开云体育

I would avoid the traces going between the pads of SMD resistors, R12 looks
particularly egregious. Also I would space R6,8,10,11 uniformly with room
to work. Sure both these would be fine for commercial pick ‘n place /
reflow, but you want it to be super easy for hand assembly, possibly with
suboptimal tools. You have real estate to burn (understatement of the
century), no reason to make assembly tricky.

Also consider making the power traces wider, and/or using a ground pour.

Just my 2c, since you did ask - not intended to start any flame wars.
I am sure it would work as it is.

On Thu, Aug 26, 2021 at 21:59 <Zentronics42@...> wrote:

I think I have gotten to the point where I have a potential PCB for 7854
test card. If there are no no glaring errors the next step will be to get
some spun up and working assembling one for testing. After laying it out I
realized I made the layout much harder then it needed to be because I fixed
the power net issues and biased to surface mount parts. Nothing but test
points are running off the digital supply. I also added some decoupling
capacitors that were not on the schematic to smooth out the power supply
rails values are still up in the air but I am thinking around 100uf should
be good. Ill give it a bit of time if anyone wants to look at the layout.
then I will spin a batch and work on notating the silk screen and make it a
more polished board. The card edge foot prints were extremely helpful.
Thanks for the scripted foot print. If anyone would like the cad files I
can upload a zip. There are some custom foot prints that are needed for the
Tek connectors. The layout was done in Kicad 5.99





--

Andy

I think I have gotten to the point where I have a potential PCB for
7854 test card. If there are no no glaring errors the next step will
be to get some spun up and working assembling one for testing. After
laying it out I realized I made the layout much harder then it needed
to be because I fixed the power net issues and biased to surface mount
parts. Nothing but test points are running off the digital supply. I
also added some decoupling capacitors that were not on the schematic
to smooth out the power supply rails values are still up in the air
but I am thinking around 100uf should be good. Ill give it a bit of time if anyone wants to look at the layout.
then I will spin a batch and work on notating the silk screen and make
it a more polished board. The card edge foot prints were extremely helpful.
Thanks for the scripted foot print. If anyone would like the cad files
I can upload a zip. There are some custom foot prints that are needed
for the Tek connectors. The layout was done in Kicad 5.99





--

I have uploaded iteration 3 of the test card. I do need to pour the
fill zones on the board but changing the resister to THT parts helped
with the routing immensely. I also bumped up the thickness of the
traces and I also took care with the 90 degree corners. If the board
looks good and there is no gross mistakes I will clean up the silk
screen, get a few boards spun, and move on to testing.





--

I have uploaded iteration 3 of the test card. I do need to pour the
fill zones on the board but changing the resister to THT parts helped
with the routing immensely. I also bumped up the thickness of the
traces and I also took care with the 90 degree corners. If the board
looks good and there is no gross mistakes I will clean up the silk
screen, get a few boards spun, and move on to testing.





--

I used a mix for a few reasons. I wanted to keep to a 2 layer board to
keep the cost down. The THT resisters and pins solved some unique
challenges to the layout. I was able to pull the board off with zero
vias. Also this needs to be a double sided board due to the card edge
connectors. An additional point is some of the connections on to the
scope are on the back of the board. The pull up resisters one the
logic lines helped with routing check out the difference between rev 1
and rev 2 of the PCB's especially in the digital section. The first
run out routing was awful, and I am saying that as the one that
created it. In the triggering section which is the only high speed
signals on the board I stayed with SMD parts to keep the inductance
down and help with the edges The transistors I have pick can run about
800 Mhz. Not crazy fast but not TTL slow either. These need to be
better than
400 Mhz as that is what the frame is. The card is used to do a thermal
compensation of the vertical amps in the scope when it is up and running.
Everything else on the board is just termination and test points. The
2 critical places are the IC's and the pre trigger section. Also due
to needing Tek connections to make the board work it will have to be
hand assembled in the lab I cant get a place to fab it for me. At
least not fully.

I have uploaded what I hope will be a final layout for a new version
of the
67-0912-00 This board has the decoupling caps in place for the IC's as
well as the ground planes and all the test points. I will be working
on a shopping list (BOM) for the parts needed. Then boards spun and testing.

A huge thanks to Andy, Ke-Fong lin, and Holger for helping me get this
project off the ground and on to a PCB. Your assistance and input is
greatly appreciated and immeasurably helpful in getting the layout to
this point.

As part of my repair and calibration of my 7854 I do have 2 questions
. I have a 7854 that has been damaged in shipping the digital section
is very compressed, but I have ruled out the tube and analog parts of
the scope as they display correctly. It is just the stored wave form
and the readout that is weird. I am curious if any one has seen this
before and knows where to look.
Also is there information about upgrading the firmware for the 7854?
My working one is a low serial number 41838 so I know it will suffer
from rom rot sooner or later so I would like to run the best firmware
on some newer chips. I am not sure if it matters but both units are 2D
so they have the expanded memory option.

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Nico
F4IAN
Sent: Friday, September 17, 2021 10:49 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

Hello
Maybe a silly question that has already been asked before, why did you
use through-hole components and not SMD ? OK, I admit, area is not an
issue here.

Nicolas
________________________________
From: [email protected] <[email protected]> on behalf of
Zentronics42@... <Zentronics42@...>
Sent: Friday, September 17, 2021 15:50
To: [email protected] <[email protected]>
Subject: Re: [TekScopes] Recreating an old board for the 7854

Andy,
That was the plan. If the digital section looked good I am
going to add the decoupling caps and then do a ground pour. Then it
will be off to fab. I am even adding a bit more decoupling then what
was originally called for in the schematic. With a few 47uf bulk caps for the board.

Zen

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Andy
Warner
Sent: Friday, September 17, 2021 12:59 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

I did not notice it before, and it apparently was missing from the
original design, but I would consider adding more decoupling caps
close to the logic chips. Plenty of 0.1uF caps sprinkled around is
cheap insurance against glitches.

Apart from that, the layout does look better.

On Wed, Sep 15, 2021 at 20:58 <Zentronics42@...> wrote:

I have uploaded iteration 3 of the test card. I do need to pour the
fill zones on the board but changing the resister to THT parts
helped with the routing immensely. I also bumped up the thickness of
the traces and I also took care with the 90 degree corners. If the
board looks good and there is no gross mistakes I will clean up the
silk screen, get a few boards spun, and move on to testing.





--

Andy






















--

Andy,
I got the u520 pad to connect. It did not line the tract running
from the bypass cap over to the pin for some reason it is all ground but it
did not want to connect to the ground plane. I am going to go with weird
software quirk. In terms of the routing between smd parts. I will see what
I can do to sharpen the pencil come more. Those 3 traces are continuing to
cause me some issues. But I will see what I come up with. Part of this is I
am being stubborn and not wanting to break down and use a via or 2.
Currently the layout doesn’t have any so I am trying to keep it that way.
Might be a bit unrealistic but I am getting closer.

Eric

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Andy Warner
Sent: Monday, September 20, 2021 1:34 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

Something is not right with the ground pour in the rev 4 drawing you
uploaded. For instance pin 7 of U520 only connects to the ground plane
indirectly. I am not a kicad user, so I cannot begin to suggest a root
cause or remedy, I am afraid.

You are also back to routing between SMT pads with rev 4 (I just realized
that I replied to the file upload message, so you might not have seen it,
repeating here in case you missed it.)

On Sun, Sep 19, 2021 at 22:59 <Zentronics42@...> wrote:

I used a mix for a few reasons. I wanted to keep to a 2 layer board to
keep the cost down. The THT resisters and pins solved some unique
challenges to the layout. I was able to pull the board off with zero
vias. Also this needs to be a double sided board due to the card edge
connectors. An additional point is some of the connections on to the
scope are on the back of the board. The pull up resisters one the
logic lines helped with routing check out the difference between rev 1
and rev 2 of the PCB's especially in the digital section. The first
run out routing was awful, and I am saying that as the one that
created it. In the triggering section which is the only high speed
signals on the board I stayed with SMD parts to keep the inductance
down and help with the edges The transistors I have pick can run about
800 Mhz. Not crazy fast but not TTL slow either. These need to be
better than
400 Mhz as that is what the frame is. The card is used to do a thermal
compensation of the vertical amps in the scope when it is up and running.
Everything else on the board is just termination and test points. The
2 critical places are the IC's and the pre trigger section. Also due
to needing Tek connections to make the board work it will have to be
hand assembled in the lab I cant get a place to fab it for me. At
least not fully.

I have uploaded what I hope will be a final layout for a new version
of the
67-0912-00 This board has the decoupling caps in place for the IC's as
well as the ground planes and all the test points. I will be working
on a shopping list (BOM) for the parts needed. Then boards spun and

testing.

A huge thanks to Andy, Ke-Fong lin, and Holger for helping me get this
project off the ground and on to a PCB. Your assistance and input is
greatly appreciated and immeasurably helpful in getting the layout to
this point.

As part of my repair and calibration of my 7854 I do have 2 questions
. I have a 7854 that has been damaged in shipping the digital section
is very compressed, but I have ruled out the tube and analog parts of
the scope as they display correctly. It is just the stored wave form
and the readout that is weird. I am curious if any one has seen this
before and knows where to look.
Also is there information about upgrading the firmware for the 7854?
My working one is a low serial number 41838 so I know it will suffer
from rom rot sooner or later so I would like to run the best firmware
on some newer chips. I am not sure if it matters but both units are 2D
so they have the expanded memory option.

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Nico
F4IAN
Sent: Friday, September 17, 2021 10:49 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

Hello
Maybe a silly question that has already been asked before, why did you
use through-hole components and not SMD ? OK, I admit, area is not an
issue here.

Nicolas
________________________________
From: [email protected] <[email protected]> on behalf of
Zentronics42@... <Zentronics42@...>
Sent: Friday, September 17, 2021 15:50
To: [email protected] <[email protected]>
Subject: Re: [TekScopes] Recreating an old board for the 7854

Andy,
That was the plan. If the digital section looked good I am
going to add the decoupling caps and then do a ground pour. Then it
will be off to fab. I am even adding a bit more decoupling then what
was originally called for in the schematic. With a few 47uf bulk caps

for the board.

Zen

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Andy
Warner
Sent: Friday, September 17, 2021 12:59 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

I did not notice it before, and it apparently was missing from the
original design, but I would consider adding more decoupling caps
close to the logic chips. Plenty of 0.1uF caps sprinkled around is
cheap insurance against glitches.

Apart from that, the layout does look better.

On Wed, Sep 15, 2021 at 20:58 <Zentronics42@...> wrote:

I have uploaded iteration 3 of the test card. I do need to pour the
fill zones on the board but changing the resister to THT parts
helped with the routing immensely. I also bumped up the thickness of
the traces and I also took care with the 90 degree corners. If the
board looks good and there is no gross mistakes I will clean up the
silk screen, get a few boards spun, and move on to testing.





--

Andy






















--

Andy

Andy,
I got the u520 pad to connect. It did not line the tract
running from the bypass cap over to the pin for some reason it is all
ground but it did not want to connect to the ground plane. I am going
to go with weird software quirk. In terms of the routing between smd
parts. I will see what I can do to sharpen the pencil come more. Those
3 traces are continuing to cause me some issues. But I will see what I
come up with. Part of this is I am being stubborn and not wanting to break down and use a via or 2.
Currently the layout doesn’t have any so I am trying to keep it that way.
Might be a bit unrealistic but I am getting closer.

Eric

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Andy
Warner
Sent: Monday, September 20, 2021 1:34 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

Something is not right with the ground pour in the rev 4 drawing you
uploaded. For instance pin 7 of U520 only connects to the ground plane
indirectly. I am not a kicad user, so I cannot begin to suggest a root
cause or remedy, I am afraid.

You are also back to routing between SMT pads with rev 4 (I just
realized that I replied to the file upload message, so you might not
have seen it, repeating here in case you missed it.)

On Sun, Sep 19, 2021 at 22:59 <Zentronics42@...> wrote:

I used a mix for a few reasons. I wanted to keep to a 2 layer board
to keep the cost down. The THT resisters and pins solved some unique
challenges to the layout. I was able to pull the board off with zero
vias. Also this needs to be a double sided board due to the card
edge connectors. An additional point is some of the connections on
to the scope are on the back of the board. The pull up resisters one
the logic lines helped with routing check out the difference between
rev 1 and rev 2 of the PCB's especially in the digital section. The
first run out routing was awful, and I am saying that as the one
that created it. In the triggering section which is the only high
speed signals on the board I stayed with SMD parts to keep the
inductance down and help with the edges The transistors I have pick
can run about
800 Mhz. Not crazy fast but not TTL slow either. These need to be
better than
400 Mhz as that is what the frame is. The card is used to do a
thermal compensation of the vertical amps in the scope when it is up and running.
Everything else on the board is just termination and test points.
The
2 critical places are the IC's and the pre trigger section. Also due
to needing Tek connections to make the board work it will have to be
hand assembled in the lab I cant get a place to fab it for me. At
least not fully.

I have uploaded what I hope will be a final layout for a new version
of the
67-0912-00 This board has the decoupling caps in place for the IC's
as well as the ground planes and all the test points. I will be
working on a shopping list (BOM) for the parts needed. Then boards
spun and

testing.

A huge thanks to Andy, Ke-Fong lin, and Holger for helping me get
this project off the ground and on to a PCB. Your assistance and
input is greatly appreciated and immeasurably helpful in getting the
layout to this point.

As part of my repair and calibration of my 7854 I do have 2
questions . I have a 7854 that has been damaged in shipping the
digital section is very compressed, but I have ruled out the tube
and analog parts of the scope as they display correctly. It is just
the stored wave form and the readout that is weird. I am curious if
any one has seen this before and knows where to look.
Also is there information about upgrading the firmware for the 7854?
My working one is a low serial number 41838 so I know it will suffer
from rom rot sooner or later so I would like to run the best
firmware on some newer chips. I am not sure if it matters but both
units are 2D so they have the expanded memory option.

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Nico
F4IAN
Sent: Friday, September 17, 2021 10:49 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

Hello
Maybe a silly question that has already been asked before, why did
you use through-hole components and not SMD ? OK, I admit, area is
not an issue here.

Nicolas
________________________________
From: [email protected] <[email protected]> on behalf of
Zentronics42@... <Zentronics42@...>
Sent: Friday, September 17, 2021 15:50
To: [email protected] <[email protected]>
Subject: Re: [TekScopes] Recreating an old board for the 7854

Andy,
That was the plan. If the digital section looked good I am
going to add the decoupling caps and then do a ground pour. Then it
will be off to fab. I am even adding a bit more decoupling then what
was originally called for in the schematic. With a few 47uf bulk
caps

for the board.

Zen

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Andy
Warner
Sent: Friday, September 17, 2021 12:59 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

I did not notice it before, and it apparently was missing from the
original design, but I would consider adding more decoupling caps
close to the logic chips. Plenty of 0.1uF caps sprinkled around is
cheap insurance against glitches.

Apart from that, the layout does look better.

On Wed, Sep 15, 2021 at 20:58 <Zentronics42@...> wrote:

I have uploaded iteration 3 of the test card. I do need to pour
the fill zones on the board but changing the resister to THT parts
helped with the routing immensely. I also bumped up the thickness
of the traces and I also took care with the 90 degree corners. If
the board looks good and there is no gross mistakes I will clean
up the silk screen, get a few boards spun, and move on to testing.





--

Andy






















--

Andy

On Sep 20, 2021, at 15:31, Andy Warner <andyw@...> wrote:

?Ship it.

On Mon, Sep 20, 2021 at 14:04 <Zentronics42@...> wrote:

I got the fix in. Kicad is weird if anything moves you need to hide and
reapply the ground planes to get them to reconnect. Also the footprints of
some of the IC's power and grounds nets are not baked in to the foot prints
so I have to set them manually. The ground planes simplified some things
and moving some parts around was able to get the layout complete. I am
currently up to REV6.

Thanks again for all the input.

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Andy Warner
Sent: Monday, September 20, 2021 9:09 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

Vias are free and reliable for signals at the speeds of this board. Use
them, is my advice.

Also, I suspect there is a systemic problem with the connectivity to the
ground pour, I used U520 as an example, as best I can tell the same applies
to the power grounds of other chips too. I would look for the systemic fix
rather thank the kludge (but I'm not the one who has to spend the time
finding that systemic fix.)

On Mon, Sep 20, 2021, 07:53 <Zentronics42@...> wrote:

Andy,
I got the u520 pad to connect. It did not line the tract
running from the bypass cap over to the pin for some reason it is all
ground but it did not want to connect to the ground plane. I am going
to go with weird software quirk. In terms of the routing between smd
parts. I will see what I can do to sharpen the pencil come more. Those
3 traces are continuing to cause me some issues. But I will see what I
come up with. Part of this is I am being stubborn and not wanting to

break down and use a via or 2.

Currently the layout doesn’t have any so I am trying to keep it that way.
Might be a bit unrealistic but I am getting closer.

Eric

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Andy
Warner
Sent: Monday, September 20, 2021 1:34 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

Something is not right with the ground pour in the rev 4 drawing you
uploaded. For instance pin 7 of U520 only connects to the ground plane
indirectly. I am not a kicad user, so I cannot begin to suggest a root
cause or remedy, I am afraid.

You are also back to routing between SMT pads with rev 4 (I just
realized that I replied to the file upload message, so you might not
have seen it, repeating here in case you missed it.)

On Sun, Sep 19, 2021 at 22:59 <Zentronics42@...> wrote:

I used a mix for a few reasons. I wanted to keep to a 2 layer board
to keep the cost down. The THT resisters and pins solved some unique
challenges to the layout. I was able to pull the board off with zero
vias. Also this needs to be a double sided board due to the card
edge connectors. An additional point is some of the connections on
to the scope are on the back of the board. The pull up resisters one
the logic lines helped with routing check out the difference between
rev 1 and rev 2 of the PCB's especially in the digital section. The
first run out routing was awful, and I am saying that as the one
that created it. In the triggering section which is the only high
speed signals on the board I stayed with SMD parts to keep the
inductance down and help with the edges The transistors I have pick
can run about
800 Mhz. Not crazy fast but not TTL slow either. These need to be
better than
400 Mhz as that is what the frame is. The card is used to do a
thermal compensation of the vertical amps in the scope when it is up

and running.

Everything else on the board is just termination and test points.
The
2 critical places are the IC's and the pre trigger section. Also due
to needing Tek connections to make the board work it will have to be
hand assembled in the lab I cant get a place to fab it for me. At
least not fully.

I have uploaded what I hope will be a final layout for a new version
of the
67-0912-00 This board has the decoupling caps in place for the IC's
as well as the ground planes and all the test points. I will be
working on a shopping list (BOM) for the parts needed. Then boards
spun and

testing.

A huge thanks to Andy, Ke-Fong lin, and Holger for helping me get
this project off the ground and on to a PCB. Your assistance and
input is greatly appreciated and immeasurably helpful in getting the
layout to this point.

As part of my repair and calibration of my 7854 I do have 2
questions . I have a 7854 that has been damaged in shipping the
digital section is very compressed, but I have ruled out the tube
and analog parts of the scope as they display correctly. It is just
the stored wave form and the readout that is weird. I am curious if
any one has seen this before and knows where to look.
Also is there information about upgrading the firmware for the 7854?
My working one is a low serial number 41838 so I know it will suffer
from rom rot sooner or later so I would like to run the best
firmware on some newer chips. I am not sure if it matters but both
units are 2D so they have the expanded memory option.

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Nico
F4IAN
Sent: Friday, September 17, 2021 10:49 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

Hello
Maybe a silly question that has already been asked before, why did
you use through-hole components and not SMD ? OK, I admit, area is
not an issue here.

Nicolas
________________________________
From: [email protected] <[email protected]> on behalf of
Zentronics42@... <Zentronics42@...>
Sent: Friday, September 17, 2021 15:50
To: [email protected] <[email protected]>
Subject: Re: [TekScopes] Recreating an old board for the 7854

Andy,
That was the plan. If the digital section looked good I am
going to add the decoupling caps and then do a ground pour. Then it
will be off to fab. I am even adding a bit more decoupling then what
was originally called for in the schematic. With a few 47uf bulk
caps

for the board.

Zen

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Andy
Warner
Sent: Friday, September 17, 2021 12:59 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

I did not notice it before, and it apparently was missing from the
original design, but I would consider adding more decoupling caps
close to the logic chips. Plenty of 0.1uF caps sprinkled around is
cheap insurance against glitches.

Apart from that, the layout does look better.

On Wed, Sep 15, 2021 at 20:58 <Zentronics42@...> wrote:

I have uploaded iteration 3 of the test card. I do need to pour
the fill zones on the board but changing the resister to THT parts
helped with the routing immensely. I also bumped up the thickness
of the traces and I also took care with the 90 degree corners. If
the board looks good and there is no gross mistakes I will clean
up the silk screen, get a few boards spun, and move on to testing.





--

Andy






















--

Andy

--

Andy

Well, the phrase from the early 80s was “burn PROMS and ship it”

DaveD

On Sep 20, 2021, at 15:31, Andy Warner <andyw@...> wrote:

?Ship it.

On Mon, Sep 20, 2021 at 14:04 <Zentronics42@...> wrote:

I got the fix in. Kicad is weird if anything moves you need to hide and
reapply the ground planes to get them to reconnect. Also the footprints of
some of the IC's power and grounds nets are not baked in to the foot prints
so I have to set them manually. The ground planes simplified some things
and moving some parts around was able to get the layout complete. I am
currently up to REV6.

Thanks again for all the input.

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Andy Warner
Sent: Monday, September 20, 2021 9:09 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

Vias are free and reliable for signals at the speeds of this board. Use
them, is my advice.

Also, I suspect there is a systemic problem with the connectivity to the
ground pour, I used U520 as an example, as best I can tell the same applies
to the power grounds of other chips too. I would look for the systemic fix
rather thank the kludge (but I'm not the one who has to spend the time
finding that systemic fix.)

On Mon, Sep 20, 2021, 07:53 <Zentronics42@...> wrote:

Andy,
I got the u520 pad to connect. It did not line the tract
running from the bypass cap over to the pin for some reason it is all
ground but it did not want to connect to the ground plane. I am going
to go with weird software quirk. In terms of the routing between smd
parts. I will see what I can do to sharpen the pencil come more. Those
3 traces are continuing to cause me some issues. But I will see what I
come up with. Part of this is I am being stubborn and not wanting to

break down and use a via or 2.

Currently the layout doesn’t have any so I am trying to keep it that way.
Might be a bit unrealistic but I am getting closer.

Eric

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Andy
Warner
Sent: Monday, September 20, 2021 1:34 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

Something is not right with the ground pour in the rev 4 drawing you
uploaded. For instance pin 7 of U520 only connects to the ground plane
indirectly. I am not a kicad user, so I cannot begin to suggest a root
cause or remedy, I am afraid.

You are also back to routing between SMT pads with rev 4 (I just
realized that I replied to the file upload message, so you might not
have seen it, repeating here in case you missed it.)

On Sun, Sep 19, 2021 at 22:59 <Zentronics42@...> wrote:

I used a mix for a few reasons. I wanted to keep to a 2 layer board
to keep the cost down. The THT resisters and pins solved some unique
challenges to the layout. I was able to pull the board off with zero
vias. Also this needs to be a double sided board due to the card
edge connectors. An additional point is some of the connections on
to the scope are on the back of the board. The pull up resisters one
the logic lines helped with routing check out the difference between
rev 1 and rev 2 of the PCB's especially in the digital section. The
first run out routing was awful, and I am saying that as the one
that created it. In the triggering section which is the only high
speed signals on the board I stayed with SMD parts to keep the
inductance down and help with the edges The transistors I have pick
can run about
800 Mhz. Not crazy fast but not TTL slow either. These need to be
better than
400 Mhz as that is what the frame is. The card is used to do a
thermal compensation of the vertical amps in the scope when it is up

and running.

Everything else on the board is just termination and test points.
The
2 critical places are the IC's and the pre trigger section. Also due
to needing Tek connections to make the board work it will have to be
hand assembled in the lab I cant get a place to fab it for me. At
least not fully.

I have uploaded what I hope will be a final layout for a new version
of the
67-0912-00 This board has the decoupling caps in place for the IC's
as well as the ground planes and all the test points. I will be
working on a shopping list (BOM) for the parts needed. Then boards
spun and

testing.

A huge thanks to Andy, Ke-Fong lin, and Holger for helping me get
this project off the ground and on to a PCB. Your assistance and
input is greatly appreciated and immeasurably helpful in getting the
layout to this point.

As part of my repair and calibration of my 7854 I do have 2
questions . I have a 7854 that has been damaged in shipping the
digital section is very compressed, but I have ruled out the tube
and analog parts of the scope as they display correctly. It is just
the stored wave form and the readout that is weird. I am curious if
any one has seen this before and knows where to look.
Also is there information about upgrading the firmware for the 7854?
My working one is a low serial number 41838 so I know it will suffer
from rom rot sooner or later so I would like to run the best
firmware on some newer chips. I am not sure if it matters but both
units are 2D so they have the expanded memory option.

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Nico
F4IAN
Sent: Friday, September 17, 2021 10:49 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

Hello
Maybe a silly question that has already been asked before, why did
you use through-hole components and not SMD ? OK, I admit, area is
not an issue here.

Nicolas
________________________________
From: [email protected] <[email protected]> on behalf of
Zentronics42@... <Zentronics42@...>
Sent: Friday, September 17, 2021 15:50
To: [email protected] <[email protected]>
Subject: Re: [TekScopes] Recreating an old board for the 7854

Andy,
That was the plan. If the digital section looked good I am
going to add the decoupling caps and then do a ground pour. Then it
will be off to fab. I am even adding a bit more decoupling then what
was originally called for in the schematic. With a few 47uf bulk
caps

for the board.

Zen

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Andy
Warner
Sent: Friday, September 17, 2021 12:59 AM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

I did not notice it before, and it apparently was missing from the
original design, but I would consider adding more decoupling caps
close to the logic chips. Plenty of 0.1uF caps sprinkled around is
cheap insurance against glitches.

Apart from that, the layout does look better.

On Wed, Sep 15, 2021 at 20:58 <Zentronics42@...> wrote:

I have uploaded iteration 3 of the test card. I do need to pour
the fill zones on the board but changing the resister to THT parts
helped with the routing immensely. I also bumped up the thickness
of the traces and I also took care with the 90 degree corners. If
the board looks good and there is no gross mistakes I will clean
up the silk screen, get a few boards spun, and move on to testing.





--

Andy






















--

Andy

--

Andy

A huge thanks to Andy, Ke-Fong lin, and Holger for helping me get this
project off the ground and on to a PCB. Your assistance and input is
greatly appreciated and immeasurably helpful in getting the layout to this point.