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Re: tektronix 214 option 94
Hi Miguel,
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I would guess that around 1984 Mercury was banned in the US around that time. But I am pretty sure Tek used rechargeable Nickle Cadmium batteries in their scopes. Nickle Cadmium has always been the rechargeable battery of choice by everyone. If you notice this modification applied to instruments starting with serial number B010100. That is the serial number of the first instrument to come off the production line so I believe you are correct. This was a flaw in the original rectifier circuit design that they were correcting. I do not believe it has anything to do with Option 94. Option 94 should have been listed in the service manual since options are always listed in the catalog and available to the customer at the time of purchase. If you look at the back pages of the service manual for the 214 you will see the options listed. But there is only Option1 and 2. There is no option 94 so the mystery remains unsolved. I have another idea that may shed some light on this. I will ask Hakan Hinze what he can find out. Dennis Tillman W7PF -----Original Message----- -- Dennis Tillman W7PF TekScopes Moderator |
Re: Is it possible to get an eye diagram on a TDS784?
Usually you want to trigger on the clock.? That way all the data transitions overlap and form the eye.? Eye closure top to bottom indicates noise, ringing, and other amplitude anomalies.? Eye closure side to side indicates jitter and other time-based anomalies.? But you probably knew that.
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Sent from my Verizon, Samsung Galaxy smartphone -------- Original message --------From: Mark Goldberg <marklgoldberg@...> Date: 8/17/18 10:28 AM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] Is it possible to get an eye diagram on a TDS784?
You really should have active data if you want a worst case eye diagram. Intersymbol interference, jitter and line reflections will vary depending on the data. Assuming your data has 2 or more states, transitions at fixed intervals,is random and has some sort of preamble that is fixed, you can trigger on one edge in the preamble and then look at the eye later down the data where it is random and see the worst case with a long persistence setting. I don't know if this will work for your data. Hold off may help triggering where you want. Regards, Mark On Fri, Aug 17, 2018 at 9:46 AM, dnmeeks <dan-meeks@...> wrote: InstaVu seems like the right place to start, but I don't know a way to |
Re: Tektronix 465,NO Trigger
Hi John,
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Ok... So it seems there's a strong DC offset pushing/pulling the A Triggering pre-amplifier way out-of-range. There can be several causes to it. My own 464, for instance, had a defective FET on the Tirggering pre-amplifier input buffer. From this point on, I can't guide you much further without knowing what version of Trigger board you have... So that I can grab the correct schematics and give you objective instructions of where to try to measure things up. If it's convenient for you, take a picture of the board and send me PM, and I can post the picture on the Tekscopes photo area. Rgrds, Fabio On Fri, Aug 17, 2018 at 01:17 PM, John Stoole wrote:
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Re: Tsk 2467b test 05 error
On Fri, 17 Aug 2018 at 13:01 <Sscandizzo@...> wrote:
1) Why would the scope appear to pass test 05 when I manually run theI don't know why this would happen, it's a mystery for you to figure out :). It might be because I'm pointing you in the wrong direction, and what's actually happening is e.g. that the trigger hybrid's connections have oxidized, and you have temperature-dependent intermittence. You might have a bad U500 trigger hybrid - it happens. It might also be because the leaked electrolyte changes its characteristics or evaporates to an extent after conducting for a while. The 05 tests effectively compare DAC-generated voltages to the line trigger input by means of the trigger hybrid, so anything involved in that process might be at fault. However, the most common failure by far leading to the 05 errors in the 24X5B scopes, is leaking electrolytics. You can conclusively answer the question of whether your DAC's compromised by opening the scope up and measuring the +1.36 and -1.25V reference voltages on the A5 board. This is the board on the right side of the scope, very easy to get to once the case is off. Even if those are good, you want to do a close visual inspection of the four SMD caps on that board and surrounding components. There are only 4 of those SMD capacitors on the A5 board, and I don't think I've ever heard of SMD caps anywhere else in those scopes. If you want to e.g. do a full power supply recap, there are recent threads here that will refer you to spreadsheets that I've never consulted. The caps in question, however, have nothing to do with the power supply, they're just bulk decoupling caps for the A5 board. |
464
can anyone advise me on a 464 ? there is no hv. checked all power supply voltages.they are ok.the hv oscillator is not running.i cant make any sense of the voltage readings i am getting on the transistors in the circuuit. they are all wrong. i suspect T1501 hv trans may be the cause. i do have schematic.
can anyone advise me on this problem ? thanks Mark D. |
Re: Is it possible to get an eye diagram on a TDS784?
Yes it's definitely possible on TDS7xx. It's a bit better on the later versions (i.e. 7xxD vs 7xxA) because InstaVu was improved to include grading. Intensity is visible through color mapping. You want to trigger on only one waveform, then change horizontal position to 3-5 events further down the line and use your persistence adjustment to fine tune your eye.?
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--Eric Sent from my Samsung Galaxy smartphone. -------- Original message --------From: Mark Goldberg <marklgoldberg@...> Date: 8/17/18 12:28 PM (GMT-06:00) To: [email protected] Subject: Re: [TekScopes] Is it possible to get an eye diagram on a TDS784?
You really should have active data if you want a worst case eye diagram. Intersymbol interference, jitter and line reflections will vary depending on the data. Assuming your data has 2 or more states, transitions at fixed intervals,is random and has some sort of preamble that is fixed, you can trigger on one edge in the preamble and then look at the eye later down the data where it is random and see the worst case with a long persistence setting. I don't know if this will work for your data. Hold off may help triggering where you want. Regards, Mark On Fri, Aug 17, 2018 at 9:46 AM, dnmeeks <dan-meeks@...> wrote: InstaVu seems like the right place to start, but I don't know a way to |
Re: Is it possible to get an eye diagram on a TDS784?
You really should have active data if you want a worst case eye diagram.
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Intersymbol interference, jitter and line reflections will vary depending on the data. Assuming your data has 2 or more states, transitions at fixed intervals,is random and has some sort of preamble that is fixed, you can trigger on one edge in the preamble and then look at the eye later down the data where it is random and see the worst case with a long persistence setting. I don't know if this will work for your data. Hold off may help triggering where you want. Regards, Mark On Fri, Aug 17, 2018 at 9:46 AM, dnmeeks <dan-meeks@...> wrote:
InstaVu seems like the right place to start, but I don't know a way to |
Re: Tsk 2467b test 05 error
Hi Siggi,
Thank you for the explanation. Two followup questions: 1) Why would the scope appear to pass test 05 when I manually run the diagnostics but fail on start-up? This probably doesn't change the solution, just curious. 2) Has anyone created a comprehensive list of the caps necessary for a full overhaul? I'd rather not re-invent the wheel if such information has already been collected. Best, Stefan |
Re: 2215A LVPS repair
Could someone please post the model # for a replacement of the Schaffner line filter unit for a standard 120V North American powered Tek 2215a scope ?
Would this new "mysterious" replacement line filter unit also work in the 2235 & 2465 Tek scope Series; Or are there different models of the New replacement line filter for each scope, individually ? -- Brand, Model # & sources (web links) for the New replacement Line Filters, please. thank you ! |
Re: Tektronix 465,NO Trigger
John Stoole
Hi Fabio, I carried out the following test .....
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While pressing the Trig View, press also the Beam Finder (you should see the trace either stuck near the top or the bottom of the screen). While keeping both pressed, move the A Trigger Level, to see if the trace shows any tendency to move towards the center of the screen... This will give you some hints if the trigger preamplifier is really stuck at some DC level, or if it still reacts to the A trig When pushing the Trig View, /Beam Finder, I get a short trace near the bottom of the screen, but moving the A Trigger Level, has no effect at all John On 17 August 2018 at 13:38 Fabio Trevisan <fabio.tr3visan@...> wrote: |
Re: tektronix 214 option 94
Hi Dennis, thanks for your answer, could be a modified rectifier board?
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Regards Miguel -----Mensaje original----- De: [email protected] [mailto:[email protected]] En nombre de Dennis Tillman W7PF Enviado el: jueves, 16 de agosto de 2018 18:24 Para: [email protected] Asunto: Re: [TekScopes] tektronix 214 option 94 Hi Miguel, That is definitely an odd number for an option. Up until now I would have said options are ALWAYS listed in the catalogs as opposed to modifications which are never listed. But I just checked the 1983 catalog and the only options are 01 and 02 and they relate to different mains power for use in foreign countries. Does your 214 have an unusual power plug? I just checked my 214 and it has no options. My option "insert" is blank. Dennis Tillman W7PF -----Original Message----- -- Dennis Tillman W7PF TekScopes Moderator |
Re: 466 power transistor
If the Mouser part is a TO-247 case, the thermal resistance, ¦¨j-c, is the same. When you get it you should see a metal (tin plated copper) pad embedded on the backside. Should work just fine if there is enough clearance for the slightly larger (+.004") leads.
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Dave On Thu, Aug 16, 2018 at 11:33 PM, Jim Olson wrote:
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Re: Tektronix 465,NO Trigger
Hi John,
No problem about the time... It's a relief for my mind to solve those puzzles. Some comments further down, just after your answers... Regards, Fabio On Fri, Aug 17, 2018 at 07:16 AM, John Stoole wrote:Hmmm... Both things above together, may mean that the triggering signal, through the triggering input and pre-amplifier stages may be so much offset in D.C. that the triggering signal coming out of the pre-amplifier into the triggering discriminator (Tunnel Diodes or Tek Custom IC yet to be clarified) is never crossing the 0V (which is a must, for the trig. discriminator to operate). **Please try this one more thing** While pressing the Trig View, press also the Beam Finder (you should see the trace either stuck near the top or the bottom of the screen). While keeping both pressed, move the A Trigger Level, to see if the trace shows any tendency to move towards the center of the screen... This will give you some hints if the trigger preamplifier is really stuck at some DC level, or if it still reacts to the A trig level pot. 2. If I switch the A COUPLING to DC, then as I step the SOURCE switch from NORM to EXT10 the trigger lamp flashes proving the lamp is OKThis is good! It gives us some indication that the triggering discriminator is working... It's probably detecting the triggering signal crossing 0V, when you're changing selections, which is probably causing some change in the DC levels at the input stages... 4. the TRIG HOLD OFF control works well and helps to lock the waveform when movedExpected... The Sweep control logic seems to be working, otherwise there wouldn't be a trace whatsoever. 5 Tried 5 v AC into the external trigger but that would not sync the waveformThis indicates that whatever the problem is, it's probably at or after the trigger pre-amplifier input selector (e.g. it sort of rules-out that your problem is at the pick-off circuitry). In time, the pick-off circuitry are the pieces of circuitry of the Vertical pre-amplifiers that "taps" the vertical signal from Channel 1, Channel 2 or from after the channel Alternating circuit (the NORM pick-off) and routes it to the trigger preamp. If the problem would be at the pick-off circuitry (only), you would still be able to trigger from an EXT input. the rest of the scope seems to work very wellTo further help you from this point on, we will need to know: A. What kind of Trigger pre-amp board your 465 has. I`m not even sure if this "doubt" applies to the 465, but I used to have a 464 and I know that (for the 464 at least) there were two versions of Trigger boards, one that uses Tunnel Diodes, and another one that uses a Tek custom IC (as the triggering signal discriminator). Many thanks again for the help |
Re: Tsk 2467b test 05 error
On Fri, Aug 17, 2018 at 04:38 <Sscandizzo@...> wrote:
Hi Everyone, Hey Stefan, This is typically because of leaking surface mount electrolytic capacitors on the A5 board. If you consult the archives, you¡¯ll find plenty of information about this problem. Those capacitors will need replacing and the PCB cleaned to prevent further damage. The error occurs because the electrolyte wrecks the resistors (or PCB tracks) that provide the reference for the DAC, so you¡¯ll have to see about replacing those and/or repairing the PCB. The A5 board generates two reference voltages, 1.36V and -1.25V. If you measure those, I bet you¡¯ll find them off a bit. Note that at least one of those resistors is a low temperature coefficient type, which helps with holding calibration and working in spec across the operating temp range. The other possibility is that there is something going on with the line triggering path, but even then you¡¯d want to replace those capacitors preemptively. Good luck, Siggi |
Re: Tektronix 465,NO Trigger
John Stoole
Thanks for the very comprehensive reply Fabio I will start to carry out the suggestions you have made, and will let you know how I get on
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73 John On 16 August 2018 at 22:02 Fabio Trevisan <fabio.tr3visan@...> wrote: |
Re: Tektronix 465,NO Trigger
Thanks Harvey, all suggestions are very helpful as I said before I am useless when it comes to scopes and it a big learning curve!!!!
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From all the tests I have made there seems to be a complete lack of any trigger action, and No trigger lamp indication, will carry out the tests you have indicated and once again thanks for taking the time to offer help 73 John On 17 August 2018 at 00:18 Harvey White <madyn@...> wrote: |
Tsk 2467b test 05 error
Hi Everyone,
I'm definitely a newb to electronics repair, so I wanted to get some advice about my Tektronix 2467b. On startup, the scope errors out with one of two codes: "Test 05 Fail 04" or "Test 05 Fail 42". However, if I run the diagnostics (single time or loop), test 5 passes. Generally, the scope seems to be behaving itself (nothing obvious). Any suggestions on where to start or why it is behaving like this? Thanks! Stefan |
466 power transistor
I have to replace the large power transistor on the A6 inter board the TIP35A one it was damaged from prior ill handling plus it appears to have been overheated at sometime as the case is deformed. I found a replacement on Mouser and have ordered it not expensive so I'm asking if ya'all think it will work as well as the original? It is a Central made & supplied version and it is now full plastic case no metal tab it is like the 475 ones. It is rated 25A, 60V 125W don't know what original is as no specs in manual.
Also I have discovered that the A6 board has been updated to the later B2000000 and on type parts added. My scope sn#168*** and my board is -09 not listed in either manual? When i get it together and calibrating I will be here for advise on proper adjustments. On the A10 storage board cap C1967 is a blue Sprague 1uf 150v aluminum lytic not a wet tant, interesting the other two are still wet tants. Jim |
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