Date   

Re: My dead 434 needs help.

Craig Sawyers <c.sawyers@...>
 

*** So the answer is according to you,yes,aside from the waffle above,NOT
ALL the 7000 series,despite this your quote " including all 7000 series
mainframes "
Blimey, folks - I was just trying to help the guy with the pulse-mode
problem on is darned 'scope. Maybe I should bave kept my mouth shut.

Craig


Re: My dead 434 needs help.

 

--- In TekScopes@yahoogroups.com, "Craig Sawyers" <c.sawyers@t...>
wrote:
The switched mode supply uses a Tek proprietary chip (common to
umpteen
scopes of the same generation, including all 7000 series
mainframes -
155-0067-xx

**** Er,what,all 7000 series mainframes???????
The 7000 series comprised (and whether they used the 155-0067-xx or
not):

7104 yes
7904 yes
7904A yes
7912AD no (logic based protection)
7912HB no (logic based protection)
7844 probably
7834 yes
7934 yes
7854 yes
7704 discrete protection circuit
7704A yes
76xx linear supply

So the answer is, apart from the 76xx series, the very early 7704
(non-A) and
the esoteric 7912's - yes.

Craig
-------
There's more to the 7k series than that:
7313 and 7403 linear similar to 76xx
7503 and 7504 linear totally different from 76xx
7514 similar to early 7704
7903 ? probably
so the answer would rather be no
/Zenith


Re: My dead 434 needs help.

Brian Goldsmith <brian.goldsmith@...>
 

-----Original Message-----
From: Craig Sawyers

The switched mode supply uses a Tek proprietary chip (common to umpteen
scopes of the same generation, including all 7000 series mainframes -
155-0067-xx

**** Er,what,all 7000 series mainframes???????
The 7000 series comprised (and whether they used the 155-0067-xx or not):

7104 yes
7904 yes
7904A yes
7912AD no (logic based protection)
7912HB no (logic based protection)
7844 probably
7834 yes
7934 yes
7854 yes
7704 discrete protection circuit
7704A yes
76xx linear supply

So the answer is, apart from the 76xx series, the very early 7704(non-A) and
the esoteric 7912's - yes.

Craig



*** So the answer is according to you,yes,aside from the waffle above,NOT
ALL the 7000 series,despite this your quote " including all 7000 series
mainframes "

Aw, come in spinner!!

Brian Goldsmith.


Re: My dead 434 needs help.

Craig Sawyers <c.sawyers@...>
 

The switched mode supply uses a Tek proprietary chip (common to umpteen
scopes of the same generation, including all 7000 series mainframes -
155-0067-xx

**** Er,what,all 7000 series mainframes???????
The 7000 series comprised (and whether they used the 155-0067-xx or not):

7104 yes
7904 yes
7904A yes
7912AD no (logic based protection)
7912HB no (logic based protection)
7844 probably
7834 yes
7934 yes
7854 yes
7704 discrete protection circuit
7704A yes
76xx linear supply

So the answer is, apart from the 76xx series, the very early 7704(non-A) and
the esoteric 7912's - yes.

Craig


FW: My dead 434 needs help.

Brian Goldsmith <brian.goldsmith@...>
 

-----Original Message-----
From: Craig Sawyers
The switched mode supply uses a Tek proprietary chip (common to umpteen
scopes of the same generation, including all 7000 series mainframes -
155-0067-xx

**** Er,what,all 7000 series mainframes???????

Brian Goldsmith


Re: My dead 434 needs help.

Craig Sawyers <c.sawyers@...>
 

You're describing pulse mode operation of the power supply. The switched
mode supply uses a Tek proprietary chip (common to umpteen scopes of the
same generation, including all 7000 series mainframes - 155-0067-xx), which
looks at the power lines and the loading - if it sees anything it doesn't
like, it closes down the switcher, waits a short time and tries again - etc.
Hence the tic-tic-tic-...

Of course, it could be a main supply component that has died, but maybe not.
A short circuit in a bypass capacitor anywhere in the scope can cause the
same problem. You just have to work logically though the options here. If
you have another scope, look at the power supply lines while it is in pulse
mode. You'll see them come up for a few tens of ms, and then drop to zero
at about a 5Hz rate. That should enable you to find the culprit line -
anything that is either significantly higher or lower than the design value
will cause pulse mode operation. That at least gets you to a starting
point.

I think that the basic switcher is probably fine - the fan line comes up for
a few tens of ms and twiches, then stops again (classic observation of pulse
mode) - so tearing out all the switcher semis may well not be the root case.

Incidentally, I have never looked at the layout of the 434 before - and to
my amazement they have mounted the fan and controller on the HV board, so
the fan and low voltage drive is in very close proximity to the 4kV supply
componentry. Wow.

Good luck

Craig

Anyhow right now it's "clicks" @ about 5Hz .. the clicking is from
the fan motor I am almost 100% .. as it sounds like its from there
and the fan turns on and off rotating just a bit.

I have power throughout the power supply board, but I do not have a
manual to tell me what voltage should be were. Just reading voltage
across the two test points makes the ticking stop, but that is kind
of the opposite direction I am looking to go in. I assume it is on
the power supply board. I have some neon lights on, and the CRT is
dead.

Anyone have a manual on PDF or have had this problem? I am going to
buy all the transitors/SCRS/Diacs on the power supply board
tomorrow, hopefully I will get lucky, as I don't really know where
to start.





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Re: FTP Site Update

pe1fbo <sh331182@...>
 

Thanks Bruce for posting these files on your system,

To clarify things,

The 2445B had a major change during it's production live. The uP
board changed.

The early model had no SMD's, and used a separate lithium backup
battery for maintaining the SRAM content. Also this uP board did not
have the readout circuits. It needed a separeate board for this.
Due to the separate battery you will not find the content of the
SRAM in the ZIP file :-)



The late model uP board came with a NVRAM (DS1245) and integrated
readout circuits. Most of this board was desingend with SMD's
This late model has also a rare Intel 27011 EPROM (a paged one)

It think the switch was made at serial number B050000

Regards,

Fred de Vries, PE1FBO



--- In TekScopes@yahoogroups.com, "Bruce Lane" <kyrrin@b...> wrote:
Hi, gang,

With thanks to Fred de Vries, the following additional file
(s) are now available on the Blue Feather FTP archive at
ftp.bluefeathertech.com.

File name: 2465A.zip, plus two others (see notes below).

Path: /pub/electronics/testgear/Tektronix/firmware

Version: Uncertain

Purpose: Firmware image for the 2465A O-scopes.

ADDITIONAL NOTES: Fred was also kind enough to send along
two different image file sets for the 2445B 'scopes firmware, noted
as 'early model' and 'late model.' Since I don't own one of these
units, I'm not certain where the dividing line is. However, both
images are present under the '2445B' subdirectory of the above path.

As always, please keep the following restrictions in mind
when accessing the archive:

(1) There is a five-user limit for anonymous logins at any
one time.
(2) Download speed is capped at 128Kbps.

Both of these limits are designed to maximize availability
of the archive for all, taking into account the limits of my DSL
pipe. Regrettably, I cannot yet afford a T1 or F-T1 line.

Access to the archive is best made with a real FTP client
program as opposed to a web browser. This is because transfers made
through a web browser are often slower, due to translation between
the HTTP and FTP protocols. There are plenty of freeware and low-
cost shareware FTP clients available. My personal favorite is
WS_FTP, by IPSwitch Software, widely available from download sites
all over the planet (including Tucows.com and ftpplanet.com).

When logging in, be sure to specify 'anonymous' (spelled
out, no quotes) as your user ID. Your E-mail address is preferred as
the password, but it is not a requirement (really, just about
anything that contains printable ASCII characters will work).

CONTRIBUTIONS: Further contributions to the archive are
always welcome, subject to the following conditions.

(1) Whatever you submit must be firmware or software that is
NO LONGER SUPPORTED OR SOLD by Tektronix, or it must be directly
related to equipment that is no longer supported or sold. Firmware
or software relating to CURRENT Tektronix equipment WILL NOT be
posted for download unless Tektronix makes the same file(s) publicly
available from their own site.

In other words, I don't want even a hint of legal trouble!
Tektronix has been very generous in allowing (mainly through not
saying 'No') the archive to stay up, and I won't do anything to
endanger that.

(2) Contributions should be sent via E-mail attachment
to 'splicer at bluefeathertech dot com,' and should be archived with
any of the common compression utilities, such as Power Archiver,
WinZip, Gzip, etc.

(3) The preferred format for EPROM or EEPROM image files is
Absolute Binary (Data I/O #16). This helps to guarantee
compatibility with the widest possible range of device programmers.
HOWEVER -- Other formats, such as Intel Hex or Motorola S-record,
may be submitted with a note indicating the format used.

(4) The preferred format for PAL or PLD image files is a
standard JEDEC fuse map.

ACCESS NOTE: There are many ISPs who, judging by their
behavior, simply do not care about how many spammers, crackers, or
other network abusers they host. With this in mind, I maintain an
extensive local blocking list, both at the mail server and at the
router level, that serves to keep such nastiness out of Blue
Feather's LAN.

The flip-side is that such blocking may prevent some of you
from E-mailing me, or accessing the archive. I can and will white-
list individual addresses, but I cannot do so if I do not know that
you tried (and failed) to get through.

If you find that mail from you to me bounces, or that you
cannot access the FTP archive, please try my backup address of kc7gr
at qsl dot net. Include the error message you received, and I'll see
what I can do for you.

Thanks to all for your contributions, your patience, and
your interest.


-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
kyrrin (at) bluefeathertech do/t c=o=m
"If Salvador Dali had owned a computer, would it have been
equipped with surreal ports?"


My dead 434 needs help.

Chas Douvier <charles@...>
 

Sigh, I bought a Tektronix 434 on ebay... of course the seller said
it worked just find before it shipped. Unfortunately I have never
worked on an oscilloscope before, other than using one.

Anyhow right now it's "clicks" @ about 5Hz .. the clicking is from
the fan motor I am almost 100% .. as it sounds like its from there
and the fan turns on and off rotating just a bit.

I have power throughout the power supply board, but I do not have a
manual to tell me what voltage should be were. Just reading voltage
across the two test points makes the ticking stop, but that is kind
of the opposite direction I am looking to go in. I assume it is on
the power supply board. I have some neon lights on, and the CRT is
dead.

Anyone have a manual on PDF or have had this problem? I am going to
buy all the transitors/SCRS/Diacs on the power supply board
tomorrow, hopefully I will get lucky, as I don't really know where
to start.


neon lights??

josefuego2002 <jose.salomon@...>
 

hello everyone, im a little new to the tek scopes, im troubleshoting
the HV section on my 454a. i only get about -300V, (should be around
2k)all the other readings at tp tested ok, but the crt remains off.
i've encounter 3 small neon light bulbs inline with the crt. can
anyone tell me the purpose of these bulbs? im assuming they protect
the crt...maybe thats my problem?? thanks


FTP Site Update

Bruce Lane
 

Hi, gang,

With thanks to Fred de Vries, the following additional file(s) are now available on the Blue Feather FTP archive at ftp.bluefeathertech.com.

File name: 2465A.zip, plus two others (see notes below).

Path: /pub/electronics/testgear/Tektronix/firmware

Version: Uncertain

Purpose: Firmware image for the 2465A O-scopes.

ADDITIONAL NOTES: Fred was also kind enough to send along two different image file sets for the 2445B 'scopes firmware, noted as 'early model' and 'late model.' Since I don't own one of these units, I'm not certain where the dividing line is. However, both images are present under the '2445B' subdirectory of the above path.

As always, please keep the following restrictions in mind when accessing the archive:

(1) There is a five-user limit for anonymous logins at any one time.
(2) Download speed is capped at 128Kbps.

Both of these limits are designed to maximize availability of the archive for all, taking into account the limits of my DSL pipe. Regrettably, I cannot yet afford a T1 or F-T1 line.

Access to the archive is best made with a real FTP client program as opposed to a web browser. This is because transfers made through a web browser are often slower, due to translation between the HTTP and FTP protocols. There are plenty of freeware and low-cost shareware FTP clients available. My personal favorite is WS_FTP, by IPSwitch Software, widely available from download sites all over the planet (including Tucows.com and ftpplanet.com).

When logging in, be sure to specify 'anonymous' (spelled out, no quotes) as your user ID. Your E-mail address is preferred as the password, but it is not a requirement (really, just about anything that contains printable ASCII characters will work).

CONTRIBUTIONS: Further contributions to the archive are always welcome, subject to the following conditions.

(1) Whatever you submit must be firmware or software that is NO LONGER SUPPORTED OR SOLD by Tektronix, or it must be directly related to equipment that is no longer supported or sold. Firmware or software relating to CURRENT Tektronix equipment WILL NOT be posted for download unless Tektronix makes the same file(s) publicly available from their own site.

In other words, I don't want even a hint of legal trouble! Tektronix has been very generous in allowing (mainly through not saying 'No') the archive to stay up, and I won't do anything to endanger that.

(2) Contributions should be sent via E-mail attachment to 'splicer at bluefeathertech dot com,' and should be archived with any of the common compression utilities, such as Power Archiver, WinZip, Gzip, etc.

(3) The preferred format for EPROM or EEPROM image files is Absolute Binary (Data I/O #16). This helps to guarantee compatibility with the widest possible range of device programmers. HOWEVER -- Other formats, such as Intel Hex or Motorola S-record, may be submitted with a note indicating the format used.

(4) The preferred format for PAL or PLD image files is a standard JEDEC fuse map.

ACCESS NOTE: There are many ISPs who, judging by their behavior, simply do not care about how many spammers, crackers, or other network abusers they host. With this in mind, I maintain an extensive local blocking list, both at the mail server and at the router level, that serves to keep such nastiness out of Blue Feather's LAN.

The flip-side is that such blocking may prevent some of you from E-mailing me, or accessing the archive. I can and will white-list individual addresses, but I cannot do so if I do not know that you tried (and failed) to get through.

If you find that mail from you to me bounces, or that you cannot access the FTP archive, please try my backup address of kc7gr at qsl dot net. Include the error message you received, and I'll see what I can do for you.

Thanks to all for your contributions, your patience, and your interest.


-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
kyrrin (at) bluefeathertech do/t c=o=m
"If Salvador Dali had owned a computer, would it have been equipped with surreal ports?"


Baking scopes? (Re: Things I have learned this week (Tek-wise))

scoper796 <scoper796@...>
 

Same here Craig. I have only done this to a 310A and the 504 rack-
mount yesterday. I don't think I would use the same technique on a
545. I take the unit outside and blow it out good with compressed
air. Then I spray everything with the Zep and let it sit for a few
minutes. After that I wash it out as completely as I can with the
garden hose, and then blow as much water as I can out with the air
hose. I have been leaving them in the oven for about 6 hours at 160F.
That seems to get all the water out, because this one fired (!) up
right away. Maybe I should talk to my wife about a bigger stove! LOL

I think it is important not to get any water in the sleeves where the
controls pass through and also in the tube sockets, so I leave the
knobs on and the tubes in place. As soon as the unit cools, I spray
everything inside with contact cleaner, which leaves a slight silicon
film.

It's just that some of these are so dirty, it is as if they were
underwater or something. They don't often show the inside on ebay,
wonder why.

Happy day.

Larry Christopher



--- In TekScopes@yahoogroups.com, "Craig Sawyers" <c.sawyers@t...>
wrote:
Sorry to bring up a question from a newbie, but:
What's all this about baking old oscilloscopes?
If you check the archives, you'll find that Stan Griffiths talks of
Tek's
own technique of servicing the old tubed scopes. Before starting,
they wash
them, and had equipment to do it - washing and drying.

Stan also uses that technique for his gear now, and IIRC uses
Simple Green.
I think that he has modified an old chest freezer with a fan and
heater to
dry it out afterwards - but like I say, check the archives in case
I haven't
remembered correctly.

I haven't got so adventurous - I have no method of drying out a
whole scope,
and where other list members in hot climes leave theirs out in the
sun, I'm
in the UK where we sit at around the triple point of water for most
of the
year. So I tip the scope and wash a section of it using a
paintbrush and
cotton tips, then dry as best I can followed by a hairdryer. More
timeconsuming but works fine.

Craig


Re: OT: Fluke, Keithley, Racal manuals?

Thomas P. Gootee
 

Robert,

In case you didn't check them, first: Fluke, Keithley, and Racal all have lots of downloadable manuals on their own websites:

http://www.fluke.com/support/default.asp
http://www.racalinst.com/downloads/manuals.htm
http://www.keithley.com

The Keithley 179 manuals are there, although I don't know if they have service info. But, I have never been able to find ANY manuals for those particular Fluke and Racal Dana models, anywhere on line, including at the LOGSA site. (So please let me know, if you DO find them.)

Good luck!

Regards,

Tom Gootee

http://www.fullnet.com/u/tomg

----------------------------------- ORIGINAL MESSAGE:


Date: Sun, 8 Aug 2004 04:58:17 -0400
From: "Robert Morein" <morepub@comcast.net>
Subject: OT: Fluke, Keithley, Racal manuals?

Sorry, but I can't resist asking:

Fluke 8110A digital multimeter
Fluke 2190A digital thermometer with attached Y2003 calibrator
Keithley 179 true RMS multimeter
Racal Dana 4002 true RMS multimeter.

Is that government website (forgot URL) still accessible?


Re: Baking scopes? (Re: Things I have learned this week (Tek-wise))

Craig Sawyers <c.sawyers@...>
 

Sorry to bring up a question from a newbie, but:
What's all this about baking old oscilloscopes?
If you check the archives, you'll find that Stan Griffiths talks of Tek's
own technique of servicing the old tubed scopes. Before starting, they wash
them, and had equipment to do it - washing and drying.

Stan also uses that technique for his gear now, and IIRC uses Simple Green.
I think that he has modified an old chest freezer with a fan and heater to
dry it out afterwards - but like I say, check the archives in case I haven't
remembered correctly.

I haven't got so adventurous - I have no method of drying out a whole scope,
and where other list members in hot climes leave theirs out in the sun, I'm
in the UK where we sit at around the triple point of water for most of the
year. So I tip the scope and wash a section of it using a paintbrush and
cotton tips, then dry as best I can followed by a hairdryer. More
timeconsuming but works fine.

Craig


Baking scopes? (Re: Things I have learned this week (Tek-wise))

Mattias Rickardsson
 

From: "scoper796" <scoper796@yahoo.com>
Subject: Things I have learned this week (Tek-wise)
...
It IS wrong to assume that baking the
scope in the wife's oven at 160 degrees for hours will not give
everyone in the house a headache though. And that a rack-mount 504
will not quite allow the oven door to close. LOL
Sorry to bring up a question from a newbie, but:
What's all this about baking old oscilloscopes?

I'm getting hungry here. :-)


/mr


Re: OT: Fluke, Keithley, Racal manuals?

benclarke_uk
 

At 09:58 08/08/04, you wrote:
Sorry, but I can't resist asking:

Fluke 8110A digital multimeter
Fluke 2190A digital thermometer with attached Y2003 calibrator
Keithley 179 true RMS multimeter
Racal Dana 4002 true RMS multimeter.
You can download the Keithley manual directly from the manufacturers
website. Go to
http://www.keithley.com/
then choose 'Document Center'

Ben


Re: OT: Fluke, Keithley, Racal manuals?

Craig Sawyers <c.sawyers@...>
 

Is that government website (forgot URL) still accessible?
Yup. https://www.logsa.army.mil/

Craig


OT: Fluke, Keithley, Racal manuals?

Robert Morein <morepub@...>
 

Sorry, but I can't resist asking:

Fluke 8110A digital multimeter
Fluke 2190A digital thermometer with attached Y2003 calibrator
Keithley 179 true RMS multimeter
Racal Dana 4002 true RMS multimeter.

Is that government website (forgot URL) still accessible?


Re: Full BW switch and labelling on volts/div on 7A26

Craig Sawyers <c.sawyers@...>
 

A couple of questions here:
I own a 7903 frame with a 7A26 vertical amplifier and 7B92 time base.
The traces are nice and super sharp with the BW limited to 20 MHz.
When I go to full BW, two things happen: the traces gets a little
fuzzy (about 3 times the thickness of the previous traces) and
they jump up about one half of a minor division. Now, I understand
that bandwidth has gone up 10 times and naturally, some noise finds
it way though the amplifier so this is normal to a certain extent
but I was surprised to see this amount (even with the coupling switch
set to GND). Brightness is set correctly and so is the focus.
I was wondering how much is typical of the 7A26 plug in ?
About a factor of 3. The bandwidth limiting is carried out just before the
connection to the mainframe - so all the amplifier noise gets through to
that point. Noise goes as root bandwidth = root 10 = about 3.

Second question (this one is easy):
The 10 mV mark on each channel is marked in reverse (white on black).
What am I missing here - What is the reason behind this ?
The reversed sensitivity marking is the setting at which vertical
calibration is set, say by using the 40mV signal from the 7903 calibrator
switch.

Craig


Full BW switch and labelling on volts/div on 7A26

Benoit Robert <robertb3@...>
 

Hello Tektronix gurus...

A couple of questions here:
I own a 7903 frame with a 7A26 vertical amplifier and 7B92 time base.
The traces are nice and super sharp with the BW limited to 20 MHz.
When I go to full BW, two things happen: the traces gets a little
fuzzy (about 3 times the thickness of the previous traces) and
they jump up about one half of a minor division. Now, I understand
that bandwidth has gone up 10 times and naturally, some noise finds
it way though the amplifier so this is normal to a certain extent
but I was surprised to see this amount (even with the coupling switch
set to GND). Brightness is set correctly and so is the focus.
I was wondering how much is typical of the 7A26 plug in ?

Second question (this one is easy):
The 10 mV mark on each channel is marked in reverse (white on black).
What am I missing here - What is the reason behind this ?

I find my unit quite nice (but it does take some getting used to -
coming from a THS720 digital scope here).
I can't believe all the nice features in this unit though.
I bought this scope used a couple of months ago mainly to
look at RF signals in the VHF/UHF region.

Thanks in advance,
Benoit Robert


Re: Connectors, adaptors etc

Miroslav Pokorni
 

I went and checked that auction #5714013511. Seller says for those BNC
adapters:

a.. 50-Ohm
b.. Nickel Plated
c.. DuPont� Delrin Insulator
d.. These are high quality adapters; not cheap imports
The first thing is that insulator in a BNC is Teflon or a variation of it.
Never heard of Delrin used for that purpose; Delrin is fine material for
gears and mechanical pieces but not for connector.

The second thing is nickel plating, it is too shinny to be good. All
reputable connectors have that dull sheen, while shine is found on
connectors sold by Radio Shack and Pasternak Enterprises. The latter is a
supplier of RF components of shady reputation. I believe that this shinny
plating is actually electroless chrome plating, which is very thin and
normally not used on connectors, it is commonly used as a base for plating
on non-conductive materials or for cheap 'nickel plating' appearance.

The seller's e-bay name is 'testparts' and a number of other parts that he
offers on e bay seem to bear his part number, for example TP060 for RF to
BNC adapter.

By the way, if Roland is game to try, this seller offers a set of four
adapters, two of which are N-male to N-female, as an auction # 5713719399.
Those adapters look like straight out Pasternak's catalog, I am not
recommending unless they will be used in audio band.

Regards

Miroslav Pokorni

----- Original Message -----
From: "Richard W. Solomon" <w1ksz@earthlink.net>
To: "Craig Sawyers" <c.sawyers@tech-enterprise.com>; "TekScopes"
<TekScopes@yahoogroups.com>
Sent: Saturday, August 07, 2004 6:59 AM
Subject: RE: [TekScopes] Connectors, adaptors etc


I find BAProducts.com to have a better selection and much better prices.

73, Dick, W1KSZ

ps: one good plug deserves another !!

-----Original Message-----
From: Craig Sawyers [mailto:c.sawyers@tech-enterprise.com]
Sent: Saturday, August 07, 2004 6:36 AM
To: TekScopes
Subject: [TekScopes] Connectors, adaptors etc


Let's just put it this way: any cable that can be terminated with
BNC or SMA
would give way long before connector becomes limiting item in
that assembly.
Incidentally, an eBay seller called testparts sells rf adaptors at pretty
decent prices. Just as an example, item 5714013511 is for five items, BNC
T, BNC-RCA, and three BNC-SMA at $19.95 on buy it now, or item 5714013497
is
four N-SMA adaptors for $15.

For some reason I have this guy's store in my favourites, so I must have
bought something from him at some stage.

Craig





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