Re: Tek W Plugin 7000 & up serial.
Jerry,
A scan would be much appreciated. Thanks for taking the time to do this!
Aaron
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--- In TekScopes@..., "technite2001" <precisioncarb@...> wrote:
Greetings to the group.
I found a copy a later W manual with the FET mod. If there is a need I will scan and post it online. Its listed in the change section and is 13 pages (schematic and pictures).
Let me know.
Regards,
Jerry
W2JI
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Re: TAS485 quirks and known issues
Thanks for the info.
From message ?#2894, which is a little history of Tektronix scopes, I found out that the TAS4xx series were made in Beaverton. Already figured out that they were the last tektronix analogue scopes from the mfg date stamped around various places: march 1993.
Here is a link to the tektronix web site??. This link convinced me to get the scope.
All in all is a nice little scope. The only thing that might be deemed as cheap is the fact that the case was the same used in the TDS scopes of the time, therefore is not balanced well (CRT on the side) and has a lot of free space (you could fit another scope in there).
If you would like to see a TAS485 in Europe, just drop me an email, I live in Europe too.
From: magnustoelle
To: TekScopes@...
Sent: Tuesday, January 24, 2012 1:07 PM
Subject: [TekScopes] Re: TAS485 quirks and known issues
?
Good Day, Gala,
I am glad to hear that you are enjoying your TAS485.
You might want to read over these messages, too: #3163 and #2894.
I once had the "pleasure" to have a TAS250 on my bench many moons ago and that unit was simply just not up to the Tektronix standard. It even looked very cheaply made. It had partially unreliable pots and front button switches. Above message 2894 explained to me, why.
I have never ever seen any TAS455/465/475 or TAS485 over here in Europe to be honest...
Cheers,
Magnus
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Re: 7T11 trace shifting left as time/div rotated.
Hi David,
The half period oscillation is normal.
I would first test Q280 before bothering about a replacement type. They should be matched at Id about 1 mA each and Vds about 15 V.
Is there any need for a curve tracer? In the absence of triggering you can measure DC levels all around, drain of Q280B (should be 15 V mine 0.7 V), common source a few volts positive, difference between gates (2.2 V?). You can even probe these points during operation; a 10x probe won't disturb the results.
Maybe there is another same type dual fet in the 7T11 that can temporarily be used/exchanged?
Albert
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Yes, a slight inbalance I could understand - but +2.2V is a LOT.
Yes you can see the ramp very nicely at 100nS/div. But regardless of the sweep speed there's a very clear problem here. As the ramp stop voltage increases (more negative), the ramp start voltage moves from close to 0V until it reaches about +2.2V when the stabilised stop voltage (after the overshoot) gets to about 4V.
I've uploaded a 3 second video clip here: <>
Time to pull Q280 and put it on the curve tracer I think. 151-1011-00 seems to cross to dual 2N3822 or 2N5565, neither of which seem readily available - any suggestions on a suitable replacement dual FET?
Thanks
Dave
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Re: 7T11 trace shifting left as time/div rotated.
Yes, a slight inbalance I could understand - but +2.2V is a LOT.
Yes you can see the ramp very nicely at 100nS/div. But regardless of the sweep speed there's a very clear problem here. As the ramp stop voltage increases (more negative), the ramp start voltage moves from close to 0V until it reaches about +2.2V when the stabilised stop voltage (after the overshoot) gets to about 4V.
I've uploaded a 3 second video clip here: <>
Time to pull Q280 and put it on the curve tracer I think. 151-1011-00 seems to cross to dual 2N3822 or 2N5565, neither of which seem readily available - any suggestions on a suitable replacement dual FET?
Thanks
Dave
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-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Albert
Sent: 23 January 2012 22:24
To: TekScopes@...
Subject: [TekScopes] Re: 7T11 trace shifting left as time/div rotated.
Hi David,
At the 50 ns range, the slope of the TTH output is 5 V/ 50 ns. You have to set your viewing speed to 10 or 20 ns/div to see this nicely. At 5 us/div all you see is the stabilizing "DC" TTH output after the stop signal was received. Also the horizontal amplifier needs (long) time to stabilize. Just after the hor. output has been sampled, the TTH returns to zero.
In the wait state Q294 conducts and ideally forms a shortcut. Then all depends on how good Q280A and B are balanced. The output at TP286 will differ from zero by the same amount as the "offset" A vs B. A slight difference from 0 V is no problem at all, can be corrected further on by some zero-adj. A large difference could be due to a damaged Q280. A not ideal Q294 would give negative TTH output, not positive.
Albert
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Re: TAS485 quirks and known issues
Good Day, Gala,
I am glad to hear that you are enjoying your TAS485.
You might want to read over these messages, too: #3163 and #2894.
I once had the "pleasure" to have a TAS250 on my bench many moons ago and that unit was simply just not up to the Tektronix standard. It even looked very cheaply made. It had partially unreliable pots and front button switches. Above message 2894 explained to me, why.
I have never ever seen any TAS455/465/475 or TAS485 over here in Europe to be honest...
Cheers,
Magnus
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Re: 2465B no trace (final ¡ì6)
Yes, it was the hybrid 155-0242-01.
Fastened to its place and everything OK.
A special thanks to Joe Mc Elvenney, G3LLV, who gave me one of those rare specimens!
I just had to re-adjust the bias grid, and will check it again according to the service manual.
I'm just wondering what can be the meaning of "A1 -0.8V ?" displayed on top left of the screen... Have to check in the manual, unless someone knows it...
Many thanks to this community
Regards,
Jose Viana CT1DGN.
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--- In TekScopes@..., "viagioz" <viagioz@...> wrote:
Yesterday envening I've been re-checking VZ OUT and VQ OUT arround DC RESTORER.
The signals in the photos I published are reversed but I updated them.
Signal VQ OUT(waveform 66) is the one which is OK. By setting INTENSITY and
READOUT to mid point and HOLDOFF as well, I can get the same waveform (66) as in
the service manual.
In DC RESTORER, signal 72 is very similar to the manual, except the clamping
levels which depend from VZ OUT.
Signal 65, issued from U950 seems to be really dead:
- Isolating U950 output by dessoldering R1913 and R1920 (in DC RESTORER), VZ OUT
is about 5V not changing with INTENSITY.
- I did not load VZ OUT comming from U950, but I think it is not a current
source (it should vary between +8 and 73V according to Figure 3-9).
- Connecting VZ OUT and VQ OUT with 4K7 resistor, the trace appears and varies
with INTENSITY.
- My last check before removing U950 will be CR987, that supplies U950 thru pins
27 and 28. Anyway, VQ OUT works and supply is the same therefore it may be ok...
Now... is it worth to X-RAY it? Can be the ceramic pad removed from the heatsink
or is it fixed with resin?
I never saw one... yet, but in some manufacturer hybrids the circuitry,
including silicon chips and bounding is visible (Hi-Fi STK power out hybrids). I
gess it is not the case...
It is still a mistery how did it fail during a measurement... and the scope was
in function for few minutes, not really hot...
Regards,
Jose
CT1DGN
--- In TekScopes@..., "Tom Miller" <tmiller@> wrote:
The readout should be set to off, the midpoint, for those two displays. Not sure what effect that will have.
Tom
----- Original Message -----
From: viagioz
To: TekScopes@...
Sent: Wednesday, December 14, 2011 5:26 AM
Subject: [TekScopes] Re: 2465B no trace (cont.¡ì4)
Hi Tom,
Yes, I uploaded 2 photos. They are visible in:
Album: 2465B no trace
Description: Z channel waveforms 65 and 66
(Readout knob is fully counterclockwise, Intensity fully clockwise)
Thanks!
--- In TekScopes@..., "Tom Miller" <tmiller@> wrote:
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Re: TAS485 quirks and known issues
So I guess this thing is bullet proof, since no one knows about any quirks or issues.
Well the scope is working fine, aside from needing calibration. It is amazing to see the technological progress in this scope, I also own a Tek 465 and a Tek 475.?
From: Gala Dragos
To: TekScopes
Sent: Monday, January 23, 2012 2:32 PM
Subject: [TekScopes] TAS485 quirks and known issues
?
I have recently?acquired?a TAS485 and I was wondering if anyone knows what are the usual quirks or known issues with this series of scopes.
Is there a blue shield for this series of scopes, because I like blue.
Thanks.
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Re: Need Manual for Type W, SN 4560 & 5336
Hi to Both and Others,
I hope Jerry will made the scans of the Mod Ducument. Nevertheless in the search for the right Manual see below:
The first one:070-432 or 070-0432-00
Type W (SN 100-6999) : 070-0432-01
Type W (SN 7000 and up): 070-1109-00
Egge Siert
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Re: Tek W Plugin 7000 & up serial.
Hi Jerry,
I think scans of the Mod Document are highly appreciated. Thank you.
Egge Siert
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DSA 602 failing self test
Folks,
I undertook the replacement of the batteries in my DSA 602 this evening. All went well, with the removal and replacement of all three batteries. When the scope was powered back up, things seemed fine, it self tested, ran enhanced accuracy and all looked good.
However, when I powered it back up a second time, and subsequently, it fails self tests on test k) acquisition, area - serial loop, Routine SL Dmx 1 mst with an error G3121 It is expecting 000 and gets 0333.
This sounds like a loose connector or board, however, there isn't anything I can find at this point.
Anyone have any suggestions as where to start looking?
Thanks
Bob KI2L
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Re: Total beginner with newly acquired 475 with issues
Here is really good reading on troubleshooting an oscilloscope. It is a Tektronix document, of course!
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Re: Total beginner with newly acquired 475 with issues
Hi Magnus,
You didn't "amend" my recommendation, you added to it. I agree, your recommendation would be the next step. Power supplies must work properly for everything else to work properly.
Arden
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.......- one shall start with some basic checks of the
power supply first. It seems you already started with that... Now, to no
surprise, a high percentage of failed Oscilloscopes results from a degraded
power supply
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Re: Tek 545A Scope + 4 Plug-ins FREE to a Good Home
I would like to be considered if the shipping is reasonable, please.
?
-Don
From: bsr9000 To: TekScopes@... Sent: Monday, January 23, 2012 4:56 PM Subject: [TekScopes] Tek 545A Scope + 4 Plug-ins FREE to a Good Home
?
Hi All,
I have a 545A, 3 pre-amps (Types CA, K and L) and 1L5 Spectrum Analyzer all on a 500/53A Scope-Mobile with manual (incl. schematics) that I would like to give to someone who will truly appreciate it for what it is. It was given to me about 15 years ago and have used it many times until about 5 years ago when I turned it on and no trace on the screen. I was working with an expert via email helping me fix it. We narrowed the problem to the CRT HV supply. Diodes are all good. It is very likely a cap in the tripler. I didn't have a HV probe or voltmeter >1kV to test the caps and was in the process of getting one when I just ran out of time. Still don't have the time. I need the space and I can't simply, well, toss it......
I would strongly prefer to give away the whole package and not parts. I'm in southern NH and would be willing to drive a couple hours to get it to the right person. If you are seriously interested in taking
the whole package, please let me know. Additional questions welcome. If multiple interested parties, I'll prioritize in the order received.
Brett
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Re: Displayed signal becomes compressed when position is moved to the left
As others have suggested, check the physical connections at the CRT before
you do anything else.
tom jobe...
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----- Original Message -----
From: "david_s5y" <david_s5@...>
To: <TekScopes@...>
Sent: Monday, January 23, 2012 11:31 AM
Subject: [TekScopes] Displayed signal becomes compressed when position is
moved to the left
Hi,
On a tek 2230 in non-store mode, the displayed signal becomes compressed
when position is moved to the left.
So if I have a 5K square wave displayed at .1 Ms the first 1/2 of the wave
will be 60% the width if I move it to the right. It also looks like
brighter.
+==+==+==+==+==+==+==+==+==+==+
---___---___--- <moved to right>
+--- Short and brighter.
V
==___---___---
What needs adjusting
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Re: Displayed signal becomes compressed when position is moved to the left
Does the trace compress to the left with both timebases? For the part which is not compressed, is the timebase still in calibration? Unfortunately I suspect the problem is going to be somewhere around U760 on schematic 7 but I would also check the levels of STORE and NOT STORE to the right of U760 on schematic 7. On Mon, 23 Jan 2012 19:31:20 -0000, "david_s5y" <david_s5@...> wrote: On a tek 2230 in non-store mode, the displayed signal becomes compressed when position is moved to the left.
So if I have a 5K square wave displayed at .1 Ms the first 1/2 of the wave will be 60% the width if I move it to the right. It also looks like brighter.
+==+==+==+==+==+==+==+==+==+==+
---___---___--- <moved to right>
+--- Short and brighter.
V
==___---___---
What needs adjusting
|
Tek 545A Scope + 4 Plug-ins FREE to a Good Home
Hi All,
I have a 545A, 3 pre-amps (Types CA, K and L) and 1L5 Spectrum Analyzer all on a 500/53A Scope-Mobile with manual (incl. schematics) that I would like to give to someone who will truly appreciate it for what it is. It was given to me about 15 years ago and have used it many times until about 5 years ago when I turned it on and no trace on the screen. I was working with an expert via email helping me fix it. We narrowed the problem to the CRT HV supply. Diodes are all good. It is very likely a cap in the tripler. I didn't have a HV probe or voltmeter >1kV to test the caps and was in the process of getting one when I just ran out of time. Still don't have the time. I need the space and I can't simply, well, toss it......
I would strongly prefer to give away the whole package and not parts. I'm in southern NH and would be willing to drive a couple hours to get it to the right person. If you are seriously interested in taking the whole package, please let me know. Additional questions welcome. If multiple interested parties, I'll prioritize in the order received.
Brett
|
I've one but wont be able to retrieve it until Friday, as I work in another school district 80 miles from the homestead.? To be clear, it is the one with the Lemo connectors, correct?? As a matter of fact, I've several 7704a spare parts; I now use when I get a chance, the 7854.? Respond off list; it wont be much, and S&H will also be relatively cheap with Priority Mailer.? Take care all; I'm reading but oh so very busy with teaching 4 subjects and two young sons.
Sent from my Milestone X
-----Original message----- From: Henry Brown <htbrown@...>
To: Tektronix Scoipes <TekScopes@...>
Sent: Mon, Jan 23, 2012 21:35:12 GMT+00:00
Subject: [TekScopes] 7704A Readout Board
?
Hello all, I have a Tek 7704A with no readout. Does any one have a readout
board (No. 34) on lower left rear or scope? Is there a source I could
contact for the board? Thanks much -- this group looks very interesting
with plenty of information on scopes. 73 de Hank
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Re: 7T11 trace shifting left as time/div rotated.
Hi David,
At the 50 ns range, the slope of the TTH output is 5 V/ 50 ns. You have to set your viewing speed to 10 or 20 ns/div to see this nicely. At 5 us/div all you see is the stabilizing "DC" TTH output after the stop signal was received. Also the horizontal amplifier needs (long) time to stabilize. Just after the hor. output has been sampled, the TTH returns to zero.
In the wait state Q294 conducts and ideally forms a shortcut. Then all depends on how good Q280A and B are balanced. The output at TP286 will differ from zero by the same amount as the "offset" A vs B. A slight difference from 0 V is no problem at all, can be corrected further on by some zero-adj. A large difference could be due to a damaged Q280. A not ideal Q294 would give negative TTH output, not positive.
Albert
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I can only think I'm not interpreting what I'm seeing on the 'scope screen correctly.
I'm probing TP286 (output of TTH) with Sweep Range set to 50nS, 5nS/div in sequential mode. I have the viewing timebase set for 5uS/div. The signal I see at high scan rates is similar to waveform capture 11 in the 7T11 and 7T11A manuals except that the top of the bright zone starts ABOVE 0V, and the bottom of it is about 5.6V below there. The picture of this signal manuals however clearly has the top of this signal at 0V with nothing above
I can't reconcile what I see with the descriptions in the manual that say the TTH ramp starts at 0V and goes more negative until stopped by the slewing ramp comparator.
How can the TTH ramp voltage ever be +ve in sequential mode???? I could possibly understand the bright zone moving down as you turn the Time Position controls CCW if the individual trace line in the brightened zone represents the value of the TTH ramp after it has been stopped by the slewing ramp comparator for this sample (I now think this is the case). But I cannot see how it can end up above zero!
If you turn the Scan control fully CCW, you can actually see the voltage ramp down and then jump back up.
D.
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S-30 delta standard and P93C pictures for 130
I just required a Tek 130 LC meter. A cute thing but it need some calibrating.
I want to make a S30 but can not find a picture of the inside (strays seem to play an important role so I picture could help)
Also I would like a picture/drawing of the P93C probe. As far as I can find it is just a piece of coax. Using only the bare center conductor. So it is shielded but that would be a very simple thing to get a real probe type number ;-)
Hope someone can help me.
Thanks,
Fred
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Re: 2901 time mark generator manual
On 23/01/2012 22:07, colingoode2000 wrote: Has anybody got a manual for a 2901 time mark generator in electronic form they are willing to share
Regards Colin
There's a copy here somewhere Gordon
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David C. Partridge
bownes
mescalero
KB6NAX
David Hess