Date   

Re: Dallas NVRAM

Dewey Wyatt
 

If they are from a 2430a the battery is inside the chip 2430 had external
battery i have heard some late 2430,s had the same as the a series

On Fri, Oct 23, 2020, 1:06 PM zenith5106 <hahi@telia.com> wrote:

I had in my used parts bin two DALLAS DS1235ABW which I'm pretty sure came
from the CPU board of a scrapped later 2400 DSO, I'm not sure which though.
On a 2430A B030000-up they are A12U350 and A12U664. In an early service
manual
they are specified as DS1235BWL with P/N 156-3870-00. In a later manual
they are
DS1230AB with the same P/N. I thought the W indicates a Vcc of 3.3V, at
least that is
true for other DS-chips. I haven't been able to find a data sheet for the
W-version.
Does anyone have the right data sheet or know if this chip actually is for
3.3V ?
If in fact it is it seems wrong that it was used in a 5V environment. For
example a
DS1230W has max Vcc specified as 3.6V

/Håkan






Re: Is it possible to start a TDS784D scope with a blank DS1486?

Rogerio O
 

I guess I would need a brief tutorial to write it back with the floppy tool also.
While I was using the TdsNvramFloppyTools I have received some write errors in most of the trials.
Is it possible that my floppy drive is broken?
I have seen some kits that replace the floppy by a UBS port.
Is it possible to use this device to make/restore backups?
Thank you


Re: Is it possible to start a TDS784D scope with a blank DS1486?

Rogerio O
 

Hi Eric,
Is it possible to send me the file?
I am almost certain that the one I have saved are corrupt.
Also, Can you give me a brief tutorial of how to burn the file to the chip using the TL866?
Is it necessary to start with address D0 (hex)?
Why is that there are several posts saying that you have to try several times "until it works"?
Thanks,
Roger


Dallas NVRAM

 

I had in my used parts bin two DALLAS DS1235ABW which I'm pretty sure came
from the CPU board of a scrapped later 2400 DSO, I'm not sure which though.
On a 2430A B030000-up they are A12U350 and A12U664. In an early service manual
they are specified as DS1235BWL with P/N 156-3870-00. In a later manual they are
DS1230AB with the same P/N. I thought the W indicates a Vcc of 3.3V, at least that is
true for other DS-chips. I haven't been able to find a data sheet for the W-version.
Does anyone have the right data sheet or know if this chip actually is for 3.3V ?
If in fact it is it seems wrong that it was used in a 5V environment. For example a
DS1230W has max Vcc specified as 3.6V

/Håkan


Re: 577D1 Phantom base current

Jack2015
 

Yes,You are right!

I suspected the "Aid" button because the photos DW provided have shown the traces moved above zero line with the "Aid" button depressed,
hope it's just an operation issue.

https://groups.io/g/TekScopes/photo/255563/1?p=Created,,,100,2,0,0
https://groups.io/g/TekScopes/photo/255563/0?p=Created,,,100,2,0,0


Re: Air filters for big 500 series scopes

snapdiode
 

...or plugins.


Re: Sphere's Holiday Stuff Season is now open....

Jared Cabot
 

I'd love to buy some stuff, but unfortunately shipping quotes all the way to Japan have always been prohibitively expensive. :P :D


Re: Is it possible to start a TDS784D scope with a blank DS1486?

EricJ
 

From what I understand some of the addresses are unused. It is possible
that they change randomly and so are different every time the NVRAM is
read. I have used the TDS Floppy Tools also - to both read and write my own
TDS scope and it worked perfectly for me. I think you should have no
problem to boot the scope with a blank NVRAM - then you ought to be able to
do a restore from one of your backups. Alternatively, program the NVRAM
with the TL before booting and see what happens. You can always re-write
with the floppy. (Thanks flyte!) If you need an ACQ or NVRAM backup let us
know - I have the backups from my TDS754D (converted to TDS784D).

--Eric

On Fri, Oct 23, 2020, 7:49 AM Rogerio O <rodd414@gmail.com> wrote:

Dear all,
I bought the "functional replacement" chips of the Dallas DS1650 and
DS1486 to replace the ones in my scope.
I have downloaded the the TdsNvramFloppyTools and read the 1486 several
times before trying to desolder it.
Unfortunately, when I compare the data, there were differences in data
located at addresses higher than D hex.
So I unsoldered the chip and read the data with a TL866A several times but
the same thing happened.
I could not find any copy of the NVRAM content for my scope anywhere on
the internet, so my question is:
Is it possible to boot the scope with a blank DS1486?
Thank you






Re: 577D1 Phantom base current

Michael W. Lynch
 

On Fri, Oct 23, 2020 at 06:26 AM, Jack2015 wrote:


when the "AID" button is off and "zero" button is off you can turn the knob to
adjust the number of steps.
The Aid and Offset buttons are independent of the Steps Knob. You may select any number of steps (1 to 9), regardless of how the Offset controls are selected or adjusted. Even with the offset control "On" and in the "Aid" position, with the offset control at "Zero", your baseline trace should and must remain at the bottom or top "zero" line. If you adjust the Offset Control vernier above Zero, then the base trace along with all subsequent traces will move up or down, depending on whether the "oppose" or "aid" button is depressed. At least, this is my understanding and how my 577 and both 576 curve Tracers operate.

--
Michael Lynch
Dardanelle, AR


Is it possible to start a TDS784D scope with a blank DS1486?

Rogerio O
 

Dear all,
I bought the "functional replacement" chips of the Dallas DS1650 and DS1486 to replace the ones in my scope.
I have downloaded the the TdsNvramFloppyTools and read the 1486 several times before trying to desolder it.
Unfortunately, when I compare the data, there were differences in data located at addresses higher than D hex.
So I unsoldered the chip and read the data with a TL866A several times but the same thing happened.
I could not find any copy of the NVRAM content for my scope anywhere on the internet, so my question is:
Is it possible to boot the scope with a blank DS1486?
Thank you


Re: Keller's CRT publications - Re: [TekScopes] Tektronix 2465A noise on readout

Peter H
 

Link replaced!
Cheers


Re: 577D1 Phantom base current

Jack2015
 

DW,

The offset is adjustable by the Offset Multi knob(the big metal knob) when "AID" button is on and "Zero" button is off,
when the "AID" button is off and "zero" button is off you can turn the knob to adjust the number of steps.
Did you try to turn the "AID" button off?


Re: smd precision resistor "paint layer" peeled off while soldering *** advice needed ***

Rogerio O
 

Thank you Chuck.
The parts have just arrived and I will post the results after replacing the damaged parts


Re: 7854 to 7804N Conversion PCB (K7-1286-XA). TOPIC WAS: 067-0912-00 needed

 

is that the same as the 7854 analogue test board?

Is so could be interested - what is the likely price?

David

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Dennis Tillman W7pF
Sent: 22 October 2020 22:28
To: TekScopes@groups.io
Subject: [TekScopes] 7854 to 7804N Conversion PCB (K7-1286-XA). TOPIC WAS: 067-0912-00 needed

Hi Clark,
No. I have been working on something else I need much more. It will be done in 2 weeks and then I am free to start on something else.

I would like to make the 7804 Conversion board but first I need to get 5 other people willing to buy the boards which would help to justify the cost of laying out the PCB and purchasing the PC boards.

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Clark Foley
Sent: Wednesday, October 21, 2020 12:17 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] 067-0912-00 needed

Dennis,

Did you ever make duplicates of that early 7804N conversion board (K7-1286-XA)?

Clark







--
Dennis Tillman W7pF
TekScopes Moderator


Re: 7A26 edge distortion

Roger Evans
 

Raymond,

My PG506 (very early model) has a similar behaviour but it is the edge moving towards ground which is cleaner so the -ve output has a clean 'positive' edge.

Roger


Re: Is it possible to test 2465B power supply boards outside of the scope?

Chuck Harris
 

Absolutely! I do it with every power supply that I recap
for myself, or my customers. I wouldn't dream of putting
a freshly fixed power supply in an instrument without testing
it first.

-Chuck Harris

Grayson Evans wrote:

OK, Thank you, I think I got it.
I need to load the 5VD line with t he 2 ohm load, and the regulator outputs with 100 ohms (or whatever for 10-20 mA).
Put 120V to J205/204, short J206/207, turn on the switch and check for smoke!
I will probably build a little test board with the resistors and wires to connect to various pins on the board.

So you have done this? and it worked?






Re: Is it possible to test 2465B power supply boards outside of the scope?

Grayson Evans
 

OK, Thank you, I think I got it.
I need to load the 5VD line with t he 2 ohm load, and the regulator outputs with 100 ohms (or whatever for 10-20 mA).
Put 120V to J205/204, short J206/207, turn on the switch and check for smoke!
I will probably build a little test board with the resistors and wires to connect to various pins on the board.

So you have done this? and it worked?


7854 to 7804N Conversion PCB (K7-1286-XA). TOPIC WAS: 067-0912-00 needed

 

Hi Clark,
No. I have been working on something else I need much more. It will be done in 2 weeks and then I am free to start on something else.

I would like to make the 7804 Conversion board but first I need to get 5 other people willing to buy the boards which would help to justify the cost of laying out the PCB and purchasing the PC boards.

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Clark Foley
Sent: Wednesday, October 21, 2020 12:17 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] 067-0912-00 needed

Dennis,

Did you ever make duplicates of that early 7804N conversion board (K7-1286-XA)?

Clark







--
Dennis Tillman W7pF
TekScopes Moderator


Sphere's Holiday Stuff Season is now open....

 

Let's face it, right about now, EVERYBODY needs some cheering up. We have put all kinds of goodies on the Holiday Stuff Season page, HP/Agilent, Tek, Fluke and more, plus all kinds of amazing, dirt cheap, hard to find parts. Don't miss the CRT and Free Stuff sections too. Summer items have been discounted to make them fit comfortably in your Christmas stocking. Some great deals on genuine Tek probes too.

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Please drop by for some cheering up, we're just sorry we can't welcome you in person.
New items get added every day, and the page is open until January 5th. Every Stuff Season shipment gets a free
goodie bag included, you never know what may be in it!

All the best,
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Sphere Research Corp.
https://www.sphere.bc.ca/test/


Re: 7A26 edge distortion

 

On Thu, Oct 22, 2020 at 09:57 PM, Roger Evans wrote:


I interpreted your first post to mean that only the falling edge was
distorted, that was the reason for thinking it couldn't be only the passive
(or more accurately the linear) components at fault.

Anyway it is good to be warned that the caps are so unreliable.
I later realized that I should have mentioned that both the falling and rising edges were affected equally or only mentioned "edge". In my first fast edge generator (a PG506), the falling edge was a bit cleaner than the rising edge, which resulted in my continued preference for using a falling edge in measurements using a PG506. I didn't realize that this might from time to time cause confusion.
Your post (msg #172512), made clear the significance of the detail / omission.

I ended up finding 12 out of 14 trimcaps in this 7A26 - my most recent - being defective! The remaining two trimcaps have a slightly different design.

Raymond

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