Date   

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@..., <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@..., <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@... [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@...>
Date: December 25, 2015 at 4:11:18 PM CST
To: David <davidwhess@...>
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@...> 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@... [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@... [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@... [TekScopes] <
TekScopes@...> wrote:



On Thu, 24 Dec 2015, Gary Robert Bosworth grbosworth@...
[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@... [TekScopes]
<
TekScopes@...> 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@... [mailto:TekScopes@...]
Sent: Thursday, December 24, 2015 8:12 AM
To: TekScopes@...
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


Re: Massive document depository

Dave Wise
 

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

________________________________________
From: TekScopes@... [TekScopes@...]
Sent: Friday, December 25, 2015 9:38 AM
To: TekScopes@...
Subject: Re: [TekScopes] Massive document depository

I can host it as a torrent for an extended time but what part do you
want? I only downloaded the HP and Tek sections.

On Fri, 25 Dec 2015 09:24:10 -0800, you wrote:

Somebody please host this as a Torrent; I hate burning out the Poles with multiple massive downloads.

Dave Wise

------------------------------------
Posted by: David <davidwhess@...>
------------------------------------


------------------------------------

Yahoo Groups Links


Re: Massive document depository

Chris Trask - N7ZWY/WDX3HLB
 

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.


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.

Chris

When the going gets weird, the weird turn pro
- Hunter S. Thompson


Re: Massive document depository

 

I used Teleport Pro to replicate the sections I was interested in
locally duplicating the directory structure on the server. This is a
pretty standard procedure for duplicating a web site for local
browsing.

On 25 Dec 2015 09:03:10 -0800, you wrote:

There's a plugin for Firefox called "DownThemAll" that will happily do exactly that.


---In TekScopes@..., <grbosworth@...> wrote :

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


Re: Massive document depository

 

I can host it as a torrent for an extended time but what part do you
want? I only downloaded the HP and Tek sections.

On Fri, 25 Dec 2015 09:24:10 -0800, you wrote:

Somebody please host this as a Torrent; I hate burning out the Poles with multiple massive downloads.

Dave Wise


Re: Massive document depository

Dave Daniel
 

With Firefox, the "Dowloadthemall" add-on allows selective bulk downloading.

"Physics always wins"

On Dec 25, 2015, at 10:29, Peter Gottlieb hpnpilot@... [TekScopes] <TekScopes@...> wrote:

Xmodem, Ymodem etc are nice for transferring files over serial port kinds of
links, for example, transferring firmware files to devices for reflashing.

Over the net there are more appropriate options and in this case you want to
"walk" the directories so something like the "wget -r" (look up the -r switch)
is the right tool.

On 12/25/2015 11:40 AM, Gary Robert Bosworth grbosworth@... [TekScopes] wrote:

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@... [TekScopes] <
TekScopes@...> wrote:



On Thu, 24 Dec 2015, Gary Robert Bosworth grbosworth@...
[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@... [TekScopes]
<
TekScopes@...> 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@... [mailto:TekScopes@...]
Sent: Thursday, December 24, 2015 8:12 AM
To: TekScopes@...
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. *
******************************************************************

--
Gary Robert Bosworth
grbosworth@...
Tel: 310-317-2247

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


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


Re: Massive document depository

Peter Gottlieb
 

Xmodem, Ymodem etc are nice for transferring files over serial port kinds of links, for example, transferring firmware files to devices for reflashing.

Over the net there are more appropriate options and in this case you want to "walk" the directories so something like the "wget -r" (look up the -r switch) is the right tool.

On 12/25/2015 11:40 AM, Gary Robert Bosworth grbosworth@... [TekScopes] wrote:

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@... [TekScopes] <
TekScopes@...> wrote:



On Thu, 24 Dec 2015, Gary Robert Bosworth grbosworth@...
[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@... [TekScopes]
<
TekScopes@...> 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@... [mailto:TekScopes@...]
Sent: Thursday, December 24, 2015 8:12 AM
To: TekScopes@...
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. *
******************************************************************

--
Gary Robert Bosworth
grbosworth@...
Tel: 310-317-2247



Re: Massive document depository

Dave Wise
 

Somebody please host this as a Torrent; I hate burning out the Poles with multiple massive downloads.

Dave Wise

________________________________________
From: TekScopes@... [TekScopes@...]
Sent: Thursday, December 24, 2015 11:42 PM
To: Gary Robert Bosworth grbosworth@... [TekScopes]
Subject: Re: [TekScopes] Massive document depository

On Thu, 24 Dec 2015, Gary Robert Bosworth grbosworth@... [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@... [TekScopes] <
TekScopes@...> 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@... [mailto:TekScopes@...]
Sent: Thursday, December 24, 2015 8:12 AM
To: TekScopes@...
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. *
******************************************************************


------------------------------------
Posted by: Sergey Kubushyn <ksi@...>
------------------------------------


------------------------------------

Yahoo Groups Links


Re: Replacing tantalum capacitors with ceramic capacitors

vdonisa
 

I think LDO's are over used these days. They were "invented" for the specific purpose of powering low voltage high current circuits (5V or less). Let's say you need 3V of overhead for a classic regulator to work properly, and you power a 3.3V circuit - then you notice that you dissipate about the same power on the regulator as on the rest of the circuit! So here we go in a race to lower the voltage drop, at the expense of stability et all. Enter the LDO world.

I miss the good old days of +-15V circuits. With 18V transformers and 7815s, the regulators would dissipate just a fraction of the total power, stable and all. Not to mention that some of those good old +-15V op amps are unmatched in performance by their 5V single supply brethren.

Now why someone would use an LDO in a high voltage circuit totally beats me. I see it done regularly by audio aficionados replacing 78xx with LT1086 - probably on the belief that if it's newer and more expensive it must be better. A cursory look at the specs would show that they actually lose both on noise and stability.

---In TekScopes@..., <yachadm@...> wrote :

I learnt about the requirement for High-ESR caps in LDO circuits, the practical way.

About 10 years ago, I had just recapped an APC 2000VA UPS, which had required about 60 caps (Panasonic FM Low-ESR), and I was very proud of my work, as I stood back and admired it before switching on.

72181 - 72200 of 194681