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Re: Tube test adaptor for Tektroinx 575 was: Re: [TekScopes] FS: miscellaneous Tektronix manuals
Dan Cordova
Brad,
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Thank you! My main interest is audio tubes. I have >1000 different tubes, mostly audio output and small signal/preamp tubes. I also own a Hickok 580A tube tester and a Tektronix 575 Curve Tracer. Thus my interest in using a Tek 575 to match tubes for use in DIY preamps and amps I am planning to make.? I was a electronics tech in the military a long time ago, in the time when tubes were going away and being replaced with solid state, but before the internet and PCs. I don't write code, although I did take a course in Fortran back in the early 1980s.? This group has been a tremendous resource. I truly appreciate the responses that I have humbly received from you and others in the group. I say humbly received because I'm just a audio hobbyist and ME who is humbled because I realize that I know so little about audio electronics who is trying to learn. For example, I didn't know until recently that tubes usually use AC voltage for the heater. I'm also learning the different terms, such as the anode is usually called the plate. It's humbling that this old technology was invented well before I was born and is still useful today.? Again, thanks to all who responded with the lessons and great information. Dan On Wednesday, December 5, 2018, 1:28:41 PM PST, Brad Thompson <brad.thompson@...> wrote:
On 12/4/2018 4:52 PM, Dan Cordova via Groups.Io wrote: ? Hi Brad,Hello, Dan and the group-- Thank you for your inquiry. Here's a column I wrote for Test & Measurement World magazine (subsequently absorbed by EDN) which describes my version of a tube-test adaptor for the Tek 575: You can view a schematic and photos here... I used an external tube socket, small PC board and some two-piece surplus connectors to build an adaptor, which suffices for small tubes that don't need plate voltages in excess of what the 575 can deliver. Heater or filament and screen voltages get supplied by "wall warts" or other power supplies In the schematic, J1 and J2 form a "crossover network" to match a particular tube's pinout. This approach requires wiring or rewiring the J1-J2 adaptor to test each tube type and thus is best suited to testing a batch of identically-pinned tubes at once. Newcomers to tube technology may be surprised to learn that many tubes with different part numbers can share a common pinout. For example, JEDEC base code 8BD defines an octal (8-pin) base which applies to the 6SN7-GT, the 6SL7-GT and their heater-voltage cognates along with 25 or so other tube-part numbers. Providing 12 pins accommodates "modern" Compactron tubes. While I noted no spurious oscillations while testing a batch of 6SN7s, you may need to slip ferrite beads onto plate and grid leads if needed for parasitic-oscillation suppression. One point: use care in selecting the grid/base voltage you apply to the tube under test. If the tube manual states "maximum positive grid voltage = 0 volts", believe it! Running the grid voltage positive causes large amounts of grid current to flow can melt the grid. Questions welcomed-- I don't have any spare adaptor boards left over but would investigate making more if there's interest. 73-- Brad? aA1IP |
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Re: TDS3032 does not boot. LCD backl-ight and fan working.
" Unfortunately, holding the B-trig during power up makes no difference. "
My experience: When I replaced by NVRAM with a fake one I bought in China, the scope would light up, but would not boot. I then order a NVRAM from a place in Florida and replaced it again and then it worked fine (Have to hold the B-TRIG in as powering up to reset the new NVRAM. It worked great then. Its out to Spectrum now for re-certification (Calibration tables were NOT lost). Dave On Tue, Dec 4, 2018 at 5:01 AM benj3867 via Groups.Io <benj3867= [email protected]> wrote: Thanks David. |
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Tube test adaptor for Tektroinx 575 was: Re: [TekScopes] FS: miscellaneous Tektronix manuals
On 12/4/2018 4:52 PM, Dan Cordova via Groups.Io wrote:
Hi Brad,Hello, Dan and the group-- Thank you for your inquiry. Here's a column I wrote for Test & Measurement World magazine (subsequently absorbed by EDN) which describes my version of a tube-test adaptor for the Tek 575: You can view a schematic and photos here... I used an external tube socket, small PC board and some two-piece surplus connectors to build an adaptor, which suffices for small tubes that don't need plate voltages in excess of what the 575 can deliver. Heater or filament and screen voltages get supplied by "wall warts" or other power supplies In the schematic, J1 and J2 form a "crossover network" to match a particular tube's pinout. This approach requires wiring or rewiring the J1-J2 adaptor to test each tube type and thus is best suited to testing a batch of identically-pinned tubes at once. Newcomers to tube technology may be surprised to learn that many tubes with different part numbers can share a common pinout. For example, JEDEC base code 8BD defines an octal (8-pin) base which applies to the 6SN7-GT, the 6SL7-GT and their heater-voltage cognates along with 25 or so other tube-part numbers. Providing 12 pins accommodates "modern" Compactron tubes. While I noted no spurious oscillations while testing a batch of 6SN7s, you may need to slip ferrite beads onto plate and grid leads if needed for parasitic-oscillation suppression. One point: use care in selecting the grid/base voltage you apply to the tube under test. If the tube manual states "maximum positive grid voltage = 0 volts", believe it! Running the grid voltage positive causes large amounts of grid current to flow can melt the grid. Questions welcomed-- I don't have any spare adaptor boards left over but would investigate making more if there's interest. 73-- Brad aA1IP |
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Re: 7T11 horizontal memory
On Wed, Dec 5, 2018 at 08:17 AM, Albert Otten wrote:
I might have good news for you.Aha! Your news is indeed good :-) I put the 7T11 in to a slot next to my 7S11 and I now have a horizontal sweep in the rea ltime ranges. You mean U512 I suppose.It was U512 when I killed it, but I swapped it with U572 to check that it was actually faulty. My 741 kludge seems to work but I'm not convinced it's perfect. The Tek chip seems specified quite fast (80MHz gain-bandwidth product!) and I think the rather pedestrian 741 may be running out of speed (or slew rate) in the faster real-time ranges. In real time ranges the horizontal amplifier now hasYes, I've observed that in the U512A/B/C/D chain too. The ramp only really makes sense properly after the last stage. The good news is that, coupled with my 7S11, I now have something resembling a working sampling system. I have three rather tired-looking sampling heads in unknown condition (an S-1 and two S-2s, one labelled 50ps risetime and the other labelled 75ps). I have only tried the S-1 but it does actually work. Observations so far: - equivalent time mode works a lot better than real time mode. At least, the waveform I see on the screen in equivalent-time mode looks like what I'd expect. I haven't tried a really fast edge in to the sampling head yet to see how the performance is at the really short time'div settings. - in real time mode, it's hard to get a trace that makes sense. presumably the 50kHz-ish clock from the real time multivibrator limits the display to about one sample every 20us, so some of the faster sweep speeds don't show a lot. Even on the slower sweeps, the edges of my test squarewave exhibit terrible risetime (about half a division) which is puzzling, and very different to the behaviour in equivalent time. Maybe it's something to do with the recovery time of the sampling head, or there's something amiss with the 7S11. I tried adjusting the 'dot response' control and making sure smoothing was switched off, but it didn't improve much. Thank you for your help so far. You can probably tell that I'm new to the 7000-series sampling world. I regularly use my CSA803A/SD24 sampling setup, but that makes it all so easy... Chris |
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Re: FS: miscellaneous Tektronix manuals
Dan Cordova
George,
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These are really outstanding!? Thank you very much, Dan On Wednesday, December 5, 2018, 6:46:28 AM PST, Glydeck via Groups.Io <glydeck@...> wrote:
Dan, Dennis¡¯ curve tracer is the more complete solution, but if you¡¯re interested in the one on my blog its in the file section of TekScopes. /g/TekScopes/files/Tek575TestFixtures.pdf George On Dec 4, 2018, at 11:01 PM, Dennis Tillman W7PF <dennis@...> wrote: |
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Re: 7T11 horizontal memory
Hi Chris,
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I might have good news for you. The real time multivibrator doesn't work when you don't have a 7S11 adjacent to (or otherwise connected to) the 7T11. So then the memory gate is always blocked and you have no sweep output at the front panel. You mean U512 I suppose. In real time ranges the horizontal amplifier now has one continuous ramp as input during the whole sweep of the 7T11. It depends on the time/div setting which outputs of U512 are really used in the amplifier chain. Not used outputs can be overdriven within short time without any consequence, and stay at some very high maximum level during the rest of the sweep . It's what I see happening. I didn't pay attention to this in my previous post about equivalent time sampling but you essentially have the same situation then. Albert On Wed, Dec 5, 2018 at 03:23 PM, cmjones01 wrote:
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Re: FS: miscellaneous Tektronix manuals
Dan,
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Dennis¡¯ curve tracer is the more complete solution, but if you¡¯re interested in the one on my blog its in the file section of TekScopes. /g/TekScopes/files/Tek575TestFixtures.pdf George On Dec 4, 2018, at 11:01 PM, Dennis Tillman W7PF <dennis@...> wrote: |
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Re: 7T11 horizontal memory
I have now replaced the faulty R541 and R542. I also found that U572B, a Tek special op-amp, was dead, I think due to a careless slip of my scope probe. For now I've kludged a 741 in its place. Joy of joys, I have a horizontal sweep in equivalent-time mode! Still blanked in real-time mode. I think there's still something not right about the horizontal memory, which seems to only be used in real-time mode (or am I wrong?). Anyhow, when I select a real-time-mode sweep range, the output of U572B wanders up to about +12V and stays there. I do have real-time sweep on the way in to the horizontal memory, though. Will investigate further.
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Chris On Wed, Dec 5, 2018 at 06:07 AM, Albert Otten wrote:
One more suggestion. Set the 7T11 for MANUAL scan. Set the test scope at 5 or |
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Re: 7T11 horizontal memory
Hi Chris,
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One more suggestion. Set the 7T11 for MANUAL scan. Set the test scope at 5 or 10 us/div, trigger from the 7T11 pulse output. Then probe all TPs 512, 515, 525, 555 of the horizontal amplifier. In each period you will see one horizontal line at a level determined by the SCAN knob setting. The level increases from ground to some maximum when you rotate SCAN from left (ccw) to right (cw). The amounts and ratios depend on the setting of the 7T11 time/div within its range. At TP555 the maximum should always be 5 V. Albert On Mon, Dec 3, 2018 at 05:13 PM, Albert Otten wrote:
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Re: Tektronix 475A intermittent / lazy sweep
Hi, From my information, it is actually the Coulsdon Amateur Transmitting Society, not Crawley. The URL below gets you to the CATS Bazaar and there are links:
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I, too have no association with the event, but I think I might try to visit next year.... Colin. -----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of george edmonds via Groups.Io Sent: 23 November 2018 23:59 To: [email protected] Subject: Re: [TekScopes] Tektronix 475A intermittent / lazy sweep Hi All The CATS (Crawley Amateur Transmitting Society) rally is correctly known as the CATS Bazaar, it was not last month but is was held on the 15th November. If you are into Amateur Radio or T&M kit it is a must go to event. Just for the record I have nothing to do with the organising of the event. 73 George G6HIG On Friday, November 23, 2018 8:35 AM, Tom Gardner <tggzzz@...> wrote: On 23/11/18 06:18, Brian Cockburn wrote: The canonical source for these rallies isAt the CATS rally (South London) ...I'm in Cambridge but I'm not familiar with 'CATS Rally'. Googling didn't turn up anything non-feline. Could you elaborate a bit pleas Since the Couldson (Surrey) rally was last month, it no longer appears there. |
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FS: 2465B A5 Boards
i have a couple of 2465B A5 boards for sale. These are the SMD version and will work in the 2445B, 2455B, 2465B, and 2467B scopes with serial # greater than B05XXXX. They have new socketed NVRAM modules and have had the electrolytic capacitors replaced. These boards have absolutely no damage on them from leaking electrolytic capacitors. Fully tested. $300 each shipped USPS Priority Mail to US 48 states. PayPal accepted.
Manuel W4SSB |
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Re: FS: miscellaneous Tektronix manuals
Hi Dan,
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I can help you test tubes on your 575. Like you I was very impressed with George Lydeck's (Glydeck) creativity and when a 575 fell into my lap for $20 it acted as a catalyst for me to build an adapter to test tubes. I went one step further than George: I came up with a way to test any tube on a 575, 576, 577, 7CT1N or 5CT1N. You can read about how you can do it in my paper which you can download at If you want to get one of my adapter boards please contact me off list at dennis at ridesoft dot com. Dennis Tillman W7PF -----Original Message----- -- Dennis Tillman W7PF TekScopes Moderator |
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Re: FS: miscellaneous Tektronix manuals
Dan Cordova
Hi Brad,
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Do you have or know anyone selling an adapter/fixture to match tubes on a Tektronix 575? Or, do you know if there is a schematic I can buy?? Glydeck has a blog about this, but there is no schematic or info to contact him. Thanks, Dan On Tuesday, December 4, 2018, 1:31:54 PM PST, Brad Thompson <brad.thompson@...> wrote:
Hello-- I'm offering FS the following original Tektronix manuals-- all are in very good condition except as noted. Please note that some of these manuals are available for downloading at no cost. However, some users prefer printed copies. Postage is extra (except as indicated). Scope-mobile 200-1 062-0870-00, May 1969 (R), 8 pp. double-sided. $3.00 postpaid via USPS first-class mail. * 4957 Series Graphics Tablet Instruction Manual, 070-4784-01, Product Group 15, Nov.1986 (revised); approx. 72 pp., in 9-inch by 7-inch three-ring binder. $7.50 plus postage. * TDS 200-series Programmer Manual, 071-0493-01, approx. 220 pp., wire-bound, in as-new condition. Asking $10.00 plus postage Note1 : "This document supports TDS 210 and TDS 220 with FV:v1.09 and above when used with TDS2CM version CMV:v1.04 and above, or TDS2MM any version, and TDS224 when used with any version of TDS2CM or TDS2MM." Note 2: Requires an optional RS-232 or GPIB interface (TDS2CM Communications Extension Module or TDS2MM Measurement Extension Module). * 11401 and 11402 Programmers Quick Reference, 070-6255-00, Product Group 47, 1988 first printing. approx. 80 pp., wire comb-bound (9-inch by 4-inch format),? In very-good-minus condition (front cover creased). Asking $7.50? plus postage. * DSA 601A and DSA 602A Digitizing Signal Analyzers Quick Reference, 070-8183-00, Product Group 47, 1991 first printing. approx. 60 pp., wire comb-bound (9-inch by 4-inch format),? In good-plus condition (front cover creased, wire comb? slightly distorted). Asking $7.50? plus postage. * P6231 10X Active Probe, DC to 1.5 GHz, Instruction Manual, 070-6027-00 Product Group 60, revised 1987, (8 1/2 inch by 5 1/2 inch plastic comb binding) approx 40 pp. In very good condition (front cover slightly faded)? Asking $7.50 plus postage. **** Question welcomed, PayPal honored. thanks, and 73-- Brad? AA1IP |
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FS: miscellaneous Tektronix manuals
Hello--
I'm offering FS the following original Tektronix manuals-- all are in very good condition except as noted. Please note that some of these manuals are available for downloading at no cost. However, some users prefer printed copies. Postage is extra (except as indicated). Scope-mobile 200-1 062-0870-00, May 1969 (R), 8 pp. double-sided. $3.00 postpaid via USPS first-class mail. * 4957 Series Graphics Tablet Instruction Manual, 070-4784-01, Product Group 15, Nov.1986 (revised); approx. 72 pp., in 9-inch by 7-inch three-ring binder. $7.50 plus postage. * TDS 200-series Programmer Manual, 071-0493-01, approx. 220 pp., wire-bound, in as-new condition. Asking $10.00 plus postage Note1 : "This document supports TDS 210 and TDS 220 with FV:v1.09 and above when used with TDS2CM version CMV:v1.04 and above, or TDS2MM any version, and TDS224 when used with any version of TDS2CM or TDS2MM." Note 2: Requires an optional RS-232 or GPIB interface (TDS2CM Communications Extension Module or TDS2MM Measurement Extension Module). * 11401 and 11402 Programmers Quick Reference, 070-6255-00, Product Group 47, 1988 first printing. approx. 80 pp., wire comb-bound (9-inch by 4-inch format), In very-good-minus condition (front cover creased). Asking $7.50 plus postage. * DSA 601A and DSA 602A Digitizing Signal Analyzers Quick Reference, 070-8183-00, Product Group 47, 1991 first printing. approx. 60 pp., wire comb-bound (9-inch by 4-inch format), In good-plus condition (front cover creased, wire comb slightly distorted). Asking $7.50 plus postage. * P6231 10X Active Probe, DC to 1.5 GHz, Instruction Manual, 070-6027-00 Product Group 60, revised 1987, (8 1/2 inch by 5 1/2 inch plastic comb binding) approx 40 pp. In very good condition (front cover slightly faded) Asking $7.50 plus postage. **** Question welcomed, PayPal honored. thanks, and 73-- Brad AA1IP |
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Re: What is this soft metal, and is it toxic?
I have a 250g ingot of pure Indium. It was purchased during the developement phase of a 500W Band II amplifier module, to see if it could be formed into thermally-conductive washers (RF transistor flange to heatsink interface). The answer was no: despite being very soft, it was not soft enought to flow at the pressures involved in bolting down the transistors. Gram for gram it's close to silver in cost. Perhaps I should make up some solder for use on gold connections?
John |
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Re: OT - Method of choice to sort and store assorted transistors (apart from having one bin for every part number)
On Tue, 04 Dec 2018 04:36:40 -0800, you wrote:
If you want, you can color code the envelopes with colored dots from a stationary store, or colored labels. And for the OT? If someone talks about spectrum analyzers, I'm not the right person. Logic analyzers, yes. OT? likely anything. Harvey Hello all, |
Glydeck
John Sykes
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