When I found the SCH option board from a 1750 scope, I contacted Tek to see if it was a 'drop in' replacement. They said 'Yes'.. Really it's "NO"
I was then given some software (DOS) that would 'calibrate'---- a nearly 70 step program that would Create the BBRAM settings for this scope-If you had to replace the BBRAM chip.
With a new 1225 chip, I practiced--repeatedly with the program, and I got pretty good at setting up Waveform and Vector display, but I had no component signals to use, and it didn't cover the SCH Option board I was trying to install during the calibrate program, nor after I was done with calibrate and stored the settings to the BBRAM... SCH Option (When I hit the button) did not work....
By this time I was communicating with a thread at TEK,? and I kept revisiting the subject of: How can I ENABLE the SCH Option?? The 3 or so people that did reply from that thread, were continually referencing to "1760SC"?? Which I could not find in the software I received from them....? During this time I was also attempting to upgrade from V2.3 to V2.4 firmware in the scope, as one of them said that would do it... but? the Upgrade software sent would not erase the NVRAM....
Finally, a fellow who had never replied to me from work, did so from home, and pointed me to a TEK U.K. site where the same software that I had been sent before was posted in a public download.... I downloaded it and found out that it was a LATER version of the same software sent to me before, but this one had 80 steps in the CAL Program, and? included references to a "SCOPE BUILD" Document, and covered all the 1700 scope family, and a reference to a TEK Document? "See PRC_LANG.DOC for instructions on building Model, Option, and Title codes from the key...." and the following information:
01 NTSC
02 PAL
04 DUAL
10 MISC STEPS (Main Board)
20 VECTOR BOARD
40 SCH BOARD
80 COMPONENT BOARD
and a rem statement of the? models:
TEK1740A ? 31
TEK 1741A? 32
TEK1745A?? 34
TEK 1750A? 71
TEK 1751A? 72
TEK 1755A? 74
TEK 1760???? B1
TEK1761????? B2
TEK 1765??? B4
TEK 1760SC F1
TEK1761SC? F2
TEK1765SC? F4
Armed with this information, I contacted everyone at TEK that I had contacted before, asking for the PRC_LANG.DOC.....
At this point, ALL Communications with the folks on that support Link STOPPED!!!!
After waiting a week... I did an online chat... and was abruptly told I would NOT Get that document.... and demanded to know how I found out about it?
"Well, it's a remark statement within the software you released to the public"
The chat link abruptly ended....? !!!
I then called Support, and was told that that document: PRC_LANG.DOC was a COMPANY DOCUMENT for Company Personnel only.... and I will never get it...
That was the end of my support ---- Support!!!?? I was officially on my own...
By this time, I had a couple spare 1225 chips, and was awaiting the Ramtoron 16W08 on a DIP Header...? and started "doing experiments" to see if I could find a way to Enable the SCH board from 1750 scope in my 1760 scope...? and I in-advertantly powered up scope WITHOUT the 1225 in the socket, and though the gain calibrations were incorrect---SCH OPTION BOARD WORKED!!!!
I then purchased a Programmer, read the contents of "stock" 1225 chip, and then by using 'Powers of 2'? I put "F" in the first half of BBRAM contents, and put that in scope... SCH WORKED!
So I then walked the "F" back until I found the ONE LOCATION (Address 0F) where an "F" would allow me to use the SCH Option.... With this (by then Ramtron chip on Dip Header arrived), I then touched up some gains, and scope was good except for SCH Gain on CRT..... (For some reason--1750 SCH Option board in 1760 scope with Firmware Hack to enable SCH Option board would not adjust SCH Gain in the updated CAL Program the guy pointed me to in the U.K.)?? I fixed this by putting a 200K pot in place of R145 (33.2K).... and adjusting SCH Gain....
So, even though TEK Said it would be Plug and Play.... It sure as hell wasn't.... and I had to HACK the BBRAM in order to enable the SCH Option board from a 1750 scope to work in a 1760 scope....
Sorry for being so wordy.... but what? a? "Long, Strange Trip this has been!!!"
Jan
On 12/6/2017 7:51 AM, Chuck Harris wrote:
Tektronix was always good about sharing parts and ideas among their > product line. Looks to me like it could share a lot in common with >
the 2465 family. Not bandwidth, so much, but certainly CRT drive and > control, CPU, front panel control mechanisms... > > I'm pretty sure that most anything that uses a 1225 would rely upon > its battery, as that is the only way it has of preserving data. The > earlier 2465B, and the 2465A used a separate battery, control, and > CMOS RAM to provide non volatile storage. > > Thanks for enlightening me. > > -Chuck Harris > > Jan J wrote: >> Does Composite, Component Waveform and Vector/Diamond display.. >> Plus, Time Code, Audio, and SCH.. SCH is an option board...
I don't know if this forum supports pictures... if it does, here
is >> what a good SCH Display looks like..... >> >> On 12/5/2017 9:21 PM, Chuck Harris wrote: >>> Obviously. >>> >>> I was simply expanding on what you stated to include the early >>> 2465B and 2465A. I can't say that I have ever run into the 1700 >>> series.. Isn't it a vector scope, or something like that? >>> >>> -Chuck Harris >>> >>> Jan J wrote: >>>> Also, the Tek 1700 series relies on battery within 1225 only... >>>> no other battery... > > >
