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Why are capstan wheels different size?

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  Why are capstan wheels different size? DaveC <not@home.cow> - 2016-03-11 13:22 -0800
    Re: Why are capstan wheels different size? Jasen Betts <jasen@xnet.co.nz> - 2016-03-11 22:25 +0000
      Re: Why are capstan wheels different size? DaveC <not@home.cow> - 2016-03-11 19:49 -0800
        Re: Why are capstan wheels different size? N_Cook <diverse@tcp.co.uk> - 2016-03-12 10:38 +0000
    Re: Why are capstan wheels different size? M Philbrook <jamie_ka1lpa@charter.net> - 2016-03-11 18:08 -0500
      Re: Why are capstan wheels different size? Les Cargill <lcargill99@comcast.com> - 2016-03-11 17:34 -0600
      Re: Why are capstan wheels different size? MJC <gravity@mjcoon.plus.com> - 2016-03-11 23:48 +0000
    Re: Why are capstan wheels different size? Phil Allison <pallison49@gmail.com> - 2016-03-11 16:33 -0800
    Re: Why are capstan wheels different size? Lasse Langwadt Christensen <langwadt@fonz.dk> - 2016-03-11 16:39 -0800
      Re: Why are capstan wheels different size? Martin Riddle <martin_ridd@verizon.net> - 2016-03-11 21:14 -0500
    Re: Why are capstan wheels different size? Tim Wescott <seemywebsite@myfooter.really> - 2016-03-11 22:35 -0600
    Re: Why are capstan wheels different size? Look165 <look165@numericable.fr> - 2016-03-12 09:36 +0100
      Re: Why are capstan wheels different size? mike <ham789@netzero.net> - 2016-03-12 02:34 -0800
        Re: Why are capstan wheels different size? M Philbrook <jamie_ka1lpa@charter.net> - 2016-03-12 15:11 -0500
    Re: Why are capstan wheels different size? jurb6006@gmail.com - 2016-03-12 04:59 -0800
      Re: Why are capstan wheels different size? jurb6006@gmail.com - 2016-03-12 05:04 -0800
        Re: Why are capstan wheels different size? DaveC <not@home.cow> - 2016-03-12 08:39 -0800
          Re: Why are capstan wheels different size? legg <legg@nospam.magma.ca> - 2016-03-12 12:37 -0500
            Re: Why are capstan wheels different size? DaveC <not@home.cow> - 2016-03-12 09:42 -0800
              Re: Why are capstan wheels different size? Phil Allison <pallison49@gmail.com> - 2016-03-12 17:28 -0800
                Re: Why are capstan wheels different size? DaveC <not@home.cow> - 2016-03-12 21:54 -0800
    Re: Why are capstan wheels different size? N_Cook <diverse@tcp.co.uk> - 2016-03-12 17:37 +0000
      Re: Why are capstan wheels different size? legg <legg@nospam.magma.ca> - 2016-03-12 13:06 -0500
        Re: Why are capstan wheels different size? John Larkin <jjlarkin@highlandtechnology.com> - 2016-03-12 12:19 -0800
          Re: Why are capstan wheels different size? Martin Riddle <martin_ridd@verizon.net> - 2016-03-12 15:21 -0500
          Re: Why are capstan wheels different size? DaveC <not@home.cow> - 2016-03-12 13:04 -0800
          Re: Why are capstan wheels different size? tabbypurr@gmail.com - 2016-03-12 14:45 -0800
            Re: Why are capstan wheels different size? Phil Allison <pallison49@gmail.com> - 2016-03-12 17:33 -0800
          Re: Why are capstan wheels different size? Phil Allison <pallison49@gmail.com> - 2016-03-12 17:50 -0800
            Re: Why are capstan wheels different size? Cydrome Leader <presence@MUNGEpanix.com> - 2016-03-13 03:45 +0000
            Re: Why are capstan wheels different size? Les Cargill <lcargill99@comcast.com> - 2016-03-13 01:37 -0600
              Re: Why are capstan wheels different size? Rob <nomail@example.com> - 2016-03-13 09:07 +0000
                Re: Why are capstan wheels different size? upsidedown@downunder.com - 2016-03-13 12:11 +0200
                Re: Why are capstan wheels different size? Les Cargill <lcargill99@comcast.com> - 2016-03-13 05:39 -0500
            Re: Why are capstan wheels different size? jurb6006@gmail.com - 2016-03-12 23:35 -0800
          Re: Why are capstan wheels different size? legg <legg@nospam.magma.ca> - 2016-03-13 10:18 -0500
            Re: Why are capstan wheels different size? MJC <gravity@mjcoon.plus.com> - 2016-03-13 15:34 +0000
              Re: Why are capstan wheels different size? Don Bruder <dakidd@sonic.net> - 2016-03-13 09:22 -0700
                Re: Why are capstan wheels different size? N_Cook <diverse@tcp.co.uk> - 2016-03-13 19:50 +0000
              Re: Why are capstan wheels different size? legg <legg@nospam.magma.ca> - 2016-03-13 14:22 -0500
              Re: Why are capstan wheels different size? Chris Jones <lugnut808@spam.yahoo.com> - 2016-03-14 10:32 +1100
    Re: Why are capstan wheels different size? Look165 <look165@numericable.fr> - 2016-03-13 19:48 +0100

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#402557

Sony TC-WR99ES.
> ** See:
> 
> 
http://bilder.hifi-forum.de/max/352931/sony-tc-wr99es-tapedeck-
innenleben_1715
> 36.jpg
> 
> The heads are all 4 track - correct ?
> 
> So no head spinning needed.
> .... Phil

2-track heads, spinning for autoreverse.

If I recall (it’s been a few decades...) Sony didn’t make a dual mech 
machine with 4-track head. It was available in single mech only. My priority 
at the time was doing extended recordings (record on mech A, automatically 
continue on mech B) so dual it was.

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#402486

On 11/03/2016 21:22, DaveC wrote:
> Oh, smarter-than-I people,
>
> http://imgur.com/WPEoOu1
>
> The 2 belt-drive capstan flywheels in an auto-reverse cassette mechanism are
> different sizes. (Motor drive pulley will be in the small loop end of the
> belt in illustration above.)
>
> How does that result in the same tape speed in both directions?
>
> Confused...
>

Aiwa AD  WX888 , 1997,I worked on once, spindle to one capstan 2.49mm
diameter and the other 2.69mm

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#402492

On Sat, 12 Mar 2016 17:37:50 +0000, N_Cook <diverse@tcp.co.uk> wrote:

>On 11/03/2016 21:22, DaveC wrote:
>> Oh, smarter-than-I people,
>>
>> http://imgur.com/WPEoOu1
>>
>> The 2 belt-drive capstan flywheels in an auto-reverse cassette mechanism are
>> different sizes. (Motor drive pulley will be in the small loop end of the
>> belt in illustration above.)
>>
>> How does that result in the same tape speed in both directions?
>>
>> Confused...
>>
>
>Aiwa AD  WX888 , 1997,I worked on once, spindle to one capstan 2.49mm
>diameter and the other 2.69mm

Aiwa ADR470, forward flywheel was inside the loop, reverse was outside
the loop. Both always driven. choice of pinch rollers determine
direction. Flywheel diameters compensate for inside/outside belt
diameter. Only speed adjustment was screw-driver inside the motor
housing itself.

Harman Kardon HK300 had a single flyheel, spindle impressed
alternately on fw or rev through a clutch that was always
disintegrating. Same in-the-motor adgustment.

RL

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#402504

On Sat, 12 Mar 2016 13:06:27 -0500, legg <legg@nospam.magma.ca> wrote:

>On Sat, 12 Mar 2016 17:37:50 +0000, N_Cook <diverse@tcp.co.uk> wrote:
>
>>On 11/03/2016 21:22, DaveC wrote:
>>> Oh, smarter-than-I people,
>>>
>>> http://imgur.com/WPEoOu1
>>>
>>> The 2 belt-drive capstan flywheels in an auto-reverse cassette mechanism are
>>> different sizes. (Motor drive pulley will be in the small loop end of the
>>> belt in illustration above.)
>>>
>>> How does that result in the same tape speed in both directions?
>>>
>>> Confused...
>>>
>>
>>Aiwa AD  WX888 , 1997,I worked on once, spindle to one capstan 2.49mm
>>diameter and the other 2.69mm
>
>Aiwa ADR470, forward flywheel was inside the loop, reverse was outside
>the loop. Both always driven. choice of pinch rollers determine
>direction. Flywheel diameters compensate for inside/outside belt
>diameter. Only speed adjustment was screw-driver inside the motor
>housing itself.
>
>Harman Kardon HK300 had a single flyheel, spindle impressed
>alternately on fw or rev through a clutch that was always
>disintegrating. Same in-the-motor adgustment.
>
>RL

All those mechanical means of reproducing sound - wax disks, tinfoil,
shellac, plastic, wire, tape - were all awful. Chemical photography
was a nuisance, too. Ditto typing and carbon paper.




-- 

John Larkin         Highland Technology, Inc

lunatic fringe electronics 

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#402505

On Sat, 12 Mar 2016 12:19:34 -0800, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

>On Sat, 12 Mar 2016 13:06:27 -0500, legg <legg@nospam.magma.ca> wrote:
>
>>On Sat, 12 Mar 2016 17:37:50 +0000, N_Cook <diverse@tcp.co.uk> wrote:
>>
>>>On 11/03/2016 21:22, DaveC wrote:
>>>> Oh, smarter-than-I people,
>>>>
>>>> http://imgur.com/WPEoOu1
>>>>
>>>> The 2 belt-drive capstan flywheels in an auto-reverse cassette mechanism are
>>>> different sizes. (Motor drive pulley will be in the small loop end of the
>>>> belt in illustration above.)
>>>>
>>>> How does that result in the same tape speed in both directions?
>>>>
>>>> Confused...
>>>>
>>>
>>>Aiwa AD  WX888 , 1997,I worked on once, spindle to one capstan 2.49mm
>>>diameter and the other 2.69mm
>>
>>Aiwa ADR470, forward flywheel was inside the loop, reverse was outside
>>the loop. Both always driven. choice of pinch rollers determine
>>direction. Flywheel diameters compensate for inside/outside belt
>>diameter. Only speed adjustment was screw-driver inside the motor
>>housing itself.
>>
>>Harman Kardon HK300 had a single flyheel, spindle impressed
>>alternately on fw or rev through a clutch that was always
>>disintegrating. Same in-the-motor adgustment.
>>
>>RL
>
>All those mechanical means of reproducing sound - wax disks, tinfoil,
>shellac, plastic, wire, tape - were all awful. Chemical photography
>was a nuisance, too. Ditto typing and carbon paper.

Yeah but look at the bit-error rate you can tolerate.
A CD would be worth less with that many errors.


Cheers

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#402515

On 12 Mar 2016, John Larkin wrote:

> All those mechanical means of reproducing sound - wax disks, tinfoil,
> shellac, plastic, wire, tape - were all awful. Chemical photography
> was a nuisance, too. Ditto typing and carbon paper.

Yeah, yeah, yeah.

Gotta have a source platform in order to digitize all that media...

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#402526

On Saturday, 12 March 2016 20:19:32 UTC, John Larkin  wrote:

> All those mechanical means of reproducing sound - wax disks, tinfoil,
> shellac, plastic, wire, tape - were all awful. Chemical photography
> was a nuisance, too. Ditto typing and carbon paper.

If your source material is on tape, it's on tape, end of story.

I don't buy the inside vs outside of belt thing.


NT

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#402541

tabb...@gmail.com wrote:
> 
>
> 
> I don't buy the inside vs outside of belt thing.
> 

** I agree.

 Where the drive belt is curved, the outside radius is greater - but both flywheels are on the INSIDE of curves.


....  Phil 

  

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#402542

John Larkin wrote:

>
> 
> All those mechanical means of reproducing sound - wax disks, tinfoil,
> shellac, plastic, wire, tape - were all awful.
>

** There was one genuinely hi-fi, analogue tape recorder available to the public. The Hi-Fi VCR, which came in Beta and VHS versions. 

Recordings were made with a pair of FM carriers in the MHz range. S/n ratio approached 90dB while all the other shortcomings of tape were rendered negligible. Up to 6 hours recording on one cassette too. 

Some studios used them as master recorders cos they outperformed R-R machines  by such a large margin.

Odd how they never caught on in this role. 


 ...  Phil 

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#402550

Phil Allison <pallison49@gmail.com> wrote:
> John Larkin wrote:
> 
>>
>> 
>> All those mechanical means of reproducing sound - wax disks, tinfoil,
>> shellac, plastic, wire, tape - were all awful.
>>
> 
> ** There was one genuinely hi-fi, analogue tape recorder available to the public. The Hi-Fi VCR, which came in Beta and VHS versions. 
> 
> Recordings were made with a pair of FM carriers in the MHz range. S/n ratio approached 90dB while all the other shortcomings of tape were rendered negligible. Up to 6 hours recording on one cassette too. 
> 
> Some studios used them as master recorders cos they outperformed R-R machines  by such a large margin.
> 
> Odd how they never caught on in this role. 

I was taught the same thing about the HiFi VCRs. Never did any testing 
with it though. Reel to reel units were more fun to play with.

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#402563

Phil Allison wrote:
> John Larkin wrote:
>
>>
>>
>> All those mechanical means of reproducing sound - wax disks,
>> tinfoil, shellac, plastic, wire, tape - were all awful.
>>
>
> ** There was one genuinely hi-fi, analogue tape recorder available to
> the public. The Hi-Fi VCR, which came in Beta and VHS versions.
>
> Recordings were made with a pair of FM carriers in the MHz range. S/n
> ratio approached 90dB while all the other shortcomings of tape were
> rendered negligible. Up to 6 hours recording on one cassette too.
>
> Some studios used them as master recorders cos they outperformed R-R
> machines  by such a large margin.
>
> Odd how they never caught on in this role.
>
>
> ...  Phil
>

I used one as a mixdown recorder. Painful - the transport was dog
slow to change states. You fast-forwarded and rewound at your peril ( 
although keeping notes on the index counter minimized that ).

The one I had also had an AGC you could not defeat. Some did,
some didn't.

They also require some sort of valid video signal when recording.

-- 
Les Cargill

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#402569

Les Cargill <lcargill99@comcast.com> wrote:
> I used one as a mixdown recorder. Painful - the transport was dog
> slow to change states. You fast-forwarded and rewound at your peril ( 
> although keeping notes on the index counter minimized that ).
>
> The one I had also had an AGC you could not defeat. Some did,
> some didn't.
>
> They also require some sort of valid video signal when recording.

No!  The old VHS HiFi recorder I had years ago actually had a separate
audio-only recording mode where it could generate everything it required
itself (I think some dummy sync was generated) and the signal levels
were somehow altered so the margins for dropouts were higher.

Still it was only useful to make recordings of concerts and play them
back entirely, not to skip back and forth all the time.

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#402572

On 13 Mar 2016 09:07:21 GMT, Rob <nomail@example.com> wrote:

>Les Cargill <lcargill99@comcast.com> wrote:
>> I used one as a mixdown recorder. Painful - the transport was dog
>> slow to change states. You fast-forwarded and rewound at your peril ( 
>> although keeping notes on the index counter minimized that ).
>>
>> The one I had also had an AGC you could not defeat. Some did,
>> some didn't.
>>
>> They also require some sort of valid video signal when recording.
>
>No!  The old VHS HiFi recorder I had years ago actually had a separate
>audio-only recording mode where it could generate everything it required
>itself (I think some dummy sync was generated) and the signal levels
>were somehow altered so the margins for dropouts were higher.
>
>Still it was only useful to make recordings of concerts and play them
>back entirely, not to skip back and forth all the time.

I had the JVC 725 which could record Hi-Fi FM audio only at half speed
for 8 hours on a 4 h VHS cassette. You could overwrite the
longitudinal track with 8 h Lo-Fi recording, so you could have 16 h of
audio on a 4 h cassette. 

It was also a nice monitor recorder (required by the law) to record
the transmission from a radio stallion (FM to the right, AM
transmitter to the left channel) for 8 hours and due to the simple
mechanical handling, even the station currently active DJ could change
the cassette every 8 hours, instead of requiring some open reel tape
changes.
  

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#402574

Rob wrote:
> Les Cargill <lcargill99@comcast.com> wrote:
>> I used one as a mixdown recorder. Painful - the transport was dog
>> slow to change states. You fast-forwarded and rewound at your peril (
>> although keeping notes on the index counter minimized that ).
>>
>> The one I had also had an AGC you could not defeat. Some did,
>> some didn't.
>>
>> They also require some sort of valid video signal when recording.
>
> No!  The old VHS HiFi recorder I had years ago actually had a separate
> audio-only recording mode where it could generate everything it required
> itself (I think some dummy sync was generated)

Most likely. It's kind of interesting that they thought about that.

> and the signal levels
> were somehow altered so the margins for dropouts were higher.
>
> Still it was only useful to make recordings of concerts and play them
> back entirely, not to skip back and forth all the time.
>

-- 
Les Cargill

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#402567

>"
>Some studios used them as master recorders cos they outperformed R-R >machines  by such a large margin."

And others did not because of their limitations. A buzz is nice when sitting around with your olady listening to some shit. It is not so nice when you are trying to make a master recording. 

All AFM hifi recording techniques sufferred from the buzz. they got rid of it with DBX but if you got ears you can still hear it. Noise reduction does ot get rid of the noise - it just asks it or puts up the sound to mask it. Then compensates on playback. 

I have had both beta and VHS hifi decks, many of them in fact. I have had them both brand new out of the box. I also had some connections to the manufacturer (Sony) and the bottom line was, if I didn't like the audio performence they would refund my money. There was NOTHING they could do about the buzz. 

This would be at 60 Hz or at 50 Hz across the pond. There simply was no way to splice the AFM back together after the head switching. the people who designed the depth multiplexing bullshit and put the extra heads on the VHS decks because they didn't have the bandwidth didn't get much farther either. What's more, their idea made the picture quality worse. In beta hifi, the modifications actually made the picture quality better.VHS had to catch up. And still beta was the better format.

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#402593

On Sat, 12 Mar 2016 12:19:34 -0800, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

>On Sat, 12 Mar 2016 13:06:27 -0500, legg <legg@nospam.magma.ca> wrote:
>
>>On Sat, 12 Mar 2016 17:37:50 +0000, N_Cook <diverse@tcp.co.uk> wrote:
>>
>>>On 11/03/2016 21:22, DaveC wrote:
>>>> Oh, smarter-than-I people,
>>>>
>>>> http://imgur.com/WPEoOu1
>>>>
>>>> The 2 belt-drive capstan flywheels in an auto-reverse cassette mechanism are
>>>> different sizes. (Motor drive pulley will be in the small loop end of the
>>>> belt in illustration above.)
>>>>
>>>> How does that result in the same tape speed in both directions?
>>>>
>>>> Confused...
>>>>
>>>
>>>Aiwa AD  WX888 , 1997,I worked on once, spindle to one capstan 2.49mm
>>>diameter and the other 2.69mm
>>
>>Aiwa ADR470, forward flywheel was inside the loop, reverse was outside
>>the loop. Both always driven. choice of pinch rollers determine
>>direction. Flywheel diameters compensate for inside/outside belt
>>diameter. Only speed adjustment was screw-driver inside the motor
>>housing itself.
>>
>>Harman Kardon HK300 had a single flyheel, spindle impressed
>>alternately on fw or rev through a clutch that was always
>>disintegrating. Same in-the-motor adgustment.
>>
>>RL
>
>All those mechanical means of reproducing sound - wax disks, tinfoil,
>shellac, plastic, wire, tape - were all awful. Chemical photography
>was a nuisance, too. Ditto typing and carbon paper.

I can't think of a single method of 'reproducing sound' that doesn't
involve mechanical means.

Sound is a mechanical phenomenon. Humans use flapping meat.

Perhaps you mean recording? No, still mechanical. Storage? Maybe.

Of course, there's nothing mechanical in electronics, is there...

It's the programme material, the idea and its conception that's
important; not the means of conveyance.

RL

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#402596

In article <2m0beb1lgja42278t1ni529ihahvjsc94q@4ax.com>, 
legg@nospam.magma.ca says...
> 
> I can't think of a single method of 'reproducing sound' that doesn't
> involve mechanical means.
> 
> Sound is a mechanical phenomenon. Humans use flapping meat.

I can imagine a method that used heat to move the air, perhaps with a 
plasma to make it fast. (Like a modulated lightning flash.) But I cannot 
be bothered to construct a search to find out if it has been done 
successfully...

Mike.

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#402602

In article <MPG.314f98caaaa273144@news.plus.net>,
 MJC <gravity@mjcoon.plus.com> wrote:

> In article <2m0beb1lgja42278t1ni529ihahvjsc94q@4ax.com>, 
> legg@nospam.magma.ca says...
> > 
> > I can't think of a single method of 'reproducing sound' that doesn't
> > involve mechanical means.
> > 
> > Sound is a mechanical phenomenon. Humans use flapping meat.
> 
> I can imagine a method that used heat to move the air, perhaps with a 
> plasma to make it fast. (Like a modulated lightning flash.) But I cannot 
> be bothered to construct a search to find out if it has been done 
> successfully...
> 
> Mike.

I recall a conversation from years ago with a *VERY* old theater 
projectionist, who spoke of what he called "flame speakers". Don't know 
if it was an artifact of his (at the time) 80+ year old mind going, or 
reality, but what he described made sense to me on several levels, 
though I've never bothered to try chasing it down. Apparently, back in 
the early days of talkies, one method of sound production involved a gas 
nozzle (unsure if he meant gasoline, or something like propane/LP gas) 
"tuned" to produce a blue flame (he was very clear on that point - lots 
of the conversation came back to how he had to tinker with the flame at 
each showing, otherwise the sound wasn't good) several feet tall in a 
combustion chamber, into which was shoved a set of tungsten electrodes. 
The 'trodes were driven at high voltages by any of several amplification 
methods (frequently varying by theater, if the old guy's tale was to be 
believed) to charge the plasma of the flame, which apparently caused it 
to "dance", driving a diaphragm like that of a speaker. Supposedly, 
amazingly high volumes with very good fidelity could be achieved. 

Like I say, I've never actually gone to the effort of tracking it down, 
and I have no idea if it was a failing mind's invention, or reality, 
but... <shrug> Seems to me like it COULD work.

-- 
Security provided by Mssrs Smith and/or Wesson. Brought to you by the letter Q

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#402636

On 13/03/2016 16:22, Don Bruder wrote:
> In article <MPG.314f98caaaa273144@news.plus.net>,
>   MJC <gravity@mjcoon.plus.com> wrote:
>
>> In article <2m0beb1lgja42278t1ni529ihahvjsc94q@4ax.com>,
>> legg@nospam.magma.ca says...
>>>
>>> I can't think of a single method of 'reproducing sound' that doesn't
>>> involve mechanical means.
>>>
>>> Sound is a mechanical phenomenon. Humans use flapping meat.
>>
>> I can imagine a method that used heat to move the air, perhaps with a
>> plasma to make it fast. (Like a modulated lightning flash.) But I cannot
>> be bothered to construct a search to find out if it has been done
>> successfully...
>>
>> Mike.
>
> I recall a conversation from years ago with a *VERY* old theater
> projectionist, who spoke of what he called "flame speakers". Don't know
> if it was an artifact of his (at the time) 80+ year old mind going, or
> reality, but what he described made sense to me on several levels,
> though I've never bothered to try chasing it down. Apparently, back in
> the early days of talkies, one method of sound production involved a gas
> nozzle (unsure if he meant gasoline, or something like propane/LP gas)
> "tuned" to produce a blue flame (he was very clear on that point - lots
> of the conversation came back to how he had to tinker with the flame at
> each showing, otherwise the sound wasn't good) several feet tall in a
> combustion chamber, into which was shoved a set of tungsten electrodes.
> The 'trodes were driven at high voltages by any of several amplification
> methods (frequently varying by theater, if the old guy's tale was to be
> believed) to charge the plasma of the flame, which apparently caused it
> to "dance", driving a diaphragm like that of a speaker. Supposedly,
> amazingly high volumes with very good fidelity could be achieved.
>
> Like I say, I've never actually gone to the effort of tracking it down,
> and I have no idea if it was a failing mind's invention, or reality,
> but... <shrug> Seems to me like it COULD work.
>

Wasn't there some scheme to generate sound for large area advertising by 
using aurora? presumably someone realised polar bears don't buy much stuff.

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#402620

On Sun, 13 Mar 2016 15:34:07 -0000, MJC <gravity@mjcoon.plus.com>
wrote:

>In article <2m0beb1lgja42278t1ni529ihahvjsc94q@4ax.com>, 
>legg@nospam.magma.ca says...
>> 
>> I can't think of a single method of 'reproducing sound' that doesn't
>> involve mechanical means.
>> 
>> Sound is a mechanical phenomenon. Humans use flapping meat.
>
>I can imagine a method that used heat to move the air, perhaps with a 
>plasma to make it fast. (Like a modulated lightning flash.) But I cannot 
>be bothered to construct a search to find out if it has been done 
>successfully...
>
See Thermoachoustic Technology.

www.lanl.gov/thermoacoustics/Pubs/

RL

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