EEVblog #720 - Mailbag - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: March 03, 2015, 11:12:48 am
content: Dave opens his mail.SPOILERS:Chip Whisperer KickStarter:https://www.kickstarter.com/projects/coflynn/chipwhisperer-lite-a-new-era-of-hardware-securitySupermicro Xeon Server Motherboard:http://www.supermicro.com/products/motherboard/Xeon/C600/X9DAE.cfmRF Solutions transmitters and receivers.Bogey Board:http://rfsolutions.co.uk/acatalog/Bogey-Board.htmlKAPPA:http://rfsolutions.co.uk/acatalog/Radio-modem-KAPPA_M868.html#SID=278BRAVO:http://rfsolutions.co.uk/acatalog/BRAVO_Module.htmlPICop II PIC Development board:http://www.bloguetronica.com/2014/12/placa-de-desenvolvimento-picop-ii.htmlAutomatic Voltage Regulator for an alternator.

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: March 03, 2015, 11:38:20 am
content: the dude who for whatever reason flipped the oscilloscope up side downhiwhyand am not sure what he think about his employer holding that knife , i will be scared

author: kayvee
author_rank: Regular Contributor
timestamp: March 03, 2015, 11:49:26 am
content: He has to ease into the limelight slowly, you know....

author: Muttley Snickers
author_rank: Unknown
timestamp: March 03, 2015, 12:02:13 pm
content: The Old Scope Inverse Manoeuvre.It's obviously so that you can trigger on either a rising or falling edgewithout wearing out the buttons on the scope, just brilliant Seppy.Muttley

author: max666
author_rank: Frequent Contributor
timestamp: March 03, 2015, 12:25:49 pm
content: I like the postcards. Maybe I'm biased

author: bundy
author_rank: Newbie
timestamp: March 03, 2015, 01:13:48 pm
content: That strange routing on the Supermicro Xeon board is called offset routing. It is to minimize the influence of the FR4 glass fibers on the controlled impedance. The Er is slightly different at the point of the woven fiber bundle than in between them.The large unpopulated area on the board is for a SAS interface, Serial Attached SCSI.

author: PinheadBE
author_rank: Regular Contributor
timestamp: March 03, 2015, 01:45:38 pm
content: The datasheet is from the big metal shielded part on the Automated Voltage Regulator. Not the whole module, but only the part (or hybrid module ?) that is under the metal casing (which apparently doubles as heatsink for some power switching devices).This would explain that there are, indeed, SMT parts under there.....BTW, Dave: you've got one of your scopes stored headside down...Please, don't drink and blog....A bit more, and you would pretend that *someone* just flipped your scope just to annoy you....Come on ......

author: jancumps
author_rank: Unknown
timestamp: March 03, 2015, 02:10:15 pm
content: Can you believe that I didn't see the apprentice.I watched again after reading all the scope comments here - and yes, now I get it.I must have been hypnotized by the knife.

author: dexters_lab
author_rank: Unknown
timestamp: March 03, 2015, 02:18:30 pm
content: Love the nonchalant attitude while your new helper makes an appearance.when does he get introduced?

author: daqq
author_rank: Super Contributor
timestamp: March 03, 2015, 02:51:31 pm
content: Hi Dave,When you are dealing with 1TB of RAM you might consider creating a RAM drive for some serious speed boost - you don't need 1 TB of RAM for your application software (not sure if windows is even capable of it) most of the time.

author: FHR
author_rank: Contributor
timestamp: March 03, 2015, 03:39:01 pm
content: Hey dave,You need at least 2 DDR3 DIMM RAM sticks, one for each CPU.Also beware that older servers may have DDR2 memory, which is not compatible. You cant also mix ECC and NON-ECC RAM.

author: elgonzo
author_rank: Unknown
timestamp: March 03, 2015, 03:46:51 pm
content: Quote from: hamdi.tn on March 03, 2015, 11:38:20 amTotally awesome and funny appearance of Seppy.Watch older Mailbags (EEVblog #680 and older) and look for that particular oscilloscope...(I have to admit, until i saw Seppy's joke i did not realize that Dave did not have that upside-down scope in the most recent mailbags anymore)

author: NRoach44
author_rank: Contributor
timestamp: March 03, 2015, 03:48:57 pm
content: The unpopulated pads at ~5:30 is for a SAS (Serial Attached SCSI) controller (big BGA pad, and the shape of the connector silkscreen give it away. And the labelling for the connectors being "SAS0~3")

author: pb2k
author_rank: Unknown
timestamp: March 03, 2015, 03:52:12 pm
content: Quote from: FHR on March 03, 2015, 03:39:01 pmThe memory is quad channel, so populate all of the blue slots on the board, if you can with with identical speed and sized modules.Also be aware that according to the quick specs on the supermicro site EEC and non-ECC are supported, but not registered (or Fully buffered, not that FB ddr3 dimms exits)Look for memory codes like PC3-10600E.

author: elgonzo
author_rank: Unknown
timestamp: March 03, 2015, 04:04:55 pm
content: Quote from: pb2k on March 03, 2015, 03:52:12 pm? Of course it supports registered ECC DDR3 DIMMs...

author: FHR
author_rank: Contributor
timestamp: March 03, 2015, 04:13:31 pm
content: Of course It supports registered RAM. It will also run in single channel mode, no need to buy 8 sticks.

author: pb2k
author_rank: Unknown
timestamp: March 03, 2015, 04:16:06 pm
content: Quote from: elgonzo on March 03, 2015, 04:04:55 pmMy bad.From the full blown manual:"The X9DA7/X9DAE motherboard supports up to 1 TB of Load Reduced (LRDIMM),512 GB of Registered (RDIMM) or 128 GB of Unbuffered (UDIMM) ECC/Non-ECCDDR3 800/1066/1333/1600/1866 MHz 240-pin 4-channel memory modules in 16DIMM slots."

author: Grapsus
author_rank: Regular Contributor
timestamp: March 03, 2015, 04:56:42 pm
content: It's a good thing that this motherboard supports both kinds of DIMM (registered and regular).Which kind of RAM to buy will depend on the desired total amount of RAM.If it's less than 128 GB, then stuffing this puppy with unregistered non-ecc 8 GB sticks will be the absolute cheapest.If more than 128 GB are required there is no choice but to buy buffered RAM which will be like two times more expensive and will maybe add a bit of access latency.In any case, I'd advise to stay away from ECC UDIMM and NON-ECC RDIMM which are uncommon and expensive.With LRDIMM it's possible to get 1 TB of RAM, but it probably costs more than a kidney.And please don't listen to stupid advice about ECC RAM on youtube. For a 32 GB machine, the real life data about RAM errors is like one over a year of continuous operation. For storage servers with certain filesystems, it's absolutely required, but for a single video rendering machine it would be a waste of money.

author: dentaku
author_rank: Frequent Contributor
timestamp: March 03, 2015, 06:16:11 pm
content: It's great to see stuff manufactured in Nova Scotia like the Chip Whisperer.Of course Colin lives near Dartmouth which seems to be the only place to get electronic related parts and tools in NS. I know you can order anything online these days but it's still nice to have a real store to check new stuff out sometimes.

author: Switching Power
author_rank: Contributor
timestamp: March 03, 2015, 06:37:08 pm
content: This would also make a nice postcardhttp://dilbert.com/strip/1999-03-02

author: Neilm
author_rank: Super Contributor
timestamp: March 03, 2015, 07:23:04 pm
content: Had to laugh at the appearance of Daves new PFY

author: max666
author_rank: Frequent Contributor
timestamp: March 03, 2015, 07:46:21 pm
content: Quote from: Switching Power on March 03, 2015, 06:37:08 pm

author: RupertGo
author_rank: Regular Contributor
timestamp: March 04, 2015, 12:39:48 am
content: Loved the ChipTorturer... er, Whisperer. Bet you can lose a few hours to that baby.I only mention this because it's normally so good, but there's a spot of hum on the audio from time to time - you can hear it most clearly at around 6:40. Sounds more like inductive hum rather than dodgy shielding, from the way the level changes between cuts. Nothing terrible and no interest in being a precious snowflake on this, but if a bit of cable repositioning can restore the pristine crispness of Dave's unique tonality, then why the hell not.And props to the Dave Soundboard chap for not doing what I'dve done, and stringing together some of the standard phrases or sayings into proper rudeness, as a bad man could so easily do...

author: miguelvp
author_rank: Super Contributor
timestamp: March 04, 2015, 01:55:18 am
content: Don't forget to put heatsinks to those Xeons, like this one that came from a DELL Precision 490

author: SL4P
author_rank: Super Contributor
timestamp: March 04, 2015, 03:23:55 am
content: Quote from: hamdi.tn on March 03, 2015, 11:38:20 amIt was done for our Northern Hemisphere viewers - who had previously been uncomfortable with the Aussie-centric nature of Dave's presentations.Date will still bedd/mm/yyoryymmdd- butNEVERmm/dd/yy -EVER!

author: scottwolf369
author_rank: Newbie
timestamp: March 04, 2015, 04:33:25 am
content: Hi Dave, I used to work for Qualcomm in the 90s as a field engineer. My job was to install the ground stations for the Globalstar system.The satellite system was a "bent-pipe" configuration to keep the costs down. Basically there's very little intelligence in the satellites.They merely repeat the signal on a different band back down to Earth from the GS phone and from the ground station back to the phone.There are three ground stations in Australia. In 1999 I visited all three sites doing upgrades and got to see a great swath of Australia.Meekatharra WA 26°36'9.40"S 118°31'39.41"EDubbo NSW 32°10'37.97"S 148°36'55.91"EMt. Isa QLD 20°41'2.48"S 139°30'17.46"EThe communications themselves use CDMA (code division multiple access) , the same as many non-GSM mobile phones in the US.However, Globalstar uses twice as many codes as terrestrial CDMA, so many more conversations can happen in the satellite footprint than in a typical cellular "cell".

author: Unknown
author_rank: Unknown
timestamp: March 04, 2015, 07:07:48 am
content: Quote from: SL4P on March 04, 2015, 03:23:55 amWhat kind of moron would ever think of such a thing? ;-)

author: miguelvp
author_rank: Super Contributor
timestamp: March 04, 2015, 07:10:34 am
content: I guess we consider the month more important than the day, and of course we like to start our week on Sunday as well

author: Stonent
author_rank: Super Contributor
timestamp: March 04, 2015, 07:15:58 am
content: Quote from: miguelvp on March 04, 2015, 01:55:18 amLast year we auctioned off our old 490s to employees, they averaged 50 to 75 a pop. They got them with 4GB of ram and XP.I think most had some $100 FirePro cards in them. Something they picked up the year prior that was marginally faster than the old Quadro cards in there, though not really for everyone. The ATIs did better in 3D but the 4 year old Nvidia cards kicked their butts when it came to viewing 2D CAD drawings. (as in people who only dealt with 2D CAD drawings complained and wanted the old cards back)

author: Stonent
author_rank: Super Contributor
timestamp: March 04, 2015, 07:16:20 am
content: Anyway, I'm guessing that may be Seppy?

author: Unknown
author_rank: Unknown
timestamp: March 04, 2015, 08:12:03 am
content: Dave: Welcome to the Supermicro owners club!I've been an advocate for Supermicro since I bought my first SuperO board back in 1999 and have used them ever since. Throw some decent RAM (Samsung, Hynix etc...), a half-decent video card and an SSD and your machine will absolutely scream along. You'll also love the reliability. You'll get several months of uptime under Windows which is often ruined with updates ;-)I order my gear through Alfa Computers in Alexandria (alfa.com.au) just in case anyone in Sydney is interested.

author: G7PSK
author_rank: Super Contributor
timestamp: March 04, 2015, 08:43:37 am
content: The scope's have to be turned like cheese in order to mature them correctly.The Newage AVR controls the field current on the alternator It takes current from one of the stator windings and feeds it to the field winding of of the exciting generator which is on the same shaft as the main rotating field. The main field windings and the stator of the exiting generator are directly connected on the shaft via a bridge rectifier which rotates with the shaft so the AVR does not control the field directly itself. That particular one registers the voltage from one phase only usually phase A there are others that monitor all three phases. The main reason the AVR's blow is a short in the field winding causing it to try and deliver to much current to the exciter in compensation. I have some that were installed in the 1980's that are still running today with the original AVR, another thing that can bring them down is uneven phase loading such as a large spot welder, such loads should be on the same phase as the AVR or a 3 phase AVR should be used. You can often tell if the AVR is failing or the field winding has a short with a scope as either the waveform will have spikes on it or the voltage will be lope sided either higher or lower about the centre line. I have sent them off in the past to get them repaired by specialist company's but found the hard way that it's best to fit an original new part as replacement.

author: Phoenix
author_rank: Frequent Contributor
timestamp: March 04, 2015, 09:20:11 am
content: The AVR (automatic voltage regulator) looks similar in operation and construction to those I've dealt with for synchronous generators on trains. Their basic operation is to regulate the generator output voltage by adjusting the excitation field (remember that the backEMF of a sync machine is proportional to the excitation current).The output specifications are designed for driving the field winding of the synchronous machine. The output resistance of these is actually an important feature as it helps provide stability/dynamic range into an otherwise almost entirely inductive load. It's also important as the regulator can really only drive a positive output voltage and thus can only actively increase the field current. If the regulator needs to reduce the current in the field it can only freewheel and let the resistor passively dissipate the energy.Droop control is used when you want to parallel generators together, such as in the main electricity grid. The hand trimmer (an external POT) adjusts the attenuation of the input/feedback signal, implicity setting your sync machine regulated output. The stability circuit would form part of the dynamics of the feedback controller and I'd expect there to be some trimmers to set it up.In order to test these things you can't really just apply an AC voltage in or else the feedback control will ramp one way or the other way and eventually saturate. Or it'll just self protect somewhere. They are a feedback controller (maybe PI, or type 2 or 3 with some other filtering like peak detection). You really need to think about the circuit operation, bias levels etc., a whole test jig (or a real motor).Here is an example of an generator that would use such a unit:http://www.globalmarket.com/product-info/hot-sale-23kw-60hz-230v-copy-stamford-generator-with-avr-2780661.html

author: rollatorwieltje
author_rank: Unknown
timestamp: March 04, 2015, 02:25:13 pm
content: Quote from: Halon on March 04, 2015, 08:12:03 amJust looked at the uptime of my routerI think I may need to update the software at some pointPerformance wise it's completly the opposite of Dave's board though, Supermicro X7SPA-HF.

author: ornea
author_rank: Unknown
timestamp: March 04, 2015, 03:12:41 pm
content: Quote from: Halon on March 04, 2015, 08:12:03 amThe Supermicro's (10 of) we maintain in our server room (total 100+ servers) seem to be the most problematic of all the servers we have to work with.

author: ornea
author_rank: Unknown
timestamp: March 04, 2015, 03:42:07 pm
content: RF Solutions - Elite-XT ... trnamsitters ... Ooops

author: G7PSK
author_rank: Super Contributor
timestamp: March 04, 2015, 04:24:14 pm
content: Newage is now part of Cummins.Here is the web page for the AVR's as they are now for the HC range of alternators which from the power range I saw on the sheet Dave had.https://www.cumminsgeneratortechnologies.com/en/products/avk/voltageregulators/

author: ornea
author_rank: Unknown
timestamp: March 04, 2015, 06:58:15 pm
content: Quote from: miguelvp on March 04, 2015, 07:10:34 amI agree, and following the importance logic the only conclusion isyyyymmddIt also sorts naturally when used for filenames.

author: max666
author_rank: Frequent Contributor
timestamp: March 04, 2015, 07:28:19 pm
content: Ok, so I just watched the ChipWhisperer-Lite kickstarter video, and I think it's a solid campaign and interesting product.But what's up with this ... ugh:I have no confidence in the qualification of the Quality Assurance Manager Luna

author: Razor512
author_rank: Regular Contributor
timestamp: March 04, 2015, 10:39:55 pm
content: If he needs a good E-ATX compatible case, he should check out the Fractal Design Define XL R2http://www.newegg.com/Product/Product.aspx?Item=N82E16811352029&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-na-_-na-_-na&cm_sp=&AID=10446076&PID=3938566&SID=Not flashy, but is very quiet (lots of sound dampening), good cable management, and enough space for long video cards (for when he decides to install a few high end videocards for gaming purposes.He can then move the rear fan, to the side of the case, then install 2 closed loop liquid coolers (1 at the back, and 1 at the top) (the fan at the side will provide some airflow for the VRM's and videocards.

author: Someone
author_rank: Super Contributor
timestamp: March 05, 2015, 01:54:10 am
content: Quote from: scottwolf369 on March 04, 2015, 04:33:25 amDoes the 112 emergency dialling number works on the satellite handsets? Without activation? Could make a useful emergency handset.

author: Unknown
author_rank: Unknown
timestamp: March 05, 2015, 02:08:37 am
content: Quote from: Someone on March 05, 2015, 01:54:10 amIt depends.For example all satellite operators in Australia support dialing 000. I know the emergency number on the Iridium system used to be 767 (SOS). 112 is considered a 'secondary international emergency number' for digital mobile phones only and won't work on fixed line, some VoIP services and satellite phones.

author: scottwolf369
author_rank: Newbie
timestamp: March 05, 2015, 04:20:48 am
content: Quote from: Someone on March 05, 2015, 01:54:10 amOne of the advantages Globalstar has over Iridium, at least as far as the local provider is concerned (in Australia's case, that would be Vodafone), is that they maintain full control over how the system operates and what it is connected to.Iridium has smart satellites. When you make a call, the signal is routed from satellite to satellite until it reaches a satellite that can make the link to the ground station, or to another satellite phone user.Globalstar's bent-pipe satellites will route through a ground station located in the same country you are calling from and is subject to their control. So if Vodafone, either through their choice or due to local laws, made emergency calling available without an actual subscription, then yes. (So, as Halon said...it depends.)My job was installing the racks of equipment, testing the satellite RF chain from the transceivers to the 5.5 meter Alcatel dishes, testing the GPS system, updating software and testing the network connection to the GOCC (Globalstar Operations Control Center). The phone side was a different set of engineers working with the local provider. So honestly I couldn't tell you how the Australian system was set up as far as the emergency calls.

author: bitwelder
author_rank: Super Contributor
timestamp: March 05, 2015, 06:11:30 am
content: Quote from: Halon on March 04, 2015, 07:07:48 amThe American date format, created by me it was.Yoda

author: Someone
author_rank: Super Contributor
timestamp: March 05, 2015, 07:11:07 am
content: Quote from: Halon on March 05, 2015, 02:08:37 amThanks, they're so cheap second hand that its becoming tempting to pick one up as an emergency alternative to HF sets. Trouble is getting a straight answer out of the providers about the ability to make emergency calls without a plan. So the Iridium handsets will handshake with the network and provide 000 access "out of the box"?

author: Unknown
author_rank: Unknown
timestamp: March 05, 2015, 08:29:14 am
content: Quote from: Someone on March 05, 2015, 07:11:07 amI honestly wouldn't bother. With the mobile network coverage provided by the three carriers in Australia, you'll almost always be in coverage if you're near population and dialing 000 will route the call using any network.If you're the type of person who goes remote on the odd occasion, you would probably rent a sat phone if voice comms was necessary, otherwise I'd just invest in an EPIRB/PLB. In case of an emergency, especially in remote areas, your location will be known within minutes. They would be far more rugged and reliable than a phone anyway and the shelf-life of the batteries are probably 10+ years.

author: 84GKSIG
author_rank: Regular Contributor
timestamp: March 05, 2015, 12:38:58 pm
content: i know i cant use all my oscilloscopes at the same time but i like my oscilloscopes the right way aroundgreat vid dave

author: Tek_TDS220
author_rank: Regular Contributor
timestamp: March 05, 2015, 04:12:11 pm
content: When Dave changed the setting for the mailbag I was one of several commenters who mentioned the upside-down scope. Ever since then, it's the first thing I look for when the mailbag video appears. Part of it is simply that I admire the scopes. This time I noticed it was right-side up, and I wondered when it was fixed. When the mysterious assistant appeared I just about fell out of my chair. Good one!

author: Someone
author_rank: Super Contributor
timestamp: March 05, 2015, 09:08:06 pm
content: Quote from: Halon on March 05, 2015, 08:29:14 amDont worry I wouldn't go anywhere interesting without a GPS equipped PLB, having toured the co-ordination centre back in the EPRIB days its a very serious response to all activations and now with the GPS equipped PLB units their targeted time to first contact is down from around 8 hours to around 1. But its those non-life threatening emergencies that it would be useful to have an option for, and also being able to communicate the requirements in case of either.We've pushed the limits of mobile coverage in Australia and I'm regularly in locations that have zero coverage or used to get CDMA and now get nothing.One final tip for anyone in a life threatening emergency while outside of cities in Australia, ask for the local Police station (you'll need to know the nearest towns name) and get them to co-ordinate the entire operation, they have many more options and resources than going through the emergency dispatchers.

author: Unknown
author_rank: Unknown
timestamp: March 05, 2015, 10:26:16 pm
content: Quote from: Someone on March 05, 2015, 09:08:06 pmReally? That seems unusual. Although if you're with anyone but Telstra, then I can believe it. Optus struggles even in the middle of Canberra.It also does largely depend on your handset. For example, my other half's iPhone struggles at the fringe of reception whereas my handset (which is Android based) will hang on until it's basically non-existent, data is slow, but it still works. My old Motorola Defy and Razr handsets were also particularly good; Telstra rated them "blue tick" for use in rural areas. On a kind-of related note:Quote from: Someone on March 05, 2015, 09:08:06 pmIn Australia, Police will automatically get notified in Search & Rescue operations. They are the primary response agency and will coordinate SARs.

author: Someone
author_rank: Super Contributor
timestamp: March 06, 2015, 04:44:51 am
content: Quote from: Halon on March 05, 2015, 10:26:16 pmPatchy coverage is of no use when you don't want to leave a patient or situation, that it works around the corner or at the top of a hill isn't useful. I know of farmers who hated the shutdown of the CDMA networks as they were left without any coverage at all.Quote from: Halon on March 05, 2015, 10:26:16 pmWhen you know your location there is no need for a search, just aid/recovery/support. Since nothing came back on the emergency services after the David Iredale inquest wrapped up (http://www.smh.com.au/national/triple0-review-urged-by-coroner-as-iredale-inquest-ends-20090508-aw1a.html) and having been involved in many interesting aid/recovery situations I'm familiar with how much better the police handle locations and events outside of the metropolitan areas. The police understand much better spatial information and have a more flexible information system that can handle situations outside of street intersection and post box addresses, and while it would be nice to get helicopter assistance every time they manage the limited resources very well.For all our international readers:http://en.wikipedia.org/wiki/Snowy_Hydro_SouthCareA Putin-esque story and the single helicopter that covers a population of 2 million across 300,000 or so square km (similar in size and shape to the whole country of Germany!)

author: Tom D
author_rank: Contributor
timestamp: March 06, 2015, 10:09:15 am
content: Quote from: Halon on March 04, 2015, 08:12:03 amSame here, my first Supermicro was the old P6SBA BX chipset PII board back in '98, it never missed a beat. My current X7DWA-N machine with dual quad core X5492's is getting quite dated now, and has been running since 2008 with no drama.The biggest single performance enhancement I've made to it was when I went to four Intel SSD's in RAID zero, so this will have to serve me for a little while yet.Tom

author: Hydrawerk
author_rank: Super Contributor
timestamp: March 09, 2015, 08:13:18 pm
content: http://youtu.be/v7TaU-N3ab0?t=21sThere is a ghost of Nikola Tesla turning your TDS3000, LOL.

author: max666
author_rank: Frequent Contributor
timestamp: March 09, 2015, 08:29:04 pm
content: Quote from: Hydrawerk on March 09, 2015, 08:13:18 pmI wonder if the ghost had to sign in his contract, that he's being filmed and surveilled