Hello Richard,
Yes, it seems so. It could be the carriers since their currency is kb/sec. Yesterday a long time friend called me on his cell phone. I could not even recognize who it was until several seconds into the conversation, and initially only by what he was talking about.
Regards, Joerg
single
to
concern,
Of course, since all of your above comments still apply.
Now try ganging 6 alkaline watch batteries together instead. There is no mystery here. If one uses exactly the same battery technology in each case, the larger battery will have more storage capacity. (packaging excepted of course, and in the case of six separate cells, this will usually increase) So the answer may be to use a larger 9V battery. Unfortunately these aren't common any more. Most people prefer to use the smaller size, and change it more often.
MrT.
They need to save their bandwidth for pictures & video....
jak
Hasn't someone already mentioned the 6X AAA pack? Only a few mm bigger than a 9V, but lasts considerably longer? There are such a thing as AAA NiMHs, aren't there? My magical charger seems to think so:
I swear, that little box is smarter than I am [not that that's that great of an accomplishment] when it comes to charging NiMHs.
And does anybody remember "The Secret of NIMH"?
Cheers! Rich
But so far we have not been able to even think of approaching the speed and functionality of the human brain with any kind of computer. There were seveal levels of "intelligence" operating to decode CW in heavy QRM/QRN.
On a bit-by-bit basis, probably not. But on a symbol basis, where a symbol is a word, probably so. Especially if the vocabulary is small and there's surrounding context.
It's just a matter of defining "symbol."
John
Hello Mr.T,
Since AA packs a lot more Watthours per cubic inch than a 9V I think it would great if all designers wised up and designed their stuff to work with AA or a couple of them. It's not rocket science. I had a radio
30-some years ago that worked nicely with two AA. It boasted the longest runtime on one set of any radio I ever had. Got lost in a move and now I am using a 9V radio. It doesn't even last a day and the batteries cost twice as much.Regards, Joerg
Hello Jak,
Let's see how that goes. Maybe it's like with pool heaters. People love it until that first bill arrives in the mail.
Regards, Joerg
Hello Rich,
Hey, I am old enough to remember CW. With morse code it has been said that the trained ear was on occasion able to beat Shannon's law. Depends on the imbabitation status though.
Regards, Joerg
What amazes me is the cost of text-messaging. Why do I want to do that again?
I've ditched my land-line and gone cell, but there are many things that make no sense. Land-lines are expensive because the government decides it is so, but that doesn't excuse the cell companies from sanity. Sure, I know, it's all the teeny-boppers that think text-messaging is cool.
-- Keith
...and if the data-rate exceeds Shannon, your "symbol" is defined wrong. ;-)
The other thing people forget is the institutional and personal information that preceeds the communication. Many CWers knew the "fist" of others and their "expressions". This information was transmitted, albeit via a side-channel. ...data comperession with a known dictionary, as it were.
-- Keith
I've clocked high-pass (300Hz) signals through a 3Khz flip-flop. Surprisingly good, using a speech radio station as a signal source.
Typing a text-message in on my phone is going to save me time? OTOH, their time is certainly cheaper.
Huh?
Huh^2?
-- Keith
Time?
If you feel comfortable talking to people by just reciting a message, then you can probably get it done faster/cheaper.
But, how often is that the case? Many people on the other end will digress into weather/how their dog is/...
Comparing the consumer cells/batteries at a given point in time from one manufacturer (GP), you have the capacity of their highest capacity AA cells is typically 2450mAh (marked "2500"), while(st) their highest capacity 9V battery is 210mAh (marked 200). Since the 9V battery is 7 cells in series, the 9V battery has only 60% of the energy storage capacity of the AA cell.
On a weight basis, the 9V battery is 42.5g and the AA cells is 31g, so the AA cell comes out even further ahead (2.28:1).
On a volume basis, the AA cell fits in a cylinder 14.5mm diameter by
50.5mm long (including the end button), so 8339mm^3. The 9V battery fits in a box 48.5mm x 26.5mm x 15.7mm (including the snaps) or 20,180mm^3.On a volume basis, the AA cell comes out ahead by 4:1. If you more realistically use a box (rectangular prism) that just encloses the AA cylinder for the occupied volume, it's still ahead by more than 3:1.
Best regards, Spehro Pefhany
-- "it\'s the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
Pry apart a 9V and you will see why the AA packs more energy per unit volume. There is a lot of the internal space used up by the need to interconnect the cells and isolate them from each other.
I suspect that the cells in the 9V are actually a little better than the AA in energy per volume but I don't think it is by enough to make up for the about 1/3rd of the space that is not actually a cell.
-- -- kensmith@rahul.net forging knowledge
Does it? I'm interested in your calculations. There should be a market then for someone to simply put the exact same technology into a 9V pack.
It's even easier now with DC-DC switching converters.
Wow, either your AAA are smaller than ours, or your talking about bigger 9V batteries than I am. Including a cell holder makes our 6*AAA packs over twice as big as a single
9V battery with snap. Even without a cell holder they still have quite a bit more volume.MrT.
Really, who cares?
This manufacturer has a wide line with three types of 9V cell alone. You think they're going to improve the 9V cell just for you? The AA cells have not made a sudden leap in capacity. Every six months or year they introduce an new model that is slightly better in capacity. They sell the lower capacity cells in lower cost markets such as mainland China (in fact, they're the only ones available). If D cells and 9V batteries are unpopular with product designers and therefore don't have the same competitive pressure to make high-performance designs, that's taken into account by looking at the "best available" units.
Only in energy storage per battery.
*If* you read and understood my entire post, you would have seen the other two comparisons-- of energy storage per gram and energy storage per unit volume. In *all* cases, the best available AA cell of that brand/series beats the best available 9V cell of that brand/series by a considerable margin.
Why don't *you* do some calculations? It should be trivially easy to find the data and the mensuration formulas if you don't remember them.
Who said anything about six? It takes seven to equal the voltage of a typical 9V battery (some are higher), and my comparison was for a single cell vs. a 9V battery. Hopefully it's easy enough to multiply by the number of batteries in the case of total capacity. It won't affect the energy storage per gram or per cubic millimeter numbers, obviously!
Got any numbers to back up that (quite dubious) assertion?
Waiting for you to calculate them. I have no need of the numbers at present.
In some cases some of it can be used by a clever designer. It can't be if the space is filled by a steel shell.
The AA cell is >3 times better than a 9V battery in *energy per cubic millimeter*. "Size difference" is already taken into account in this number. You want to take it into account again?
Best regards, Spehro Pefhany
-- "it\'s the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
diameter by
9V batterysnaps) or
Readily available DC-DC converters seem to want at least 2.7 volts input voltage, to produce 5 volts. So, you're stuck with using 2 AA cells, which are somewhat longer and wider than one 9 volt cell.
OTOH, Maxim shows a wide range of converters with inputs as low as 0.6 volts and plenty rated at 1.5 volt input. A wide range of output voltages is listed as well.
you more
encloses the AA
than 3:1.
It looks like the DC-DC converter could be packaged so it had about 1/6 the volume of a 9 volt battery.
All things considered the 2-AA cell solution is still ahead by something like 2:1 in terms of power per volume, but at a significant cost in terms of minimum size and cost.
It's probably the cost that dominates most design decisions for consumer products. A DC-DC converter could add $20-30 to the final cost.
It seems like a single-AA cell solution could be practical for higher end wireless mics and earphones for pro audio, for example.
Krueger"
2.7wider
a single
I don't know what they use for power internally. Based on the limited headphone drive they provide, they may in fact be running off the 1.5 volt directly.
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The prices I see are in the 10x range.
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AAA cells.
Agreed, and no DC-DC converter would be required.
practical
sleeker.
Trouble with the Li-ion cells is that every device seems to want a different one.
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