Opinions on SI
"k7udr" <bhhoyer@...>
After a recent presentation I was approached by a fellow Ham who noted that my presentation did not conform to SI (International system of units). He offered a training exercise in the proper usage which I accepted. I must admit, I was ignorant of SI prior to that time.
Apparently, SI is taught in grade school throughout the world, whereas my US education seems to be lacking. So I went through my material fixing obvious offenders, like proper capitalization and the use of a space between value and units. the K in kilo should be lowercase 70cm should be 70 cm 12VDC should be DC 12 V (looks pretty awkward to me) I then learned that bps should be b/s and dBm don't exist. Further ppm is incorrect. Now I've never seen b/s used by anyone, anywhere and I certainly wouldn't want a table of values expressed as: dB referenced to 1 mW instead of dBm When I purchase an oscillator, tolerance is expressed in ppm, so apparently the manufacturers are unaware of their non-conforming usage. Am I out of touch with reality? Are you offended by 56 kbps? I'd like to hear others thoughts on this, particularly those of you educated somewhere other than the US Bryan
|
|
"qrv@..." <qrv@...>
Who created that "training exercise" and who claims it is taught
toggle quoted messageShow quoted text
worldwide and accepted everywhere? It is a favorite hobby of wanna-be one-world everything to claim that the USA is wrong ... and an island of non-conformity ... sigh. I think someone is borrowing credibility for pet-peeves by claiming consensus where it does not exist.
After a recent presentation I was approached by a fellow Ham who --
Thanks! & 73, KD4E.com David Colburn nevils-station.com I don't google I SEARCH! duckduckgo.com Network: groups.yahoo.com/group/qrv Restored to design-spec at Heaven's gate 1Cor15:22
|
|
Darren Long <darren.long@...>
Comments in-line.
On 24/11/12 17:37, k7udr wrote: Indeed.
The former versions look better to me. Better 70cm than 2.3ft. Either bps or b/s is fine with me, as is ppm.
dBm FTW!
Those are my thoughts. I learned the SI system at school and have an engineering degree. I may laugh at the imperial units system on a regular basis but there's nothing wrong with the examples you've quoted. I'd rather not get drawn into a discussion on gibibits and those other awful prefixes though. Confusion often arises from the notion that 1kB can not be sent in 8 seconds through a 1kb/s channel, as 1kB is 1*2^10 bytes and 1kb/s is 1*10^3 bits per seconds, but more confusion arises from using ridiculous prefixes. For that reason alone, I prefer sticking to the base unit of bps or b/s. I think you've been trolled :P Cheers, Darren, G0HWW
|
|
Jeff Francis™ <jeff@...>
As a Sales Engineer (ie, someone who communicates technical data and solutions for a living), I've adopted the very pragmatic approach of "speak in terms your audience will recognize, appreciate, relate to, and understand", regardless of personal feelings, standards, conventions, or anything else. Be flexible, be conversant with all the various standards, and know your data well enough to convert it on-the-fly to fit the needs of your audience. As a rule of thumb, the best you can do is to please 80% of your audience. Just make sure it's the right 80%. Sometimes it all comes down to just one guy, and to hell with all the rest. It's all a grand psychological game that you have to learn to play to be a solid communicator. In the end, it's about moving data from my head to your head. I work in the area of network and computer security. I have an entirely different vocabulary and style that I use when communicating the exact same information to the networking/security group of a Fortune 100 company, a public school district, a regional healthcare provider, a talk at a convention or show, a university, people I meet at random who ask what I do for a living, and my peers within my company. Sometimes all of these in a single day. You'll never make everybody happy. Learn to read your audience, and tailor your presentation to their needs. What's "right" for one group is completely "wrong" for another. There's no objective right and wrong in cases like this. Every group has their own standards, and you either tailor your talk to their standards, or you don't fit in (ie, you're "wrong"). Europe is different than the US. I just spend a week in England adjusting to their vocabulary and ways of doing things. It's not right or wrong, nor is it entirely better or worse. But it's different, and the better and quicker you adapt to the differences, the more effectively you communicate. The Brits are entirely conversant in American English, and you'll get what you're asking for if you ask for the parking garage, the elevator, or the intersection. But you'll get your answer with a much different attitude if you ask for the car park, the lift, or the crossroads. And sometimes that matters.
toggle quoted messageShow quoted text
N0GQ
On Sat, Nov 24, 2012 at 9:37 AM, k7udr <bhhoyer@...> wrote:
--
-=jeff=-
|
|
"Rick Muething" <rmuething@...>
Well Bryan,
The international screw thread committee was supposed to standardize screw
sizes and threads in the early 19th century ....of course they didn’t do too
good a job so now we have US Fine, US Coarse, Metric, each with many variations
etc. much to the benefit of those making wrenches, sockets and
drivers!) As long as you are communicating clearly I don’t think it is a
big deal. For me: (a US educated Engineer)There is no confusion
with:
70cm vs. 70 cm,
12VDC vs DC 12 V (I am sure 12VDC is more common)
bps vs. b/s
dBm
or ppm (most xtals and oscillators are specified in ppm)
So I would vote use standards where appropriate (please avoid furlongs per
forte night when possible! ) and push on! Those that want to
retranslate to the latest “approved” standards can contribute by doing a
translation if necessary.
Keep up the good work!
Rick Muething, KN6KB
From: k7udr
Sent: Saturday, November 24, 2012 12:37 PM
Subject: [UniversalDigitalRadio] Opinions on SI After a recent presentation I was approached by a fellow Ham who noted that
my presentation did not conform to SI (International system of units). He
offered a training exercise in the proper usage which I accepted. I must admit,
I was ignorant of SI prior to that time.
|
|
Michael Schulz <mschulz@...>
Some comments from someone who actually is from Germany and grew up
on the
toggle quoted messageShow quoted text
metric system. And yes, sorry to say but the US is pretty much the only country in the western world on he Imperial system, the UK uses a mix of both. The k in Kilogram indeed is lower case as is the c the d the m (centi, deci, milli). There is a space between the 70 and the cm or m or km or mm or you name it. Not so sure at the moment about the DC 12V .. most I have seen is simply 12 V or 220 V with either ~ (AC) or = (DC) as leading sign. bps vs b/s is the same. You need to define the relation of one unit to the other. If you omit that it's not clear. If I say b/s (or km/h or m/h) the it's unmistakenly defining the relationship between the two. Of course everybody in the IT field knows what bps are, but outside maybe not :). As a side note, it's always interesting to see as a European living in this very nice country how easily offended Americans can get when they have to learn or deal with the fact that the US is not the center of the universe, and not everybody is looking to the US only to see how to do things. 73 Mike K5TRI
On 11/24/2012 9:56 AM, qrv@... wrote:
|
|
"k7udr" <bhhoyer@...>
Reminds me of a joke,
toggle quoted messageShow quoted text
2 salesman walk into an engineer's office engineer: "I need a 10.0 MHz TCXO 2 ppm" salesman 1: "ppm is not a SI recognized unit" salesman 2: "I have 1000 in stock at $2.19" Bryan
--- In UniversalDigitalRadio@yahoogroups.com, Jeff Francis™ <jeff@...> wrote:
|
|
"k7udr" <bhhoyer@...>
So now i had to look up FTW in the Urban Dictionary,
toggle quoted messageShow quoted text
An enthusiastic emphasis to the end of a comment, message, or post. Sometimes genuine, but often sarcastic. For The Win!
--- In UniversalDigitalRadio@yahoogroups.com, Darren Long <darren.long@...> wrote:
|
|
"Tim Hardy AF1G" <hardyt@...>
Keep doing it the way you’ve been doing it. I don’t care how the rest of the world does it. In fact, if you look hard enough, you’ll find a dozen different “standards” or more in use around the world for various things. The USA did not wholly adopt the metric system when THAT push came along, either. We still customarily write numerical dates as month-day-year instead of the European “standard “ of day-month-year and it doesn’t cause us any problems. I know how to interpret the date of the contact on a QSL card received from outside the USA. The British police clock vehicles with radar in miles-per-hour and not in kilometers, so I suppose they are non-conforming as well. We don’t write our “ones” to look like “sevens” and we don’t draw short horizontal lines across our “sevens” and our “zees” and it doesn’t cause us problems.
Your fellow Ham sounds like he/she might be a science or engineering-trained person who was taught the “proper” way of doing things in those communities.
Tim, AF1G
From: UniversalDigitalRadio@... [mailto:UniversalDigitalRadio@...] On Behalf Of qrv@...
Sent: Saturday, November 24, 2012 12:56 PM To: UniversalDigitalRadio@... Subject: Re: [UniversalDigitalRadio] Opinions on SI
Who created that "training exercise" and who claims it is taught No virus found in this message. No virus found in this message.
|
|
"Tim Hardy AF1G" <hardyt@...>
Mike,
Many of us Americans don’t get offended – we just see no reason to change what works.
Tim, AF1G
From: UniversalDigitalRadio@... [mailto:UniversalDigitalRadio@...] On Behalf Of Michael Schulz
Sent: Saturday, November 24, 2012 1:29 PM To: UniversalDigitalRadio@... Cc: qrv@... Subject: Re: [UniversalDigitalRadio] Opinions on SI
Some comments from someone who actually is from Germany and grew up on the
No virus found in this message. No virus found in this message.
|
|
"k7udr" <bhhoyer@...>
Mike, thanks for your perspective.
toggle quoted messageShow quoted text
The metric vs imperial argument has little direct impact in electronics, as electrical units came along late enough not to be damned with imperial equivalents. Although it's interesting that Antennas are described in meters until we go to build one, then we switch to tape-measure mode. PC Board layout went metric in 1988 although there are still a lot of imperial packages for older components. I still use 0.1 Headers for their price and availability. I have been bitten more than once by english/metric smt packages which have the same designation but are not the same size. I note that when I sent my extrusion files out in metric, vendors both in the US and Asia requested english drawing files. Cheers, Bryan
--- In UniversalDigitalRadio@yahoogroups.com, Michael Schulz <mschulz@...> wrote:
|
|
"qrv@..." <qrv@...>
Actually, in this case it is someone elsewhere attempting to
toggle quoted messageShow quoted text
impose an external standard upon the USA. After Europe, and most of the rest of the world, refunds the cost of the USA repeatedly liberating them from dictators - due to their hubris - perhaps we will become less "offended" when told we must conform. Oh, and until the economic stability of Europe (can you say "Greece" or "Spain") becomes a model of success the platform from which to point fingers simply does not exist. Despite the efforts of some egg-head academics, and one political wing, to destroy things here ... most Americans have been rather happy to live in freedom & prosperity. "Thank you very much" ... he said, as he gingerly climbed down off his caffeine-challenged soap box.
As a side note, it's always interesting to see as a European living --
Thanks! & 73, KD4E.com David Colburn nevils-station.com I don't google I SEARCH! duckduckgo.com Network: groups.yahoo.com/group/qrv Restored to design-spec at Heaven's gate 1Cor15:22
|
|
Michael Schulz <mschulz@...>
Just WOW .. and very close to Godwin .. so you loose.
toggle quoted messageShow quoted text
On 11/24/2012 11:09 AM, qrv@...
wrote:
|
|
"qrv@..." <qrv@...>
Who? What?
toggle quoted messageShow quoted text
Michael Schulz wrote: --
Thanks! & 73, KD4E.com David Colburn nevils-station.com I don't google I SEARCH! duckduckgo.com Network: groups.yahoo.com/group/qrv Restored to design-spec at Heaven's gate 1Cor15:22
|
|
"Tony Langdon, VK3JED" <vk3jed@...>
At 04:37 AM 11/25/2012, you wrote:
After a recent presentation I was approached by a fellow Ham who noted that my presentation did not conform to SI (International system of units). He offered a training exercise in the proper usage which I accepted. I must admit, I was ignorant of SI prior to that time.I think someone's being anal retentive here. Strictly speaking, SI is a very formalised way of expressing measurements based on the metric system. However, the strict usage tends to only apply to scientific works. More general technical articles have a degree of flexibility and their own conventions. First, the must have So I went through my material fixing obvious offenders, like proper capitalization and the use of a space between value and units.Most definitely. Case is something you must get right, sometimes it makes a big difference. For example, the common practice of writing "mhz" instead of "MHz" - "m" means "milli", or 0.001x, where 'M" means "Mega", or 1,000,000x. That's a big difference! Not to mention that "hz" is meaningless, since the correct abbreviation is "Hz". And a network card capable of 1000 mbps is not that impressive and hardly useful (except maybe for controlling a QRSS keyer! :) ). 70cm should be 70 cmThese ones are tidy and should be taken care of. I then learned that bps should be b/s and dBm don't exist. Further ppm is incorrect.Actually, it would often be expressed as an exponent, which I can't do in plain text bs^-1 would be the closest approximation, since the -1 would be written in superscript, just like the "2" in "squared" or "3" in "cubed". You only see this in scientific papers. I certainly wouldn't be going that far in a ham radio technical article, because this is not a convention widely understood. I'd find b/s or bps to be acceptable. Just make sure any multipliers are written in the correct case. b/s is certainly the more correct of the two, but bps is probably the more widely understood. The correct presentation of units is more important in scientific work, because units are an integral part of a lot of scientific (and engineering) calculations, and correct expression of units for all variables in an equation here makes it clearer what the units of the result should be. In ham radio, the most important thing is getting your message across. Now I've never seen b/s used by anyone, anywhere and I certainly wouldn't want a table of values expressed as:Again, while technically correct, I think this is a bit over the top for a ham article. The latter is widely understood by the intended audience. The former _should_ be understood (we do know how decibels work, don't we? :) ), but it doesn't speak as well to the intended audience. However, if I was writing a scientific paper, I'd be using the first one. When I purchase an oscillator, tolerance is expressed in ppm, so apparently the manufacturers are unaware of their non-conforming usage.Again, ppm is another one well understood by your audience, I'd certainly use it. I'm not sure what the strict SI equivalent is, off the top of my head. Am I out of touch with reality? Are you offended by 56 kbps?For the purposes most of us are likely to encounter, it's perfectly fine by me. I'd only take exception if you were presenting a scientific paper. I'd like to hear others thoughts on this, particularly those of you educated somewhere other than the USLike a lot of things, there's the strict system, typically embraced only by groups that need it, and there's general usage. You do have to consider what is going to communicate your message better to your intended audience as well. For the record, I grew up in an era of changing over from Imperial to metric units. I studied engineering at university, where correct SI usage was expected, so I am fairly familiar (though maybe a little rusty at times!) with proper SI usage. Whenever we worked through deriving a new quantity, the units were properly calculated as well, which is easier when proper SI notation is used. 73 de VK3JED / VK3IRL http://vkradio.com
|
|
"Tony Langdon, VK3JED" <vk3jed@...>
At 05:18 AM 11/25/2012, you wrote:
Those are my thoughts. I learned the SI system at school and have an engineering degree. I may laugh at the imperial units system on a regular basis but there's nothing wrong with the examples you've quoted.Actually in communications, "kb" has always meant 1000 bits, and "Mb" 1000000 bits. The only place where this was different was when talking about memory or storage capacity on computers. The "bi" versions of the units weren't used back in the late 1980s or early 1990s, as they are now, we just had to know by context, or state what conventions we were using when writing reports. :) 73 de VK3JED / VK3IRL http://vkradio.com
|
|
"Tony Langdon, VK3JED" <vk3jed@...>
At 05:25 AM 11/25/2012, you wrote:
As a Sales Engineer (ie, someone who communicates technical data and solutions for a living), I've adopted the very pragmatic approach of "speak in terms your audience will recognize, appreciate, relate to, and understand", regardless of personal feelings, standards, conventions, or anything else. Be flexible, be conversant with all the various standards, and know your data well enough to convert it on-the-flyI'd agree with this, on the proviso of not being "obviously incorrect" while doing so, meaning not doing sloppy things like using "mbps" when you mean "Mbps" or "KHZ" when you mean "kHz", etc. 73 de VK3JED / VK3IRL http://vkradio.com
|
|
"Steven" <baxter@...>
http://en.wikipedia.org/wiki/Godwin';s_law
toggle quoted messageShow quoted text
Now can we please put the flame throwers away and get on with some ham radio? [Moderator's note: Steven is correct, we don't want this to devolve into a flame war or personal attacks. The moderator reserves the right to delete any posts considered inflammatory or intended to goad another forum member. We walk a fine line between encouraging open discussion and keeping the discussion civil and on topic. Since we want a friendly place to exchange ideas relative to digital radio, we tend to err on the side of openness of expression. Political debate in the US has moved from civil disagreement to visceral attacks, so we ask members of the list not to make disparaging remarks about political parties, elected officials, or ideologies in the forum. Discussion of radio and networking policy issues, in a civil manner, are acceptable.]
--- In UniversalDigitalRadio@yahoogroups.com, "qrv@..." <qrv@...> wrote:
|
|
Kristoff Bonne <kristoff@...>
Just a small note. As far as my history lessons go, units like the pound (both in weight and as currency) and derived units are actual roman units that where standarised in Europe (including the British Isles) by Charlemagne; and pushed further into Europe via the Hanza trading-systems. The imperial system is in that sence as much "external" then the SI. It's nothing else but the unit-system of the old collonial master of the British collonies in America that became the US. Well, at least, they descided to standardise the units inside their country which was something that was not even the case in all countries. :-) Well, we are kind of seeing an inverse movement here. Up to some 5 years ago, televisions-screens where sold as (say) 107 cm; now they are marketed as "42 inch". I guess they are just doing this to try to confuse us. :-) 73 Kristoff - ON1ARF
|
|