Date   

Re: Plug-ins that use the high power slot in TM500/5000

Mark Wendt
 

On 12/25/2015 11:11 AM, David davidwhess@gmail.com [TekScopes] wrote:
On Fri, 25 Dec 2015 09:11:30 -0500, you wrote:

On 12/24/2015 11:14 AM, David davidwhess@gmail.com [TekScopes] wrote:

David,

That's great news! I've always enjoyed your posts here on the list, and
I really appreciate all the help you gave me on that one plugin that had
me pulling out my remaining hairs while troubleshooting. You should be a
teacher. You'd make a great one.

Mark
Thank you for the kind words.

My desk is starting to look like a medical workstation from a late
20th century version of Frankenstein - medication, gauze pads, medical
adhesive tape, TM504, 2232, 2247, disassembled DC505 and 7603,
soldering iron.
You could always use the soldering iron to cauterize new wounds. ;-)

Mark


Re: Advice for a sick DC505a

mosaicmerc
 

Well, I went thru all the configuration tests, which were fine.

Did the voltage cals etc...everything was in spec.

I calibrated it at a max resolution of 1Hz fed by a 9.999,999 Mhz synth. sinus signal from a newish Rigol 1022A function gen.

So the accuracy is within ±1 count of that sig. or 0.1 ppm . Crosschecked with the Freq counter in the 6.5 digit DMM. I wtached it hold for about 15 min and it's good. Cooling it causes a -1 count, letting it heat with no A/C causes + 1 count.

The hottest components are about +20°C over ambient (30°C)

Phase lock V was well in spec. @2.7V

Ran into a small prob. not having a 'Sealectro' adapter to connect to the A->B out connector in step 7 CH A/B level out cal. Might have to jury rig a paper clip 'probe' to make a squeeze connection to the little male pin inside there. Or try to tap off the PCB with soldered wires.

Later today...too tired now to do that.



.


Re: Advice for a sick DC505a- discovered a mainframe issue as well.

 

On Fri, 25 Dec 2015 20:45:28 -0500, you wrote:



On 12/25/2015 7:12 PM, David davidwhess@gmail.com [TekScopes] wrote:

<snip>

A couple of the 2N3565 transistors in mine were bad and about half
were "soft" on my curve tracer so I replaced them all.

Hello, David--

Thank you for your extended repair suggestions. I'm uncertain what you
mean by the 2N3565s'
"soft" characteristics-- were the V-I curves drifting as the
transistor(s) under test warmed up?
They had poor (high) collector to emitter saturation voltage and poor
(low) collector resistance.

How did the replacements look on the curve tracer, and were the
replacements made by
the same manufacturer as the originals? IIRC, a Fairchild 2N3565 has a
round grayish-colored
bodies topped by a dome of black epoxy. Again IIRC, some 2N3565s are in
conventional TO-92
There was nothing special about the application of these transistors.
I used 2N4401s as replacements but 2N3904s will work and 2N5088s would
be ideal.


Re: Massive document depository

Dwayne Verhey <yg@...>
 

There's one in there about making your own TM-500 extender. Wasn't someone looking for extender info recently?

http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/Make_your_own_Tektronix_TM-500_extender.pdf

On 24/12/2015 10:31 AM, Dave Daniel kc0wjn@gmail.com [TekScopes] wrote:

There is actually a lot more than just Tektronix documents. If one moves
up a couple of levels, one sees directories for many other
manufacturers. Even going up just one level reveals more Tektronix files.

In the Tektronix area, I looked at a file named tek_575_use.pdf, which
was written by Dennis Feucht, who is the author of the excellent
four-volume "Analog Circuit Design" set of books.

DaveD


Re: Tek 314

John Clark
 

OK, using my now pristine 475 (thanks to everyone here,) I did a little more probing around on my dead 314. I checked the L/R horizontal deflector pins and have nice opposite sawtooth waveforms there. I then checked CRT pins 9 & 5. I have a 100vpp square wave on pin 9. Just as you say, the pulse is on longer than it's off. The on/off time does change when I change the tim/div knob, which makes sense to me. I'm pretty sure that's all as it should be.

On the other side, on pin 5, I have a steady +100VDC. Seems to me that's what I should be seeing there, too. If there's 100v on each side then the display should be unblanked. When one side goes to zero then it blanks...am I understanding that correctly? If so, I'm thinking I either have a bad CRT or a problem in the HV section. I did order a Fluke 80k-40 to go with my 87V that should be here in a day or two as I figure I'll need it sooner or later.

Anything else I can check before my HV DVM probe arrives?

John

Key section is at the bottom of FO 10.
I must admit that I have not done much of anything inside my 314 but I
guess you really need to know what is happening at CRT socket pins 9 & 5
before you can call the CRT bad.
The circuit is a bang-bang it just switches from a low near 0V( blank )
to a high near 100V ( unblank ).
In a normal ( auto trigger ) sweep mode the low pulses should be short.

Please other list members check me up on this since I've been mostly a
software guy since this was built even though I started in electronics
in the late 50s.

Bert


If you are aware of this, just let it go by...
On the 314 blanking is accomplished by a extra deflection plate which

moves the beam off screen.

When blanked the deflection voltages are not relevant.
Bert


Re: Massive document depository-bigger than I thought

Sergey Kubushyn
 

On Fri, 25 Dec 2015, mosaicmerc@yahoo.com [TekScopes] wrote:

110 Gbytes total. It took me something like 36 hours to mirror it.

Does this mean there's more Tek stuff at this link...and the OP only posted one folder?
http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/ http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/
---
******************************************************************
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
******************************************************************


Re: Massive document depository-bigger than I thought

mosaicmerc
 

Does this mean there's more Tek stuff at this link...and the OP only posted one folder?
http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/ http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/


Re: Advice for a sick DC505a- discovered a mainframe issue as well.

Brad Thompson <brad.thompson@...>
 

On 12/25/2015 7:12 PM, David davidwhess@gmail.com [TekScopes] wrote:

<snip>

A couple of the 2N3565 transistors in mine were bad and about half
were "soft" on my curve tracer so I replaced them all.

Hello, David--

Thank you for your extended repair suggestions. I'm uncertain what you mean by the 2N3565s'
"soft" characteristics-- were the V-I curves drifting as the transistor(s) under test warmed up?

How did the replacements look on the curve tracer, and were the replacements made by
the same manufacturer as the originals? IIRC, a Fairchild 2N3565 has a round grayish-colored
bodies topped by a dome of black epoxy. Again IIRC, some 2N3565s are in conventional TO-92
(semicylindrical) packages.

Thanks, and enjoy this Christmas day!

73--

Brad AA1IP


Re: Upgrading the DC505

mosaicmerc
 

The dimensions of the 7 Digit LED display look pretty close to a bare 16x2 LCD.
I could do a uC driving a 16 x2 LCD (using line 1) to replace the LED digits to display the 7 digits with correct postscript text, like ####### Mhz/uS/nS etc. It will also knock out some of that high current LED synchronous switching. They produce a lot of transient edges.

That leaves line 2 to always display both A and B trigger level set points, 12 bit accuracy, should be ok.

Shouldn't be too tricky, just yank the 7447 BCD to 7 segment (U780) and the 74145 (U755) BCD to decimal digit scanning display driver and jumper direct into those sockets. Tap into the decimal dot drive jumper, the nS, uS & mS Led drives and the mode selector rotary switch then remove the LED panel and replace with the LCD.

In fact, looking at the main-board layout (A1,B1,C1,A2,B2,C2 grid squares), U755 and associated common anode resistors (14) & 2n2907 transistors (7) can be completely removed and replaced by the uC PCB socketed into the U755 socket for power and signals and feeding the existing LED com. anode. digit jumper currently fed by the common anode transistor collectors.
The 7 common anode drive lines are repurposed for the 16x2 LCD using 4 bit mode. So that's convenient, being able to reuse the existing jumpers to the display board without mods. Only the Gate LED will remain as OEM.
The Mhz/us, Khz/ms and nS LEDs will all be made redundant by the context sensitive LCD display. Should be able to display the ratios & event counts etc. using proper terminology as well.

Certainly a lot better man machine interface plus less transients & current draw.


Re: Massive document depository

vdonisa
 

There's only one proper way to do it and that's JCL. :-)


---In TekScopes@yahoogroups.com, <tothwolf@...> wrote :

Pine is very much still in use. I'm using 'Alpine' to read the email list
and compose this reply. I find GUI email clients to be extremely
inefficient and frustrating for reading moderate to high traffic email
lists.


Re: Replacing tantalum capacitors with ceramic capacitors

vdonisa
 

Before the battery systems we had the Pentium 4 era, when low drop off point of load regulators became mandatory (or you would had additional heat guns on the board in addition to the processor itself).

You'd be wrong about noise. At 5V for example the 7805 is specced at 45uVrms while the LM317 would be 150uVrms.

Also not all 78xx are created equal. Some of the better specced ones are those from ON Semi. Compare with let's say TI and ST and you'll notice some differences not only in specs but also on the schematic diagram. Apparently some manufacturers made some improvements although they still sell under the generic 78xx name.

---In TekScopes@yahoogroups.com, <mosaicmerc@...> wrote :

The LDOs rise have to do more with battery powered devices and portable
devices. For line powered devices I go with the LM317 series for DC reg.
as it has better regulation/noise spec than the 78xx series and can be
set for anything >1.25V up to 37V with a single ended supply.


Re: Advice for a sick DC505a- discovered a mainframe issue as well.

 

On Fri, 25 Dec 2015 16:56:51 -0400, you wrote:

The DC505a transistors are not in sockets, most of the discrete logic is.
Is the functionality the same between the DC505 and 505a?
All of the transistors and ICs on my DC505 are in sockets. The TTL
ICs, some of the ECL logic ICs, and the 723 regulators use those
crummy TI sockets and the transistors and selected ECL logic IC use
the flush mounted Berg miniserts.

So far I have replaced the TI sockets for the 723s with flush mounted
collet pins and I have added flush mounted collet pins for a couple of
the parts around Q680 shown on schematic 3 which I changed. I added a
ferrite bead to the emitter of Q680.

A couple of the 2N3565 transistors in mine were bad and about half
were "soft" on my curve tracer so I replaced them all.

I do not know of any significant differences between the DC505 and
DC505A. The DC505 lacks the trigger level output jacks and switch
which are on the front of the DC505A and that is the only difference I
am aware of.

I don't like the 'blind' level trigger adjustment. Tek could have
showed the trigger voltage on the LED DIGITs when those level pots are
tweaked using a CD4066 analog switch and a 555 monostable one shot,
triggered by a voltage phase shift comparator created by feeding both of
the comparator inputs with the Pot output excepting using a fast RC
filter on one of the comparator inputs.
The boards are pretty packed to add something like that. I do not
miss having a trigger level readout as I think my only counters which
do are my Racal-Dana 1992 and the one included in my 2247A
oscilloscope.

I think the DC503A, DC509, and DC510 have a readout of the trigger
voltage.

It would not be difficult to route one or both trigger level voltages
through the rear interface and into one of the DM series of
multimeters.

One change I made on my DC505 to help with troubleshooting is to
connect the internal sources to the frequency reference and display
multiplexing frequency reference.


Re: Massive document depository

Tothwolf
 

On Fri, 25 Dec 2015, Chris Trask christrask@earthlink.net [TekScopes] wrote:

Aha! So, I'm not the only one who misses the older transfer protocols. I really miss the PINE email reader. It was text-only, meaning you could not inherit a virus unless you foolishly launched it manually. It was fat and efficient. But then, nobody could intrude on your computer and install keyloggers and other forms of spying on you.
Pine is very much still in use. I'm using 'Alpine' to read the email list and compose this reply. I find GUI email clients to be extremely inefficient and frustrating for reading moderate to high traffic email lists.


Update Re: Tek 455 UnRegulated 32 volt to CRT PS HV Question SN B056113 Q552/556

Leanna L Erickson <lle@...>
 

Sent from my iPad

Begin forwarded message:

From: "Keith R. Erickson" <kognw@gte.net>
Date: December 25, 2015 at 4:11:18 PM CST
To: David <davidwhess@gmail.com>
Subject: Update Re: Tek 455 UnRegulated 32 volt to CRT PS HV Question SN B056113 Q552/556

Here is an update


Got this transistors out and tested using my trusty RCA WV38A, vintage 1961, RX1 position

Q556. PNP D43C8
Check B-E and B-C. Front. To back, good diode indication
C-E. High resistance both polarities.

Q552. NPN D44H11
Checked B-E and B-C. Front to back, good diode indication
However when C-E Zero ohms, both polarities.

That would seem to tell me that Q552 needs to be replaced!

Q552 is on order from DigiKey and Q556 I found on EBay.

Keith Erickson
Wayzata, MN

Sent from my iPad

On Dec 25, 2015, at 12:32 PM, David <davidwhess@gmail.com> wrote:

I have not been ignoring you. I just have not been following your 455
closely enough to have any good suggestions which others have not
covered. I will take another look through the discussion thread.

On Thu, 24 Dec 2015 09:57:36 -0600, you wrote:

Best of Season's Greetings

Glad to hear that you are doing better.

I think my next step is to replace Q552 and Q556.

I would appreciate any other suggestions.

Thanks


Re: Replacing tantalum capacitors with ceramic capacitors

mosaicmerc
 

The LDOs rise have to do more with battery powered devices and portable devices. For line powered devices I go with the LM317 series for DC reg. as it has better regulation/noise spec than the 78xx series and can be set for anything >1.25V up to 37V with a single ended supply.


Re: Advice for a sick DC505a- discovered a mainframe issue as well.

mosaicmerc
 

The DC505a transistors are not in sockets, most of the discrete logic is.
Is the functionality the same between the DC505 and 505a?

I don't like the 'blind' level trigger adjustment. Tek could have showed the trigger voltage on the LED DIGITs when those level pots are tweaked using a CD4066 analog switch and a 555 monostable one shot, triggered by a voltage phase shift comparator created by feeding both of the comparator inputs with the Pot output excepting using a fast RC filter on one of the comparator inputs.

Ancel


Re: 576 HV transformer

Ed Breya
 

Update. What a PITA it was to transplant the HVPS from the junker to the new 576, but it worked. The CRT is still too dim and flakey - I hope it's not the CRT gone bad, but by the looks of things I suspect I have some big line ripple in the LV supplies, so next will look at that and the big filter caps. Also need to make accurate checks of the HV and the high megohm resistors in the HV divider string when I get the right equipment over here.

The HVPS seems to work OK, and can run for a long time, unlike the bad one. I left it running overnight with a low brightness (that's all it can do anyway), out of focus display, and it was just the same this morning - kind of a Christmas gift after all the work I did on it.

When the brightness knob is increased beyond a certain point, it dims and blooms and gets jiggly, hopefully due to line ripple rather than the CRT. There are also various jiggles and noises with certain setups, even at low brightness, pointing more toward LVPS ripple or regulation issues.

Hope everyone has a good and Merry Christmas.

Ed


Re: Massive document depository

Sergey Kubushyn
 

On Fri, 25 Dec 2015, Chris Trask christrask@earthlink.net [TekScopes] wrote:

This one is sent from Pine :) Actually it is a fork called Alpine but it is
essentially the same old Pine. Nothing is better...

And for usenet I still use tin. There is nothing even close to it.

_ABSOLUTELY ALL_ GUI mail/news clients are light years worse in usability.
They might have all those idiot lights and flashy-farting things attached
all over but as far as the actual purpose, mail/news, they are not even
close to good old pine/tin.

Aha! So, I'm not the only one who misses the older transfer protocols. I really miss the PINE email reader. It was text-only, meaning you could not inherit a virus unless you foolishly launched it manually. It was fat and efficient. But then, nobody could intrude on your computer and install keyloggers and other forms of spying on you.
---
******************************************************************
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
******************************************************************


Re: Massive document depository

Sergey Kubushyn
 

On Fri, 25 Dec 2015, Gary Robert Bosworth grbosworth@gmail.com [TekScopes] wrote:

man wget.

Whatever happened to XMODEM and other data transfer protocol mechanisms to
allow transfer of large amounts of data in continuous flow? We are
supposed to be such techies and wizards. I would like to download all the
data and put it on my hard disks for future use.

Gary


On Thu, Dec 24, 2015 at 11:42 PM, Sergey Kubushyn ksi@koi8.net [TekScopes] <
TekScopes@yahoogroups.com> wrote:



On Thu, 24 Dec 2015, Gary Robert Bosworth grbosworth@gmail.com
[TekScopes] wrote:

You seem to underestimate the sheer size of that treasure trove...

I'm running "wget -r" on it since the announcement first appeared and it is
already 49Gbytes downloading Tek/2215a.pdf right now. I estimate it will
reach 100Gbytes fully mirrored...

Many manuals there are in greyscale (that is very good) that makes them
over
100Mbytes each (that is not good :))

It can easily take 25-30 DVDs to archive and a lot of work to split the
entire thing into separate DVDs. A hard drive would be much better suited
for storing the collection that big.

It would be very helpful if someone would put it all into a single
massive
file so it could be downloaded just once and put on a DVD.

Gary


On Thu, Dec 24, 2015 at 8:43 PM, 'John Miles' john@miles.io [TekScopes]
<
TekScopes@yahoogroups.com> wrote:



Good find! wget snagged 13 GB from the Tek directory alone.

There are a lot of documents that look like internal training manuals
and
lecture notes, some of them incredibly detailed:


http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/publikacje/556_Lecture_Notes
.pdf

-- john, KE5FX

From: TekScopes@yahoogroups.com [mailto:TekScopes@yahoogroups.com]
Sent: Thursday, December 24, 2015 8:12 AM
To: TekScopes@yahoogroups.com
Subject: Re: [TekScopes] Massive document depository

A great Christmas present, indeed!! One of the first files I downloaded
(tek_made_sm.pdf) describes the internals of many of the
Tektronix-manufactured ICs for which, I'm sure, no other documentation
exists.
There are lots of other documents on analog theory circuit design. A bit
dated, perhaps, but the theory still applies.
---
******************************************************************
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
******************************************************************


Re: Massive document depository

 

Ok. I will add a couple of other sections for which I have
instruments, setup a torrent using DHT and an open tracker, and post a
link here.

My connection is not all that fast but I regularly host torrents over
the long term. I have been hosting the 40 GB Bell System Technical
Journal for about a year and have uploaded 829 GB from it.

On Fri, 25 Dec 2015 10:28:39 -0800, you wrote:

Thank you, David. The HP and Tek sections are this group's primary interest, but I'll enter any swarm you start. Once I have it, I will continue to seed until I have passed it on several times.

Dave Wise

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