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Re: Important notice
On Friday, January 26, 2024 at 11:14:09 AM GMT+1, David C. Partridge <david.partridge@...> wrote:
IMPORTANT NOTICE - PLEASE READ Groups.io has been working at re-verifying members of its Groups in response to an spam filtering service called Spamhaus affecting users. This process has been ongoing and those members of Groups.io groups whose e-mail domains are problematic will have already been notified. This is the bulk of the text of the message I received from Groups.io: On Saturday January 13th, 2024, an anti-spam service called Spamhaus labeled one of our email servers as a spam sender. This caused any email service that uses Spamhaus to stop accepting email from our server. Because of this, we began a reverification process and sent out reverification emails to a subset of our users on Sunday January 14th. Spamhaus lifted their block on Monday, January 15th, 2024, but we need to continue the reverification process. You can see which, if any, of your users are affected. Go to the Admin section of your group and look at the Members page. Next to each user's email, there may be a badge with the letters RI or RS. RI means the confirmation/reverification is in progress, but has not been completed. RS means the confirmation/reverification has been successfully completed. Here are the next steps in the reverification process: 1.??? On Sunday, January 28th, group emails to people in the RI state will be disabled. Messages from moderators and login link emails will still work. 2.??? Until February 11th, people will still be able to reverify themselves and the RI and RS badges will still show up in the Members page. 3.??? After that, members still in the RI state will be removed from groups. The activity log entry will be Membership - Member Removed, with the added reason of reverification failed. For domains where no reverifications happened, no invites or direct adds will be permitted going forward. If there is a valid person on one of those domains, they should contact [email protected] to have the domain ban lifted. We apologize for the inconvenience this process may cause, but it is necessary to ensure that we are able to continue delivering group email reliably. Thank you for using Groups.io. So, if you received an e-mail from Groups.io explaining what is going on , and asking you to verify your e-mail address, and you have not yet done it, please do so. |
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Re: 2465B Probe Compensation Output
This is just a guess, but how long was the earth connection for the probe? Not using a short earth lead is a classic cause of ringing.
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Cheers, David -----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Wm. Davis via groups.io Sent: 10 February 2024 20:46 To: [email protected] Subject: [TekScopes] 2465B Probe Compensation Output I discovered that the probe compensation output signal shows pretty significant ringing at time bases of 200 ns or faster. |
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2465B Probe Compensation Output
I have a new to me Tek 2465B - a dream come true. As I was putting the scope through the paces, I discovered that the probe compensation output signal shows pretty significant ringing at time bases of 200 ns or faster. I've never had a scope with this fast a time base. Is the ringing normal? I suspect that it is because I've always done probe compensation at a slower time base. Just checking, because if I need to return this, I'm on a pretty tight time base (pun intended).
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Re: Walter Shawlee obituary in the NY Times
I too thought the article was quite wonderful....and re slide rules. Walter and I talked about them a bit. great guy and sorely missed..i still use my 6 in slide rules ....my 18 in is bamboo and belonged to my dad. Dad gave me a 6 in pickett aluminum while in high school....I used it in College along with my 6 in circular ( it was tossed by friend after getting "the? NEW hp35") for my engineering classes...most? of my colleagues had the HP calculators (( out of my budget!)...so on the top on exams I had to write "slide rule" since my numbers were not "EXACT"...but good enough....I Still use them all....but I do like my HP35, 25 and 11C all of which I use...but the slide rule is always around if the batteries die..especially in the 25 and 35...battery packs need rebuilding....a 6 inch is always in arms reach even in the car!
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oh well fond memories, Walter will not be forgotten. ¸é±ð²Ô¨¦±ð On 2/10/24 7:50 PM, Jim Ford wrote:
Yes, I had only bought once or twice from Sphere, but Walt and Susan did include some useful goodies.? Say, that NYT article mentioned slide rules made out of bamboo, and I'd never thought about it until today, but my dad's old slipstick from the 1960s had the open grain at the ends and was almost certainly made of bamboo!? I'm too young (born in 1965, engineering school 1983-1991 including grad school) to have used one, but I'm starting to think I missed out.? Say, what make and model would you folks recommend for an EE with a bent toward RF, microwaves, and fiber optics?? Steve, interestingly enough, my dad is a chemist turned software engineer who used to teach p-chem! Definitely not my thing, and I jumped to EE after starting freshman year as a biochemistry major; those chem labs blew it for me.? Rest In Peace, Walter.? ? ? ?Jim Ford?Sent from my T-Mobile 4G LTE Device |
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Re: Walter Shawlee obituary in the NY Times
I totally understand,? Dave!? Same issue here....? ? ? ? ? Jim FordSent from my T-Mobile 4G LTE Device
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-------- Original message --------From: Dave Casey <polara413@...> Date: 2/10/24 6:52 PM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] Walter Shawlee obituary in the NY Times There's a Stuff Day scheduled for 2/24. Wish I could go.Well, I can, but I wish my wife would let me come home if I did.Dave CaseyOn Sat, Feb 10, 2024, 8:08 PM stevenhorii <sonodocsch@...> wrote:> I miss Walt. I first got acquainted with Sphere Research through slide> rules. I had saved mine from my university days. I still have the Dietzgen> N1725 Vector Log Log. My father was an architect and bought it for me at a> discount since the firm he worked for had a contract with Dietzgen for> drafting instruments. That slide rule got me through p-chem. I only used> the hyperbolic scales to see how they worked. I did use most of the others> for homework problems.>> A lot of my collection came from Sphere Research - new-in-the-box Pickett> rules including their famous N4, also a vector log log. I have one of those> nuclear bomb effects circular slide rules and got it in the book ¡°The> Effects of Nuclear Weapons¡± but on eBay, not from Walt. Since then, I also> found a Soviet version. Being a radiologist, I thought that understanding> the dangers of the radiation from these weapons was something I should know> about.>> It was only later that I started buying electronics from Walt. He was> always generous and would include a bonus bag of parts. Most were far> better than the usual ¡°floor sweeping¡± sorts of stuff; a lot of usable> parts in those bags.>> I¡¯m sad that he¡¯s gone but glad Susan carries on. The effects of his years> of catering to many of those in this group are probably well known since> I¡¯m sure many of you would turn your browser to his site the minute his> ¡°Stuff Day¡± announcements appeared.>> Steve H.>> On Sat, Feb 10, 2024 at 16:37 John Griessen via groups.io <john=> [email protected]> wrote:>> > That was a nicely done bio.> >> >> >> >> >> >>>> >>>
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Re: Walter Shawlee obituary in the NY Times
Yes, I had only bought once or twice from Sphere, but Walt and Susan did include some useful goodies.? Say, that NYT article mentioned slide rules made out of bamboo, and I'd never thought about it until today, but my dad's old slipstick from the 1960s had the open grain at the ends and was almost certainly made of bamboo!? I'm too young (born in 1965, engineering school 1983-1991 including grad school) to have used one, but I'm starting to think I missed out.? Say, what make and model would you folks recommend for an EE with a bent toward RF, microwaves, and fiber optics?? Steve, interestingly enough, my dad is a chemist turned software engineer who used to teach p-chem! Definitely not my thing, and I jumped to EE after starting freshman year as a biochemistry major; those chem labs blew it for me.? Rest In Peace, Walter.? ? ? ?Jim Ford?Sent from my T-Mobile 4G LTE Device
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-------- Original message --------From: stevenhorii <sonodocsch@...> Date: 2/10/24 6:08 PM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] Walter Shawlee obituary in the NY Times I miss Walt. I first got acquainted with Sphere Research through sliderules. I had saved mine from my university days. I still have the DietzgenN1725 Vector Log Log. My father was an architect and bought it for me at adiscount since the firm he worked for had a contract with Dietzgen fordrafting instruments. That slide rule got me through p-chem. I only usedthe hyperbolic scales to see how they worked. I did use most of the othersfor homework problems.A lot of my collection came from Sphere Research - new-in-the-box Pickettrules including their famous N4, also a vector log log. I have one of thosenuclear bomb effects circular slide rules and got it in the book ¡°TheEffects of Nuclear Weapons¡± but on eBay, not from Walt. Since then, I alsofound a Soviet version. Being a radiologist, I thought that understandingthe dangers of the radiation from these weapons was something I should knowabout.It was only later that I started buying electronics from Walt. He wasalways generous and would include a bonus bag of parts. Most were farbetter than the usual ¡°floor sweeping¡± sorts of stuff; a lot of usableparts in those bags.I¡¯m sad that he¡¯s gone but glad Susan carries on. The effects of his yearsof catering to many of those in this group are probably well known sinceI¡¯m sure many of you would turn your browser to his site the minute his¡°Stuff Day¡± announcements appeared.Steve H.On Sat, Feb 10, 2024 at 16:37 John Griessen via groups.io <john@...> wrote:> That was a nicely done bio.>>> >>>
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Re: Walter Shawlee obituary in the NY Times
There's a Stuff Day scheduled for 2/24. Wish I could go.
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Well, I can, but I wish my wife would let me come home if I did. Dave Casey On Sat, Feb 10, 2024, 8:08 PM stevenhorii <sonodocsch@...> wrote:
I miss Walt. I first got acquainted with Sphere Research through slide |
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Re: Walter Shawlee obituary in the NY Times
I miss Walt. I first got acquainted with Sphere Research through slide
rules. I had saved mine from my university days. I still have the Dietzgen N1725 Vector Log Log. My father was an architect and bought it for me at a discount since the firm he worked for had a contract with Dietzgen for drafting instruments. That slide rule got me through p-chem. I only used the hyperbolic scales to see how they worked. I did use most of the others for homework problems. A lot of my collection came from Sphere Research - new-in-the-box Pickett rules including their famous N4, also a vector log log. I have one of those nuclear bomb effects circular slide rules and got it in the book ¡°The Effects of Nuclear Weapons¡± but on eBay, not from Walt. Since then, I also found a Soviet version. Being a radiologist, I thought that understanding the dangers of the radiation from these weapons was something I should know about. It was only later that I started buying electronics from Walt. He was always generous and would include a bonus bag of parts. Most were far better than the usual ¡°floor sweeping¡± sorts of stuff; a lot of usable parts in those bags. I¡¯m sad that he¡¯s gone but glad Susan carries on. The effects of his years of catering to many of those in this group are probably well known since I¡¯m sure many of you would turn your browser to his site the minute his ¡°Stuff Day¡± announcements appeared. Steve H. On Sat, Feb 10, 2024 at 16:37 John Griessen via groups.io <john= [email protected]> wrote: That was a nicely done bio. |
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Re: Tektronix TDS3034B Boot Challenge - Help Needed
Hi Mike,
Here are a couple of thoughts... (i) The early DRAM checks only test the Buses, I/O pads, and a few memory locations - far from comprehensive. (ii) Symptomatically you likely have either a DRAM or Flash problem - either the DRAM is corrupting the code, or the code is not reading correctly from Flash. (iii) Also check the refresh lines on the DRAM cold vs warm and measure the refresh cycle time. (iv) Heat guns and freeze spray can be a bit hit and miss, although good once you know where the area of the fault is. I'd be inclined to cool or heat the entire board and see if you can change the ~5min period. Assuming you don't have access to a thermal test chamber... Maybe use a fan heater blowing into a small closed space to ensure everything is heated, but be careful to monitor the temp inside. Don't exceed 50 Degrees C. Place the PCB assembly or entire unit in a large freezer bag and cool it below zero degrees. Ensure the bag is well sealed as you don't want any moisture inside. Good luck. Regards, - Guy |
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Re: Extender Cables for TM500/5000 series - Alternatives?
@Victor,
Fair enough. I just wouldn't compare the work I did to the soldering job done by a prior owner which I would agree was hacked. Yes I did joke in my video about the mess of jumper wires. But I was actually a bit proud that the modifications I made could be reversed back to the original easily. In the event I come across the parts at a fair price. But thank you. Maybe I overreacted. -Frank |
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Re: Extender Cables for TM500/5000 series - Alternatives?
Frank,
I re-read my message and I don't believe it was condescending at all, except possible saying it was hacked. When I said hacked up I was referring to mods not made by you - as you mentioned in your video, on youtube. In fact you implied that the mods you say were substandard. I am not a collector and I use a CG5011/SG5030 in my business. However I do like to keep equipment original. Good luck with your project. --Victor |
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Re: Walter Shawlee obituary in the NY Times
Alternate link for those who get poleaxed by the paywall:
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-- john, KE5FX -----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Mark Kahrs Sent: Saturday, February 10, 2024 11:04 AM To: [email protected]; [email protected] Subject: [TekScopes] Walter Shawlee obituary in the NY Times |
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Re: Extender Cables for TM500/5000 series - Alternatives?
Thank you Shaun! I'm going to try to emulate your daughter cable. I got one of these - advertised as a dual-sided 15x2 HP extender card (). I plan to desolder the connector from the card and solder two 15 ribbon cables to it. Then use the connector at the other end of the cables. Hopefully this will work!
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David C. Partridge
Frank Mashockie
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