Date   
Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Paul Amaranth
 

Email addresses are of the form

<ID> @ <Organization>

If it isn't in that form it's not an email address. Period.
Color has no meaning for email.

Groups.io disguises email addresses so harvesting of email address from
the public website is more difficult. This is a good thing as it
prevents some amount of spam.

I generally do not use the web interface, but I think the assumption
here is you would go to the member's profile and either get the
correct email address from there or send them a private message.

If you got the list as an email instead of looking at the website,
email addresses would be visible since they are not redacted.

I think groups.io did a really nice job with that.

Paul

On Fri, Jan 17, 2020 at 06:42:49AM -0800, Lawrance A. Schneider wrote:
Same happens to me.
further, what it the difference between @Dennis_Tillman_W&PF and the same thing in blue??? I saw a missive saying to use the above in blue and the same thing in black. I again tried each at PayPal and got the same thing asking for an :an error saying please enter valid email, name or mobile phone m=number.
I know I'm getting old, but what is going on???????

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

Re: 2445 EPROMs

Mark Litwack
 

Hi Chuck and Chris,

The external clock input on the 6802 is divided internally by four to create an internal two-phase clock (one phase is output as signal "E"). So, with a 5MHz input, the cycle time is actually 800ns, which well within range of the Intel D27128 with 250ns access time I mentioned before.

There is also the NOP exerciser which can be enabled with jumper P503. This is good for getting to the bottom of possible processor and/or bus buffer issues by looking at E, address lines, and other signals as the processor is looping. Its operation is described in the service manual.

I do recall one instance of a bad processor, but granted, they are rare.

-mark

Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Lawrance A. Schneider
 

Same happens to me.
further, what it the difference between @Dennis_Tillman_W&PF and the same thing in blue??? I saw a missive saying to use the above in blue and the same thing in black. I again tried each at PayPal and got the same thing asking for an :an error saying please enter valid email, name or mobile phone m=number.
I know I'm getting old, but what is going on???????

larry

Re: 7A26 transient response 5 nS all atten

Jean-Paul
 

Colin! Many thanks, My manuals cover only B serials. Changes in Guernsey version?

All: My first reaction was calibration; page 5-7 sec 8, High Freq compensation.
But there are 10 adjustments per channel listed!
What order of adjustment? Which one might be for just the first 5-10 nS?

Mille mercis,

Jon

Re: Remote CSA803 / HP1180x programming (yet again)

GerryR
 

It must have been "Recommended Standard," because I had (have somewhere?) a book that had 132 or so versions of the RS-232 "standard" interface. That's a lot of versions of a so-called standard!
GerryR
KK4GER

----- Original Message -----
From: "Leo Bodnar" <leo@...>
To: <TekScopes@groups.io>
Sent: Friday, January 17, 2020 8:18 AM
Subject: Re: [TekScopes] Remote CSA803 / HP1180x programming (yet again)


What I really like about RS-232 is that RS stands for "Recommended Standard"!
Leo
On Fri, Jan 17, 2020 at 10:59 AM, Roy Morgan wrote:
Among my coworkers were the folks who organized and chaired the international committees that wrote the standards. (One fellow had chaired the committee that developed RS-232.)

Re: "liquid crystal driver" sighting

Glenn Little
 

I am currently working on drawing a schematic. Slow going. Hope to have it done and posted sometime in February.

Glenn

On 1/17/2020 3:04 AM, p mc wrote:
Thank you, Mr. Little, for starting to fill in a blank spot on the map.

At TekWiki I cleaned out the obsolete stub text and poor front panel image.


--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

Re: Looking for cabinet top for 465M

Bert Haskins
 

On 1/16/2020 7:29 PM, KB6NAX wrote:
I'll buy a junked 465M if it will go for cheap just to get a top cover. Just let me know. Thanks. -Ard
Where are you located?

Re: Remote CSA803 / HP1180x programming (yet again)

Leo Bodnar
 

What I really like about RS-232 is that RS stands for "Recommended Standard"!
Leo

On Fri, Jan 17, 2020 at 10:59 AM, Roy Morgan wrote:
Among my coworkers were the folks who organized and chaired the international committees that wrote the standards. (One fellow had chaired the committee that developed RS-232.)

Re: 7A26 transient response 5 nS all atten

Colin Herbert
 

Hi,
I, too, have a 7A26 with no letter at the front of the serial-number (102925). The label with this serial-number on it also identifies the plug-in as having been manufactured in Tektronix, Guernsey, which is why there is no "B" or "H" in front of the serial-number.
My manual, though originally produced in Beaverton (as I think all may have been), has a page in the "Change Information" section at the back referring to changes to Guernsey-produced 7A26s from tentative S/N 100396 and 100777.
I don't know how much use this will be to you, but I also have a source of the ICs used in the 7A26 (unless they have all been sold). They don't usually fail, but swapping them between channels (they are plug-in but be careful of bending the legs) is a pretty simple way of verifying them.
There are also a couple of resistors, one in each channel, which are at about their wattage limit, get hot and sometimes change value because of this. They are R1327 and R1329 (8K2, 0.25W. Carbon comp.) and would benefit in being replaced with resistors of higher wattage.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Jean-Paul
Sent: 17 January 2020 12:20
To: TekScopes@groups.io
Subject: [TekScopes] 7A26 transient response 5 nS all atten

Hello all: My workhorse 7A26 needed rework, in 7804 mainframe.
Cleaned the AC/DC/GR contacts on attn with the iso alcohol-paper strips, and exercised some scratchy controls.
Poor fast transient response on CH2, same dip and peak ~ 5 nS at ALL V/div.

Setup: Leo Bodnar pulser 40 pS>Mini Ckt HAT-15>>Mini Ckt HAT 20>>precision 50 Ohm thru>>7A26 input
Same result if 7A26 is in L or R side 7804.
Shots are: Affected 7A26, CH2, CH1, Good 7A26 Ch2 Ch1
http://crypto-museum.org/TEK/7A26/7A26.pdf

Since the aberration is constant on every V/DIV, the attenuator and 2X amp seem to be exonerated.

Before I dare probe the CH 2 amp circuit, a few questions please:

1/ Test points mentioned on schematic are NOT in PCB photos, only the parts numbers. Need a board layout with test pts.
2/ Using normal P6137 probe. placement of ground lead ?
3/ Precautions in probing around the custom TEK hybrid ICs, eg U2350, U2450?
4/ Serial: Manual has sch versions for SN B179999 < and B180000>.
My other 7A26s have this format SN, but this has no letter, 708058. I think its a late model, but see no IC date codes.
Readout PCB is 672-0051-13 Amplifier PCB is 670-2549-21 attenuators are PN200-1442-00

Hope to receive some tips from our TEK veterans!

Jon in Paris

Re: Remote CSA803 / HP1180x programming (yet again)

Don Bitters
 

Ah yes, an impressive o-scope, that I too loved to hate.  With the right plugins it would do 20+ GHz.  My experience with them was to calibrate them - manually! for HP/Agilent.  IBM had a ton of them on their optical amp production lines.  Nobody at Tek or HP ever automated the cal procedure.  I have cal'd about 50 of the CS803's and 1180x's with the SD22 and SD24 plugins, the plugins have plugins!!!.  Through a lot of diligence and practice I could get the cal procedure down to 3.5 hrs on the mainframe and 5.5 hrs. on the plugins with full data taken.  I think the data stack for 12 ea. 11803's with plugins with 3 slots occupied with 2ea. SD24's/ plugin was over 10 in. tall. That was over a week of calibration alone at 10+ hr. days, definitely not fun.I have never heard of anyone automating the cal on these, probably too much programming effort.IBM did run them full automation on their production lines for their testing.Don Bitters

7A26 transient response 5 nS all atten

Jean-Paul
 

Hello all: My workhorse 7A26 needed rework, in 7804 mainframe.
Cleaned the AC/DC/GR contacts on attn with the iso alcohol-paper strips, and exercised some scratchy controls.
Poor fast transient response on CH2, same dip and peak ~ 5 nS at ALL V/div.

Setup: Leo Bodnar pulser 40 pS>Mini Ckt HAT-15>>Mini Ckt HAT 20>>precision 50 Ohm thru>>7A26 input
Same result if 7A26 is in L or R side 7804.
Shots are: Affected 7A26, CH2, CH1, Good 7A26 Ch2 Ch1
http://crypto-museum.org/TEK/7A26/7A26.pdf

Since the aberration is constant on every V/DIV, the attenuator and 2X amp seem to be exonerated.

Before I dare probe the CH 2 amp circuit, a few questions please:

1/ Test points mentioned on schematic are NOT in PCB photos, only the parts numbers. Need a board layout with test pts.
2/ Using normal P6137 probe. placement of ground lead ?
3/ Precautions in probing around the custom TEK hybrid ICs, eg U2350, U2450?
4/ Serial: Manual has sch versions for SN B179999 < and B180000>.
My other 7A26s have this format SN, but this has no letter, 708058. I think its a late model, but see no IC date codes.
Readout PCB is 672-0051-13 Amplifier PCB is 670-2549-21 attenuators are PN200-1442-00

Hope to receive some tips from our TEK veterans!

Jon in Paris

Re: Risetime calculator (in tekwiki)

Jean-Paul
 

I have the circular slide rule version, Tektronix Circuit Computer (TEK 003-023) circa 1961, risetime, resonance, impedance, etc.
https://vintagetek.org/tektronix-circuit-computer/

Any others have one?
Looking for another one!

Jon

Re: Risetime calculator (in tekwiki)

GerryR
 

Is there a Tek part number associated with this unit? How is it used to calculate rise time?
Thanks,
GerryR

----- Original Message -----
From: "Tim Phillips" <timexucl@...>
To: <TekScopes@groups.io>
Sent: Friday, January 17, 2020 2:32 AM
Subject: [TekScopes] Risetime calculator (in tekwiki)


from Tim P (UK)
What is this, please? It seems to be a simple analog computer, maybe with
Log pots.
In case the link doesn't work, the device is in tekwiki Other Instruments.

http://w140.com/tekwiki/wiki/Risetime_Calculator

Appears to give f = sqrt(a^2 + b^2 + c^2)

thanks
Tim P

Re: Remote CSA803 / HP1180x programming (yet again)

Roy Morgan
 

Leo,

I do remember Hays modem commands, though only dimly.

I wonder if "AT" stands for "Attention, Terminal ! ".

On a related bit of lore: while I worked at NIST, I used a bit of SQL and learned that the letters originally stood for Structured Query Language but that later the official name of the standard was changed to "Database Language SQL", with no meaning for the letters.

Among my coworkers were the folks who organized and chaired the international committees that wrote the standards. (One fellow had chaired the committee that developed RS-232.)

IBM used to mean "International Business Machines" didn't it?

And so we "Graybeards" mumble off into the mists of time. ... ...

Roy Morgan
K1LKY Western Mass

On Jan 17, 2020, at 4:31 AM, Leo Bodnar <leo@...> wrote:
...
If you are old enough - think modems Hayes AT commands.
...

Re: Risetime calculator (in tekwiki)

Leo Bodnar
 

It can be also done with linear pots and quadratic scale markings around the pot.
Or a slide rule with two sliders.
Leo

Remote CSA803 / HP1180x programming (yet again)

Leo Bodnar
 

Has anybody produced anything interesting recently for CSA803 / 1180x series that allows remote comms? Apart from screen shot capture and printing.
The talks about these instruments spring up now and then only to die again.

Here is what I have cooked up quickly to avoid facing its excruciating UI. As you can see - I don't know python (and not willing to learn it.)

http://www.leobodnar.com/pulser/

I have used Prologix for this so "++.." commands are GPIB adapter configuration. If you are old enough - think modems Hayes AT commands.

CSA803 is the instrument I love to hate. There is nothing right with it apart from its raw functionality and market abundance.
I'd like to write more code to get nicer looking charts but I have run out of patience.

Cheers
Leo

Re: Risetime calculator (in tekwiki)

Albert Otten
 

Ideally you would use pots (as variable resistors) for which the resistance increases quadratically from ccw to cw. Then compare the sum of the first 3 resistances with the 4th resistance in a bridge circuit and tune the 4th pot to zero reading. I don't think that the quadratic behavior can be approached good enough with log pots and some trimpots and extra resistors.

Albert

On Fri, Jan 17, 2020 at 08:31 AM, Tim Phillips wrote:


from Tim P (UK)
What is this, please? It seems to be a simple analog computer, maybe with
Log pots.
In case the link doesn't work, the device is in tekwiki Other Instruments.

http://w140.com/tekwiki/wiki/Risetime_Calculator

Appears to give f = sqrt(a^2 + b^2 + c^2)

thanks
Tim P

Re: "liquid crystal driver" sighting

p mc
 

Thank you, Mr. Little, for starting to fill in a blank spot on the map.

At TekWiki I cleaned out the obsolete stub text and poor front panel image.

Risetime calculator (in tekwiki)

Tim Phillips
 

from Tim P (UK)
What is this, please? It seems to be a simple analog computer, maybe with
Log pots.
In case the link doesn't work, the device is in tekwiki Other Instruments.

http://w140.com/tekwiki/wiki/Risetime_Calculator

Appears to give f = sqrt(a^2 + b^2 + c^2)

thanks
Tim P

Re: 2445 EPROMs

Chuck Harris
 

Hi Chris,

My humble apologies, the CPU uses a 5MHz square wave clock. The
processor is a 68A02.

Early microprocessors usually took several cycles per instruction.
5, I think was the minimum for the 6800 family... leading to a 200ns
requirement on access time.

It has been a long, long, time since I last had to design with, or
debug a 6800 series microprocessor. I have never found one bad in
all of the 2465's I have calibrated... actually, I have never found
one bad in anything I have worked on.

200ns is what tektronix used as the access time for the RAM, and EPROM.

I would put the probably that the EPROM is good at 99.999%... unless
you have had a power supply problem that has elevated the 5V to above
7V... in which case, most everything on the CPU card will be bad.

Look instead at the jumpers on the board. There are test jumpers that
will prevent boot up.

Also, look at the reset circuitry. A single bad part, and the CPU
will never get out of power on reset. Pay particular attention to the
0.1uf and 2.2M resistors that provide the timing.

Assuming that there is CPU activity, there should be an LED lit on the
front panel indicating the failure cause.

-Chuck Harris

christopherbath@... wrote:

Hi Chuck,

Looking at the schematics the processor seems to be driven by a 5MHz clock (the clock being generated by a 10MHz crystal). According to the datasheet for the 6802 the maximum clock frequency is 4MHz so I am not sure what is going on here? Possibly the processor is a MC68A02 or MC68B02. I guess you would need to look into the bus timing is more detail to work out the access time requirements for the ROM but agree that 250ns or less would be more than enough.

The 2445 won’t power up properly. It seems to me as if the processor hangs on start-up. Given that the scope seems to do slightly different things on start-up I am suspicious about the EPROMs that would have been programmed about 30 years or more ago. The power supply rails all seem to be ok so I think the EPROMs are the next place to be looking. Perhaps I should also check the clock and reset for the microprocessor.

Regards,

Chris