Low Frequency Radio Transmission for long distance.

On Wed, 04 May 2016 15:27:21 -0700, Jeff Liebermann Gave us:

You left out Jackson... errr... Tubman notes.

Next thing will be transgender 2 or 3 dollar notes. From the land down under.

I agree, when unqualified, db always means power. However, using it with a suffix for other base units is a valid evolution of the language, and doesn't make it "useless as a term for technical communication", i.e. by conflicting with its default usage for power. (When did we start saying dB by the way; that paper says it's db?).

But then I guess some of us think that everything was perfect and complete at its point of creation, and that any departure is sin. Others admit that things evolve and always have. I prefer to live in the 21st century, not 1929. :-P

Clifford Heath.

Those values convert in the wrong direction.

Clifford Heath.

I really hated pF at first, but got used to it after a while. I also got used to nF with time so that now if I see something like 2000 pF or

0.001 uF I wonder why they aren't calling them 2 nF and 1 nF. How often do you write a measurement as 1000 mm or 0.001 meter?

BTW, I really hate that some fields still use angstroms. Go SI or go home!

Technically decibels is not an SI unit, but even if it were, the unit is bels, not Bels, so decibels would be correct. In SI units the symbols (which are *NOT* abbreviations) are capitalized when derived from a person's name and lower case when not with the exception of Celsius, but the unit name is always lower case. I have had such a hard time remembering this, I started to remember the URL at nist.gov to look it up before I remembered all the SI unit rules. lol

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Rick C

On Wed, 4 May 2016 19:06:22 -0400, rickman Gave us:

Depends on what is being measured. Want graphene film thickness? talk nm. Want wavelength talk Angstroms.

snip

I may have mentioned this in s.e.d. in the past, so please forgive the repetition. Find yourself a suitable victim and ask them to name who is on the front of various US currency denominations. Most adults will get the $1 and $5 bills correct, but will have little memory of who is on the $10, $20, $50, and $100 bills. If they do get some of these correct, it probably will not be an instantaneous recall, but require some concentration to drag the names from out of the depths of their memory. If you're unlucky and select a person with a photographic memory, ask them if they remember what is on the back of the various bills. A few people will remember the back of a $1 note, but the others will draw a blank.

Often it takes too much time to go through all the various bills. I've noticed that most people have problems with the $10 bill. If you're rushed, try just asking who's on the front and what's on the back of a $10 bill.

Part two is more interesting. Wait about 4 days and ask the same person again the same questions. Despite having been informed who's picture is on the front, and what's on the back, most people will not remember much more than what they could recall 4 days before. When I was doing this regularly, I noticed that a few people actually remembered less when asked for a second time.

Bonus test: Ask the same questions of a 14 year old. They'll tell you what's on both sides, and in detail.

Ok, so what's happening here? The problem is that we equate money with responsibilities, which most people try to avoid. With money being the symbol of responsibilities, we pay little attention to it in the hope that the responsibilities might go away. Despite the fact that currency is the most common unchanging document that we all see on a regular basis, we push it out of our minds and memories.

The reason a 14 year old remembers everything is that he doesn't yet quite understand what responsibility means, but knows that money is useful, has no reason to avoid money, and will therefore remember most everything on currency he has handled. However, for larger and less common demonominations, I would not expect him to remember.

The US already has a $2 bill. $3 bills are quite common. However, transgender presidents and personalities will need to wait their turn: Note that your hero is already printing his own 4 gigaDollar currency:

--
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

Not weird. SI capitalizes the abbreviations of units named after someone and not if it's spelled out (OK, that part is weird). So decibels isn't capitalized (it should be decibells ;-).

I expect the treasury to go to dB$ for the national debt any day now. Hillary is going to need it.

dbA is a good example. It's not convertible to power or to any other unit, yet it almost perfectly matches the logarithmic response of the human ear. (yes, I know that the frequency response curve is somewhat volume dependent.)

I don't agree at all. Can you give a concrete example where your proposed extension to the established usage of nearly a century adds clarity or expressiveness sufficient to outweigh the likelihood of confusion?

Cheers

Phil Hobbs

On Thu, 5 May 2016 08:58:37 +1000, Clifford Heath Gave us:

Wow... That got past all of us but you.

Almost as bad as my failure to use an infinity symbol.

Except that nobody is going to fault him for it.

On Wed, 04 May 2016 16:22:40 -0700, Jeff Liebermann Gave us:

snip

No shit. Jock types call it and consider it "gay" though.

Didn't need a primer.

"my hero"? Fuck you. I get called "libtard" as do others who express hatred for that inane idiot all the time.

I am a republican. Trump is not. He is a party interloper, at best.

You get a different moniker. LiebTard.

** Not for your mad case it's not.

** Firstly - the correct term is dB SPL (= sound pressure level)

( dBA is a short hand for dB SPL when A weighting is applied.)

SPL directly relates to power - to double the SPL at a point, the power output of the source must be increased by four times.

Four times power = 6dB increase.

Sound level meters measure relative power, on a dB scale.

... Phil

** A decibel increase is always a power ratio of 1.26.

** Provides a reference level for 0dB, so one can convert a dB reading to an actual level rather than a ratio of change.

.... Phil

On Wed, 4 May 2016 18:58:02 -0700 (PDT), Phil Allison Gave us:

But for a human to "think" a sound is twice as loud requires ten times power increases for each doubling.

I believe he is saying this is how you convert.

1 daB = 0.1 * bels

just as

1 dB = 10 * bels

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Rick C

Argh and thanks. I plugged 1 bel into the web page calculator and just cut and pasted the resultant numbers without thinking or checking. I was more concerned with proper formatting of the table than accuracy. It didn't "feel" quite right, but I let it go so that I could leave for lunch on time. The corrected table:

You can also use: bels (B) 1 bel decabels (daB) 10 bels hectobels (hB) 100 bels kilobels (kB) 1000 bels

decibels (dB) 0.1 bels centibels (cB) 0.01 bels millibels (mB) 0.001 bels

Grumble...

--
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

On Wed, 04 May 2016 21:32:08 -0700, Jeff Liebermann Gave us:

That came thru at 1 femtobel.

(...)

True. I couldn't figure out what to call it. SI only concerns itself with powers of 10. So a $20 note might be a vigintidollar:

As for the proposed changes in US currency, I believe it should be done in the same manner as ballparks, where the name of the ballpark is changed in honor of the largest donor. Since our government operates on the principle of rule by the largest political donations, it would be proper to honor those who do the most to keep our government supplied with politicians. For 2016, it looks like Donald Trump might be the biggest contributor (to his own campaign): To be fair, there's room for 6 major contributors ($1 thru $100) on the front of the various notes, with room on the back for the losers. To insure that our currency is up to date, the faces should change every 4 years.

--
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

At least this would solve the problem with billion dollars, i.e. is it G$ or T$.