EEVblog #1163 - Xmas Mailbag - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: December 24, 2018, 09:40:01 pm
content: Xmas MailbagSPOILERS:Mand Labs electronics learning kit:https://mandlabs.com/27:08 Petzl climbing harness33:20 RC2014 home brew DIY Z80 computer kithttps://rc2014.co.uk/https://www.tindie.com/products/Semachthemonkey/rc2014-pro-homebrew-z80-computer-kit/39:00 Custom test leads40:40 Aircraft 121.5MHz emergency beacon and altitude sensor teardown51:30 Monero miner, and some Linux GPL hate!

author: tineibous
author_rank: Newbie
timestamp: December 24, 2018, 10:28:31 pm
content: Hey dave at 05:33 you said they sent a acqua blue leds to you, could you show a close up of them to us? Like they glowing and off pls?

author: SeanB
author_rank: Super Contributor
timestamp: December 24, 2018, 10:30:23 pm
content: Polyurethane hydrolysis is common, and will fail any polyurethane plastic within 5 years for the cheap stuff, and 10 years for the better stuff. Keeping it in a dark place and humid makes it worse. Same thing for fall arrestors, they have an expiry date as well, because of the built in frangible section of the main webbing strap, that tears out a sewn section of web, to absorb in a controlled manner, the fall energy and stop you slowly with only minimal risk of injury.Funny enough the same applies for hard hats, if they are over 5 years old they should be replaced, the plastic they are made from loses plasticisers and gets brittle.

author: EEVblog
author_rank: Unknown
timestamp: December 24, 2018, 10:47:19 pm
content: Quote from: tineibous on December 24, 2018, 10:28:31 pmMaybe on the 2nd channel, or just a photo, remind me.

author: tsman
author_rank: Frequent Contributor
timestamp: December 25, 2018, 12:19:51 am
content: A Monero miner installer that is difficult to remove sounds far too much like malware to me.The mysterious screw + nut is from the gauge adjustment slot on the wire strippers.

author: nuclearcat
author_rank: Unknown
timestamp: December 25, 2018, 12:39:10 am
content: It is not suspicious, it is alarming red bad, letter look like one big scriptkiddie attempt to distract Dave and lure to install this crap.My guess he doesn't know Dave at all, IMHO, it was supposed to trigger Dave, so in rage he plug USB(and get infected) and start to protect fiercely Linux or 1070ti (while it is known for all viewers - he doesn't give a shit on both points).

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 25, 2018, 01:05:23 am
content: It seems some of the past few videos have been much blurrier or less sharp than they should be for a given resolution. More specifically, it seems to be the head shot in the mailbag videos. I assume you recorded them together, so a rogue setting may have impacted more than video?

author: boffin
author_rank: Unknown
timestamp: December 25, 2018, 02:40:34 am
content: I'm impressed that the RC2014 is RFC2795 compliant. I only thought it was only my last employer that was fully 2795 compliant.

author: johnlsenchak
author_rank: Frequent Contributor
timestamp: December 25, 2018, 04:55:49 am
content: He asks " what is this nut doing here" You're the guy with the Dundee Knife ! LOLYou should have wrapped up that "Mand Labs electronics learning kit" and gave it to Sagan as a Christmas gift ,that's if he goes in that direction asa hobby . No , I don't think he would understand all that electronic theory at his age, I started the theory around the age of 13That Mand Labs kit is way better then those Radio Shack "All in one" kits that I learned on as a teenagerThose Indian guys real suck , they sound like the scammers that call me all the time

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: December 25, 2018, 07:07:39 am
content: Since you asked for viewer opinion re: mand labs content let me offer my dissenting contrarian voice to your conclusions. When I was in the age range 9-14 I would have been overjoyed to get just the mand lab book. In particular when I was 9 years old I accidentally discovered a book about nuclear physics at the local library. It was intentioned for mid-teenager age range and started with some pictures of theBohr model(planetary style) atoms. I found it utterly fascinating and it changed my life. I was the youngest member of a STEM-academically oriented family and everyone figured I was the dumbest and not headed for that type of career. Instead after devouring that book it switched me " on" and I became a voracious consumer of any technical non-fiction and top of the class star pupil.OK, I was a weird kid and eventual classic math-science nerd, but even for those that aren't so inclined they know how to skip over the few pages /video scenes of theory and equations to get to the hands on "good" stuff". I found your over-dubbing you-tube rant type commentary on top of the mand video some of the most annoying minutes of video you have ever produced. If you want us to judge the mand productshut up for 10 seconds and let us watch and listen!. I came away with a much better impression of the mand people and a much lessor one of you.well you had to ask for our opinion.

author: HighVoltage
author_rank: Super Contributor
timestamp: December 25, 2018, 12:34:05 pm
content: Indeed a very nice kit the mand labs, I would have loved it as a kid, especially the book!My first electronics book was called "Radiobasteln für Jungen" from 1970.

author: johnlsenchak
author_rank: Frequent Contributor
timestamp: December 25, 2018, 12:49:43 pm
content: I started electronic theory with the Radio Shack " DC and AC Circuits - Basic Circuit Concepts " The red and blue four books.The problem is with the A/C theory you neededalgebra/trigonometryto understand the concepts which most grade school kids don't have

author: DL3CE
author_rank: Newbie
timestamp: December 25, 2018, 01:06:35 pm
content: QuoteThat book had a whole lot of editions, I think the first one was 1955(?) and there were predecessors. The older editions used valve circuits connected directly to the mains quite often, and I don't remember any (serious) warnings about the possibly live chassis.The Mand Labs kit made me look into the current state of electronics kits for kids and .. I'm shocked how pathetic they got. Nothing compared to those I had in my youth and they already were on their downfall back then. Relatives often gifted me new ones up to my 11-12th birthday or so (after that I got my first soldering iron and some Veroboard) and the newer ones got more and more in the direction of cheap toy and stripped the really cool projects. This kit is a step in the right direction, but they don't seem to have deceided if they want to target elementary school kids or college students, the complexity of the explanations is all over the place somehow?With the older ones you could build amplifiers, tone controls .. and there was even one for a functional television! And they explained everything .. they weren't mathurbating of course, but more in "Art of Electronics"-style: "This transistor does that and its operating point is stabilized via this DC feedback .. "If I ever have kids, I think I would be looking for an NOS one or create one myself. Basic electronics didn't change THAT much in the last decades, a transistor amplifier is still made the same way it was in the 1960ies.

author: timgiles
author_rank: Regular Contributor
timestamp: December 25, 2018, 02:54:03 pm
content: The Mand Kit looked great - at last a well put together quality product that does not break the bank. Sure, there are cheaper products out there, but, the literature alone is worth most of the money. And, I also believe very strongly that children who are going to go in to engineering, comp sci, etc... should have nice things so they can learn to take care, think twice etc... And that kit fits that description.I think we should lay off the indian chaps a bit. Sure, they speak with an indian accent in not so perfect english, but I doubt many of us can speak any of the many indian languages that there are. Also - at least they have done this! They have actually produced the book(s), the kit, with a serious nood in the direction of quality. Also it is aimed at a younger audience, young uns today do expect a different approach to videos. I doubt there are too many PewDiPie followers out there watching Dave (note I said too many and not any).Well done to them for sending it in - even though I would suggest they tipped Dave off next time. But Mail bag is mail bag !-) I hope it takes off during 2019 and we can see a few follow on kits come on line in the sam style 2019/20.

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 25, 2018, 04:55:23 pm
content: I agree with most people here that it's hard to provide too much information. Children may not be able to comprehend it all, but exposing them to it can't hurt and probably even helps. Meanwhile they can pick up the parts they do understand. Exposing yourself to things you don't understand yet is a classic way of learning something complicated. Even just having heard of some of the more technical terms can massively help later on, and some will just run with it.Both the Indian accent and the video presentation may be a bit of an issue. Most children grow up learning English, but combined with the unfamiliar accent it may be a bit too much. It's not about whether we speak the many Indian languages and dialects, it's about whether the children viewing the video will have trouble with it. It's fairly obvious the pair presenting the video aren't very accustomed to that, making the video less engaging and clear than it could have been. It's not a total disaster, but it does seem to be the roughest part of an otherwise rather polished and well-made product.

author: timelessbeing
author_rank: Frequent Contributor
timestamp: December 26, 2018, 12:04:22 am
content: So what was that thing you couldn't tell us in the Youtube video? You can say it here right? Are you live streaming somewhere else?

author: jonovid
author_rank: Super Contributor
timestamp: December 26, 2018, 12:18:35 am
content: Mand Labs electronics learning kit: their still learningtruly cringeworthy Mand Labs video,a thousand apologies for the thick accentwhy Dave you need to do the video for them.and redesign their kit for them , maybe add your own DMM and more electronic components.

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 26, 2018, 05:38:35 am
content: I have no problems with the accent, but I agree they start out with too much history and theory. The format I suggest to start with basic information on how to use the component, with the history and theory part moved to optional "learn more" sections.

author: Smokey
author_rank: Super Contributor
timestamp: December 26, 2018, 06:59:03 am
content: Watch this video from a company that makes climbing gear:https://dmmclimbing.com/Knowledge/September-2013/Slings-at-AnchorsSaying your gear doesn't need to be rated for falls if you are only canyoneering and rappelling is just not true. If things go sideways (and they will go sideways at some point) you can still pretty easily generate enough force to break your gear (and anchors), or your back. Even if your gear is brand new. I've found that canyoneers that are not also rock climbers have a poor understanding of this stuff.One big problem is static links in the system. This includes static ropes (no stretch), static cord, and sewn static slings. These are all used to attach yourself to an anchor or other rigging/rope system. A falling body generates high forces much faster than you would imagine and theses static links transmit those forces straight to the linkages (carabiners, etc) and your body (spine, organs).Because they are typically only rappelling, canyoneers often use static ropes (ie they don't stretch like normal climbing ropes). Even if you do use dynamic ropes that stretch, you are still using other static elements like cords and slings at various times like when attached to an anchor waiting to rappel. This disastrous situation can easily happen when clipping into a hanging anchor waiting to rappel and slipping with slack in the system.From the video:For an 80kg mass and 120cm dynema sling........fall factor 1 falls (falling from the height of the anchor) generated 16kN......fall factor 2 falls (falling from above the anchor) generated 27kN.For some gear references:... A typical anchor carabiner might be rated at 25kN (major axis, gate closed)"Black Diamond Positron Screwgate Locking Carabiner"https://www.rei.com/product/899070/black-diamond-positron-screwgate-locking-carabiner... and a dynema sling rated at 22kN"Black Diamond 10mm Dynex Runner",https://www.rei.com/product/899001/black-diamond-10mm-dynex-runnerSo as shown in the video, the above listed fall factor 2 breaks brand new gear. What if the carabiner got turned sideways? It's only good to 8kN now and broken in less than a fall factor 1...... and this all ignores the fact that you will have serious internal injuries (broken pelvis, busted organs, etc) at around a 12kN shock.So ya, even canyoneering gear needs to be fall rated (and you need to be really careful to avoid static falls!!).

author: FrankBuss
author_rank: Unknown
timestamp: December 26, 2018, 07:45:05 am
content: Quote from: HighVoltage on December 25, 2018, 12:34:05 pmRight, girls don't tinker with electronicsI started with a Kosmos Elektronik kit when I was young, and I remember later reading the very good book "Einführung in die Elektronik" by Jean Pütz when I was older:It started with some theory as well, but lots of practical circuits and easy to understand explanations.

author: Fungus
author_rank: Super Contributor
timestamp: December 26, 2018, 08:13:07 pm
content: Quote from: Smokey on December 26, 2018, 06:59:03 amHow exactly do you "fall" when you're rappelling? All ropes/slings are under tension at all times, no slack.(if you're doing it right).

author: Smokey
author_rank: Super Contributor
timestamp: December 27, 2018, 01:22:46 am
content: If we could all be 100% sure we were NEVER going to fall/slip/static load anything then why have any gear at all?No one wants to make an impact on a static system, but that doesn't mean you aren't in the situation where is can happen pretty often if you or someone else makes a mistake or something happens out of your control..What if you have a wacky anchor (as canyoneers often do) that has long tails to points far from each other. While starting the rap one of those anchor points (or tails) fails. That will drop you and the rap rope together until the other side of the anchor catches. Boom. Shock load.Much more common would be slipping while clipped to an anchor with slack in the system (like standing on a small ledge with the anchor at your waist but not having your teather tight)People die like that.

author: thm_w
author_rank: Super Contributor
timestamp: December 27, 2018, 10:18:33 pm
content: Quote from: Smokey on December 26, 2018, 06:59:03 amYou can tell when the mental gymnastics started, to justify that he knew the harness was good because his buddy owned it, that its not a great idea to use.A new harness is $75? A new helmet is another 75? To spend that every 5 years or so on a hobby you enjoy is quite reasonable. I would have no problem donating a bit to get some new gear if thats what it took.

author: Grapsus
author_rank: Regular Contributor
timestamp: December 28, 2018, 01:24:54 pm
content: I remember the hate about the GTX 1070 Ti is that it came out just a few tens of dollars more expensive that the 1070 while having almost the performance of a 1080.So both 1070 owners and 1080 owners felt ripped off. Also everybody was expecting a new architecture instead of a refresh. Gaming hardware circlejerk...I really don't get the guy's stance on the GPL. Is it cancer ? People who develop stuff for free, let you use and modify it for free dare to impose conditions on commercial use of their work ? The bastards !

author: LapTop006
author_rank: Unknown
timestamp: December 28, 2018, 02:10:52 pm
content: Quote from: Grapsus on December 28, 2018, 01:24:54 pmNot commercial use (that would be more the CC-NC licences, which end up being very restrictive since many things are commercial use that you might not think of at first), but redistribution.In some ways I guess it's just slightly different direction from the "free software" hardliners (Richard Stallman etc.). The FreeBSD developers I know have always been fairly pragmatic about it.Personally, if I'm not contributing to an existing project I'll use GPL or CC-BY-SA for content.

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 28, 2018, 04:14:59 pm
content: The main controversy over GPL is that barring (developer specific) exceptions, code that links against GPL must also be GPL. The LGPL is an alternative that does not have that linking clause.

author: Zom-B
author_rank: Regular Contributor
timestamp: December 29, 2018, 06:29:29 pm
content: Quote from: timelessbeing on December 26, 2018, 12:04:22 amI came here because I was wondering the same thing.

author: bryanrj1
author_rank: Contributor
timestamp: January 01, 2019, 09:14:58 pm
content: Mand Labs must be a fan of the Breakfast Club. That's the first thing that came to my mind with the loose screw in the box. Screws fall out all the time.

author: tineibous
author_rank: Newbie
timestamp: January 02, 2019, 03:35:39 pm
content: Quote from: EEVblog on December 24, 2018, 10:47:19 pmA late reminder that I forgot