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Re: Tek 7854 intermittent issues
Hi Nick,
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My 7854 is an earlier version. Strange, if that makes any difference I would expect the newer version to have a faster sampling rate. Albert On Thu, Sep 3, 2020 at 04:48 AM, Paul wrote:
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Re: Tek 7854 intermittent issues
Alright, sorry for the quality I had it on the bench rather than in a rack so my angle is quite bad (looking down from the top) but, I have a video of the behavior!
Video: If you have time watch the whole thing, it shows some strange artifacts as it goes, if not have some time stamps of the more interesting things. Immediately after power up: 00:00 Switch to stored: 00:05 Start of first AQR: 00:08 Things start happening: 02:11 End of first AQR: 02:25 Final result after 3 more AQR's: 02:32 |
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Re: HAPPY 20th BIRTHDAY TEKSCOPES!!!
Dennis,
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I’m very thankful for this online community, especially now. I miss Stan, one of the originals. Thank you! George On Sep 2, 2020, at 4:11 PM, Morris Odell <vilgotch1@...> wrote: |
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Re: Tek 7854 intermittent issues
It seems like my issue might be thermal related. When it cold starts (everything is at room temperature) it almost always is missing parts of the digital waveform, but if I set it to AQR (and since parts are missing it won't complete) and watch it in stored mode, after a few minutes the missing parts start to fill with noise then the correct data starts to fill in a short while after that, once that has occurred, it seems (most of the time) that the digital side will capture properly until I turn it off and it cools down for a while again. When I'm able I'd like to capture a video of this in action to better describe what's happening.
Also I genuinely didn't know you were supposed to use a specific plugin for AQS until just now, when I very first set up this machine to test it, it would AQS for anything, in auto trigger mode, using just a 7B85 in the left horizontal slot, at any time per div I selected. When this stopped I thought there was an issue. Finally have the power supply slid out as well so I can finally make some measurements to see if I'm getting some noise or something that's messing with everything until it's "warmed up". Though the fact that the issue disappears randomly makes me not very confident in any correct looking readings. Still have some occasional other issues as well, like the cal out reading (both on the scope and on another scope) around 2.6 times what it should, but only for a few minutes and SUPER intermittently (like I might not see it for 20 or 30 power cycles or more) This thing causes me great confusion. |
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Re: Tek 7854 intermittent issues
Albert -
Yep, those are the steps I'm following. Oddly though, my 0.5ms/div works as reported at 512 P/W, and fails gracefully as described at 0.2ms/div, but at 1024 P/W, it works at 2ms/div & fails at 1ms/div. I never get the immediate error. I've got a 'newer' model w/ combined RAM/ROM board, you? Nick - Happy to poke around & take readings for ya - let me know if I can be of help. |
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Re: 1S1 sampling unit; (also 7B53AN & 7A18 plugins)
I believe it, Harvey.? A former coworker had experimented with tubes, and he said that while you can run the filaments from A.C., try D.C. for audio; you'll like it.Jim Ford?Sent from my Verizon, Samsung Galaxy smartphone
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-------- Original message --------From: Harvey White <madyn@...> Date: 9/2/20 7:01 PM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] 1S1 sampling unit; (also 7B53AN & 7A18 plugins) I once had a Heathkit OM3, which had a horrible hum problem (eventually).? I solved it by running the filaments off DC.? If you ever have that problem, I can suggest it.? The IO-14 was billed as a lab scope, I think.HarveyOn 9/2/2020 9:19 PM, David Collier wrote:> Hi Garth,> I'm in Canberra (Oz).> Some US sellers won't ship to Oz, a few charge ridiculous shipping of US$400 to 500, which is where they hope to profit!> A Heathkit IO-14 from USA is costing me US$50 carriage via the Global Shipping Program, which seems very inexpensive.> David C.>> >>
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Re: 1S1 sampling unit; (also 7B53AN & 7A18 plugins)
I once had a Heathkit OM3, which had a horrible hum problem (eventually).? I solved it by running the filaments off DC.? If you ever have that problem, I can suggest it.? The IO-14 was billed as a lab scope, I think.
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Harvey On 9/2/2020 9:19 PM, David Collier wrote:
Hi Garth, |
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Re: 1S1 sampling unit; (also 7B53AN & 7A18 plugins)
David Collier
Hi Garth,
I'm in Canberra (Oz). Some US sellers won't ship to Oz, a few charge ridiculous shipping of US$400 to 500, which is where they hope to profit! A Heathkit IO-14 from USA is costing me US$50 carriage via the Global Shipping Program, which seems very inexpensive. David C. |
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Re: HAPPY 20th BIRTHDAY TEKSCOPES!!!
Thanks for the mention Dennis and your efforts as a moderator. I've really enjoyed being a member of this group and look forward to the daily digest I receive. The knowledge and helpfulness of the other members here is a great resource. I also enjoy helping other when I can too.
I hope this group continues for a long tiome to come! Morris Odell VK3DOC locked down in Melbourne, Australia |
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Re: TWD 120's FREE
Charlie,
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Well, I have SCSI adapters galore, and an operating PC running Windows 98, necessary for operation of a legacy DSP analyzer (PC bus hardware). So, I have a system that could PROBABLY work with it. There is already a Tek analog scope on that bench, but the storage capability could be handy. If no one more needy puts up their hand, I would take one of those. Zip code 97520. Thomas Garson Aural Technology, Ashland, OR By my calculation, the dynamic range of the universe is roughly 679dB, which is approximately 225 bits, collected at a rate 1.714287514x10^23 sps. On 9/2/20 1:24 PM, Charlie Conger wrote:
I just found one, maybe two, complete TWD120's while unpacking after a move. These had been missing for years. These are 100 Mhz 2channel Digital Storage Digitizers originally made for GE medical. They require a PC to act as a display to be fully functional. As I last recall these were fully functional the last time I used them. |
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Re: TWD 120's FREE
Looks like an interesting bit of hardware.
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Does it use all three interfaces to communicate with the PC (as listed in the wiki)? or just the SCSI: " Adaptec ASPI SCSI driver is required for the software to communicate with the digitizer. SCSI configuration can be tricky." and the serial and parallel were for other things? That it was designed to work with windows 3.1 and becomes a tough thing to keep operational as OSes progressed is why these PC based scopes are such a mixed bag. Makes me glad I have older hardware based scopes. :-) On Wed, Sep 2, 2020 at 1:24 PM Charlie Conger <ctconger@...> wrote:
I just found one, maybe two, complete TWD120's while unpacking after a |
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Re: Strange Tek2440 issue
On 09/02/2020 02:50 PM, Siggi wrote:
On Wed, Sep 2, 2020 at 2:07 PM Vince Vielhaber <vev@...> wrote:Double checked, followed the foil, Channel 2 is definitely on pin 1.I had actually done that last nite, but didn't have the parts layout I got the power supply board out right now so it's definitely going to see some new caps. I'll also take a real close look at Q870 and Q879. I measured R478 with a 4 wire ohmmeter and it's 10.01. Haven't checked any of the other ... yet. I did look at the +8 and _15v rails as well as the 5V unreg and the +10 ref. All were ok with both the voltmeter and the scope. While the board's out I'm also going to track down U870's inputs to see if something's backward in the schematic. More later! Thanks! Vince. Even so, it still doesn't make sense, as the voltage-control op-amp starts-- K8ZW |
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TWD 120's FREE
I just found one, maybe two, complete TWD120's while unpacking after a move. These had been missing for years. These are 100 Mhz 2channel Digital Storage Digitizers originally made for GE medical. They require a PC to act as a display to be fully functional. As I last recall these were fully functional the last time I used them.
see here for more details If anyone is interested PM me and I will be happy to send for cost of shipping. |
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Re: HAPPY 20th BIRTHDAY TEKSCOPES!!!
Hmmm. Mine shows I joined 09/30/03 (Account -> Identity - Account Profile). I must've been a lurker for a while.
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Thanks, Barry - N4BUQ ----- Original Message -----
From: "Dave Daniel" <kc0wjn@...> |
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Re: HAPPY 20th BIRTHDAY TEKSCOPES!!!
Oh. Duh. The date is on the “personal” under “Account Settings”.
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On Sep 2, 2020, at 15:45, n4buq <n4buq@...> wrote: |
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Re: HAPPY 20th BIRTHDAY TEKSCOPES!!!
I searched for my member ID. Apparently I joined on or about April 7, 2004.
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I smile when I see that I asked my first Tek question and the second reply was from none other than Stan Griffiths. Then I see my reply to his saying "Yes, you are correct". How embarrassing. I didn't know who he was at the time. Thanks, Barry - N4BUQ ----- Original Message -----
From: "Dave Daniel" <kc0wjn@...> |
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Re: HAPPY 20th BIRTHDAY TEKSCOPES!!!
Is there a way to figure out when one joined the original (Yahoo groups) list?
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DaveD On Sep 2, 2020, at 14:06, Dennis Tillman W7pF <dennis@...> wrote: |
Glydeck
Charlie Conger
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