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Re: Calibration Fixture Question
The differences between the 067-0587-xx standardizer plug-ins for the 7000-series 'scopes are primarily bandwidth. IIRC, the -00 has a bandwidth of 250 MHz, the -01 500 MHz and the -02 1 GHz. There may be other differences - check the TekWiki site or any other website (K04BB, BarryTech, etc.) that spells out the specs of each.
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They won't be useful for calibrating non-7xxx 'scopes. I don't know what the bandwidth of the 067-0508 is, but you can download the manual from the TekWiki site. DaveD On 12/13/2018 8:54 AM, David Berlind wrote:
Hi all,... |
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Calibration Fixture Question
Hi all,...
I have 5 Tek scopes... 3 7603s, a 2220, and a 466. Earlier this year, I missed out on a good deal for a calibration plug-in and so I'm still looking for one at reasonable price. eBay's got a couple of expensive ones but the one I missed out on was about $100. I was looking for input on this...and have a couple of questions: 1. Would this external fixture be a reasonable solution for me: 2. I've been keeping my eye out for a 067-0587-01 plug-in, or a 067-0587-02 am a curious to hear opinions on why choose one over the other. 3. With the calibration plug in (vs external fixture) in the 7603, can I use it to calibrate external scopes (other than the 7603 that it's mounted to)? Thank you! |
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S-2 sampling head fault symptoms
I've searched the archives, which revealed lots of useful information, but I'd like to get a better understanding of the likely fault symptoms when sampling heads go bad.
I have two S-2 heads here, and I fear I may have killed one of them. The first one, s/n B084970, had a short-circuit 3.3uF tantalum capacitor in, which I replaced with a 10uF 25V ceramic. It now works but shows overshoot for about 500ns after the edges of a square wave. Intriguingly it also shows overshoot *before* the edge of the square wave (this is in equivalent-time sampling mode in a 7T11/7S11). Either it contains a time machine or there's something funny going on with the sampling pulse getting in to the signal. The second one, s/n B030787 has 'risetime <=50ps' on the front so it's obviously an early example. When I first tried it, I got just noise, then on the second try I got a good waveform but with bursts of noise every few seconds. While wiggling things to try and see if a bad contact was the source of the noise, the sampling head came out of its socket and I stupidly pushed it straight back in. Now it shows a significant offset (turning the 7S11's offset control all the way to the right just about brings the trace on screen). It does still show a signal, but with the following features: - there's a big disturbance for the first division or so of the trace, regardless of the setting of the time position on the 7T11 or the scan (this is still in equivalent-time mode) - the waveform is about twice as large in amplitude as it should be, and shows overshoot which depends on the scan rate. At slow scan rates there's no overshoot, but it gets progressively worse at faster rates. - there are still big bursts of noise every few seconds I looked inside the second sampling head and it doesn't have a plastic carrier for the sampling diodes. They're soldered in, so presumably are making good contact. My 7T11/7S11 seem to be fairly healthy (see separate thread) giving what seem to be reasonable results with an S-1 head. Any clues as to how to go ahead with diagnosing the faults would be very much appreciated. Chris |
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Re: 7T11 horizontal memory
On Thu, Dec 6, 2018 at 02:56 AM, Albert Otten wrote:
On Wed, Dec 5, 2018 at 10:19 PM, cmjones01 wrote:I've been back in the office today and have done some more experiments. I have no known-good sampling heads, only one S-1 and two S-2s bought very cheap and in unknown condition.- in real time mode, it's hard to get a trace that makes sense. presumablythe50kHz-ish clock from the real time multivibrator limits the display to aboutthe The risetime thing is interesting. If I use the 7T11 in real-time mode with my S-1 head, the risetime is about 100us. However, in equivalent-time mode, I can quite easily see the 350ps risetime of the head and the waveform looks accurate. With my least-broken S-2 head, the risetime in real-time mode is definitely faster than with the S-1. But the waveform as seem through the S-2 is definitely not accurate, though in equivalent-time mode the its risetime is fast (definitely better than 100ps). I'll start a separate thread about sampling head fault symptoms. Chris |
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Re: More stuff found For sale, 7000 series on cart and 7834, many modules
What Re you asking for the 7834, do you have a 7844 and 7104 ????
On Wed, Dec 12, 2018 at 5:46 PM, devin davison<lyokoboy0@...> wrote: Greetings. I hope that these listings are not bothering anyone, I am overstocked on this stuff and trying to find it a good home. I found another scope on a cart in storage, a 7000 series. It powers up but i am unable to get a trace. I also have a 7834, although i havent gotten arount to testing that one out. Also, a metric ton of 7000 series modules. Many of them are too high up on the shelf for me to see the module numbers at the moment, i need to take time to take inventory and list them all out here. I am open to offers on any of this equipment. Again, it is all located in Melbourne Fl, and i would be happy to ship if needed. --Devin D. |
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Re: Seco 250 Transistor & Tunnel Diode Tester
I've heard that Seco changed their name to Sencore.
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Michael A. Terrell -----Original Message-----
From: bobkrassa <bob@...> |
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Seco 250 Transistor & Tunnel Diode Tester
I have recently acquired one of these and am looking for a copy of the manual, "Operating Instructions Seco Model 250 Transistor & Tunnel Diode Analyzer." Not off topic as I hope that it may turn out to be a quick way to check the current inflection point of tunnel diodes in Tek equipment in-circuit, without mobilizing the 575.
If anyone has the manual, I would very much appreciate a scan including the schematic. I believe I checked the websites of all of the regular manual providers, but if one of them can provide this I would be glad to purchase a copy. My direct e-mail is bob at krassa.com for any messages that would not be of interest to the group. However, if anyone has any experience using this unit, please tell us about it! 73s Bob Krassa AC?JL |
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Model 2246
sid_saul
Hello, New member with limited scope background. I aquired this model 2246 a few months ago. The good folks at the Vintage Tech Museum fixed my triggering problem, but now something new. I cant us my cursors for both time and amplitude. Get the "Time Self Cal Failed". Also Search "Returned Bad Value at 5 us" warning. The message "Outch turn volts/div CCW turned up early on, without remedy. Tried all the service menu routines to no avail. I even replaced the backup battery without a change. Is there a routine that I might try before another visit to the museum?
This is my first data readout model. I have been using the 545B and the 2215 before now. Enjoying the discussions, and appreciate the assistance and learning experience. Sid Saul Hebo, OR |
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2246 Self Timing Calc Failed
sid_saul
Hello, New to this group. Just when the triggering problem was solved by my friends at the Tek Museum. Now the self timing failure. Reporting Time Self Cal Failed . Also reports Bad Value At 5 us. I took it upon my self to replace the 3V lithium battery but no change. Tried running all the self calibration functions to no avail. So now I can't use any of the cursor functions for time and voltage. Is there anything I can try as a complete novice on my bench?
Than you, Sid Saul |
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Big 555 scope on cart For sale must go
devin davison
Greetings. New to the list here. I was unaware of such a list until moments
ago. I have many old computers I am working on restoring, I had originally posted about this on the cctech mailing list and was advised to post about it here. I have this big ol oscilliscope on a cart that needs to go. Might be of use to someone here or a collector. I cleared out a community workshop and this was part of the equipment in the lot. I was planning to clean it up and put it to work, but i no longer have the space for it, and I have a HP logic analyzer that fits on the desk that does the job nicely in less space. make a offer and come pick it up in Melbourne Fl. --Devin D. |
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More stuff found For sale, 7000 series on cart and 7834, many modules
devin davison
Greetings. I hope that these listings are not bothering anyone, I am
overstocked on this stuff and trying to find it a good home. I found another scope on a cart in storage, a 7000 series. It powers up but i am unable to get a trace. I also have a 7834, although i havent gotten arount to testing that one out. Also, a metric ton of 7000 series modules. Many of them are too high up on the shelf for me to see the module numbers at the moment, i need to take time to take inventory and list them all out here. I am open to offers on any of this equipment. Again, it is all located in Melbourne Fl, and i would be happy to ship if needed. --Devin D. |
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Re: 2465/2467 power supply outside chassis
Chuck Harris
The inverter board creates the DC, and has its own
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feedback regulator. It can be run by itself, with a suitable dummy load. The information about the load is hidden away inside of the 2465B manual's flow charts on the power supply, between chart 10, and 11. The part they call the Primary Test Load is for running the inverter section separate from the regulator when the supply is removed from the scope. It is comprised of 3, 3.5K 20W resistors, a 3.3uf capacitor, and a 150 ohm 1W resistor. The fuse will protect the resistor from blowing, but probably costs more than the resistor... If you want to run the supply with the regulator board installed, outside of the scope, you have to use at least one 2 ohm 25W resistor shunted across the +5VD supply. It is a good idea to put a load on the other regulated supplies, just for testing purposes. I used to use some loose resistors and clip leads, but I bought a test load board from one of the members of the group, a long time ago, and it has done a nice job. -Chuck Harris thespin@... wrote: Okay apologies, I should have read the manual in more detail. I'm a bit confused by some of the flowcharts though-- If I detach the inverter board from the regulator board, can I just load it up with the 2 ohm resistors and power it, or do the two boards have to be attached to each other with the load attached to run ok? |
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Re: 2465/2467 power supply outside chassis
Okay apologies, I should have read the manual in more detail. I'm a bit confused by some of the flowcharts though-- If I detach the inverter board from the regulator board, can I just load it up with the 2 ohm resistors and power it, or do the two boards have to be attached to each other with the load attached to run ok?
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On Wed, Dec 12, 2018 at 11:31 AM, Chuck Harris wrote:
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Re: 2465/2467 power supply outside chassis
Chuck Harris
I think everyone that is serious about repairing supplies
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has run them outside of the chassis. The 2465 supplies require a minimum loading on the regulators for them to work. If this is not done, the supply will burn up. The loading requirements are described in the maintenance section of the manual. -Chuck Harris thespin@... wrote: Has anyone debugged the 2465 power supply by running it outside the unit? Can it be hooked up to line voltage and run, or is it necessary to load up the rails with resistors so it can regulate properly? If anyone has done this, would they mind sharing the proper resistors? |
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2465/2467 power supply outside chassis
Has anyone debugged the 2465 power supply by running it outside the unit? Can it be hooked up to line voltage and run, or is it necessary to load up the rails with resistors so it can regulate properly? If anyone has done this, would they mind sharing the proper resistors?
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Re: Oscilloscope 221
I use these guys a fair bit. On Tuesday, December 11, 2018, 4:45:08 PM EST, Jeff Urban <JURB6006@...> wrote:
The original is rated 45 volts. Does it really see 45 volts ? If not it looks like a 2N2369 would do but is only rated 15 volts. Take a look at the schematic. Also note your original is emitter in the middle. Reminds me of an oscillator in a UHF tuner. They usually had the emitter in the middle. If you can use the 2N2369 Digikey has them for $2.34. The BF224 is probably better but I don't see where to get any. Google comes up with total BS. Also with the BF224 the emitter is in the middle so no bending the leads around. |
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Re: Looking for 604 XY monitor
Roy Morgan
You could suspect the filter caps. They may have died.
On Dec 11, 2018, at 7:03 PM, Bill (Doc) Courtright via Groups.Io <doxemf@...> wrote:Roy Morgan K1LKY since 1958 k1lky68@... |
Jeff Urban
Michael A. Terrell
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