Date   

FW: [Test-Equipment] textronix 2710 analyzer problem

John Miles <jmiles@...>
 

Forwarded to list, so the original poster will see it...

-- jm

-----Original Message-----
From: elie shvarzman [mailto:eliesh@zahav.net.il]
Sent: Friday, November 07, 2003 7:38 AM
To: John Miles
Subject: Re: [Test-Equipment] textronix 2710 analyzer problem


Dear Mr. Miles
The 2710 problem is very interesting duo to the fact that the "markers"
spacing change linarity with the sweep speed (like osciloscope display) that
gave me a conclusion that your problem is a analog noise recived somewere at
the if units to the deflaction amps.
To isolate it try to seperate (diconnect) the if stages by order or try to
"hunt" with osciloscope thru the if/video chain, tune the S.A to a random
center frequency (make shure its not reciving anything including "zero
frequency" marker) at this condition should be no if/video signal (exept
random white noise) and now you can trace the circuits with osciloscope.
My impresion is that this problem is from the chain between the detector to
the deflection amps. of cource the power supply can generate noise that may
picked up by the units.

Elie Shvarzman


Re: What's the best manual? / Microfiche

Stan & Patricia Griffiths <w7ni@...>
 

Hi Roland,

Some sets of microfiche have cross reference information to cover the
instruments made in Guernsey, Heerenveen, etc. but I am not sure they all
do.

I have not seen the Mod Summary info in hard copy form (except for the few
pages that I have converted myself). I don't think Tek ever made it
available in hard copy form.

Stan
w7ni@easystreet.com

----- Original Message -----
From: "maddisassembler" <320041677522-0001@t-online.de>
To: <TekScopes@yahoogroups.com>
Sent: Friday, November 07, 2003 12:18 AM
Subject: [TekScopes] Re: What's the best manual? / Microfiche


For myself I basically encounter two different situations:

I buy one Tek instrument together with the manual
which intially accompanied it. (A rare case because
mostly you get only the bare instrument with all
accessories gone) No problem here because I have
the right manual with it.

I buy single instruments, whole batches, or
receive an instrument for repair (all without
manual). The only clue then is the serial number
and so I need my own manual collection or some
kind of digest to find info on that particular
serial number.

It seems that the only *real* way is to have all
microfiche at hand and so have the complete
modification information (...what about Guernsey,
Heerenveen, Tek England & Israel and so on?)

I also have the impression that microfiche info
only ranges into the 1990s years but for all
the 'new' instruments after that time there is no
information available (to the 'public') compared
to what was on microfiche.

Does anyone know if there are printed versions of
the modification information? (e.g. assorted by Type
and serial number range)


Best regards
-Roland


Re: Which scope to buy?

zenith5106 <zenith@...>
 

--- In TekScopes@yahoogroups.com, "rollsroyce1_92394" <rhesley@g...>
wrote:
I've been looking at older Tek 465, 475, 485 series scopes on EBay,
and have a question for those of you in the know. I want to use the
scope to precisely adjust G2 voltages on my Mitsubishi widescreen
TV. The service manual procedure calls for adjusting them to 190V
using a scope set to 50V/div vertically and 2msec/div horizontally.
The manual further specifies the use of 10:1 probes. Before I cough
up the money for something that might not do the job and then turn
out to be nonreturnable, can one of the Tektronix scopes I
mentioned
above do what I need? The specs I've seen don't really cover the
50V/division part of the requirement.

If these won't work, what older (read: inexpensive used) scope(s)
would?

Thanks for any help you can give me.

Royce
------
What your TV manual means is 50 V/div at the probetip which is what
you get when using a X10 probe on 5 V/div. All of the scopes you
mention can do that.
/Zenith


Re: 7613 HV problem

Stan & Patricia Griffiths <w7ni@...>
 

I don't recall seeing a response to this one. I checked the Modification
Summary to see if failures of these parts are common and fixed by some
change in the 7613. Sorry, no luck there . . . I don't really have any
other suggestions for you but I thought you would want to know that I
researched for you anyway . . .

Sorry about the long delay. I'm swamped!

Stan
w7ni@easystreet.com

----- Original Message -----
From: "sittners" <sittners@sbcglobal.net>
To: "tekscopes" <tekscopes@yahoogroups.com>
Sent: Saturday, August 09, 2003 11:15 AM
Subject: [TekScopes] 7613 HV problem


I need a little help here and throw my open question out to the group. I
have a 7613 that continues to blow the HV regulator transistor, Q1314, and
diode CR1215 (from the collector of Q1314 to ground). The switching
transistors Q1216, Q1218 are fine, and the rectifiers test OK. How can I
go
about isolating the problem; also, can the scope operate with the readout
system board disconnected.

Phil






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Re: What's the best manual? / Microfiche

maddisassembler
 

For myself I basically encounter two different situations:

I buy one Tek instrument together with the manual
which intially accompanied it. (A rare case because
mostly you get only the bare instrument with all
accessories gone) No problem here because I have
the right manual with it.

I buy single instruments, whole batches, or
receive an instrument for repair (all without
manual). The only clue then is the serial number
and so I need my own manual collection or some
kind of digest to find info on that particular
serial number.

It seems that the only *real* way is to have all
microfiche at hand and so have the complete
modification information (...what about Guernsey,
Heerenveen, Tek England & Israel and so on?)

I also have the impression that microfiche info
only ranges into the 1990s years but for all
the 'new' instruments after that time there is no
information available (to the 'public') compared
to what was on microfiche.

Does anyone know if there are printed versions of
the modification information? (e.g. assorted by Type
and serial number range)


Best regards
-Roland



--- In TekScopes@yahoogroups.com, "Stan & Patricia Griffiths"
<w7ni@e...> wrote:
Tek no longer sells microfiche individually or by subscription.
They MAY
have kept one set for their own use . . . and they may have tossed
the LAST
set into the dumpster . . .

Tek Service Centers used microfiche and I don't know of any of them
that had...

...................


Re: The 74L72 IC

Miroslav Pokorni
 

Well, John, you got me to dig out the collector's item, hardbound TI's TTL
book. The power ratio is around 10:1, specifically, plain 7472 draws 10 mA
typical, 20 mA maximum, while Low Power does 0.76 mA & 1.44 mA. Input
current for low level is 3.2 mA vs. 0.36 mA.

The low power device must have been dropped from product line early on. The
hardbound book, second edition (copyrighted 1976) lists low power, but a
later book from 1988 does not, though there are number of other low power
devices listed in the later book.

Regards

Miroslav Pokorni

----- Original Message -----
From: "John Doran" <johnd@epiloglaser.com>
To: <Tekscopes@yahoogroups.com>
Sent: Thursday, November 06, 2003 2:57 PM
Subject: [TekScopes] The 74L72 IC



Howdy! I thought I'd add my two bits to the discussion of this
IC.

Miroslav was being generous--standard TTL actually requires
*ten times* as much power as L TTL! Still, I cannot imagine
that one hotter logic chip would load the 'scope's power supply
excessively. The more likely problem is that whatever drives the
74L72's inputs might not be able to handle standard TTL.

I'd bet that you could substitute an LS TTL part with no problems,
but--total bummer--the 7472 was an old design that, as far as I know,
was only made in standard, L, and H TTL variants (H TTL requires
twice the power of standard TTL).

There appear to be no direct, pin-compatible replacements
for the 74L72 in any more recent logic family. Further, it's not
just a flip-flop; it has gated J and K inputs. It seems to me that
there are only two solutions here; you must find the same part or
you must wire up an equivalent circuit (I'd use 74 HCT) on
some sort of kluge-board.

Oh, one more thing--you can use a 54L72 (military version).

-John


Re: need IC

Miroslav Pokorni
 

The 74C series was a derivative of RCA's CD4000 series (metal gate CMOS), I
believe it was matter of trademark that prevented use of 4000 designation.
Some people paid royalties to RCA but National came up with 74C and
functional equivalent designation of TTL. In the process, some DIPs did get
weird pinouts.

Regards

Miroslav Pokorni

----- Original Message -----
From: "Michael Dunn" <mdunn@cantares.on.ca>
To: <TekScopes@yahoogroups.com>
Sent: Thursday, November 06, 2003 1:51 PM
Subject: Re: [TekScopes] need IC


At 12:51 PM -0800 2003/11/6, Miroslav Pokorni wrote:
can use either package material. However, watch out that you do not get
ceramic flat pack; the 74L72 was also made in that style. Also watch that
you do not get regular TTL, 7472 (no L). They draw double current,
roughly,
and can possibly cause problem with a small scope like 212.
I'm not sure about the '72, but if I remember correctly, a lot of
L TTL had (oddly enough) different pinouts from the other varieties.
I have a vague memory of wiring up some 40085s once (some company's
name for a 74C85, which I assumed to have a standard 74_85 pinout),
and having the circuit not work too well until I rewired them as
74L85s!

Of course, if you end up subbing and rewiring, a 74HC(T) series
part might work well too...

Michael


Re: Tek 310 and Looking for Advice

stan mcintosh <mcintosh@...>
 

With respect to ripple measurements, all I can say is oops. I was measuring with a true RMS meter, but my results were thus off by a factor of 2.8. So, the +300 and -150 are within the 10 mV spec, but just barely. The +100... well, seeing as it's under 60 volts, I'm not sure it counts.

I'll check the resistors. I'm starting to really suspect that one has drifted, or something has drifted, based on my 5651 results. All of the tubes I tried were NOS, warfare-grade tubes. I'm wondering if the circuit is off and the tube is not being fed properly.

As another thought, I may break out the +300V supply to -150, and feed from an outboard source. Well, this depends on whether the resistor hunt turns up anything. A 300V source indepenent of the -150 should help bless or curse the -150, right?

Thanks for the suggestions, Stan G.; I'm going to work my way through them. I'm grateful for this group. Without it, this scope wouldn't have had a chance.

Sincerely,
stan


Re: The 74L72 IC

Jeff W <vwthingy@...>
 

I agree with John, and if I was the original poster, I would first
check the function of this flip-flop and what drives the inputs, and
see if the standard 7472 TTL part would work. It could be that Tek
went with the L version just to save power, and the standard TTL part
would work just fine. If I recall, John is absolutely correct in the
power dissipation ratio between the two families (10:1, 10mW per gate
for TTL, 1 mW per gate for L TTL), however I don't recall that the
input drive current was significantly different between the two. (I
could be waaay wrong on this as it has been 20 years since I last
designed anything with TTL!)

Jeff

John Doran wrote:
Still, I cannot imagine
that one hotter logic chip would load the 'scope's power supply
excessively. The more likely problem is that whatever drives the
74L72's inputs might not be able to handle standard TTL.


The 74L72 IC

John Doran <johnd@...>
 

Howdy! I thought I'd add my two bits to the discussion of this
IC.

Miroslav was being generous--standard TTL actually requires
*ten times* as much power as L TTL! Still, I cannot imagine
that one hotter logic chip would load the 'scope's power supply
excessively. The more likely problem is that whatever drives the
74L72's inputs might not be able to handle standard TTL.

I'd bet that you could substitute an LS TTL part with no problems,
but--total bummer--the 7472 was an old design that, as far as I know,
was only made in standard, L, and H TTL variants (H TTL requires
twice the power of standard TTL).

There appear to be no direct, pin-compatible replacements
for the 74L72 in any more recent logic family. Further, it's not
just a flip-flop; it has gated J and K inputs. It seems to me that
there are only two solutions here; you must find the same part or
you must wire up an equivalent circuit (I'd use 74 HCT) on
some sort of kluge-board.

Oh, one more thing--you can use a 54L72 (military version).

-John


Re: need IC

Michael Dunn <mdunn@...>
 

At 12:51 PM -0800 2003/11/6, Miroslav Pokorni wrote:
can use either package material. However, watch out that you do not get
ceramic flat pack; the 74L72 was also made in that style. Also watch that
you do not get regular TTL, 7472 (no L). They draw double current, roughly,
and can possibly cause problem with a small scope like 212.
I'm not sure about the '72, but if I remember correctly, a lot of L TTL had (oddly enough) different pinouts from the other varieties. I have a vague memory of wiring up some 40085s once (some company's name for a 74C85, which I assumed to have a standard 74_85 pinout), and having the circuit not work too well until I rewired them as 74L85s!

Of course, if you end up subbing and rewiring, a 74HC(T) series part might work well too...

Michael


HC01 and HC02 Hard Copy Unit Manuals

Dennis Tillman <Dennis@...>
 

Hi everyone,

Does anyone know where I can buy a copy of the manual for an HC01 or HC02 Video Hard Copy Unit.

Tek sold them from 1987 through at least 1991.

In reality Tek OEM'd a Mitsubshi P61U Video Copy Processor unit.

The Tek unit is identical in appearance and specs to the Mitsubishi unit.

So a copy manual for the Mitsubishi P61U unit would be just as useful.

Thanks, Dennis
dennis AT silicondesigns DOT com


Re: need IC

Miroslav Pokorni
 

Do a search on Google and you will get few sources, among them
http://www.hobid.com/inventory/7/12.html and
http://www.sphere.bc.ca/test/hpparts.html . Parts will probably not be
cheap; I would guess several bucks a piece. The last letter in part number
specifies package and it can vary with manufacturer; the N is TI's
designation for plastic DIP, while their ceramic DIP is designated J. You
can use either package material. However, watch out that you do not get
ceramic flat pack; the 74L72 was also made in that style. Also watch that
you do not get regular TTL, 7472 (no L). They draw double current, roughly,
and can possibly cause problem with a small scope like 212.

You can also use 54L72, what is military temperature range, basically same
part just tested for that temperature range and parameters adjusted to hold
over that range.

Regards

Miroslav Pokorni

----- Original Message -----
From: "Dan Tulloss" <dtulloss@ntecusa.com>
To: <TekScopes@yahoogroups.com>
Sent: Thursday, November 06, 2003 7:17 AM
Subject: [TekScopes] need IC


Hello,

I am having a problem finding a replacement IC for a Tektronix 212 scope.
The Tek part
number is 156-0280-00 and the MFR part number is SN74L72N. Does anyone
have
one or know where I can get this part?

Thanks,
Dan Tulloss


plug ins

Richard Oglebay <richardoglebay@...>
 

Dear Chuck: I want to thank you for the referal on the man in ohio, He already contacted me on my request and does have one of the things I need. yours truly Richard Oglebay




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Re: need IC

Craig Sawyers <c.sawyers@...>
 

Standard low power TTL, yes. However, very obscure part; single J-K
flip flop. Out of production by the majors. So Digikey, Mouser, and
the like will not have it. Suggest you go to the surplus houses
looking for it.
Or do what I've done in the past to replace an obsolete TTL part - shoehorn
in a modern part. If it is a JK, use instead a dual JK such as an LS73.
Solder or plug in power and ground, then cross wire the other pins into the
original '72 connections. Might have to be careful with preset and clear
connections - but beyond that it should be possible to stitch something
together that works.

Last thing I resurrected this way was my HP5328A counter.

Craig


Re: need IC

John Miles <jmiles@...>
 

Couple of vendors on www.findchips.com show it in stock. Their
minimum-order fees may be prohibitive, though.

-- jm

-----Original Message-----
From: Jeff W [mailto:vwthingy@cox.net]
Sent: Thursday, November 06, 2003 10:09 AM
To: TekScopes@yahoogroups.com
Subject: [TekScopes] Re: need IC


Standard low power TTL, yes. However, very obscure part; single J-K
flip flop. Out of production by the majors. So Digikey, Mouser, and
the like will not have it. Suggest you go to the surplus houses
looking for it.

You may have more luck with the straight SN7472N part. I doubt that
it will affect the operation of the circuit; you should check it out
to be sure.

I know the local surplus place here in San Diego, Gateway, carries
the SN7472N, but not the L version.

Jeff



Re: need IC

ROLYNN PRECHTL K7DFW
 

Dan,

Use this tool......
http://www.findchips.com/avail

No luck with SN74L72N.
Got a hit using SN7472N.

K7DFW

..._._


Re: need IC

Bruce Lane
 

Hi, gang,

*********** REPLY SEPARATOR ***********

On 06-Nov-03 at 18:09 Jeff W wrote:

Standard low power TTL, yes. However, very obscure part; single J-K
flip flop. Out of production by the majors. So Digikey, Mouser, and
the like will not have it. Suggest you go to the surplus houses
looking for it.

You may have more luck with the straight SN7472N part. I doubt that
it will affect the operation of the circuit; you should check it out
to be sure.
Suggestion: If the original chip is socketed, it would probably be pretty easy to construct an adapter to allow the use of a more modern replacement, such as a 74L or LS76.


-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
ARS KC7GR (Formerly WD6EOS) since 12-77 -- kyrrin@bluefeathertech.com
"Quando Omni Flunkus Moritati" (Red Green, aka Steve Smith)


Re: need IC

Jeff W <vwthingy@...>
 

Standard low power TTL, yes. However, very obscure part; single J-K
flip flop. Out of production by the majors. So Digikey, Mouser, and
the like will not have it. Suggest you go to the surplus houses
looking for it.

You may have more luck with the straight SN7472N part. I doubt that
it will affect the operation of the circuit; you should check it out
to be sure.

I know the local surplus place here in San Diego, Gateway, carries
the SN7472N, but not the L version.

Jeff


Robert Morein wrote:
THe part number is standard low power TTL.
Possibly Digikey.
Hello,

I am having a problem finding a replacement IC for a Tektronix
212 scope.
The Tek part
number is 156-0280-00 and the MFR part number is SN74L72N. Does
anyone have
one or know where I can get this part?


Re: need IC

Robert Morein <morepub@...>
 

THe part number is standard low power TTL.
Possibly Digikey.

----- Original Message -----
From: Dan Tulloss
To: 'TekScopes@yahoogroups.com'
Sent: Thursday, November 06, 2003 10:17 AM
Subject: [TekScopes] need IC


Hello,

I am having a problem finding a replacement IC for a Tektronix 212 scope.
The Tek part
number is 156-0280-00 and the MFR part number is SN74L72N. Does anyone have
one or know where I can get this part?

Thanks,
Dan Tulloss


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