if you are not able to record your work in a way that people later will be able to learn what you have done. This includes the somewhat more common misspelling of "solder" with the variant of "soder" being seen more often now. This is a case where many people are not studying the English language and know nothing of the etymology or history and origin of the words that they are using. They are just making up words that they think sound like the words that they hear. I wonder if they are reading the textbooks with any intent for learning and comprehension of what is in the book.

The recommended "two percent silver bearing solder" or 62%-36%-2% Sn-Pb-Ag alloy has a melting point down to 354 degrees F. which is about 15 degrees lower than the common 60%-40% Sn-Pb alloy, and that could be significant, but the major advantage in this case is that the addition of the silver to the alloy will reduce the tendency to leach silver out of the metalized ceramic terminal, and make the terminal more reliable over a longer time period.

Tek had a lot of really good talented people working for it. Not just electronics engineers, but chemists, physicists, and others also. Between Tektronix, Hewlett-Packard, and General Radio, they provided most of the instruments that we used to design the systems that put men on the moon.

Enjoy;

Ralph, N7KGA
Latte Land, Washington

Re: Re-introduction to the group

 

WTF……………..?

On Feb 26, 2018, at 6:58 PM, jafinch78 . <jafinch78@...> wrote:

On Mon, Feb 26, 2018 at 03:11 pm, Tom Gardner wrote:


There are many ways to skin a cat; TENS is one designed specifically to skin
cats, rather than a mere side side-effect.
Definitely keep skinning the aliens and enemies of the U.S. Jurisdiction... including with internal affairs operations when required when enemies are found. Wonder what Trump's announcement regarding death sentencing Edwards, Schriever, Malmstrom and the other cocaine pedos higher up will result in... then I see lately F.E. Warren is in the mix as the scapegoat? At least the Navy and Air Force comes clean at lower ranks, though like CIA DEA and their NOC's... higher up is all sorts of shady. Even worse I'm sure is the Army that comes out gets their family murdered and the informant gets pinned wrongfully like Ted Gunderson noted with one case that comes to mind.

OK... emotionally magnified moment... Here are some sites with more info for those interested:
https://distrowatch.com/table.php?distribution=tens
https://en.wikipedia.org/wiki/Lightweight_Portable_Security

The AF site makes me think Transcutaneous Electrical Nerve Stimulation (TENS) Therapy

Then there is the site: https://www.spi.dod.mil/lipose.htm

I'm thinking after seeing both sites... is the TENS Therapy performing liposuction or something to cause less fat? jk ;-)


Re: P6058 vs P6058A

RalphJ
 

Where is Russ Fillinger, W7LXR, when you really need him?

He could answer that question just from memory.

Ralph, N7KGA
Latte Land, Washington

Re: Cheap differential probe ?

Peter Brown
 

Jim Williams tackled this

https://books.google.com/books?id=H9rAU4Rf--YC&pg=PA270&lpg=PA270&dq#v=onepage&q&f=false



On Thu, Mar 1, 2018 at 9:54 PM, Dennis Tillman W7PF <@Dennis_Tillman_W7PF>
wrote:

There is no such thing as a cheap differential probe. They have to be
matched across a wide frequency range to have good CMRR. If you want a
cheap CMRR the solution may be on your scope. All dual trace scopes have an
ADD function for both traces. They all haave a way to invert a trace on one
of the channels. So switch to Add, Invert one channel, and use the gain
knob of one channel to adjust the trace to a straight line when you put a
signal in through two same number probes - any two will do as long as they
are the same (two P6109 probes for example).

Voila, a poor man's Differential probe.

As long as there isn't too much of a voltage difference between the two
channels the waveform will stay on the screen where this will work OK. It
isn't much but that is probably the best you are going to get when you
require "cheap"

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of David
Slipper
Sent: Thursday, March 01, 2018 6:45 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Cheap differential probe ?


Sadly, nothing under £100 on fleaBay :-(

Anything in the DIY arena ??

Dave




--
Dennis Tillman W7PF
TekScopes Moderator



Tek 2445B Focus Problem

peteq1@...
 

Hi everyone, this is my first post in this group, maybe someone can help?

I bought a Tektronix 2445B (same as a 2465B except bandwith), Serial below 050000, so it has the old-style A5 board without SMD and without the leaking caps.
It looks almost like new, has below 900h of operation, came from a broadcasting station (sfb, Sender Freies Berlin) here in Germany. I did the bandwith "hack" on the A1 board (seems to work very close to my 2465B).

But it has a focus problem: When cold, it is extremely out of focus (and astig as well), it takes 5 to 10 minutes to get a sharp image. My other 2465BDV is perfect from the first second.

I did replace all caps in the power supply. But I am not sure if this problem was there before the re-cap, because this was one of the first things to do after getting the scope.

Any suggestions? I did check the supply voltages (J119 on Board A1), all stable from the beginning.

I did check all input voltages to the HV board, and even took the HV board from my other 2465B and put it into this one, same result.

I checked all voltages around Q1851 and Q1852, all very stable from the beginning. -300V is stable. Focus can also be bad if other voltages of the tube are wrong, so I have to look elsewhere.

I checked the Output of the High Voltage Module U1830, pin 4, which should be -900V, according to the schematics. It is only -617V.
The Output of the High Voltage Module U1830, pin 4 is also 617V on my other 2465B, so I think 900V is an error in the schematics.

Someone said it could be a "gassy" CRT. But it is bright, and sharp after warm up.

Thanks
Peter
from Germany (-12 °C at the moment)

2465 Question

rjv100mailbox-public@...
 

Hello everyone, I'm new to this group and hope to learn from your discussions. I am learning electronics via books, YouTube, and hands on experimentation. Perhaps a class at a local college in the future. The other day I bought a Teks 2465 Scope , which I now regret after reading the forums. I guess I should have bought a 2465B. The scope should arrive in the next couple of days and would ask what startup procedures other than that listed in the manual would you advise. I have 14 days to return it and want to run it through the mill to ensure it's a good unit. Thanks to all.

Bob

SG505 THD issues

EJP
 

I've owned two SG505s for several years and never really achieved the specified performance from either of them.

#1 has .0030% THD into AA501 unfiltered at 0dBm 1KHz. It improves to .0020% with 22-22kHz filter in. I acquired this one about ten years ago, not working, with shorted C1201 or C1210: I replaced both with aluminium electro to fix this. Last week I remembered they were originally tantalum and got curious as to whether they needed to be, so I replaced again with 100uF 20V tantalum: no improvement; if anything, 0.0001-2% worse. THD improves after 20 minutes or so to 0.0023% unfiltered, .0015% filtered as above. Every now and again it comes up from power-on at .0012% THD filtered, which I cannot explain or reproduce on demand. The distortion is mostly 3HD with a little kink at the bottom of each cycle. This one is cohoused in a TM515 with the AA501/01. AA501 has been calibrated for minimum THD and correct V and dB readings.

#2 has 0.0038% THD unfiltered as above, improves to 0.0022% with 22-22kHz filter. This one has a frequency instability when first powered up for a few seconds, something like 10kHz superimposed on 1kHz which dies down and locks after 3-4 seconds. #2 is the later one with the extra circuitry around the BAL/COMP pins of the NE5534s and also has the IMD option 01, but it has always been slightly worse than #1 for THD. This one is housed in a separate TM515 along with an AF501 and two FGs.

SNR for #1 is -100dBm, #2 -90dBm which I had never noticed (i.e. measured) before today, rather a big difference.

Both have been recapped as far as electrolytics go, and calibrated for output level: nothing else done to them at all apart from replacing C1601, a 6u8F 10Hz range capacitor, in #1. In this one I also did briefly try LME49710s in the three critical positions (U1401/1520: the two with BAL/COMP circuits; and U1510 the initial oscillator) but if anything it got slightly worse again, which is interesting.

All these THD figures are 3-4x too high. Should I be looking into these SG505s? and if so where? or should I take another look at the AA501? and if so ditto.

TIA

EJP

Re: What calibration items to buy.

Brendan
 

Im looking at an agilent 33220a for timebase calibration? and a tek attenuator set off of the auction site.Thank you for the link to the pulser.

Re: What calibration items to buy.

 

Brian,
An ideal cal package is the one I have (all TM500 plugins)TG501 time mark gen
SG503 leveled sig gen up to 250 MHzPG506 Standard amplitude generator + fast-rise output pulse

Beware of the SG504 which goes up to a Ghz; the lowest freq does not go low enough to cover anyfreqs below 250 MHz, which is where the SG503 stops.The ideal setup would be to have both SGs.
HankC, Boston, WA1HOS

Re: Tekmate floppy setup problem.

Fabio Trevisan
 

Hi Szabolcs...
It may be a long shot but, have you considered that the very first disk, or
one of the first that you tried, could have been contaminated by fungae,
mold, etc... And that it could have made the drives head dirty?
Have you tried to clean the heads using a cleaning floppy disk and IPA, or
using a cotton swab?
In the begginig of the years 2000 when floppy disks were already on their
way out, but lots of people still had large sets of years past backups, it
was very common for my customers to trash a lot of floppies, thinking they
were bad, just to find out that there was only one bad disk, which
eventually clogged the heads of the reader, rendering all other disks
unreadable.
Fungae love the kind of lubricant that used to be used back then, to
protect the disks from abrasion.
Brgrds,
Fabio

On Mar 5, 2018 11:34 AM, "Szabolcs Szigeti" <szigiszabolcs@...> wrote:

Hi,

Thanks, but I doubt it. I have tried a number of disks, even one from an
original packaging. I'm able to use them in a notebook. The imteresting
thing is that if I try to format them in in the Tekmate, then format stops
with unusable track 0, but it formats that track. or at least does
something with that, because then I have to reformat the disk to use it
again. This is why i suspect that there is some discrepancy in what
bios/dos thinks about the drives and what they are really. But, I do not
see anything else other than the bios setup to change the floppy type.
I can still not beleive that I have 3 equally faulty floppy drives, but
I'll try and get hol of a fourth one or try them in a PC. I'll also try
cleaning them, to make sure that that is not the problem.

Szabolcs


2018-03-05 4:04 GMT+01:00 battyhugh <@Hugh>:

It might surprise you, but your floppys are corrupt. I would suggest
getting a tube of disk cleaner (10%alcohol and a drop of detergent) - and
using a nice clean tissue - I recommend toilet paper - open the shutter
and
clean the disk carefully on both sides. I have to do this to recover old
disks with files.

Good luck

Hugh @Hugh



Re: How to Use this Forum ..... ????

tinkera123
 

Thanks for all the responses ... some via PM .... I now have a couple of solutions to suit my needs.

Cheers,
Ian

Re: How to Use this Forum ..... ????

Richard Knoppow
 

If you get messages via e-mail the address of the original poster is included in the header. Some add their e-mail address to their signature (as I do). One has only to copy that address and paste it into the To field without the list address or you can send a new e-mail. Lists vary as to what shows up on the reply choices so you must check to see which addresses the particular list uses. Some have a "Reply all" and also a "Reply" choice, however, they do not always go the same places. This list sends to both list and original sender when you click "reply all" but only to the list for "Reply". To send to the original poster only one has to edit the To field or cut and paste.
The archive for messages is automatic. If you post to the list the message will go into the archive. Some lists also have a place on their web sites to put pictures, documents, etc. Yahoo lists will notify subscribers when this is done, not sure about IO.

On 3/5/2018 1:54 PM, David DiGiacomo wrote:
On Sun, Mar 4, 2018 at 7:04 PM, tinkera123 <@tinkera123> wrote:
I cannot find anywhere, including in "Help", as to how to do the following. Can some either explain how it works .... or point to somewhere I can read it myself ....?????
1. How do I Private Message another Member of this Group ??
2. How do I 'archive' Topics that I feel I will need to refer to in the future ?? I am aware of the "Search" function.
Both of these are extremely easy on groups.io:
1. Starting from the message page or topic page, click on Reply, then Private.
2. Go to the topic page, then save the URL (or just print the page to
PDF from your browser).
--
Richard Knoppow
dickburk@...
WB6KBL

Re: How to Use this Forum ..... ????

David DiGiacomo
 

On Sun, Mar 4, 2018 at 7:04 PM, tinkera123 <@tinkera123> wrote:
I cannot find anywhere, including in "Help", as to how to do the following. Can some either explain how it works .... or point to somewhere I can read it myself ....?????
1. How do I Private Message another Member of this Group ??
2. How do I 'archive' Topics that I feel I will need to refer to in the future ?? I am aware of the "Search" function.
Both of these are extremely easy on groups.io:

1. Starting from the message page or topic page, click on Reply, then Private.

2. Go to the topic page, then save the URL (or just print the page to
PDF from your browser).

Re: Right / Best way to rename a topic

Fabio Trevisan
 

Thanks Chuck and David (Partridge),

You both share the same opinion (That I better not change the subject of an
existing thread) so I`ll follow.

Rgrds,

Fabio

2018-03-05 12:06 GMT-03:00 Chuck Harris <cfharris@...>:

There really is only one way to rename a topic, and that
is to change what is in the Subject box.

The problem with renaming a topic, is that all previous
posts, and all replies to previous posts, keep the same
topic. The only posts that change are yours, and anyone
that replies to you. Further, the renamed topic retains
its position in the threading of the original topic.

Changing the topic as a means of starting a new topic is
strictly frowned upon. Doing so keeps the "new" topic in
the threading of the old topic, and seriously confuses
the readers.

I would venture that the best thing to do, is to compose
a new thread with a new topic, and be happy.

-Chuck Harris



Fabio Trevisan wrote:
Hello Folks,
My last topic was about the Tek 7623A I was prospecting to purchase.
Well, it's purchased already and I even started discussing its problems
and getting replies...
So I would like to rename the topic, so the subject reflect the ongoing
discussion...
Is there a right way to give the topic a new name, like I see sometimes
on the list... e.g.: New Subject... (was old subject)?
I`m taking the opportunity to improve my usage of the group, in order to
maintain the topic integrity and assure search-ability, etc...
Rgrds,
Fabio


Re: Can I install a 2465B motherboard in a 2445B chassis? What will I get?

Sergey Kubushyn
 

On Mon, 5 Mar 2018, David Thomas wrote:

No upside/downside -- as somebody already mentioned firmware is the same
between 2445B and 2465B and it learns what it is running on by checking
jumpers/straps on the A1 board. Just get the latest version available and
you are good to go.

I have one 2445B gathering dust on a shelf myself and couple of 2456B A1
boards so I'll convert it to 2465B when time permit. I do even have a 2465B
label :)

Not going to sell it; it is a spare and current prices make it not worth
bothering with selling. My primary analog scope is 2467B and I also have a
spare one but 2465B has bigger screen...

...so what would be the downside to installing a 2465 A5 ROM in a 2445?  Do you think it might be capable of those extended sweep rates? Any other pro's \ cons?
I have a 2445 which might thank me for a little upgrade, if its possible... :-)
--
Best Regards

David Thomas
---
******************************************************************
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
******************************************************************

Re: Can I install a 2465B motherboard in a 2445B chassis? What will I get?

David Thomas
 

...so what would be the downside to installing a 2465 A5 ROM in a 2445?  Do you think it might be capable of those extended sweep rates? Any other pro's \ cons?
I have a 2445 which might thank me for a little upgrade, if its possible... :-)
--
Best Regards

David Thomas

Re: Tek 547 A Sweep display during retrace

Dave Wise
 

Thank you, Chris, for your kind gift of a Siemens AF118 transistor for testing.

At least in the Q373 position*, your sample AF118 performed like a 2N2207.  I saw 60ns delay and 25ns rise vs 50ns/35ns for 2N2207, giving the same turn-on time.

That said, my recommendation stands: BC556 or KSA992, with 220pF added to the speedup cap.  That's cheap and abundant and anyone can do it, not just the oddball with a box of AF118's.  :)

Thanks,
David

* Should be the same in the Q173 position but I didn't test it.
________________________________________
From: TekScopes@... on behalf of Christopher Hilton-Johnson chj@... [TekScopes] <TekScopes@...>
Sent: Saturday, November 25, 2017 2:15 AM
To: TekScopes@...
Subject: Re: [TekScopes] Re: Tek 547 A Sweep display during retrace

Have you looked at the AF118 as a replacement for the 2N2207?

I ask, because most of my pulls were AFs pretending to be 2Ns

Chris HJ​

Heathkit EU-81A

Leon Robinson
 

I picked up a Heathkit EU-81A Function Generator at the Russelville, AR
Hamfest Saturday, it works OK but only has a "partial" manual without any
schematic.
The only manual I can find on the Internet is the same one I got with it.
It looks a lot like a Khron-Hite but different.

Does anyone have a copy or know where there is one.

Thanks
Leon Robinson    K5JLR

Political Correctness is a Political Disease.

| | Virus-free. www.avg.com |

Re: TekScope PDFs

bobh@joba.com
 

Just to tag on to Fabio's recommendations I'll add that if you can't find what you want there are several people who sell manuals on ebay.  And, Dave at Artek http://artekmanuals.com/manuals/tektronix-manuals/ is the best for getting an excellent copy either on disk or by ftp download.

There is also the internet archive https://archive.org/details/manuals_tektronix

Occasionally I use the Wayback machine to got back in time and find a text file or maybe a pdf that was available but seemed to disappear from the net.

Ok, there is also http://www.ko4bb.com/getsimple/index.php?id=manuals&dir=Tektronix

The VintageTek museum sells original hardcopy Tek manuals and other items on ebay and also thru their website https://vintagetek.org/

Bob.

On 3/5/2018 8:54 AM, Fabio Trevisan wrote:
Hello Gary,
Desirable as it is, I don't think there's such one place...
Assuming that you're not familiar with...
There's the "TekWiki" website, kindly run and maintained by one of the
members - Kurt - and it's a good place to start (
http://w140.com/tekwiki/wiki/Main_Page).
As complete as it is, it's an autonomous effort and hosts a bunch of
information, not only product manuals, but other Tektronix publications,
but for a few models there's no manual available.
There's also the "Boat Anchor Manual Archive" another individual
innitiative: http://bama.edebris.com/manuals/
Some of the manuals are available at the internet archive:
http://bama.edebris.com/manuals/
And there's the Tektronix website... They still have some stuff, and not
only of the new things... e.g. I found the manual for the Tektronix 468
there (which is more than 30 yo).

Those are the ones I know that have scanned PDF manuals that have manuals
or other publications that are allowed to be freely distributed (e.g. clear
of copyrights issues)... And the quality of the scans are assorted. You
will find some very good scans, as well as scans with missing pages...
Split-apart schematics and drawing pages (large pages that were scanned in
2 pieces, instead of one single big scan).

There are many other sites on the web (I won't mention names, just Google
for them), that hosts manuals that are not cleared of copyrights... but
it's a scattered resource at best.

What you wish, would probably need to be an initiative by Tektronix
themselves... but Tek under Danaher seems not to be so fond of their own
history and legacy as one (or as us, Tek enthusiasts) would wish.

Rgrds,

Fabio

2018-03-05 1:58 GMT-03:00 Gary Robert Bosworth <@grbosworth>:

Does anyone know a website where I can download ALL of the TekScope
publications in PDF format?
Gary



Re: TekScope PDFs

Fabio Trevisan
 

Hello Gary,
Desirable as it is, I don't think there's such one place...
Assuming that you're not familiar with...
There's the "TekWiki" website, kindly run and maintained by one of the
members - Kurt - and it's a good place to start (
http://w140.com/tekwiki/wiki/Main_Page).
As complete as it is, it's an autonomous effort and hosts a bunch of
information, not only product manuals, but other Tektronix publications,
but for a few models there's no manual available.
There's also the "Boat Anchor Manual Archive" another individual
innitiative: http://bama.edebris.com/manuals/
Some of the manuals are available at the internet archive:
http://bama.edebris.com/manuals/
And there's the Tektronix website... They still have some stuff, and not
only of the new things... e.g. I found the manual for the Tektronix 468
there (which is more than 30 yo).

Those are the ones I know that have scanned PDF manuals that have manuals
or other publications that are allowed to be freely distributed (e.g. clear
of copyrights issues)... And the quality of the scans are assorted. You
will find some very good scans, as well as scans with missing pages...
Split-apart schematics and drawing pages (large pages that were scanned in
2 pieces, instead of one single big scan).

There are many other sites on the web (I won't mention names, just Google
for them), that hosts manuals that are not cleared of copyrights... but
it's a scattered resource at best.

What you wish, would probably need to be an initiative by Tektronix
themselves... but Tek under Danaher seems not to be so fond of their own
history and legacy as one (or as us, Tek enthusiasts) would wish.

Rgrds,

Fabio

2018-03-05 1:58 GMT-03:00 Gary Robert Bosworth <@grbosworth>:

Does anyone know a website where I can download ALL of the TekScope
publications in PDF format?
Gary