Date   

Re: Tek manuals saved from the dumpster - free for postage

Pete Lancashire
 

Steve thanks for rescuing the manuals for everybody

-pete

On Mar 4, 2018 5:48 PM, "Steve Goldstein" <sgold@...> wrote:

All the manuals I listed are spoken for. Thanks to all who expressed
interest.

Steve




How to Use this Forum ..... ????

tinkera123
 

I cannot find anywhere, including in "Help", as to how to do the following. Can some either explain how it works .... or point to somewhere I can read it myself ....?????
1. How do I Private Message another Member of this Group ??
2. How do I 'archive' Topics that I feel I will need to refer to in the future ?? I am aware of the "Search" function.
Thanks,
Ian


Re: Diode 5082-2068 Substitute or Source

 

That is indeed the HP part the Tektronix part number is 152-0457-00. The Xref says it is a general purpose signal Schottky diode 25V PIV.

Dave

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of brasscat
Sent: 05 March 2018 01:01
To: TekScopes@groups.io
Subject: [TekScopes] Diode 5082-2068 Substitute or Source

Hello the Forum, this number looks like an HP part number but these are used in the FG503 Tektronix Function Generator. It is a silicon "hot-carrier" diode. I have a bad one. What is a good substitute? What are the specs?

Stan


Free scopemobile - must pick up vicinity of North Reading, MA

Steve Goldstein
 

One of the narrow scopemobiles, suitable for the 76xx series, has been
sitting in my garage for a few years after I rescued it from impending
dumpster doom. It's time for it to sit somewhere else. It's in good
working condition, but dusty.

Pick up only, I don't want the hassle of shipping it. I can meet you with
it somewhere if it's not too far (I'll have to borrow my wife's car for
this and don't want to leave her stranded for too long - she can't drive a
stick and doesn't want to learn - while I run this little errand of mercy).

Please email me directly off-list.

Thanks.
Steve


Re: Tek manuals saved from the dumpster - free for postage

Steve Goldstein
 

All the manuals I listed are spoken for. Thanks to all who expressed
interest.

Steve


Re: Typo in 2901 SM or wrong value resistor?

Glydeck
 

I just checked two units, B041697 and B041608. They both have 1k 5% carbon resistors.

George

On Mar 4, 2018, at 6:48 AM, Dave Daniel <kc0wjn@...> wrote:

I took a look and that's what I see. The R364 on the divider board is a 1k resistor and the manual calls out a 100 ohm resistor.

DaveD

On 3/3/2018 6:32 PM, Brian Bloom via Groups.Io wrote:
I'm replacing out-of-tolerance resistors in my 2901 time mark gen and ran across a 1k resistor where the SM says it should be 100R. The resistor in question is R364 on the divider board directly behind Q347. This isn't a model number dependent resistor, but my SN is B041433.

Does anyone have a 2901 they can pop the top on and have a look?

Thanks,
Brian





Re: Another 455 bad HV multiplier ?

Jeff Woolsey
 

On 2/21/18 12:35 AM, Jeff Woolsey wrote:
I don't see my message detailing earlier progress, so I'll mention it
here.   I replaced the cap in the inside corner of the HV cage (the old
one had an ESR of 140 ohms).  Doing this brought back all the low
voltages (-5, +5, +32), except +95, which is about 12V now.  The 51V
line on the rear inner fuse is normal now, too, without the hideous
ripple that dragged it to near 0V.  Instead it has 400mV of ripple. 
Probably not to worry about.   The scale illumination works, and the
calibrator is working too.
I found the thing that lost its magic smoke:  R553, 100R to ground. 
Something tells me I'll fry it again if I replace it.  Indeed, it did. 
So what's causing that?


--
Jeff Woolsey {{woolsey,jlw}@jlw,first.last@{gmail,jlw}}.com
Nature abhors straight antennas, clean lenses, and empty storage.
"Delete! Delete! OK!" -Dr. Bronner on disk space management
Card-sorting, Joel. -Crow on solitaire


Diode 5082-2068 Substitute or Source

brasscat
 

Hello the Forum, this number looks like an HP part number but these are used
in the FG503 Tektronix Function Generator. It is a silicon "hot-carrier" diode. I
have a bad one. What is a good substitute? What are the specs?

Stan


Re: 7D20 pull tab

Dave Voorhis
 

At a glance it seems quite different, but maybe I can construct a hybrid.

On 4 Mar 2018, at 22:46, Dave Daniel <kc0wjn@...> wrote:

I seem to recall that someone on this list was or is making pull tabs for 7000-series plug-ins.

DaveD

On 3/4/2018 3:41 PM, Dave Voorhis wrote:
I snapped the pull tab on my 7D20. The knob is intact, but the plastic to which it attaches, isn’t. Anybody parting out a 7D20 and willing to sell the plastic tab?


Re: 7D20 pull tab

Dave Daniel
 

I seem to recall that someone on this list was or is making pull tabs for 7000-series plug-ins.

DaveD

On 3/4/2018 3:41 PM, Dave Voorhis wrote:
I snapped the pull tab on my 7D20. The knob is intact, but the plastic to which it attaches, isn’t. Anybody parting out a 7D20 and willing to sell the plastic tab?


7D20 pull tab

Dave Voorhis
 

I snapped the pull tab on my 7D20. The knob is intact, but the plastic to which it attaches, isn’t. Anybody parting out a 7D20 and willing to sell the plastic tab?


Re: Tekmate floppy setup problem.

Szabolcs Szigeti
 

Hi,

No, I don't think so. All 3 drives i tested are TEAC FD-235HF, which should
be the factory installed ones in the TekMate, and they are 1.44 as far as I
can tell. The TekMate specification also mentioned 1.44 drives. I'm using
HD floppies. But I can try setting it to 720k and use a SD disk just to
make sure.

Szabolcs


2018-03-04 20:18 GMT+01:00 Dave Casey <polara413@...>:

Are you using 1.44MB disks in 720kB drives?

Dave Casey

On Sun, Mar 4, 2018 at 10:35 AM, Szabolcs Szigeti <szigiszabolcs@...
wrote:

Hi,

Now here is an interesting problem. I have two 2402A Tekmates, for my
2440
and 1430a. I was using one of them with an USB floppy emulator, which
works
just fine. I have actually never used the floppy drives (both have HDDs),
but I finally did find my stack of 3 1/2 floppies, so I wanted to try and
use the floppy on the other one, as it is way more col thank the cheep
USB
emulator :-), and it did not work. It accesses it, but then gets an
abort-retry-fail. Ok, no problem, probably the drive is bad. Swapped to
an
other one, the one that actually came out of the other Tekmate, when I
installed the USB drive. That didn't work either. Hmmm. Get a 3rd drive,
no
luck. Now let's try the floppies in the other Tekmate. They don't work
either!

I really don't believe that I have 3 failed drives, and the controllers
are
OK, because the emulator works. Scoping the drive line don't show
anything
out of order, I see the data coming, drive rotates, head moves, etc. So
the
only thing I can think is that there has to be some BIOS or whatever
setting about the size/type that was lost when the NVRAM battery failed.
I
have hacked in external batteries, so that is ok. Obviously, the drive is
set up as a 1.4M drive in the setup.

Am I missing something? Is there any other setting that needs to be
there?
I really don't believe that all 3 drives are bad, but unfortunately I
don't
have any other means to test. I have already swapped cables, drives, even
controller chips.
Not a big problem, but it is bugging me now.

Thanks,

Szabolcs






Re: Tekmate floppy setup problem.

Dave Casey
 

Are you using 1.44MB disks in 720kB drives?

Dave Casey

On Sun, Mar 4, 2018 at 10:35 AM, Szabolcs Szigeti <szigiszabolcs@...>
wrote:

Hi,

Now here is an interesting problem. I have two 2402A Tekmates, for my 2440
and 1430a. I was using one of them with an USB floppy emulator, which works
just fine. I have actually never used the floppy drives (both have HDDs),
but I finally did find my stack of 3 1/2 floppies, so I wanted to try and
use the floppy on the other one, as it is way more col thank the cheep USB
emulator :-), and it did not work. It accesses it, but then gets an
abort-retry-fail. Ok, no problem, probably the drive is bad. Swapped to an
other one, the one that actually came out of the other Tekmate, when I
installed the USB drive. That didn't work either. Hmmm. Get a 3rd drive, no
luck. Now let's try the floppies in the other Tekmate. They don't work
either!

I really don't believe that I have 3 failed drives, and the controllers are
OK, because the emulator works. Scoping the drive line don't show anything
out of order, I see the data coming, drive rotates, head moves, etc. So the
only thing I can think is that there has to be some BIOS or whatever
setting about the size/type that was lost when the NVRAM battery failed. I
have hacked in external batteries, so that is ok. Obviously, the drive is
set up as a 1.4M drive in the setup.

Am I missing something? Is there any other setting that needs to be there?
I really don't believe that all 3 drives are bad, but unfortunately I don't
have any other means to test. I have already swapped cables, drives, even
controller chips.
Not a big problem, but it is bugging me now.

Thanks,

Szabolcs




Tekmate floppy setup problem.

Szabolcs Szigeti
 

Hi,

Now here is an interesting problem. I have two 2402A Tekmates, for my 2440
and 1430a. I was using one of them with an USB floppy emulator, which works
just fine. I have actually never used the floppy drives (both have HDDs),
but I finally did find my stack of 3 1/2 floppies, so I wanted to try and
use the floppy on the other one, as it is way more col thank the cheep USB
emulator :-), and it did not work. It accesses it, but then gets an
abort-retry-fail. Ok, no problem, probably the drive is bad. Swapped to an
other one, the one that actually came out of the other Tekmate, when I
installed the USB drive. That didn't work either. Hmmm. Get a 3rd drive, no
luck. Now let's try the floppies in the other Tekmate. They don't work
either!

I really don't believe that I have 3 failed drives, and the controllers are
OK, because the emulator works. Scoping the drive line don't show anything
out of order, I see the data coming, drive rotates, head moves, etc. So the
only thing I can think is that there has to be some BIOS or whatever
setting about the size/type that was lost when the NVRAM battery failed. I
have hacked in external batteries, so that is ok. Obviously, the drive is
set up as a 1.4M drive in the setup.

Am I missing something? Is there any other setting that needs to be there?
I really don't believe that all 3 drives are bad, but unfortunately I don't
have any other means to test. I have already swapped cables, drives, even
controller chips.
Not a big problem, but it is bugging me now.

Thanks,

Szabolcs


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

 

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


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

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


Re: Typo in 2901 SM or wrong value resistor?

Dave Daniel
 

I took a look and that's what I see. The R364 on the divider board is a 1k resistor and the manual calls out a 100 ohm resistor.

DaveD

On 3/3/2018 6:32 PM, Brian Bloom via Groups.Io wrote:
I'm replacing out-of-tolerance resistors in my 2901 time mark gen and ran across a 1k resistor where the SM says it should be 100R. The resistor in question is R364 on the divider board directly behind Q347. This isn't a model number dependent resistor, but my SN is B041433.

Does anyone have a 2901 they can pop the top on and have a look?

Thanks,
Brian


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

 

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


Re: Replacement of Tantalum cap removal of U450??

 

I would probably just clip the leads as you suggested and solder the
new capacitor on from the top of the board instead of messing with it
and risking damage if you are not familiar with removal and assembly.
Wherever possible, I try and pull the leads by leaving a length while clipping, heating and pulling the remaining length, for fear of a remaining piece of wire dropping off inside while soldering the new part on top.

Raymond


Dating a 555

MoparWade
 

I’m trying to approximate the year that my 555 was made. Maybe there’s some way other than just looking at the date codes on components? What I know is the serial number is 601 and the center strip on the scope head is chrome not Tek blue. To be fair I haven’t really poked around too much in the head as I’m working my way the through power supply first. If you have any thoughts or suggestions I’d love to hear them. Oh and the connections are all SO-239 which could be nothing more than an option but I don’t know. Thanks in advance!