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Re: Hello everyone @ tekscopes
In a message dated 11/1/00 5:52:38 PM Eastern Standard Time, sjhel@...
writes: I checked out the SND tube sales site the other day & discovered thatThe 570 is a very rare item even here in the US. A friend of mine had one and sold it to a collector for a quite high price. You can see that very unit on the cover of Alan Douglas's "Tube Testers and Classic Electronic Test Gear". According to the book, only about 1000 were made over a period of ten years, starting in 1956. Mike Csontos |
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Re: Parts needed
Arnoud van der Wel
Hi Michael,
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I have the pot here for you. Can you give me a postal address? Regards, Arnoud. -----Original Message----- |
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Re: 1S1 repair news :-)
--- In TekScopes@..., Michael Dunn <mdunn@c...> wrote:
As for the six missing GaAs diodes in the sampling bridge andunit is now working somewhat - there are some triggering and offsetvalid trace!!! Whether these probs are a result of the Schottkys, Idon't yet know. All I can say is, it's VERY cool to scroll over a 200MHzuseless, as the risetime of the thing is *only* about 300ps...Hi, replacing the GaAs diodes with Schottkys sounds extremly interesting. Could you write which type of Schottky diodes you used? I think a lot of (potential) sampling plugin repairers would appreciate this information, at least I would. Thanks a lot, Laurent Lamesch |
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Re: Hello everyone @ tekscopes
Stan or Patricia Griffiths
Hello Stuart,
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Welcome to this group of Tek scope fans! The type 570 Tube Curver Tracer is probably the most desired of early Tek scopes. This also makes is rare and expensive. Tek only made about a thousand of them and most of the remaining ones are in the hands of "glass audio" enthusiests who value them very highly. Pristine ones are worth about $3000 USD in the Far East, as I understand it. You would be very lucky to find one at any price . . . I have one in my collection, but I was lucky to find it in an estate sale in a barn about 30 miles from my home near the orignal Tek plant. Mine is a proto-type and was built before regular production on them started. I got it for $40 USD, as I recall it. You might find the web page dedicated to early Tek scopes at <> to be of interest to you. There is a list of people who can supply manuals or copies of manuals there for Tek instruments. I sell some manuals myself on eBay so you might want to check that out too. I have a rather huge collection of old Tek stuff (665 instruments) and I might be able to help you solve some of your 545B/CA problems if you describe them to me. You will need manuals for each of those instruments and it would help if you had them first so we can have a common ground for discussing the circuitry. Stan w7ni@... Stuart Hellier wrote: I have been looking for other fans of vintage tektronix stuff for |
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Re: Parts needed
Michael
Hi Arnoud, :)
Sometime on Thu, 02 Nov 2000, you wrote: -Hi Michael,Sure can. :) Michael Dunn PO Box 103 Woodford NSW 2778 Australia How would you like me to pay you for it...? Thanks and regards, :) Michael -- Michael VK2XMD 0404-478-205 I used to have a handle on life, but it broke ... |
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Arnoud van der Wel
Hi Michael,
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Sorry: the request for you address should have gone to you directly, not to the list. I don't need payment; happy to be able to help you out. Regards, Arnoud. -----Original Message----- |
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Re: Hello everyone @ tekscopes
Hi stan, thanks for the website info. Stefan has kindly offered to photocopy
his 545b manual so that's one hurdle crossed. The problems i'm having with my 545b are: The trace stops and becomes a stationary dot once the scope has been on for around 10-15 minutes. Channel A of the CA plug in does not match the voltage settings of CH B even when adjusting the gain pot. Horizontal display selections other than B and B intensified by A only display a dull "cloudy" hue, occasionally showing a trace as you turn the time / cm control. I have a tube tester & tested all tubes for quality and leakage & they all checked out okay so I guess these problems are to do with other parts of the circuitry. Bye for now Stuart |
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Re: 1S1 repair news :-)
Michael Dunn
At 5:13 PM +0000 2000/11/02, jlamesch@... wrote:
Hi,Giving you part numbers would not be too useful, since the 1S1 still has the offset problems I mentioned. I got a couple of different types through Digikey. If you want to experiment, I expect it's best to look for low-capacitance parts, say, 1-2pF. I'll get back to the 1S1 when I have time. It *is* a weird circuit, and difficult to troubleshoot, even with the manual! BTW, the Sept 18th Electronic Design has a design idea circuit that's very similar to the Tek design, but modernized and simplified. Quite a coincidence! ----------------------------------------------------------------- Michael Dunn | Surround Sound Decoder & Stereo Enhancement Cantares | Self-Amplified Speakers, Test Equipment 74 George St. | Ambisonic Surround Sound CDs and Recording Waterloo, Ont. | (519) 744-9395 (fax: 744-7129) N2J 1K7 | mdunn@... Canada | ----------------------------------------------------------------- |
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Re: Hello everyone @ tekscopes
Stan or Patricia Griffiths
sjhel@... wrote:
Hi stan, thanks for the website info. Stefan has kindly offered to photocopyMost scope problems, it seems, are in the power supplies. I would check the power supplies to make sure they are still regulating when the problem shows up. It would be helpful to know if both A and B sweeps stop at the same time or if it is just one of them. Channel A of the CA plug in does not match the voltage settings of CH B evenOn this problem, I would like to know if it appears that the gain is too low or too high and which channel seems to have the problem? Is the same problem evident in all setting of the volts/div switch or is it just one position? Horizontal display selections other than B and B intensified by A onlySince the trace seems to be there only occasionally, it sounds related to the first problem you mentioned. The dull "cloudy" hue may be due to faceplate clouding on the CRT. Take a close look at the pads cushioning the CRT inside of the shield at the faceplate. Are these BLACK foam rubber or are they sort of orange-brown in color? If it is a strip of black foam-like material, this is bad news and needs to be replaced with different cushion material. There was a chemical reaction between the material that bonds the plastic implosion shield to the front of the CRT and the black cushion material that results in the bonding material in front of the CRT turning cloudy. There is a cure for this and I can share more information with you about it if the cushion materials are black or you thing the CRT faceplate bonding material has become cloudy. I have a tube tester & tested all tubes for quality and leakage & they allOK Stuart, we are started now and the 545B is certainly worth the trouble to fix. Stan w7ni@... |
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FS/For Trash? Type 502 Dual Beam Oscilloscope
Jeramy Ashlock
Hello, I just rescued an old 502 Dual Beam Oscilloscope that
was about to be thrown out, tubes and all. It is in slightly beat up shape. I am wondering if it would have any value to anyone here, or should I just trash it? What do you think I could I get for this thing on ebay? |
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Re: FS/For Trash? Type 502 Dual Beam Oscilloscope
Michael Dunn
At 2:30 PM -0700 2000/11/03, Jeramy Ashlock wrote:
Hello, I just rescued an old 502 Dual Beam Oscilloscope thatNot sure what you could get on eBay, but don't trash it! I'll pay you a reasonable amount for stripped parts if you don't want to keep it together. Shipping intact might be prohibitive. Does it have PCB vertical amps, or little sub-chassis with ceramic strips? ----------------------------------------------------------------- Michael Dunn | Surround Sound Decoder & Stereo Enhancement Cantares | Self-Amplified Speakers, Test Equipment 74 George St. | Ambisonic Surround Sound CDs and Recording Waterloo, Ont. | (519) 744-9395 (fax: 744-7129) N2J 1K7 | mdunn@... Canada | ----------------------------------------------------------------- |
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Re: FS/For Trash? Type 502 Dual Beam Oscilloscope
Stan or Patricia Griffiths
Hi Jeramy,
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An old Tek scope like a 502 always has SOME value but whether it is worth the cost the box and ship it is a good question. It is always a good idea to offer these things to the list but it would be helpful to know WHERE it is located to know if one could pick it up without boxing and shipping. As to what it might be worth on eBay . . . good question. I have sold tons of stuff on eBay and I have really been surprised at what some of it went for. I have also put some stuff up for auction that never got a single bid . . . sometimes I have relisted a "no bid" item and gotten good bids on the second try. It is hard to guess what will happen on eBay. Here is my guess at what it is worth: If it looks dead with no trace when you plug it in and turn it on: $10.00. If it has a trace and appears to work: $25.00. A little more if it has a manual and/or probes or a scope cart. I already have two of them plus two 502A models but I would still find a place for it here to save it from the landfill if it was close to here and I could get it just for picking it up. Stan w7ni@... Jeramy Ashlock wrote: Hello, I just rescued an old 502 Dual Beam Oscilloscope that |
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Re: FS/For Trash? Type 502 Dual Beam Oscilloscope
In a message dated 11/03/2000 9:56:55 PM Eastern Standard Time,
w7ni@... writes: It is hard to guess what will happen on eBay. Here is my guess atit just for picking it up.My experience is about the same. I have 5 or 6 502s and would really like to have one operating on each bench that I use for audio work, but they really need thorough servicing and recapping. I burned out two transformers before I learned not to turn them on. I have paid $0.00 to $25.00 for them. I would pick up any similar vintage Tek equipment that are available for the hauling within 50 miles of Rochester, NY or $5 to $15 for one that sits in front of me at a Hamfest. At that rate I get about all I can handle. Mike Csontos |
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Re: Tek 7B87 Question
Dear Don!
The 7B87 is a timebase that features a pretrigger aquire clock to enable a pretrigger otion in the digital storage mode of the 7854. It works in all other 7k scopes i own. The main disadvantage of this timebase is that it does not have the delta delay or normal delay for a delayed timebase. Also the independent/runs after delay/triggerable after delay button is not available because it will control the pretrigger operation. When You use it as delayed timebase (eg with a 7B15 or 7B85) it will work fine. (similar to a 7B80) Michael B. Haubmann mhaubmann@... --- In TekScopes@..., "Don Crano" <donc@s...> wrote: I know the 7B87 plug in is designed to support the features of the7854 frame, but can it be used in a 7904 frame, or is it strictly forthe 7854 frame? |
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Re: Tek 7B87 Question
Stan or Patricia Griffiths
HI Don,
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The 7B87 can be used in any 7000 series main frame, including the 7904. Stan w7ni@... Don Crano wrote: I know the 7B87 plug in is designed to support the features of the 7854 |
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What to do with a pile of 7A16P's?
walter shawlee
We have a pile of 7A16P's, the programmable version of the 7A16, used
in waveform digitizers like the 7912D and 7612AD. Unfortunately, we have no digitizers, so these are worthless to us, and do NOT work in regular frames. Rats. Other than landfill, any suggestions? Note that we have lots of other mor useful Tek items, parts and CRTs on our website here: Also have about 150 pounds of partial and failed 5K/7K plug ins we are scrapping. Free to anybody that wants to pay the freight. We are also looking for CRT's, nixie tubes and HP repair parts. all the best, walter walter2@... |
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Re: What to do with a pile of 7A16P's? CADC?
Michael Dunn
At 4:24 PM +0000 2000/11/09, walter shawlee wrote:
We have a pile of 7A16P's, the programmable version of the 7A16, usedStrip off any easily strippable parts, hardware, knobs, etc, and sell grab bags of Tek parts. Also have about 150 pounds of partial and failed 5K/7K plug ins weTempting :-) Could you post a rough list of 7000 modules...? Any particularly "interesting" ones? (7C,D,L,M,Snn) BTW, is the 5000 series a successor to the 7000, or concurrent? What's the difference? I'm quite amazed at the tube/SS overlap - the 7000 series started to happen in the late 60s, yet tube units were produced till perhaps 1973(?). Semi-related question for Canadians out there: Anyone know if CADC (Crown Assets Disposal Corp) or a successor is still in operation? I used to get all sorts of interesting junk through them. ----------------------------------------------------------------- Michael Dunn | Surround Sound Decoder & Stereo Enhancement Cantares | Self-Amplified Speakers, Test Equipment 74 George St. | Ambisonic Surround Sound CDs and Recording Waterloo, Ont. | (519) 744-9395 (fax: 744-7129) N2J 1K7 | mdunn@... Canada | ----------------------------------------------------------------- |
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1A5, 1A7
Michael Dunn
Does anyone know the difference between the 1A5 and 1A7 differential plug ins?
thx ----------------------------------------------------------------- Michael Dunn | Surround Sound Decoder & Stereo Enhancement Cantares | Self-Amplified Speakers, Test Equipment 74 George St. | Ambisonic Surround Sound CDs and Recording Waterloo, Ont. | (519) 744-9395 (fax: 744-7129) N2J 1K7 | mdunn@... Canada | ----------------------------------------------------------------- |
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