Re: Those funny 311-0603-00 pots
I'll try... I'll also try ammonium bifluoride, if it won't touch it, it's Teflon...
Of course the paradox is, what keeps the grey end cap glued to the pot?
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Re: 7A22 Differential Amplifier Calibration
Can you make a measurement of the rise and fall times (check both just
to be sure) in the working configuration and non-working
configuration?
I do not remember what mainframe and timebase you are using but a 100
MHz mainframe like a 7603 and 100 MHz timebase like a 7B53A are more
than fast enough to do this. You may need to use the fast rise or
fall output from your PG506; I do not remember if the other outputs
are fast enough. The square wave output on my 3 MHz function
generator was not quite fast enough but only contributed like 10%
error.
My 7A22 measured very close to 350 nanoseconds which equates to a 1
MHz bandwidth. I am hoping that asymmetrical rise and fall times or
something about the difference between working and non-working reveals
something.
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On Mon, 21 Mar 2016 18:54:14 -0000, you wrote: ...
I am attaching two photos which hopefully show the traces that I see. A 50mV
1KHz square-wave from a PG506 is connected to the +ve input of the 7A22 with
DC coupling in both cases. The photo ¡°Input+ve_Input ¨Cve GND¡± is what shows
when the ¨Cve input coupling switch is at ¡°GND¡±. It seems like pretty good
square-wave to me. The photo Input+ve_Input-ve DC¡± is what appears when the
¨Cve coupling switch is set to ¡°DC¡±. A rounding of the upper leading corner
can be seen. According to the Service Manual, the aberration should not
exceed ¡À1%. Is this so in my case and how can one estimate or measure that
anyway? If the 50mV 1KHz square wave is connected to the ¨Cve input, there
is no perceptible change when the +ve input coupling is changed between
¡°GND¡± and ¡°DC¡±.
I haven¡¯t adjusted C241 at all. It has occurred to me that some insect may
have crawled into the zone where C241 and C141 are located and died close to
C241, changing the capacitance just enough¡..
Colin.
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Re: Those funny 311-0603-00 pots
Hi Snapdiode,
There is a slim chance it might be Teflon which is white and almost
impossible to glue. One way to tell if it is Teflon is that it will feel
extremely slippery to the touch. Another way to tell is that Teflon has a
very high heat resistance. If you hold a soldering iron to it nothing
happens.
Dennis Tillman W7PF
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-----Original Message-----
Sent: Monday, March 21, 2016 6:25 PM
Subject: [TekScopes] Those funny 311-0603-00 pots
I thought the white part is made of Delrin, but so far it has shrugged off
every glue and solvent I threw at it.
MEK, dichloromethane, hot glue, cyanoacrylate, plastic bonder epoxy,
nothing affects or sticks to it.
How can I be sure the material is Delrin, and not say, Nylon?
------------------------------------
Posted by: snapdiode@...
------------------------------------
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Hoard of gear for sale in NYC
Hi Folks -
Those in the NYC area may want to check this out. I picked up a 7854 (needs work), but he's still got a room full of scopes, meters & gak. Lots of 7603s, some 7k series plugins, a few 475s, fluke meters, etc...
He's hosting an open house this Saturday from 12pm-5pm @ 562 west 162ND street. His name is Will, and he's reachable at (347) 688-3051
No affiliation, just helping out. He really just wants to get rid of it, so head on over & make a reasonable offer! I took some pics for him, that he'll be putting on the Craigslist post shortly.
Cheers,
Paul
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Anybody have a Xantrex XT-series schematic?
These are great power supplies, the XT series started out as Xantrex, then became Sorensen, and were private labeled to at least one other company. The manual for them is all over, BUT the schematic is removed.
I'd really like to fix and adjust two I have, but need the schematic, all models have the same print, the manual (which I HAVE) explains the parts changes. Does anybody have the missing schematic? I could really use a copy.
all help appreciated,
all the best,
walter (walter2 -at- sphere.bc.ca)
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11K frame power supply and other boards
In our pile of 11K stuff (for stuff day), there is a complete 11401/402 power supply assembly (known good), a universal 11K PSU regulator card, an 11402 memory card, a waveform compressor card and two big system cards, plus the rear IEEE488 interface panel and board. All look good, anti-static wrapped, and should be a big help to anybody with 11K stuff to support. Like to sell it all as one cheap lot. We used to have a bunch of 11K frames, but all gone now, so these spares can leave too.
Let me know if any interest, I can give you all the 670 assy. number and pics if required.
all the best,
walter (walter2 -at- sphere.bc.ca)
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Tek 7D01/DF2 Logic Analyzers and P6451 pods
If anybody is looking for 7K compatible logic analyzers, I have two 7D01's, one with a DF2 formatter, and 4ea. of the wickedly hard to find P6451 pods.
These were all working when I pulled them from frames last year, but have to say as-is now, since I don't see the pod leadsets anywhere. I have some other leadsets and grabbers that might work, but don't know the Tek p/n of the intended one, or exactly what it should look like.
Anyway, these will go out for stuff day, there is a way to get them back to the USA with no shipping with Larry to the Oregon area. Let me know if anybody is interested in them, we don't have a lot of dollars tied up in them so the whole batch (2 ea. 7D01, 1 ea. DF2, 4ea P6451) can go for $120 if anybody wants them. Appearance is excellent on all items.
all the best,
walter (walter2 -at- sphere.bc.ca)
sphere research corp.
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Re: X-Y mode for Tektronix 2465A
On Tue, Mar 22, 2016 at 4:46 PM, ballen4705@... [TekScopes] < TekScopes@...> wrote: Chris, that was the answer, thank you very much! It's obvious once you
realise that all four channels by default are modulating the Y position.
Problem solved. Cheers, BruceOutlook, AOL and more) in one place. Never
delete an email again with 1000GB of free cloud storage.
You're very welcome! I'm glad to hear it worked for you. Chris
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Re: Those funny 311-0603-00 pots
For anyone needing to glue polyethylene or other tricky plastics, I think there are special adhesives meant for that. I bought some a while back at an auto parts store, but haven't tried it, so don't know if it actually works. As I recall, it had an extra bottle of a surface-activating chemical that had to be applied before the adhesive. It should help to roughen up the surface too, with an abrasive.
Ed
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Thank you Tom, Dave and Raymond for your suggestions. I did check the 15V bridge last night and it's ok so I likely will swap out a few of the IC's and see what happens as I'm getting some wacky voltage readings around them. I will keep the group posted on my progress or lack of.
Gary
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Re: Tek 485 - Intensity at Max, Cannot Adjust Down
Hi,
It smells like a DC restorer problem. The best test is to replace the diodes unless you have facilities to test the leakage at high voltage, the circuit is very sensible to diode leakage and a DMM test usually is not enough. Since anyway you have to remove them, it is safer to replace them. Another suspects are the restorer's capacitors.
Regards,
Ignacio
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Re: X-Y mode for Tektronix 2465A
Chris, that was the answer, thank you very much! It's obvious once you realise that all four channels by default are modulating the Y position. Problem solved. Cheers, Bruce
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Re: Tek 485 - Intensity at Max, Cannot Adjust Down
Hi,
It smells like a DC restorer problem. The best test is to replace the
diodes unless you have facilities to test the leakage at high voltage,
the circuit is very sensible to diode leakage and a DMM test usually is
not enough. Since anyway you have to remove them, it is safer to
replace them. Another suspects are the restorer's capacitors.
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On 21/03/2016 at 0:26, otrfan01@... [TekScopes] wrote:
Hi,
I have been working on a non-functional 485 that I picked up. I
discovered that the inverter was cycling rapidly on and off. I
resolved an issue that was shorting out the +15V power line, which
restored all power supply voltages to their correct levels.
Now, the trace is very bright (enough that if it is moved down onto
the screen, it will occasionally trip the protection circuit and cause
the power supply to cycle). The intensity control has no effect.
I have checked the DC restorer diodes with my DMM - all appear OK.
Would anyone familiar with this type of problem be able to advise next
troubleshooting steps?
Thanks, Wayne
------------------------------------------------------------------------
Posted by: otrfan01@...
------------------------------------------------------------------------
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Re: X-Y mode for Tektronix 2465A
Dear Chris, bingo! We will try again and report back. Cheers, Bruce
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Re: Those funny 311-0603-00 pots
Hi,
I'm not sure what parts you are referring to, but I discovered "Gorilla
glue" some time ago. This works really well on lots of materials and
requires a little water, clamping and about 2 hours to set. Don't confuse it
with Gorilla super-glue, which is a cyanoacrylate. The info on the package
has the caveat that it is not recommended for use on polyethylene and
polypropylene. Since Delrin is polyoxymethylene, it should be ok, I think.
Try it first on somewhere hidden, as the saying goes.
Good Luck, Colin.
From: TekScopes@... [mailto:TekScopes@...]
Sent: 22 March 2016 01:25
To: TekScopes@...
Subject: [TekScopes] Those funny 311-0603-00 pots
I thought the white part is made of Delrin, but so far it has shrugged off
every glue and solvent I threw at it.
MEK, dichloromethane, hot glue, cyanoacrylate, plastic bonder epoxy, nothing
affects or sticks to it.
How can I be sure the material is Delrin, and not say, Nylon?
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Re: X-Y mode for Tektronix 2465A
On 22 March 2016 at 11:56, Chris Jones chris@... [TekScopes] < TekScopes@...> wrote: To get true X-Y plotting, connect your X input to CH1, make sure only CH2
is selected, and connect Y input to CH2. That works for me.
?I knew someone else would answer before me :). It's the same for 2445A?. Malcolm [Non-text portions of this message have been removed]
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Re: X-Y mode for Tektronix 2465A
On 22 March 2016 at 10:56, Bruce Allen ballen4705@... [TekScopes] <TekScopes@...> wrote: Thanks very much for the manual page. This page describes exactly what we
are doing.
The reason we grounded first one input and then the other input was to
force the trace motion to be purely horizontal or vertical. In fact we
achieved purely vertical motion with CH1 grounded but did not get purely
horizonal motion with CH2 grounded. Instead we got diagonal motion. Do you
agree that this is not what should happen?
With TB in X-Y mode, make sure only CH2 is on. CH1 is your X input, CH2 is your Y input. Malcolm? [Non-text portions of this message have been removed]
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Re: X-Y mode for Tektronix 2465A
I've just tried this on a 2465 and 2465A here. I turned the SEC/DIV knob all the way counterclockwise to the X-Y position. CH1 then acts as the X input, and you can use any of the other channels as Y inputs. The trick is that you can also select CH1 as a Y input (either by selecting it, or selecting no input at all so it defaults to CH1) in which case CH1 acts as both X and Y and you get the diagonal movement as described. To get true X-Y plotting, connect your X input to CH1, make sure only CH2 is selected, and connect Y input to CH2. That works for me. Chris On Tue, Mar 22, 2016 at 9:08 AM, Mark Huffstutter mhuffstutter@... [TekScopes] <TekScopes@...> wrote:
Bruce,
If You don't have a copy I've attached
the page from the 2465B manual that
speaks to XY operation. This works on My 2465.
If You are comparing channels 1 and 2, only CH2 should be selected in
Vertical Mode. You should not ground any inputs,
that is Your comparison signal.
Mark
At 12:33 AM 3/22/2016, you wrote:
Gary, thanks for the suggestion. Yesterday we
tried all possible combinations of turning off
CH1 and CH2. Also setting the input of CH2 to
GND. But we'll double check, just to be sure. Any other ideas? Cheers,
Bruce
[Non-text portions of this message have been removed]
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Re: X-Y mode for Tektronix 2465A
Hi Mark,
Thanks very much for the manual page. This page describes exactly what we are doing.
The reason we grounded first one input and then the other input was to force the trace motion to be purely horizontal or vertical. In fact we achieved purely vertical motion with CH1 grounded but did not get purely horizonal motion with CH2 grounded. Instead we got diagonal motion. Do you agree that this is not what should happen?
Cheers,
Bruce
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On 22 Mar 2016, at 09:08, Mark Huffstutter <mhuffstutter@...> wrote:
Bruce,
If You don't have a copy I've attached the page from the 2465B manual that
speaks to XY operation. This works on My 2465.
If You are comparing channels 1 and 2, only CH2 should be selected in
Vertical Mode. You should not ground any inputs, that is Your comparison signal.
Mark
At 12:33 AM 3/22/2016, you wrote:
Gary, thanks for the suggestion. Yesterday we tried all possible combinations of turning off CH1 and CH2. Also setting the input of CH2 to GND. But we'll double check, just to be sure. Any other ideas? Cheers, Bruce
<2465B XY.pdf>
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Re: Timebase and CRT Issues on Tektronix Type 545A
On 21 Mar 2016 16:49:36 -0700, you wrote: @David,
Never mind, I had never seen bumble bee capacitors before I Googled them. They are all over the place. I'll have to look into buying a jumbo set of capacitors, it looks like. Is there a preferred replacement? Electrolytic, ceramic, polyester, etc? I forget exactly who but the bumble bee capacitors came from one particular manufacturer (Sprague?) of oil and paper capacitors and earned the name just because of their looks. All paper and oil capacitors suffer from the same problems though. I have had to replace a few myself. Polyester film would be the natural and superior replacement. Ceramic capacitors could be suitable in some applications. The ripple in A seems to go away after the unit running for around 15 minutes.
I think somebody earlier mentioned a tube tester. I do not have one personally. Could a dead tube render Timebase A inoperable? Is there a visual check that can be done on tubes to find out if they are dead? The trouble with Timebase A is that is harder to work with than Timebase B, which just swings out. The tube part of the Timebase A circuit is upside down, making it harder to see the tubes.
Alex Brinister You will not be able to visually find bad tubes unless the failure is an open heater. Someone more familiar with the 545A will have better troubleshooting suggestions. I have not used mine in a while.
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David Hess