Re: An actually rare Tektronix item
That most definitely was NOT done by Tektronix. Too bad, nice piece, even without any documentation. 73, Dick, W1KSZ On Fri, Mar 30, 2018 at 12:24 AM, Michael A. Terrell < mike.terrell@...> wrote: They did a nasty job installing that IEC power connector!
-----Original Message-----
From: "snapdiode via Groups.Io" <snapdiode@...>
Sent: Mar 30, 2018 1:04 AM
To: [email protected]
Subject: [TekScopes] An actually rare Tektronix item
POWER-SUPPLY-TUBE-AMP-BUILD-DESIGN-AMPLIFIER/282840945013?
ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649
Never seen this before. Must have been an in-house tool.
Michael A. Terrell
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Re: An actually rare Tektronix item
No business that I've worked for would allow equipment to have an opening around the power connector, for liability reasons. A metal plate would have been made, to go between the connector and the chassis. That looks to be the handiwork of someone who was too lazy to do things right.
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-----Original Message----- From: Dave Voorhis <voorhis@...>
Sent: Mar 30, 2018 6:05 AM
To: [email protected]
Subject: Re: [TekScopes] An actually rare Tektronix item
If it was formerly in regular industrial use, I imagine changing the connector so it could be powered up and used to meet some urgent deadline was of vastly greater priority than preserving either history or aesthetics.
On 30 Mar 2018, at 09:35, Adrian <Adrian@...> wrote:
Good grief! Someone must have worked really, really hard to make that much of a mess of it!
On 3/30/2018 8:24 AM, Michael A. Terrell wrote:
They did a nasty job installing that IEC power connector!
-----Original Message-----
From: "snapdiode via Groups.Io"<snapdiode@...>
Sent: Mar 30, 2018 1:04 AM
To:[email protected]
Subject: [TekScopes] An actually rare Tektronix item
Michael A. Terrell
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Hello, to excuse my English this is a translation .j have an oscilloscope
tektro on 2235 which n has not to work since a moment and he(it) does not
hold the avec track the trigger on a wave squares, would have you one ideas
or to look with the textbook(manual worker)
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Re: Back feet for 335 scope
I uploaded the photos taken from having the feet installed on Bert's 314 to the photo gallery this morning. The album name is "Tektronix 314 and 335 Replacement Feet" Jeff ________________________________ From: [email protected] < [email protected]> on behalf of toby@... <toby@...> Sent: Thursday, March 29, 2018 1:31 PM To: [email protected]Subject: Re: [TekScopes] Back feet for 335 scope On 2018-03-29 3:19 PM, Jeff Davis wrote:
Hi Bert,
I think you want to send the photos to me, not Lee (Lee was test fitting the feet on his 335). I was the one who
sent you the samples. You can send the photos to me at n0dyjeff@... or jeff@....
Thanks!
Jeff
It might be good to post pics to the gallery here, for other people contemplating ordering replacement feet? --T
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Re: An actually rare Tektronix item
If it was formerly in regular industrial use, I imagine changing the connector so it could be powered up and used to meet some urgent deadline was of vastly greater priority than preserving either history or aesthetics.
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On 30 Mar 2018, at 09:35, Adrian <Adrian@...> wrote:
Good grief! Someone must have worked really, really hard to make that much of a mess of it!
On 3/30/2018 8:24 AM, Michael A. Terrell wrote:
They did a nasty job installing that IEC power connector!
-----Original Message-----
From: "snapdiode via Groups.Io"<snapdiode@...>
Sent: Mar 30, 2018 1:04 AM
To:[email protected]
Subject: [TekScopes] An actually rare Tektronix item
|
Re: An actually rare Tektronix item
Booze and metal files don't mix very well. :(
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-----Original Message----- From: Adrian <Adrian@...>
Sent: Mar 30, 2018 4:35 AM
To: [email protected]
Subject: Re: [TekScopes] An actually rare Tektronix item
Good grief! Someone must have worked really, really hard to make that
much of a mess of it!
On 3/30/2018 8:24 AM, Michael A. Terrell wrote:
They did a nasty job installing that IEC power connector!
-----Original Message-----
From: "snapdiode via Groups.Io"<snapdiode@...>
Sent: Mar 30, 2018 1:04 AM
To:[email protected]
Subject: [TekScopes] An actually rare Tektronix item
Michael A. Terrell
|
Re: An actually rare Tektronix item
Good grief! Someone must have worked really, really hard to make that much of a mess of it!
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On 3/30/2018 8:24 AM, Michael A. Terrell wrote: They did a nasty job installing that IEC power connector!
-----Original Message-----
From: "snapdiode via Groups.Io"<snapdiode@...>
Sent: Mar 30, 2018 1:04 AM
To:[email protected]
Subject: [TekScopes] An actually rare Tektronix item
|
Re: Tek 7623A - Lowest HF Step response adjustment issue (Mid Frequency Lacking)
Fabio,
I have just checked on my 7A26 and the Low Frequency Compensation (attenuator) adjustments do have about the correct time constant to correct for your 3usec lag in response (I only checked one of the attenuator settings, 0.1V and C114,C115). You could try using the 7A26 LF compensation to flatten the 1 - 3usec region before going back to the mainframe adjustments for the higher frequency components. I am sure you can see why the standardizer plugin is useful - you have HF compensation both in the mainframe and the plugins.
I think the sharp 'knee' you have shown on the YT video is due to trying to correct the low frequency error in the plugin with the HF adjustments in the mainframe. Adjusting the lowest frequency / latest time errors first reduces the interaction between the adjustments.
I hope I am helping rather than adding confusion, best wishes,
Roger
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Re: An actually rare Tektronix item
They did a nasty job installing that IEC power connector!
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-----Original Message----- From: "snapdiode via Groups.Io" <snapdiode@...>
Sent: Mar 30, 2018 1:04 AM
To: [email protected]
Subject: [TekScopes] An actually rare Tektronix item
Never seen this before. Must have been an in-house tool.
Michael A. Terrell
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Re: The vintageTEK Museum needs your help
The last time that I checked, my local library was using microfilm on reels, not Microfiche. Even they were confused by the name, and I was going to donate the two Microfiche viewers that I have. Luckily, I took a look at their machines before lugging mine in.
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-----Original Message----- From: John Griessen <john@...>
Sent: Mar 29, 2018 10:08 PM
To: [email protected]
Subject: Re: [TekScopes] The vintageTEK Museum needs your help
I think both have moved on from that era. Our Austin American Statesman
newspaper was bought out in 76 when I was studying at UT by Cox media,
related to Cox Cable, and became a generic paper with some local color.
they just print articles by the big remaining papers and the wire
services, plus a few columnists.
A few years ago the local building emptied and the paper is printed somewhere else.
No machines there. The public library is going virtual in a big way.
They rent as many as 60 copies of Blu-ray discs, then circulate 3, 2, 1
depending on popularity. They moved the main library location to a new
trendy spot by the river and probably lost a lot of heavy stuff -- that
was 6 months ago.
Other towns may be less speedy than Austin, but the end is near for
the niche market machines that transcribe from one phase of media to the next.
Microfiche ?
MIcrofish ?
Microsquish ?
MICR checks ?
Satire ? [still a little of that left thankfully] Michael A. Terrell
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Re: An actually rare Tektronix item
Yep, the rarer it is, the quicker it gets hacked. And that's not a pun ... look at the nice job done on the AC Plug in the rear. Sometimes I wonder what people are thinking. 73, Dick, W1KSZ ps: should be interesting to see if anyone bites at that price. On Thu, Mar 29, 2018 at 10:04 PM, snapdiode via Groups.Io < snapdiode@...> wrote:
POWER-SUPPLY-TUBE-AMP-BUILD-DESIGN-AMPLIFIER/282840945013?
ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649
Never seen this before. Must have been an in-house tool.
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An actually rare Tektronix item
Never seen this before. Must have been an in-house tool.
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Re: Back feet for 335 scope
Hi Jeff - I got the final version of the feet today & put them on my 335,
they fit and look beautiful!
I'm going to look through my collection of 2445's to see if I can find one
good foot to send you a picture of. I'm guessing they are a high breakage
rate part and likely common for the 24xx family so probably a fair demand.
They are a fairly large part though; they run vertically up the back of the
scope on either side so they are close to 6" high, 1/2" wide and 1-1/2 inch
deep. They are not solid though, there is a lot of open space. Kind of like
a tall, skinny, rectangular letter "D" with tabs at all four corners.
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On Thu, Mar 29, 2018 at 4:50 PM, Jeff Davis <n0dyjeff@...> wrote: Good thought. If Bert doesn't do that, I will when I get the photos.
________________________________
From: [email protected] <[email protected]> on behalf of
toby@... <toby@...>
Sent: Thursday, March 29, 2018 1:31 PM
To: [email protected]
Subject: Re: [TekScopes] Back feet for 335 scope
On 2018-03-29 3:19 PM, Jeff Davis wrote:
Hi Bert,
I think you want to send the photos to me, not Lee (Lee was test fitting
the feet on his 335). I was the one who
sent you the samples. You can send the photos to me at n0dyjeff@... or jeff@....
Thanks!
Jeff
It might be good to post pics to the gallery here, for other people
contemplating ordering replacement feet?
--T
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Re: The vintageTEK Museum needs your help
On 03/29/2018 07:47 PM, Brad Thompson wrote: Back in the day, two users of fiche archives were libraries and newspapers. It
might be worthwhile contacting either or both institutions in the Tek Museum area
to see whether either could provide machine time on a pro bono basis. I think both have moved on from that era. Our Austin American Statesman newspaper was bought out in 76 when I was studying at UT by Cox media, related to Cox Cable, and became a generic paper with some local color. they just print articles by the big remaining papers and the wire services, plus a few columnists. A few years ago the local building emptied and the paper is printed somewhere else. No machines there. The public library is going virtual in a big way. They rent as many as 60 copies of Blu-ray discs, then circulate 3, 2, 1 depending on popularity. They moved the main library location to a new trendy spot by the river and probably lost a lot of heavy stuff -- that was 6 months ago. Other towns may be less speedy than Austin, but the end is near for the niche market machines that transcribe from one phase of media to the next. Microfiche ? MIcrofish ? Microsquish ? MICR checks ? Satire ? [still a little of that left thankfully]
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Re: The vintageTEK Museum needs your help
I have used a flatbed scanner to scan small parts, by adding a backlight. For some things I simply laid a clean, white teeshirt over the item, and pulled my magnifying florescent ringlight down to eliminate shadows on the edges. It proveded a lot more detail than my digital camera. One thing that I learned scanning printed material was to angle it slightly, then use software to straighten it rather than to attempt to align each page by hand. About 15 degrees gave good results. I got a lot loer error rate when doing scan to OCR with this method.
The white light spreader from an LCD monitor and the CFL or white LEDs should make a nice backlight to scan entire sheets of Microfiche. I have a pile of old USB flatbed scanners, (~25) and several came with an adapter to scan 35mm film or slides. Each of them came with a backlight module that plugs into the base for power.
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-----Original Message----- From: cnc_joker <peter@...>
Sent: Mar 29, 2018 12:31 PM
To: [email protected]
Subject: Re: [TekScopes] The vintageTEK Museum needs your help
I had a look for any old microfiche but did not find any. My Epson V700 scanner
came with a number of film carriers of various sizes. One looked like it could hold
2 microfiche but it was just a little too small for the 105 x 148 mm size of a microfiche.
But the carrier is nothing special, it just serves to hold the film flat and away from
the glass. I could make something that would work out of cardboard.
I will see if I can pickup some microfiche at flea markets of junk shops.
I searched online and a lot of people have scanned microfiche with a bed scanner.
Some with better results than others. One person got good results with a 3200 DPI
scanner so my 4800 DPI unit should do better.
Does anyone want to send me some example microfiche that they don't care about?
Pete. Michael A. Terrell
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Tek P6042 Current Probe repair
Good day to all.
My trusty P6042 current probe died several years ago and I've not yet taken the time to repair (replace) the probe cable. This cable has died on me several times in the past and it's now too short to be useable.
Searching past messages suggested that I might be able to use a HDMI cable as a suitable replacement. I had originally thought of using a standard VGA cable - I will cut open as many samples of these and HDMI cables as I can lay my hands on and see if one is more suitable than the others. Guidance appreciated.
However, the reason for this post is to ask about replacing the electrolytic caps. I see that I did replace the original power supply reservoir caps quite some time ago - I haven't used Rubycon capacitors in more than a decade or two. I'll replace them again.
But I haven't looked closely at the other large capacitors on the board yet. If they are wet-slug tantalum, I'm tempted to leave them alone. If they are indeed simple electrolytic caps, I had better plan on replacing them as well.
My question to the group is this: what else should I be looking at when working on this instrument? It has worked fabulously for me for many years and I keep needing to use it - but just haven't made the time to repair it. That time is now, I guess.
Again - guidance is greatly appreciated.
Many thanks!
dwayne
--
Dwayne Reid <dwayner@...>
Trinity Electronics Systems Ltd Edmonton, AB, CANADA
780-489-3199 voice 780-487-6397 fax 888-489-3199 Toll Free
www.trinity-electronics.com
Custom Electronics Design and Manufacturing
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Re: The vintageTEK Museum needs your help
On 3/29/2018 12:31 PM, cnc_joker wrote: I had a look for any old microfiche but did not find any. <snip> Hello-- Back in the day, two users of fiche archives were libraries and newspapers. It might be worthwhile contacting either or both institutions in the Tek Museum area to see whether either could provide machine time on a pro bono basis. It's a long shot. I unfondly recall viewing microfilm for a research project and getting a headache and nausea due to the motion of the film in fast-forward mode.
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Re: TM 504 came today DC 504 not counting
Manual calls Y160 a 1Mhz quartz crystal. I ordered this
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Re: Tek 7623A - Lowest HF Step response adjustment issue (Mid Frequency Lacking)
Roger,
Well... I can't tell I`m 100% sure.
I can tap with a x10 oscilloscope probe onto the 11A and 11B signals coming out of the 7A26 Vertical plugin, and the waveform, although not perfectly square (it's a little roundy in the corner), it doesn't show that slowly flattening voltage over this long 3us time period...
I assume the non-perfect corner I see (while probing the plugin output) is because I cannot properly reference the probe with a short ground lead so, I cannot take seriously anything immediately following the sharp edge. but the passive probing + long ground lead could not be concealing this 3us long voltage lagging.
If the problem I would be having would be in the first 100ns or so, I reckon that any artifacts I see could be coming either from the plugin or from the mainframe misalignment (or a combination of both), but 3us is just too much.
For a circuitry of that grade... anything slower than 1us is almost the same as DC... lol.
I also reckon that in the 10s or 100s of milliseconds, there can be other disturbances at play, like thermal imbalance (between different sides of complementary designs) or power supply mains ripple... but that's not the case here.
Yesterday, while I still didn't have chance to probe the P.S. voltages (inside the board, after decoupled), I was really convinced there was a decoupling issue... that right after the fast corner which consumes a lot of current... the available voltage was depleting and the output would be - then - being limited by the available supply, until the - lacking - decoupling would have time to recover.
But yesterday evening I probed all the important voltage supplies and bias points, and they're pretty much rock steady.
Not happy, I added additional decoupling in parallel, to each of those voltages... and neither made any difference to the displayed waveform so, I think it's safe to conclude that there's no decoupling issue (at least not on the Vertical Amplifier board).
I still need to find ways to rule-out a possible decoupling issue on the Vertical Channel switching board, that's difficult to reach and to probe at.
Happy easter to you all.
FT
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Friend of mine has a 2215 and a 2225 I think. One of them is pretty much parts for some reason and we took the knobs for the other one. If the CRT will fit I can ask if he is willing to part with it.
But then you might find one elsewhere anyway with all that unobtaimium in there.
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Michael A. Terrell
Lee Houde
Fabio Trevisan
Jeff Urban