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Jeff Liebermann <jeffl@cruzio.com>: Feb 15 11:21AM -0800 On Thu, 14 Feb 2019 14:45:39 -0600, Fox's Mercantile <jdangus@att.net> wrote:   >The 465 is a reasonably sized scope. Quite good all in all,until the >triggering fails. Good luck finding tunnel diodes these days.   Ahem... <http://www.learnbydestroying.com/jeffl/crud/Tek-Tunnel-Diodes.jpg> I sold some to someone in sci.electronics.design years ago, so I think some of those in the picture are now gone.   There's also Sphere, which usually has some in stock: <https://www.sphere.bc.ca/test/tek-parts/tekparts5.html>       -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

etpm@whidbey.com: Feb 15 11:37AM -0800 On Thu, 14 Feb 2019 11:47:41 -0800 (PST), "pfjw@aol.com"   >https://www.ebay.com/itm/Rigol-DS1052E-50MHz-Digital-Oscope-with-2-Channels-USB-Storage-Access-1-GSa-se/303061791574?epid=26027068917&hash=item468fe3f356:g:dD4AAOSwCuBcZPw7:rk:12:pf:0   >Peter Wieck >Melrose Park, PA Yeah, the first two are just a little above my price range. The last one though looks promising. Thanks, Eric

etpm@whidbey.com: Feb 15 11:42AM -0800 On Thu, 14 Feb 2019 15:59:01 -0500, Ralph Mowery   >https://www.circuitspecialists.com/hantek-200mhz-digital-storage- >oscilloscope-dso5202p.html   >There are a few other DSO scopes at the same place.   Now I have two 'scopes to compare. The Hantek is a 200 MHz bandwidth and the Rigol is only 50MHz. Just how much bandwidth should I be looking for? Thanks, Eric

ggherold@gmail.com: Feb 15 12:30PM -0800 > So, any advice? Did I leave out something? > Thanks, > Eric   Hi Eric, this is a bit outside your price range, but I love my keysight infinium 1000 https://www.keysight.com/en/pcx-2759552/infiniivision-1000-x-series-oscilloscopes?&cc=US&lc=eng   It's an awesome 'scope for the money.   George H.

Fox's Mercantile <jdangus@att.net>: Feb 15 03:51PM -0600 > Hi Eric, this is a bit outside your price range, but I love my keysight infinium 1000   Equally a bit of over kill, is My HP Infiniium <https://www.rescienceinc.com/product-page/hp-infinium-54825a-oscilloscope>     -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

ehsjr <ehsjr@verizon.net>: Feb 15 06:43PM -0500 > looking for? > Thanks, > Eric   The 50 MHz Rigol is fine for most people, most of the time. It's a good 'scope. I don't have any experience with the Hantek, so I can't comment on it, but you don't need 200 MHz for CNC and audio.   The standard answer might be "buy as much bandwidth as you can afford" or "it depends on what signals you need to see".   Selecting which 'scope to buy can drive you nuts. I feel your pain. :-)   Ed

tabbypurr@gmail.com: Feb 15 03:44PM -0800 > looking for? > Thanks, > Eric   Both of those are way above audio, which only extends to 20kHz. To get a reasonable picture of a waveform you'd want at least 8 - 10 samples per cycle. A 1MHz scope would be more than enough for audio. You can get a 200kHz pocket scope for under £20 :) It might well suffice for what you're doing.     NT

etpm@whidbey.com: Feb 15 09:17AM -0800 >George H. >*gun taps is what I call them, there is a GN on the >stem. The taps that direct the chips back out of the hole are called high spiral taps. Spiral point taps, AKA gun taps, eject the chips ahead of the tap. I use high spiral taps a lot but I don't like them. They are weaker than spiral point taps. I know, the terminology is confusing, especially since the high spiral taps are actually high helix taps. For blind holes in ductile materials, such as wrought aluminum and mild steel, I like to use roll form taps, AKA form taps, AKA roll taps. In fact, I use roll taps whenever I can because of the stronger thread and because no chips are generated. These taps require a larger hole and hole size must be controlled well because the tap just displaces the metal. With a roll tap you can tap right down to the bottom of a hole because there are no chips generated. Because form taps displace the material the thread is stronger than a cut thread. Virtually all the fasteners you will find in your local hardware store will have formed threads. Materials that can be roll or form tapped include all the wrought aluminum alloys, such as 6061, 6063, 5052, etc. Mild steel, 1144 steel (stressproof), 12L14 steel (leadloy) and 303 stainless steel also tap well with form taps. 304 and 316 can be form tapped but great care must be taken to avoid broken taps. Tap life will also be short in 304 and 316. But if you need threads all the way to the bottom and want to do it in one pass roll taps can work. Materials that should not be formed tapped are the cast aluminum alloys, half hard brass, cast iron, and the like. This is because the material is not ductile and the resulting thread will have tiny fractures, resulting in a weak thread. I have tapped thousands of holes with 2-56 form taps. Always use cutting oil when drilling and tapping holes, never motor oil. Using motor oil leads to broken taps and bad finishes and poor tool life. Hope that helped. Eric

etpm@whidbey.com: Feb 15 10:56AM -0800 On Thu, 14 Feb 2019 13:47:40 -0600, Fox's Mercantile <jdangus@att.net> wrote:   >probe to "look right" the probe has to match that. >Mostly it's a matter of the scopes input stage being >properly compensated for the probe's cable. Can this basic input impedence be adjusted? Should it be? Eric

etpm@whidbey.com: Feb 15 11:07AM -0800 On Thu, 14 Feb 2019 13:09:32 -0800, Jeff Liebermann <jeffl@cruzio.com> wrote:   >This one is closer to what I think you bought: ><https://www.tiepie.com/en/usb-oscilloscope/accessories/oscilloscope-probe-60mhz-x1-x10> >60MHz bandwidth in X10 and 6MHz bandwidth in X1. The frequency I was using was 1KHz. That's what the 'scope puts out and what the function generator was set at. With a 100MHz probe shouldn't a 1 KHz signal be low enough to avoid the rise time issue? I didn't even know about the difference in the frequency response. Is this one of the reasons that people recommend using the 10X setting unless the 1x setting is needed? That the only time the 1X setting is used is when the signal needs to be measured un-attenuated? Thanks, Eric

etpm@whidbey.com: Feb 15 11:34AM -0800 >What's the output impedance of your function generator? >What do you see when you plug the function generator directly >into the scope, via what kind of cable? I forgot to write the frequency. The frequency being used was 1KHz at 300 MV, from both the 'scope and the function generator. I only have 1 cable that connects to the function generator, it has a BNC connector at one end and alligator clips at the other end. So at this time I cannot directly connect it to the 'scope, I must use the probes. But the probes are what I was testing and I got the same results no matter where the signal was coming from, as I stated in my original post. The output impedence of the function generator is 50 ohms. If I was able to connect the function generator directly to the 'scope with the proper cable what would this tell me? I guess if the square wave shape was still distorted the same way and the same amount then it would be the 'scope that has the problem? And if the square wave was perfect then it would be the probes causing the distortion. Look, I try to post a question with adequate information. It seems like I'm always leaving something out though. It's not because I'm being lazy or trolling. It's because I miss shit, just like eveyone else. And I don't mind being asked for more info, especially if the reasons for the requested info are listed. This helps me to be more accurate in my replies. And helps me learn, which is why I post questions in the first place. Thanks, Eric

ggherold@gmail.com: Feb 15 12:05PM -0800 > tool life. > Hope that helped. > Eric   Helped yes.. thanks. I don't do much tapping.. and all of that by hand on the mill. (with starter drill in the chuck, centering the hand tap.) I looked at those spiral taps and thought.. 'dang I'm just going to bust on of those.' I never heard of form taps, but I'll look into them.   Thanks again, George

dplatt@coop.radagast.org (Dave Platt): Feb 15 11:44AM -0800 In article <4q2e6edk9gfhulp323o1svs1mln43k7a26@4ax.com>,   >Can this basic input impedence be adjusted? Should it be?   Sometimes, but that's usually a "service adjustment and repair" sort of thing, not something that one is usually expected to do during normal use. In a lot of scopes there's no adjustment that doesn't require e.g. unsoldering parts.   There's enough variation between types of scope, that it's probably most common to have a set of probes for each scope. Pick (and if necessary adjust) the probes to match the input characteristics of the scope, and then don't fiddle with 'em.

Mike <ham789@netscape.net>: Feb 15 12:48PM -0800 > questions in the first place. > Thanks, > Eric   And yet, the best description you can give for the observed waveform is "distorted". How can you expect a solution to a problem you won't disclose? At the risk of repeating myself...

etpm@whidbey.com: Feb 15 02:06PM -0800 <SNIP> > >> At least describe it in such a way that one could draw an > >> accurate picture from your description. And yes, the time > >> dimension is relevant. Whoops! It looks like the wave is over compensated. So it looks like at the beginning of the flat waveform it has a little peak that then drops down to form a flat line for the rest of the wave. This of course repeats but in the negative direction for the negative part of the wave. I thought you meant frequency for the time dimension but now I think what you mean is how long does it take for the waveform to become flat. It looks like it takes .1 mS. And the overshoot is about 30mV Eric

Phil Allison <pallison49@gmail.com>: Feb 15 02:00PM -0800 Mike wrote: > >> At least describe it in such a way that one could draw an > >> accurate picture from your description. And yes, the time > >> dimension is relevant.     ** Ask "et" to describe a match box.   Bet he will struggle and make no sense.       .... Phil

Phil Allison <pallison49@gmail.com>: Feb 15 02:15PM -0800 > It didn't seem to matter if the 'scope was set to AC or DC > coupling. It also didn't matter if the signal being measured came from > the 'scope or from the function generator.   ** Now that you have finally DESCRIBED the "distortion" ( a 10% overshoot) the answer is obvious.   The 465 scope is the culprit, the vertical attenuator needs frequency adjustment.   With the various probes in 10:1 setting, the trim cap allows you to compensate for the error in the scope.       .... Phil

Jeff Liebermann <jeffl@cruzio.com>: Feb 15 02:56PM -0800 >The frequency I was using was 1KHz. That's what the 'scope puts out >and what the function generator was set at. With a 100MHz probe >shouldn't a 1 KHz signal be low enough to avoid the rise time issue?   No. The rise time and bandwidth are not related to the frequency of the input waveform. Basically: Bandwidth * RiseTime = 0.35 <https://www.tek.com/support/faqs/how-bandwidth-related-rise-time-oscilloscopes> If the rise time of the 1KHz waveform is very small, you will need a probe and scope with a high bandwidth in order to see it. If these are lacking, the scope will display a much slower rise time than what the 1KHz generator is actually producing.   For the two scope probes I mentioned above, both probes have 6MHz bandwidth. RiseTime = 0.35 / Bandwidth = 0.35 / 6*10^6 = 0.058 * 10^-6 = 58 * 10^-9 = 58 nsec rise time with an X1 probe.   You can also mangle the waveform by setting the vertical amplifier set to AC instead of DC. That will cause the top and bottom of the square wave to sag like a capacitor charge/discharge curve.   I can't tell which of these is the problem because your description of the waveform as "really weird results" and "slightly distorted" isn't really sufficient.   >I didn't even know about the difference in the frequency response.   Now, you know. There should be something on the web that covers all this. Search for: <https://www.google.com/search?q=analog+oscilloscope+basics>   EEVblog #453 - Mysteries of x1 Oscilloscope Probes Revealed <https://www.youtube.com/watch?v=OiAmER1OJh4> (29:48)   ABCs of Probes <https://download.tek.com/document/02_ABCs%20of%20Probes%20Primer.pdf> See Pg 8, 35-37.   >Is >this one of the reasons that people recommend using the 10X setting >unless the 1x setting is needed?   Yep.   >That the only time the 1X setting is >used is when the signal needs to be measured un-attenuated?   Nope. There are plenty of uses for an X1 probe. If the signal is very low amplitude, it's easier to see using either a direct connection to the scope input or an X1 problem. If the frequency is low enough that you don't care about bandwidth, then X1 is just fine.   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

etpm@whidbey.com: Feb 15 03:33PM -0800 On Fri, 15 Feb 2019 14:56:25 -0800, Jeff Liebermann <jeffl@cruzio.com> wrote:   >very low amplitude, it's easier to see using either a direct >connection to the scope input or an X1 problem. If the frequency is >low enough that you don't care about bandwidth, then X1 is just fine. Thanks Jeff, Below is an answer I gave to Mike about the wave shape and other features. The description should give you a better idea of what I am seeing. At least I hope it does.   "Whoops! It looks like the wave is over compensated. So it looks like at the beginning of the flat waveform it has a little peak that then drops down to form a flat line for the rest of the wave. This of course repeats but in the negative direction for the negative part of the wave. I thought you meant frequency for the time dimension but now I think what you mean is how long does it take for the waveform to become flat. It looks like it takes .1 mS. And the overshoot is about 30mV Eric"   Thanks Again, Eric

Phil Allison <pallison49@gmail.com>: Feb 15 03:37PM -0800 Jeff Liebermann wrote:   > You can also mangle the waveform by setting the vertical amplifier set > to AC instead of DC. That will cause the top and bottom of the square > wave to sag like a capacitor charge/discharge curve.   ** No sign of that will be seen with a 1kHz square wave.   > I can't tell which of these is the problem because your description of > the waveform as "really weird results" and "slightly distorted" isn't > really sufficient.   ** That info was posted by the OP 3 or 4 hours ago.   You must read all the posts in a thread before posting replies with dumb error like that.   .... Phil

Andy Burns <usenet@andyburns.uk>: Feb 15 07:42PM The Real Bev wrote:   > Everything worked, but the screen was unresponsive.  For once, I googled > before asking.  The problem is crud between the screen and the frame.   If nooks operate in the same way as kobo screens it's not actually resistive or capacitive touch at all, it's breaking a grid of infrared beams that criss-cross the screen.

"pfjw@aol.com" <peterwieck33@gmail.com>: Feb 15 12:26PM -0800 On Monday, December 3, 2018 at 3:07:15 PM UTC-5, The Real Bev wrote: > The website guy used paper; what if I'd used a tiny bit of > toothpick sliver or wire or plastic?   Paper (or very thin cardboard) will absorb oils and grease - with special reference to skin oils. A toothpick is to coarse, and silver, wire or plastic will not.   A common practice is to clean out variable capacitors with business cards - for just that reason.   Peter Wieck Melrose Park, PA

"pfjw@aol.com" <peterwieck33@gmail.com>: Feb 15 12:26PM -0800 On Friday, February 15, 2019 at 2:42:17 PM UTC-5, Andy Burns wrote:   > If nooks operate in the same way as kobo screens it's not actually > resistive or capacitive touch at all, it's breaking a grid of infrared > beams that criss-cross the screen.   That would be quite expensive in terms of battery use. And Nooks are known for very long battery life. My wife will go for over a week, easily, reading several hours per day.   Peter Wieck Melrose Park, PA

The Real Bev <bashley101@gmail.com>: Feb 15 02:13PM -0800 >> toothpick sliver or wire or plastic?   > Paper (or very thin cardboard) will absorb oils and grease - with special reference to skin oils. A toothpick is to coarse, and silver, wire or plastic will not.   > A common practice is to clean out variable capacitors with business cards - for just that reason.   Can you still get matchbooks? Similarly useful.     -- Cheers, Bev I can picture a world without war, without hate. I can picture us attacking that world, because they'd never expect it.

John Robertson <spam@flippers.com>: Feb 15 10:14AM -0800 > copy /b CPU_5B.128 + CPU_5B.128 + CPU_5C.256 CPU_5C.512   > how do i do that with the rom burning software?   > thanks   Normally you set the destination for the code that you are storing on the EPROM to defaults - so that would be starting at 0000h and filling the EPROM with the contents of the file.   To achieve this combination you need to assign the first (128) EPROM to 0000h-3FFFh, the second (128) to 4000h - 7FFFh, and the last (256) to 8000H to FFFFh.   I don't use the Willem so have no idea how this works with their interface, but that is what you are trying to accomplish.   Is this for your Data East pinball that you asked about on RGP?   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

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