Date   

Re: Fluke group

Don Black <jeans@...>
 

Hi Jim, what type of Fluke are you working on?
Don Black.

nats6035 wrote:

Hi ,
Looking for a discussion group on older Fluke instruments.
Something similar to this "TekScopes" group, which has been very
usefull getting my 465M working again.
Thanks,
Jim




Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/


Would the Tekscopes list manager.....

Bruce Lane
 

...please contact me via E-mail. I'd like to discuss the possibility of hosting the list on my domain to get away from all the drenn associated with YahooGroups, and to be able to more easily give spammers the boot.

FWIW: I'm currenly looking at installing Majordomo list management software. The current list manager would, of course, have admin rights for the list itself.

Thanks much.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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)


Fluke group

nats6035
 

Hi ,
Looking for a discussion group on older Fluke instruments.
Something similar to this "TekScopes" group, which has been very
usefull getting my 465M working again.
Thanks,
Jim


Re: Tek 465B with less than good focus

Denis Cobley <denis.cobley@...>
 

Hi George
These are getting old (like all of us).
The CRT's lose sharpness with age - my best suggestion is to get a 2200 CRT
(154-0861-00) from any 2213A, 2215A, 2220, 2221/A 2230, 2232, 2235/A 2236.
These CRT's were much sharper new and will always give better results.
You can buy a dead / damaged unit on ebay very cheap.
Pull the CRT, remove the trace rotation coil and it's a perfect fit (gains
and timing will be very close).
This CRT can then be you test tube - swap it into each scope - if the trace
is still bad you have a fault - if it comes good then your old CRT is beyond
it's useful life.
Regards
Denis
Regards
Denis Cobley
Newtek Support Pty Ltd
11 Lyon Park Rd
North Ryde 2113
Australia
Ph 61 2 9888 0162
Fax 61 2 9888 0125
www.newteksupport.com

----- Original Message -----
From: "George Headley" <georgeheadley@mybluelight.com>
To: <TekScopes@yahoogroups.com>
Sent: Friday, November 21, 2003 12:46 PM
Subject: [TekScopes] Tek 465B with less than good focus


Hello Group: This is my first post but I feel that I know all of the
regulars. I'm very impressed with your knowledge and have learned a lot from
your experiences. I an an old computer tech , retired but not ready to give
up the challenges relating to Tektronix scopes. I have been buying them
mostly for the challenges found in the repairs but somewhat out of respect
for equipment that is fun to work on because of the quality. I have several
465B that have poor focus. Not really bad but not good enough. There is some
improvement when I limit to 20MHz. I dont have a HV probe but I suspect HV
problems. I know from experience that low HV will cause a blooming of the
trace. I have adjusted the CRT bias as per the manual. Slight improvement,
astig and sweep ckts within spec. If I can trouble you for a minute of your
time do you have any suggestions. one more thing , it may be my imagination
but the rise and fall lines seem to be sharper than the time base lines..
George Headley

Sign up for Internet Service under $10 dollars a month, at
http://isp.BlueLight.com




Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/


Tek 465B with less than good focus

George Headley
 

Hello Group: This is my first post but I feel that I know all of the regulars. I'm very impressed with your knowledge and have learned a lot from your experiences. I an an old computer tech , retired but not ready to give up the challenges relating to Tektronix scopes. I have been buying them mostly for the challenges found in the repairs but somewhat out of respect for equipment that is fun to work on because of the quality. I have several 465B that have poor focus. Not really bad but not good enough. There is some improvement when I limit to 20MHz. I dont have a HV probe but I suspect HV problems. I know from experience that low HV will cause a blooming of the trace. I have adjusted the CRT bias as per the manual. Slight improvement, astig and sweep ckts within spec. If I can trouble you for a minute of your time do you have any suggestions. one more thing , it may be my imagination but the rise and fall lines seem to be sharper than the time base lines..
George Headley

Sign up for Internet Service under $10 dollars a month, at http://isp.BlueLight.com


L20 and 53x/54x/55x extender for sale

Jim Reese
 

Hello all.

Just picked up the latest pile (532, 533, 3-CA, carts, etc). Have
the following to offer to the first one that wants them (includes
shipping in CONUS):

Pentrix L20 (made by Tek, similar to 1L20): $100
(Complete, very clean front, provides trace, needs usual
overhaul/TLC, and needs plastic shaft adapter repaired/glued on the
Narrow/Wide Dispersion knob/switch)

EP53 Plug-In Extension (Letter and 1 series) plus Gain Adjust
Extension: $25

Regards,

Jim


eBay item

Craig Sawyers <c.sawyers@...>
 

Hi all

For anyone interested in a TD pulser with less than 30ps rise time, one is
for sale on eBay on 2574320490 at $9.99.

I already have one, and it is really good for checking out fast samplers
(which is what I mainly have used mine for). The disadvantage is that the
pre-trigger is only 60ns before the fast pulse, and the 7T11 needs 75ns to
get going. The solution is to splice a little extra cable into the delay
lines - about 9 feet in total. Small diameter (2.8mm) RG174 seems to work
well.

I've no personal interest in the sale, BTW.

Craig


Re: P6046/P6045 probes

Miroslav Pokorni
 

No Tim,
P6045 is a 230 MHz, 10 MOhm single ended FET probe, completely different
beast. When P6046 is broken down to components they bear part numbers of the
style xxx-yyyy-zz.

Regards

Miroslav Pokorni

----- Original Message -----
From: "Tim Phillips" <t.phillips@ucl.ac.uk>
To: <tekscopes@yahoogroups.com>
Sent: Thursday, November 20, 2003 7:05 AM
Subject: [TekScopes] P6046/P6045 probes


Hi, all;
Is the P6045 probe just the P6046 Differential probe
without the pre-amp and transformer?
regards
Tim.



P6046/P6045 probes

Tim Phillips <t.phillips@...>
 

Hi, all;
Is the P6045 probe just the P6046 Differential probe
without the pre-amp and transformer?
regards
Tim.


Re: TeK 453 Scope Questions Please Help?

Howard Matthews
 

My first guess, Jon, would be a problem in the horizontal
amplifier. Check the horizontal deflection pins, they should both
read about 48 volts (+/- a few volts). I'll bet they don't. (Well,
according to your description, that is a DUH!) But if the
horizontal amp is working, the two voltages should add up to about
96 volts. If not, then there is a problem in this balanced
amplifier.

I had one scope with similar problems. The horizontal and vertical
output transistors for all these Tek scopes are in an odd holder,
with a rigid plastic strap across the top that both holds the
transisters in place, and provides the collector (as I recall)
connection to the transistor through it's case. During transit,
these straps can be jiggled out of place. Look for these four
transistors with the rigid strap across the top. Check the
transistors connected to the "horizontal amp" board - wiggle,
tighten as needed - simple fix.

If the transistors are all seated correctly, I would probe through
the horizontal amp checking voltages against the manual. But I'm a
relative newbie to fixing scopes, so there should be some other good
suggestions.... If you don't have the manual, checking the
horizontal amp is going to be a bit tough.

-Howard

--- In TekScopes@yahoogroups.com, "jonkzak" <jonkzak@y...> wrote:
All,

I've just received my used 453 and when I turned it on The only
way
to get a trace is to hold the trace find button down and then the
trace is very small located on the right side of the screen. I
did
open the covers and just looked around to see if anything looked
burned etc. I did notice this effect. When I toggle the on/off
switch to 'on' there is a lamp located on the bottom pc board that
will flash on then off and stays off. Turning the on/off switch
to 'off' will also flash this lamp. I don't know if this is
normal
or not. Also all other pilots on the front of the scope function
as
normal. The small trace does seem to look correct using the
calibrate signal as input. Any help would be greatly
appreciated.
I'm sure that this has been covered but my search has not resulted
in
any hits.

Best Regards,

Jon


Tek 465B OPT 93???

firmecivic
 

Does anyone know what OPT 93 on the 465B is? It's not listed in the
manual. Thanks for any help!


Re: TeK 453 Scope Questions Please Help?

ehsjr@...
 

jonkzak wrote:

All,
I've just received my used 453 and when I turned it on The only way to get a trace is to hold the trace find button down and then the trace is very small located on the right side of the screen. I did open the covers and just looked around to see if anything looked burned etc. I did notice this effect. When I toggle the on/off switch to 'on' there is a lamp located on the bottom pc board that will flash on then off and stays off. Turning the on/off switch to 'off' will also flash this lamp. I don't know if this is normal or not. Also all other pilots on the front of the scope function as normal. The small trace does seem to look correct using the calibrate signal as input. Any help would be greatly appreciated. I'm sure that this has been covered but my search has not resulted in any hits.
Best Regards,
Jon
Maybe this is a horizontal centering problem, or the scope is in
non-standard mode (delayed sweep, A intensified during B,
something other than standard). Double check that the controls
are all set where they should be. Someone may have removed
knobs and reinstalled them in the wrong orientation.

Ed


Re: 475A/DM44 - intensity control locked out

ehsjr@...
 

dynasor1 wrote:

I was watching the screen when it happened - suddenly went from a normal trace to super bright. Now the intensity control doesn't reduce the brightness at all, although it does alter the background scatter a little. After fiddling the controls to obtain a trace that wouldn't burn lines in the screen (x10 mag, high sweep rate), I was able to ascertain that all other scope functions still work properly. In other words, a working scope, but with no means of controlling the intensity (naturally, the trace is now a full minor division wide as well, even when set for optimum focus, the retrace is visible, and the screen background is somewhat lit up). Interestingly, the scope's Delay Time Position control and the Delta Time control on the attached DM44 still shift a perceptibly intensified portion of the already-intense trace, so I don't guess the trouble is in the "A Intensify" circuit path.
The z-axis input has no effect when connected to an amplitude calibrator and varied, so I suspect either the z-axis amplifier or DC restoration circuit. I did a visual inspection of these areas and wiggled all the associated transistors in their sockets hoping to find an intermittent contact, but no luck. I've also "bounced" all the switch contacts, to no avail. Before tearing into this further and testing individual components out-of-circuit, has anyone experienced a similar situation, or is there a known failure mode that corresponds to this problem? HELP - this was my only working scope!
I just repaired a 475 with similar problem. The cause was a broken wire
to a choke made from a few turns of wire and physically located over
the 100 volt trace on the board within a few inches of Q1338. When the
wire broke it touched the 100 volt circuit trace and killed Q1338 and
Q1332. I could not find the choke on the schematic - the copy of the
schematic I have is poor. Now to the point.

I found in troubleshooting this that a junk box transistor of the
right polarity will work in place of the proper transistor for those
two - Q1228 & Q1332 during diagnosis. You do need to pay
attention to lead orientation when you are not using the identical
part. For final repair, you want to use the correct parts if those
transistors are bad - that is particularly true of Q1338 which needs
to be very fast. The intensity control connects to Q1338 (can't
remember if it is direct or through some components), so that is a
prime area for investigation.

Ed


Help!

regman10
 

I was troubleshooting the horizontal sweep problems (no trace
above .5 us) on a 475. I figured it might be a transistor problem so
I pulled the transistors, one at a time (on the A7 PCB), and tested
them in a B&K 530 transistor testor) Now I really have problems! I
was very careful to note orientation and double checked each one.
This circuit is difficult to troubleshoot as its buried in the
instrument. All of the transistors tested good incidentally. If
I "unlock" the knobs or pull on the middle hoizontal sweep knob
(where the microswitch releases) then I get a horizontal sweep. The
schematic I downloaded is tiny and illegible and not much help.

By the way what is that stuff around most of the sockets, conductive
paste? Some kind of sealer? Anyone have any problems with it? I
think I might clean the leads of the transistors - they do look a
little oxidized. Any advice on this?

Earlier I cleaned the horizontal sweep switch contacts with small
strips of paper and alcohol and there was no change in the problem,
hence the need to troublehoot further.


Re: Seek Horz mode switch for R7704

Miroslav Pokorni
 

I found hot melt as very helpful when there is not enough material for
welding with soldering iron. Hot melt sticks quite well to most plastics,
the only draw back is that it can get bulky.

Regards

Miroslav Pokorni

----- Original Message -----
From: "zenith5106" <zenith@telia.com>
To: <TekScopes@yahoogroups.com>
Sent: Monday, November 17, 2003 3:29 PM
Subject: [TekScopes] Re: Seek Horz mode switch for R7704


--- In TekScopes@yahoogroups.com, "Jeff W" <vwthingy@c...> wrote:
Hi all,

I'm fixing a R7704 that is in need of a replacement horz mode
switch. It is stuck on "B", and even if you pull out the B switch,
internally it will not switch. (I shudder when I think about
taking
it apart, what with the grain 'o wheat bulbs, plastic welds, etc).

Tek P/N is 670-1330-00. I don't know if it is special to the R7704
(I
checked my 7904 switch, and it looks physically similar but is
different P/N)

Anyone have a swtich they'd be wiling to part with?

TIA


Jeff
---------
It's not a big deal to take it apart. If you cut around the plastic
welds and leave as much as possible of the plastic you will be able
to seal it again (once) with a soldering iron. The problem may be if
there is a broken switch inside.
/Zenith


Re: Seek Horz mode switch for R7704

zenith5106 <zenith@...>
 

--- In TekScopes@yahoogroups.com, "Jeff W" <vwthingy@c...> wrote:
Hi all,

I'm fixing a R7704 that is in need of a replacement horz mode
switch. It is stuck on "B", and even if you pull out the B switch,
internally it will not switch. (I shudder when I think about
taking
it apart, what with the grain 'o wheat bulbs, plastic welds, etc).

Tek P/N is 670-1330-00. I don't know if it is special to the R7704
(I
checked my 7904 switch, and it looks physically similar but is
different P/N)

Anyone have a swtich they'd be wiling to part with?

TIA


Jeff
---------
It's not a big deal to take it apart. If you cut around the plastic
welds and leave as much as possible of the plastic you will be able
to seal it again (once) with a soldering iron. The problem may be if
there is a broken switch inside.
/Zenith


Seek Horz mode switch for R7704

Jeff W <vwthingy@...>
 

Hi all,

I'm fixing a R7704 that is in need of a replacement horz mode
switch. It is stuck on "B", and even if you pull out the B switch,
internally it will not switch. (I shudder when I think about taking
it apart, what with the grain 'o wheat bulbs, plastic welds, etc).

Tek P/N is 670-1330-00. I don't know if it is special to the R7704 (I
checked my 7904 switch, and it looks physically similar but is
different P/N)

Anyone have a swtich they'd be wiling to part with?

TIA


Jeff


475A/DM44 - intensity control locked out

dynasor1 <dynasor1@...>
 

I was watching the screen when it happened - suddenly went from a
normal trace to super bright. Now the intensity control doesn't
reduce the brightness at all, although it does alter the background
scatter a little. After fiddling the controls to obtain a trace that
wouldn't burn lines in the screen (x10 mag, high sweep rate), I was
able to ascertain that all other scope functions still work properly.
In other words, a working scope, but with no means of controlling the
intensity (naturally, the trace is now a full minor division wide as
well, even when set for optimum focus, the retrace is visible, and
the screen background is somewhat lit up). Interestingly, the scope's
Delay Time Position control and the Delta Time control on the
attached DM44 still shift a perceptibly intensified portion of the
already-intense trace, so I don't guess the trouble is in the "A
Intensify" circuit path.

The z-axis input has no effect when connected to an amplitude
calibrator and varied, so I suspect either the z-axis amplifier or DC
restoration circuit. I did a visual inspection of these areas and
wiggled all the associated transistors in their sockets hoping to
find an intermittent contact, but no luck. I've also "bounced" all
the switch contacts, to no avail. Before tearing into this further
and testing individual components out-of-circuit, has anyone
experienced a similar situation, or is there a known failure mode
that corresponds to this problem?

HELP - this was my only working scope!


TeK 453 Scope Questions Please Help?

jonkzak <jonkzak@...>
 

All,

I've just received my used 453 and when I turned it on The only way
to get a trace is to hold the trace find button down and then the
trace is very small located on the right side of the screen. I did
open the covers and just looked around to see if anything looked
burned etc. I did notice this effect. When I toggle the on/off
switch to 'on' there is a lamp located on the bottom pc board that
will flash on then off and stays off. Turning the on/off switch
to 'off' will also flash this lamp. I don't know if this is normal
or not. Also all other pilots on the front of the scope function as
normal. The small trace does seem to look correct using the
calibrate signal as input. Any help would be greatly appreciated.
I'm sure that this has been covered but my search has not resulted in
any hits.

Best Regards,

Jon


475 sweep problems

regman10
 

Does anybody have any troubleshooting hints why my 475 won't display
a horizontal trace above .5 us? (Vertical is fine). I cleaned all
of the horizontal sweep switch contacts to no effect (and that was
quite a delicate little job). All of the supply voltages are normal,
trigger works well. I am using a CFG250 for the signal source.

I have a copy of the service manual but the timing and horizontal
display switching schemo is illegible (along with the horizontal
amplifier schematic).

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