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Can I install a 2465B motherboard in a 2445B chassis? What will I get?

 

I have an old A1 board with part number 671-0722-02, with a date of 1987 (design or manufactured?). I believe this part number is for a 2465B oscilloscope. Also, I can obtain a non-working 2445B for a low price. I am considering placing this 2465B A1 board in the 2445B chassis, clean it up, give it a hobbyist calibration. Will this give me a poor mans 2465B? What advice can the experts give me before setting out on this mission?
 

On Sat, 3 Mar 2018, machineguy59 via Groups.Io wrote:

I have an old A1 board with part number 671-0722-02, with a date of 1987
(design or manufactured?). I believe this part number is for a 2465B
oscilloscope. Also, I can obtain a non-working 2445B for a low price. I
am considering placing this 2465B A1 board in the 2445B chassis, clean it
up, give it a hobbyist calibration. Will this give me a poor mans 2465B? What advice can the experts give me before setting out on this mission?
It will give you a full featured 2465B, not a poor man's one. All parts
other than A1 board and front panel label are exactly the same for 2445B and
2465B. Ah, the A5 ROM is different too.

---
*
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
*
 

Thanks for the answer.? That is what I expected but needed and expert opinion.? I don't mind the problem with the A5 ROM because it will probably need replacement anyway for battery problems.? Seems my biggest problem will be to calibrate the result.

On ?Saturday?, ?March? ?3?, ?2018? ?03?:?03?:?37? ?PM? ?CST, Sergey Kubushyn <ksi@...> wrote:

On Sat, 3 Mar 2018, machineguy59 via Groups.Io wrote:

I have an old A1 board with part number 671-0722-02, with a date of 1987
(design or manufactured?).? I believe this part number is for a 2465B
oscilloscope.? Also, I can obtain a non-working 2445B for a low price.? I
am considering placing this 2465B A1 board in the 2445B chassis, clean it
up, give it a hobbyist calibration.? Will this give me a poor mans 2465B?
What advice can the experts give me before setting out on this mission?
It will give you a full featured 2465B, not a poor man's one. All parts
other than A1 board and front panel label are exactly the same for 2445B and
2465B. Ah, the A5 ROM is different too.

---
*
*? KSI@home? ? KOI8 Net? < >? The impossible we do immediately.? *
*? Las Vegas? NV, USA? < >? Miracles require 24-hour notice.? *
*
 

On Sat, 3 Mar 2018, machineguy59 via Groups.Io wrote:

Thanks for the answer.? That is what I expected but needed and expert
opinion.? I don't mind the problem with the A5 ROM because it will
probably need replacement anyway for battery problems.? Seems my biggest
problem will be to calibrate the result.
A5 ROM has nothing to do with calibration -- that is stored in NVRAM -- but
it adds those higher sweep rates that 2445B doesn't have i.e. it changes the
scope identity. It is no biggie -- you simply erase old EPROMs and
re-program them with 2465B firmware.

You will have to re-calibrate it even if existing 2445B NVRAM still held the
calibration constants -- your A1 board will be diffrent and it has a lot of
trimpots/inductors/capacitors to play with while calibrating the assembled
instrument. There is absolutely no chance its setup would match whatever is
still in NVRAM.

On Saturday, March 3, 2018 03:03:37 PM CST, Sergey Kubushyn <ksi@...> wrote:

On Sat, 3 Mar 2018, machineguy59 via Groups.Io wrote:

I have an old A1 board with part number 671-0722-02, with a date of 1987
(design or manufactured?).? I believe this part number is for a 2465B
oscilloscope.? Also, I can obtain a non-working 2445B for a low price.? I
am considering placing this 2465B A1 board in the 2445B chassis, clean it
up, give it a hobbyist calibration.? Will this give me a poor mans 2465B?
What advice can the experts give me before setting out on this mission?
It will give you a full featured 2465B, not a poor man's one. All parts
other than A1 board and front panel label are exactly the same for 2445B and
2465B. Ah, the A5 ROM is different too.
---
*
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
*
 

On Sat, Mar 3, 2018 at 02:59 pm, Sergey Kubushyn wrote:


A5 ROM has nothing to do with calibration -- that is stored in NVRAM -- but
it adds those higher sweep rates that 2445B doesn't have i.e. it changes the
scope identity.
ISTR that enabling 500 ps/div horizontal speed to a 2445B just takes adding a jumper near the edge of the main board, at one of the connectors. Sorry, don't remember exactly where and I have no doc. where I am at the moment. I trust this'll ring a bell with someone on this forum who has the details.

Raymond
Chuck Harris
 

The ROM's on the A5 board contain everything they need to
know about being a 2467B, 2465B, 2445B, or 2455B.

The A5 controller's are interchangeably the same. You can
take one out of any member of the 24[4,5,6]5A or B family,
and swap around. The only significant difference has to do
with the separate Display board on A's, and early B's. You
can swap a controller/display board from an A into a late B,
and vice versa, if you want... [The "A" controllers have some
ROM omissions for the extra diddly stuff that the "B" can do,
and some changes in the calibration routines, battery voltage
sensing...]

The way the A5 controller knows what scope you have is by
reading the P/J512, pin 11, and pin 32. Pin 11 goes with
a jumper, W120, which if missing is a 2445B/2455B, if grounded,
is a 2465B.

P32 determines whether the scope is a 2465B, or a 2467B. The
significant difference (board wise) between a 65, and a 67, is
the HV power supply board, the 67 board has the control voltages
necessary for the MCP. As a result, the 67 Board grounds P32,
and passes the signal through the A1 motherboard to P/J512, P32,
on the A5 Controller board.

The only schematic where Tektronix forgot to erase this information
is the analog control <2> schematic for B050000 and above in the
2465B/2467B manual (070-6863-01).

Someone once said: "What a tangled web we weave, when first we
practice to deceive." One of the girl poets, as I recall. Emily
Dickinson maybe?

I hope you won't use this information for evil.

-Chuck Harris

Raymond Domp Frank wrote:

On Sat, Mar 3, 2018 at 02:59 pm, Sergey Kubushyn wrote:


A5 ROM has nothing to do with calibration -- that is stored in NVRAM -- but
it adds those higher sweep rates that 2445B doesn't have i.e. it changes the
scope identity.
ISTR that enabling 500 ps/div horizontal speed to a 2445B just takes adding a jumper near the edge of the main board, at one of the connectors. Sorry, don't remember exactly where and I have no doc. where I am at the moment. I trust this'll ring a bell with someone on this forum who has the details.

Raymond
 

Walter Scott :-)

On 4 Mar 2018, at 15:30, Chuck Harris <cfharris@...> wrote:

The ROM's on the A5 board contain everything they need to
know about being a 2467B, 2465B, 2445B, or 2455B.

The A5 controller's are interchangeably the same. You can
take one out of any member of the 24[4,5,6]5A or B family,
and swap around. The only significant difference has to do
with the separate Display board on A's, and early B's. You
can swap a controller/display board from an A into a late B,
and vice versa, if you want... [The "A" controllers have some
ROM omissions for the extra diddly stuff that the "B" can do,
and some changes in the calibration routines, battery voltage
sensing...]

The way the A5 controller knows what scope you have is by
reading the P/J512, pin 11, and pin 32. Pin 11 goes with
a jumper, W120, which if missing is a 2445B/2455B, if grounded,
is a 2465B.

P32 determines whether the scope is a 2465B, or a 2467B. The
significant difference (board wise) between a 65, and a 67, is
the HV power supply board, the 67 board has the control voltages
necessary for the MCP. As a result, the 67 Board grounds P32,
and passes the signal through the A1 motherboard to P/J512, P32,
on the A5 Controller board.

The only schematic where Tektronix forgot to erase this information
is the analog control <2> schematic for B050000 and above in the
2465B/2467B manual (070-6863-01).

Someone once said: "What a tangled web we weave, when first we
practice to deceive." One of the girl poets, as I recall. Emily
Dickinson maybe?

I hope you won't use this information for evil.

-Chuck Harris

Raymond Domp Frank wrote:
On Sat, Mar 3, 2018 at 02:59 pm, Sergey Kubushyn wrote:


A5 ROM has nothing to do with calibration -- that is stored in NVRAM -- but
it adds those higher sweep rates that 2445B doesn't have i.e. it changes the
scope identity.
ISTR that enabling 500 ps/div horizontal speed to a 2445B just takes adding a jumper near the edge of the main board, at one of the connectors. Sorry, don't remember exactly where and I have no doc. where I am at the moment. I trust this'll ring a bell with someone on this forum who has the details.

Raymond
 

...so what would be the downside to installing a 2465 A5 ROM in a 2445?? Do you think it might be capable of those extended sweep rates? Any other pro's \ cons?
I have a 2445 which might thank me for a little upgrade, if its possible... :-)
--
Best Regards

David Thomas
 

On Mon, 5 Mar 2018, David Thomas wrote:

No upside/downside -- as somebody already mentioned firmware is the same
between 2445B and 2465B and it learns what it is running on by checking
jumpers/straps on the A1 board. Just get the latest version available and
you are good to go.

I have one 2445B gathering dust on a shelf myself and couple of 2456B A1
boards so I'll convert it to 2465B when time permit. I do even have a 2465B
label :)

Not going to sell it; it is a spare and current prices make it not worth
bothering with selling. My primary analog scope is 2467B and I also have a
spare one but 2465B has bigger screen...

...so what would be the downside to installing a 2465 A5 ROM in a 2445?? Do you think it might be capable of those extended sweep rates? Any other pro's \ cons?
I have a 2445 which might thank me for a little upgrade, if its possible... :-)
--
Best Regards

David Thomas
---
*
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
*
 

The 2445B is on its way. Its not working but I don't expect much trouble fixing that. I have a 2465 parts mule so repairs should go quickly. Then its all about putting the 2465B A1 board in the 2445B frame. I will post here for help and give progress reports as I go. My first question has to do with the attenuators. The 2465B A1 board does not have attenuators installed. Can I use attenuators from the 2465 parts mule? Or do I need attenuators unique to the 2465B?

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