From vintage-audio@mailman.qth.net  Thu Jan  1 21:48:16 2004
From: vintage-audio@mailman.qth.net (Duane Fischer, W8DBF)
Date: Thu Jan  1 21:48:16 2004
Subject: [Vintage-Audio] Donation Deadline Extended On National SW-54
Message-ID: <200401020242.i022gve12279@hades.usol.com>

	
Al Waller advised me today that he thought it would be proper to extend the
deadline for making a donation of $25 to qth.net/qsl.net to get in on the
drawing to win the donated National SW-54 receiver to midnight on January3rd. 
Because this offering was made so late in the month of December, and many who
might want to participate were gone for the holidays, two extra days would give
them a opportunity to make a contribution if they wanted to.   	
	
If you missed the original post, John Mudd has donated a fully functional and
cosmetically good National SW-54 receiver in an effort to help generate funds to
support qth.net/qsl.net All who donate $25 (more if you would like to) by
midnight on January 3, 2004 will have their name put into Al's Daniel Boone
coonskin cap and a winner will be drawn on January 4th. 	
	
Be SURE to indicate on your donation that it is for the drawing of the SW-54!
Otherwise Al will not know to include you in the drawing. 	
	
Now John Mudd was the unfortunate victim of some medical problems and ensuing
surgical complications in 2002. He is in a wheelchair, hopefully not for good.
John could not afford to make a cash donation, so he offered to support
qth.net/qsl.net by this receiver being awarded to those who donated $25 and
whomever's name was drawn getting the SW-54.  	
	
Now I have to admire John for his over the top effort to help out to keep the
servers turning so that all of us can enjoy, and profit by, the qth.net/qsl.net
mail reflectors and web sites. If John can make this kind of extraordinary
donation under the circumstances he is currently in, I sure hope that some of
you who are more fortunate will plunder the piggy bank and make a donation too!
This is not a one man show, it is a team effort! If we pull together, we can
keep those servers serving and assure ourselves of qth.net/qsl.net being there
in 2004 and beyond.    	
	
Send your donations to one of the three options shown below. Make them payable
to QSL.net or Al Waller, K3TKJ. Rememer, back date them for a tax write off for
2003! Be sure to indicate you are donating $25 and want to be included in the
drawing for the National SW-54 receiver! 	
	
Thanks to John Mudd for his incredible generosity, to Al Waller, K3TKJ for
making it all possible and to EACH of you who cared enough to let Al know you
appreciate his tireless efforts to help us enjoy the wonderful world of Ham
radio and the radio hobby in general by making a donation. 	
	
If any of you have a working or repairable radio related item that is just
collecting dust in the radio room or Ham Shack and would like to donate it to
the cause, contact myself, or Al Waller, and it will be used in fund raising
efforts throughout 2004. Every item helps Al keep the system operating and you
have the good feeling of knowing that you did your part. If you don't have any
extra cash, an item that is excess to your needs is just as good! 	
	
Here is where to send donations: 	
	
For PayPal: k3tkj@qsl.net

For a credit card on the secure server: proxy.qsl.net

Regular mail:
QSL.NET
C/O Al Waller, K3TKJ
34087 Old Hickory Road
Laurel, DE 19956




From vintage-audio@mailman.qth.net  Fri Jan  2 21:44:01 2004
From: vintage-audio@mailman.qth.net (Paul DeFayette)
Date: Fri Jan  2 21:44:01 2004
Subject: [Vintage-Audio] Radio Craftsmen C550 amp questions
Message-ID: <000601c3d1a2$c6ca26f0$96f1fea9@Paul>

Good evening all,

I had the the good fortune of aquiring two Radio Craftsmen C550 ultra linear
amps over the last year.  Are they the same as the Craftsmen C500 amps,
except for the addition of the 5NO03 time delay relay?  If not, what are the
differences?  Is there any difference in audio quality between the two?  I
still have to check them out and recap where required, etc.  Both of mine
came with 6L6's instead of the KT66 outputs.  Is there a noticeable
difference worth upgrading to the KT66 tubes?  Which are recommended by the
group, especially of the new production?  I thank one and all in advance for
any help you can provide.  Also, I would like to purchase a xerox copy of
the original Radio Craftsmen owner/operator manual and service manual for
these amps, if anyone has them available to copy.  Happy New Year to
everyone.

Best regards,

Paul DeFayette



From vintage-audio@mailman.qth.net  Mon Jan 12 15:30:04 2004
From: vintage-audio@mailman.qth.net (Duane Fischer, W8DBF)
Date: Mon Jan 12 15:30:04 2004
Subject: [Vintage-Audio] Re Frequency Behavior
Message-ID: <200401122029.i0CKTPe14975@hades.usol.com>

	
Is it true that a higher note is often easier to hear, but a lower note travels
a greater distance? 

Now leaving the length of the sound wave out of the discussion momentarily,
given a male and a female announcer for a radio station, speaking at the same
volume into the same mike, which signal will be heard at the greatest distance?
The one with the highest voice pitch or the one with the longest wave length?	
	
Duane W8DBF	
  

From vintage-audio@mailman.qth.net  Mon Jan 12 15:45:01 2004
From: vintage-audio@mailman.qth.net (Sheldon Daitch)
Date: Mon Jan 12 15:45:01 2004
Subject: [Vintage-Audio] Re Frequency Behavior
References: <200401122029.i0CKTPe14975@hades.usol.com>
Message-ID: <400306BC.A58814D3@ibb.gov>

Duane,

Maybe we are trying to compare apples and oranges here.

In general, lower audio frequencies are attenuated less than
higher frequencies, thus, you can hear the rumble of the loud
bass much further away than the higher frequencies from the
same boom box.

When you get into the second part of your question, which
announcer would be "heard" at a greater distance, assuming
no interference, one would think there should be no
difference in radio range, if that is the intent of your question.

Now let's subject the signals to some interference, and
then it becomes a little more difficult to answer, as the filtering
necessary to reduce or eliminate the interference  might also
be the same frequency range as the announcers voice.

So now, at the RF side of the equation, I am at a loss for
a definitive answer, as I think it might be a lot more
subjective and related to the skills of the listener.

More thoughts?

Sheldon

"Duane Fischer, W8DBF" wrote:

>
> Is it true that a higher note is often easier to hear, but a lower note travels
> a greater distance?
>
> Now leaving the length of the sound wave out of the discussion momentarily,
> given a male and a female announcer for a radio station, speaking at the same
> volume into the same mike, which signal will be heard at the greatest distance?
> The one with the highest voice pitch or the one with the longest wave length?
>
> Duane W8DBF
>
> _______________________________________________
> Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer@usol.com **


From vintage-audio@mailman.qth.net  Mon Jan 12 17:57:07 2004
From: vintage-audio@mailman.qth.net (Duane Fischer, W8DBF)
Date: Mon Jan 12 17:57:07 2004
Subject: [Vintage-Audio] Re Frequency Behavior
Message-ID: <200401122256.i0CMu7e28247@hades.usol.com>

Sheldon, 	
	
First, the human ear is trained from before an infant is born to listen in a
specific frequency range for vocal patterns. Hence, humans focus on certain
frequency ranges and filter out others without even realizing they are doing so.
A higher pitched voice tends to be heard above the general din of noise
pollution we all experience in our daily comings and goings.     	
	
The best example of this filtering I can think of, is that of a mother hearing
her child several rooms away with a TV set going, people talking and all sorts
of other racket. She hears the child whimpering and nobody else in the room
hears a thing. 	
	
The low note carries the greater distance because it has a longer wavelength.
For instance, the kid down the street with the kickers in his trunk. You can
hear the bass a quarter mile away, but nothing else.	
	
It was said that a female announcer on a radio station could be heard at a
greater distance because of her high pitched voice. I disagreed. The radio
signal carries only so far, regardless of what sex is doing the talking.
However, because her voice is generally of a higher pitch it may be easier to
hear because it is above the area of the general noise. So it 'appears that she
is heard farther away simply because the frequency of her voice is higher than
the background noise.   	
	
Your thoughts?   	
	
DBF 	


----------
From: Sheldon Daitch <sdaitch@ibb.gov>
To: vintage-audio@mailman.qth.net
Subject: Re: [Vintage-Audio] Re Frequency Behavior
Date: Monday, January 12, 2004 3:42 PM

Duane,

Maybe we are trying to compare apples and oranges here.

In general, lower audio frequencies are attenuated less than
higher frequencies, thus, you can hear the rumble of the loud
bass much further away than the higher frequencies from the
same boom box.

When you get into the second part of your question, which
announcer would be "heard" at a greater distance, assuming
no interference, one would think there should be no
difference in radio range, if that is the intent of your question.

Now let's subject the signals to some interference, and
then it becomes a little more difficult to answer, as the filtering
necessary to reduce or eliminate the interference  might also
be the same frequency range as the announcers voice.

So now, at the RF side of the equation, I am at a loss for
a definitive answer, as I think it might be a lot more
subjective and related to the skills of the listener.

More thoughts?

Sheldon

"Duane Fischer, W8DBF" wrote:

>
> Is it true that a higher note is often easier to hear, but a lower note
travels
> a greater distance?
>
> Now leaving the length of the sound wave out of the discussion momentarily,
> given a male and a female announcer for a radio station, speaking at the same
> volume into the same mike, which signal will be heard at the greatest
distance?
> The one with the highest voice pitch or the one with the longest wave length?
>
> Duane W8DBF
>
> _______________________________________________
> Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer@usol.com **

_______________________________________________
Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
List Administrator: Duane Fischer, W8DBF
** For Assistance: dfischer@usol.com ** 

From vintage-audio@mailman.qth.net  Mon Jan 12 18:29:00 2004
From: vintage-audio@mailman.qth.net (Peter Markavage)
Date: Mon Jan 12 18:29:00 2004
Subject: [Vintage-Audio] Re Frequency Behavior
Message-ID: <20040112.182715.-780799.1.manualman@juno.com>

The speed of a sound wave at 0 degrees C is 331 meters/sec.  
The speed of a sound wave in air depends upon the properties of the air,
namely the temperature and the pressure not the frequency. The pressure
of air (like any gas) will effect the mass density of the air (an
inertial property) and the temperature will effect the strength of the
particle interactions (an elastic property). At normal atmospheric
pressure, the temperature dependence of the speed of a sound wave through
air is approximated by the following equation:
v = 331 m/s + (0.6 m/s/C)*T
where T is the temperature of the air in degrees Celsius. 
Example: Using this equation is used to determine the speed of a sound
wave in air at a temperature of 20 degrees Celsius yields the following
solution.
v = 331 m/s + (0.6 m/s/C)*T 
v = 331 m/s + (0.6 m/s/C)*20 C
v = 331 m/s + 12 m/s
v = 343 m/s  Speed of sound at 20 degrees C.
Pete, WA2CWA
On Mon, 12 Jan 2004 15:26:49 -0500 "Duane Fischer, W8DBF"
<dfischer@usol.com> writes:
> 
>         
> Is it true that a higher note is often easier to hear, but a lower 
> note travels
> a greater distance? 
> 
> Now leaving the length of the sound wave out of the discussion 
> momentarily,
> given a male and a female announcer for a radio station, speaking at 
> the same
> volume into the same mike, which signal will be heard at the 
> greatest distance?
> The one with the highest voice pitch or the one with the longest 
> wave length?        
>         
> Duane W8DBF        

--- StripMime Report -- processed MIME parts ---
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From vintage-audio@mailman.qth.net  Mon Jan 12 18:46:04 2004
From: vintage-audio@mailman.qth.net (Duane Fischer, W8DBF)
Date: Mon Jan 12 18:46:04 2004
Subject: [Vintage-Audio] Re Frequency Behavior
Message-ID: <200401122345.i0CNjAe32375@hades.usol.com>

This fails to take into account the altitude variant which is a factor in
determining the density of said particles. There is a median above and below sea
level. Additionally, the velocity factor is also affected by the temperature at
the source and reception points, plus any inversions in between. Further, the
effect of inner space and interplanetary gravitational fields must be factored
in to the equation to calculate the true velocity. Which as you have stated is
only an approximation at best. Theoretical and applied physics aside, I will put
my money on an angry female being heard at a greater distance than any male!
Your bets, gentlemen?  	
  

----------
From: Peter Markavage <manualman@juno.com>
To: vintage-audio@mailman.qth.net
Subject: Re: [Vintage-Audio] Re Frequency Behavior
Date: Monday, January 12, 2004 6:27 PM

The speed of a sound wave at 0 degrees C is 331 meters/sec.  
The speed of a sound wave in air depends upon the properties of the air,
namely the temperature and the pressure not the frequency. The pressure
of air (like any gas) will effect the mass density of the air (an
inertial property) and the temperature will effect the strength of the
particle interactions (an elastic property). At normal atmospheric
pressure, the temperature dependence of the speed of a sound wave through
air is approximated by the following equation:
v = 331 m/s + (0.6 m/s/C)*T
where T is the temperature of the air in degrees Celsius. 
Example: Using this equation is used to determine the speed of a sound
wave in air at a temperature of 20 degrees Celsius yields the following
solution.
v = 331 m/s + (0.6 m/s/C)*T 
v = 331 m/s + (0.6 m/s/C)*20 C
v = 331 m/s + 12 m/s
v = 343 m/s  Speed of sound at 20 degrees C.
Pete, WA2CWA
On Mon, 12 Jan 2004 15:26:49 -0500 "Duane Fischer, W8DBF"
<dfischer@usol.com> writes:
> 
>         
> Is it true that a higher note is often easier to hear, but a lower 
> note travels
> a greater distance? 
> 
> Now leaving the length of the sound wave out of the discussion 
> momentarily,
> given a male and a female announcer for a radio station, speaking at 
> the same
> volume into the same mike, which signal will be heard at the 
> greatest distance?
> The one with the highest voice pitch or the one with the longest 
> wave length?        
>         
> Duane W8DBF        

--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
The reason this message is shown is because the post was in HTML
or had an attachment.  Attachments are not allowed.  To learn how
to post in Plain-Text go to: http://www.expita.com/nomime.html  ---
_______________________________________________
Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
List Administrator: Duane Fischer, W8DBF
** For Assistance: dfischer@usol.com ** 

From vintage-audio@mailman.qth.net  Tue Jan 13 08:42:00 2004
From: vintage-audio@mailman.qth.net (Sheldon Daitch)
Date: Tue Jan 13 08:42:00 2004
Subject: [Vintage-Audio] Re Frequency Behavior
References: <200401122256.i0CMu7e28247@hades.usol.com>
Message-ID: <4003F502.426662D4@ibb.gov>

Duane,

I think we may be in total agreement.  Maybe I wasn't quite as elegant in
writing.  The only part where I might disagree, in regards to radio
reception, is under the situation where next channel interference is
high enough, and the receiver has variable bandwidth filtering, so
that the higher audio frequencies are filtered out.  Depending on the
depth and shape of the filters, one could strip out most of the higher
audio frequencies, of a high pitched female announcer, and yet
still pass the lower frequencies of a heavy-bass announcer.  Under
this unique set of circumstances, you could make a case for
the lower audio frequencies.

Pete has a nice explanation of the speed of sound, but I think what he
overlooked is the attenuation factor of higher audio frequencies
vs lower audio frequencies.  I believe that was part of your concern,
wasn't it, range, not velocity.

Sheldon

"Duane Fischer, W8DBF" wrote:

> Sheldon,
>
> First, the human ear is trained from before an infant is born to listen in a
> specific frequency range for vocal patterns. Hence, humans focus on certain
> frequency ranges and filter out others without even realizing they are doing so.
> A higher pitched voice tends to be heard above the general din of noise
> pollution we all experience in our daily comings and goings.
>
> The best example of this filtering I can think of, is that of a mother hearing
> her child several rooms away with a TV set going, people talking and all sorts
> of other racket. She hears the child whimpering and nobody else in the room
> hears a thing.
>
> The low note carries the greater distance because it has a longer wavelength.
> For instance, the kid down the street with the kickers in his trunk. You can
> hear the bass a quarter mile away, but nothing else.
>
> It was said that a female announcer on a radio station could be heard at a
> greater distance because of her high pitched voice. I disagreed. The radio
> signal carries only so far, regardless of what sex is doing the talking.
> However, because her voice is generally of a higher pitch it may be easier to
> hear because it is above the area of the general noise. So it 'appears that she
> is heard farther away simply because the frequency of her voice is higher than
> the background noise.
>
> Your thoughts?
>
> DBF
>
> ----------
> From: Sheldon Daitch <sdaitch@ibb.gov>
> To: vintage-audio@mailman.qth.net
> Subject: Re: [Vintage-Audio] Re Frequency Behavior
> Date: Monday, January 12, 2004 3:42 PM
>
> Duane,
>
> Maybe we are trying to compare apples and oranges here.
>
> In general, lower audio frequencies are attenuated less than
> higher frequencies, thus, you can hear the rumble of the loud
> bass much further away than the higher frequencies from the
> same boom box.
>
> When you get into the second part of your question, which
> announcer would be "heard" at a greater distance, assuming
> no interference, one would think there should be no
> difference in radio range, if that is the intent of your question.
>
> Now let's subject the signals to some interference, and
> then it becomes a little more difficult to answer, as the filtering
> necessary to reduce or eliminate the interference  might also
> be the same frequency range as the announcers voice.
>
> So now, at the RF side of the equation, I am at a loss for
> a definitive answer, as I think it might be a lot more
> subjective and related to the skills of the listener.
>
> More thoughts?
>
> Sheldon
>
> "Duane Fischer, W8DBF" wrote:
>
> >
> > Is it true that a higher note is often easier to hear, but a lower note
> travels
> > a greater distance?
> >
> > Now leaving the length of the sound wave out of the discussion momentarily,
> > given a male and a female announcer for a radio station, speaking at the same
> > volume into the same mike, which signal will be heard at the greatest
> distance?
> > The one with the highest voice pitch or the one with the longest wave length?
> >
> > Duane W8DBF
> >
> > _______________________________________________
> > Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
> > List Administrator: Duane Fischer, W8DBF
> > ** For Assistance: dfischer@usol.com **
>
> _______________________________________________
> Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer@usol.com **
> _______________________________________________
> Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer@usol.com **


From vintage-audio@mailman.qth.net  Tue Jan 13 12:11:01 2004
From: vintage-audio@mailman.qth.net (Duane Fischer, W8DBF)
Date: Tue Jan 13 12:11:01 2004
Subject: [Vintage-Audio] Re Frequency Behavior
Message-ID: <200401131710.i0DHA8e18442@hades.usol.com>

Sheldon, 	
	
Yes, on all points. 	
	
Pete was having some fun throwing math equations around, but Pete, I have a
minor in mathematics from the University of Michigan, so be careful! You might
have to buy some new batteries for your calculator OM! (chuckle)		
	
Because I am blind, I know far more about what people hear, listen to, filter
out and so forth than anyone who is sighted. I use it every single day. A
sighted person learns 92% of everything visually. That means all of the other
senses, and there are far more than the five people think of, only 8% get used.
What is the greatest sense organ anyhow? The skin! What do we do? We cover most
of it up so its functionality is severely limited. Before we go down the path of
nudists ... Ha Ha.  	
	
Bob? If you want to debate hearing, write me off list. Who was it that said:
"Everybody is talking, but nobody is saying anything?" 	
	
DBF	
  
	


----------
From: Sheldon Daitch <sdaitch@ibb.gov>
To: vintage-audio@mailman.qth.net
Subject: Re: [Vintage-Audio] Re Frequency Behavior
Date: Tuesday, January 13, 2004 8:39 AM

Duane,

I think we may be in total agreement.  Maybe I wasn't quite as elegant in
writing.  The only part where I might disagree, in regards to radio
reception, is under the situation where next channel interference is
high enough, and the receiver has variable bandwidth filtering, so
that the higher audio frequencies are filtered out.  Depending on the
depth and shape of the filters, one could strip out most of the higher
audio frequencies, of a high pitched female announcer, and yet
still pass the lower frequencies of a heavy-bass announcer.  Under
this unique set of circumstances, you could make a case for
the lower audio frequencies.

Pete has a nice explanation of the speed of sound, but I think what he
overlooked is the attenuation factor of higher audio frequencies
vs lower audio frequencies.  I believe that was part of your concern,
wasn't it, range, not velocity.

Sheldon

"Duane Fischer, W8DBF" wrote:

> Sheldon,
>
> First, the human ear is trained from before an infant is born to listen in a
> specific frequency range for vocal patterns. Hence, humans focus on certain
> frequency ranges and filter out others without even realizing they are doing
so.
> A higher pitched voice tends to be heard above the general din of noise
> pollution we all experience in our daily comings and goings.
>
> The best example of this filtering I can think of, is that of a mother hearing
> her child several rooms away with a TV set going, people talking and all sorts
> of other racket. She hears the child whimpering and nobody else in the room
> hears a thing.
>
> The low note carries the greater distance because it has a longer wavelength.
> For instance, the kid down the street with the kickers in his trunk. You can
> hear the bass a quarter mile away, but nothing else.
>
> It was said that a female announcer on a radio station could be heard at a
> greater distance because of her high pitched voice. I disagreed. The radio
> signal carries only so far, regardless of what sex is doing the talking.
> However, because her voice is generally of a higher pitch it may be easier to
> hear because it is above the area of the general noise. So it 'appears that
she
> is heard farther away simply because the frequency of her voice is higher than
> the background noise.
>
> Your thoughts?
>
> DBF
>
> ----------
> From: Sheldon Daitch <sdaitch@ibb.gov>
> To: vintage-audio@mailman.qth.net
> Subject: Re: [Vintage-Audio] Re Frequency Behavior
> Date: Monday, January 12, 2004 3:42 PM
>
> Duane,
>
> Maybe we are trying to compare apples and oranges here.
>
> In general, lower audio frequencies are attenuated less than
> higher frequencies, thus, you can hear the rumble of the loud
> bass much further away than the higher frequencies from the
> same boom box.
>
> When you get into the second part of your question, which
> announcer would be "heard" at a greater distance, assuming
> no interference, one would think there should be no
> difference in radio range, if that is the intent of your question.
>
> Now let's subject the signals to some interference, and
> then it becomes a little more difficult to answer, as the filtering
> necessary to reduce or eliminate the interference  might also
> be the same frequency range as the announcers voice.
>
> So now, at the RF side of the equation, I am at a loss for
> a definitive answer, as I think it might be a lot more
> subjective and related to the skills of the listener.
>
> More thoughts?
>
> Sheldon
>
> "Duane Fischer, W8DBF" wrote:
>
> >
> > Is it true that a higher note is often easier to hear, but a lower note
> travels
> > a greater distance?
> >
> > Now leaving the length of the sound wave out of the discussion momentarily,
> > given a male and a female announcer for a radio station, speaking at the
same
> > volume into the same mike, which signal will be heard at the greatest
> distance?
> > The one with the highest voice pitch or the one with the longest wave
length?
> >
> > Duane W8DBF
> >
> > _______________________________________________
> > Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
> > List Administrator: Duane Fischer, W8DBF
> > ** For Assistance: dfischer@usol.com **
>
> _______________________________________________
> Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer@usol.com **
> _______________________________________________
> Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer@usol.com **

_______________________________________________
Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
List Administrator: Duane Fischer, W8DBF
** For Assistance: dfischer@usol.com ** 

From vintage-audio@mailman.qth.net  Tue Jan 13 18:01:05 2004
From: vintage-audio@mailman.qth.net (Peter Markavage)
Date: Tue Jan 13 18:01:05 2004
Subject: [Vintage-Audio] Re Frequency Behavior
Message-ID: <20040113.175950.-531949.1.manualman@juno.com>

Ok, I'll dance with you one more time.
I wasn't having fun. I thought you were asking about the speed of sound
at various tones and I told you. The speed of sound is not dependent on
the frequency of the sound wave. Given the same starting point of the
sound, the same amplitude, the same medium, and the same temperature, a
100 Hz tone, 1000 Hz tone, or 5000 Hz tone will all travel the same
speed. Given that they travel the same distance, they all should hit the
receiver at the same time. Obviously, the farther they travel, all tones
will be proportionally weaker by the time they get to the receiver. How
the receiver interprets these sounds, the receiver limitations, etc.
would determine ultimately whether all tones would be heard. If you guys
believe that  some frequencies, traveling the same distance, through the
same medium, the same temperature, etc. are attenuated (high or low), I
want to see the math for that

Since you want to throw some credentials around, I  have a Master's in
EE, major in physics, and minors in business and math. (chuckle, chuckle
to you too)

Pete, WA2CWA

On Tue, 13 Jan 2004 12:07:24 -0500 "Duane Fischer, W8DBF"
<dfischer@usol.com> writes:
> Sheldon,         
>         
> Yes, on all points.         
>         
> Pete was having some fun throwing math equations around, but Pete, I 
> have a
> minor in mathematics from the University of Michigan, so be careful! 
> You might
> have to buy some new batteries for your calculator OM! 
> (chuckle)                
>         
> Because I am blind, I know far more about what people hear, listen 
> to, filter
> out and so forth than anyone who is sighted. I use it every single 
> day. A
> sighted person learns 92% of everything visually. That means all of 
> the other
> senses, and there are far more than the five people think of, only 
> 8% get used.
> What is the greatest sense organ anyhow? The skin! What do we do? We 
> cover most
> of it up so its functionality is severely limited. Before we go down 
> the path of
> nudists ... Ha Ha.          
>         
> Bob? If you want to debate hearing, write me off list. Who was it 
> that said:
> "Everybody is talking, but nobody is saying anything?"         
>         
> DBF        
>   
>         
> 
> 
> ----------
> From: Sheldon Daitch <sdaitch@ibb.gov>
> To: vintage-audio@mailman.qth.net
> Subject: Re: [Vintage-Audio] Re Frequency Behavior
> Date: Tuesday, January 13, 2004 8:39 AM
> 
> Duane,
> 
> I think we may be in total agreement.  Maybe I wasn't quite as 
> elegant in
> writing.  The only part where I might disagree, in regards to radio
> reception, is under the situation where next channel interference 
> is
> high enough, and the receiver has variable bandwidth filtering, so
> that the higher audio frequencies are filtered out.  Depending on 
> the
> depth and shape of the filters, one could strip out most of the 
> higher
> audio frequencies, of a high pitched female announcer, and yet
> still pass the lower frequencies of a heavy-bass announcer.  Under
> this unique set of circumstances, you could make a case for
> the lower audio frequencies.
> 
> Pete has a nice explanation of the speed of sound, but I think what 
> he
> overlooked is the attenuation factor of higher audio frequencies
> vs lower audio frequencies.  I believe that was part of your 
> concern,
> wasn't it, range, not velocity.
> 
> Sheldon
> 
> "Duane Fischer, W8DBF" wrote:
> 
> > Sheldon,
> >
> > First, the human ear is trained from before an infant is born to 
> listen in a
> > specific frequency range for vocal patterns. Hence, humans focus 
> on certain
> > frequency ranges and filter out others without even realizing they 
> are doing
> so.
> > A higher pitched voice tends to be heard above the general din of 
> noise
> > pollution we all experience in our daily comings and goings.
> >
> > The best example of this filtering I can think of, is that of a 
> mother hearing
> > her child several rooms away with a TV set going, people talking 
> and all sorts
> > of other racket. She hears the child whimpering and nobody else in 
> the room
> > hears a thing.
> >
> > The low note carries the greater distance because it has a longer 
> wavelength.
> > For instance, the kid down the street with the kickers in his 
> trunk. You can
> > hear the bass a quarter mile away, but nothing else.
> >
> > It was said that a female announcer on a radio station could be 
> heard at a
> > greater distance because of her high pitched voice. I disagreed. 
> The radio
> > signal carries only so far, regardless of what sex is doing the 
> talking.
> > However, because her voice is generally of a higher pitch it may 
> be easier to
> > hear because it is above the area of the general noise. So it 
> 'appears that
> she
> > is heard farther away simply because the frequency of her voice is 
> higher than
> > the background noise.
> >
> > Your thoughts?
> >
> > DBF
> >
> > ----------
> > From: Sheldon Daitch <sdaitch@ibb.gov>
> > To: vintage-audio@mailman.qth.net
> > Subject: Re: [Vintage-Audio] Re Frequency Behavior
> > Date: Monday, January 12, 2004 3:42 PM
> >
> > Duane,
> >
> > Maybe we are trying to compare apples and oranges here.
> >
> > In general, lower audio frequencies are attenuated less than
> > higher frequencies, thus, you can hear the rumble of the loud
> > bass much further away than the higher frequencies from the
> > same boom box.
> >
> > When you get into the second part of your question, which
> > announcer would be "heard" at a greater distance, assuming
> > no interference, one would think there should be no
> > difference in radio range, if that is the intent of your 
> question.
> >
> > Now let's subject the signals to some interference, and
> > then it becomes a little more difficult to answer, as the 
> filtering
> > necessary to reduce or eliminate the interference  might also
> > be the same frequency range as the announcers voice.
> >
> > So now, at the RF side of the equation, I am at a loss for
> > a definitive answer, as I think it might be a lot more
> > subjective and related to the skills of the listener.
> >
> > More thoughts?
> >
> > Sheldon
> >
> > "Duane Fischer, W8DBF" wrote:
> >
> > >
> > > Is it true that a higher note is often easier to hear, but a 
> lower note
> > travels
> > > a greater distance?
> > >
> > > Now leaving the length of the sound wave out of the discussion 
> momentarily,
> > > given a male and a female announcer for a radio station, 
> speaking at the
> same
> > > volume into the same mike, which signal will be heard at the 
> greatest
> > distance?
> > > The one with the highest voice pitch or the one with the longest 
> wave
> length?
> > >
> > > Duane W8DBF
> > >

________________________________________________________________
The best thing to hit the internet in years - Juno SpeedBand!
Surf the web up to FIVE TIMES FASTER!
Only $14.95/ month - visit www.juno.com to sign up today!

From vintage-audio@mailman.qth.net  Tue Jan 13 19:19:04 2004
From: vintage-audio@mailman.qth.net (Robert    J. McKee)
Date: Tue Jan 13 19:19:04 2004
Subject: [Vintage-Audio] Re Frequency Behavior
Message-ID: <410-2200413140241270@mindspring.com>

Easy there Peter, thin skin can bring lurkers out of the woodwork.
Think how much damage can be done with a 15 K Hz "tone"
the same amplitude as say a 32 Hz.  Iz it real or iz it; what wuz
the brand of that tape, oh yeah, Memorex?


> [Original Message]
> From: Peter Markavage <manualman@juno.com>
> To: <vintage-audio@mailman.qth.net>
> Date: 1/13/04 6:01:07 PM
> Subject: Re: [Vintage-Audio] Re Frequency Behavior
>
> Ok, I'll dance with you one more time.
> I wasn't having fun. I thought you were asking about the speed of sound
> at various tones and I told you. The speed of sound is not dependent on
> the frequency of the sound wave. Given the same starting point of the
> sound, the same amplitude, the same medium, and the same temperature, a
> 100 Hz tone, 1000 Hz tone, or 5000 Hz tone will all travel the same
> speed. Given that they travel the same distance, they all should hit the
> receiver at the same time. Obviously, the farther they travel, all tones
> will be proportionally weaker by the time they get to the receiver. How
> the receiver interprets these sounds, the receiver limitations, etc.
> would determine ultimately whether all tones would be heard. If you guys
> believe that  some frequencies, traveling the same distance, through the
> same medium, the same temperature, etc. are attenuated (high or low), I
> want to see the math for that
>
> Since you want to throw some credentials around, I  have a Master's in
> EE, major in physics, and minors in business and math. (chuckle, chuckle
> to you too)
>
> Pete, WA2CWA
>
> On Tue, 13 Jan 2004 12:07:24 -0500 "Duane Fischer, W8DBF"
> <dfischer@usol.com> writes:
> > Sheldon,         
> >         
> > Yes, on all points.         
> >         
> > Pete was having some fun throwing math equations around, but Pete, I 
> > have a
> > minor in mathematics from the University of Michigan, so be careful! 
> > You might
> > have to buy some new batteries for your calculator OM! 
> > (chuckle)                
> >         
> > Because I am blind, I know far more about what people hear, listen 
> > to, filter
> > out and so forth than anyone who is sighted. I use it every single 
> > day. A
> > sighted person learns 92% of everything visually. That means all of 
> > the other
> > senses, and there are far more than the five people think of, only 
> > 8% get used.
> > What is the greatest sense organ anyhow? The skin! What do we do? We 
> > cover most
> > of it up so its functionality is severely limited. Before we go down 
> > the path of
> > nudists ... Ha Ha.          
> >         
> > Bob? If you want to debate hearing, write me off list. Who was it 
> > that said:
> > "Everybody is talking, but nobody is saying anything?"         
> >         
> > DBF        
> >   
> >         
> > 
> > 
> > ----------
> > From: Sheldon Daitch <sdaitch@ibb.gov>
> > To: vintage-audio@mailman.qth.net
> > Subject: Re: [Vintage-Audio] Re Frequency Behavior
> > Date: Tuesday, January 13, 2004 8:39 AM
> > 
> > Duane,
> > 
> > I think we may be in total agreement.  Maybe I wasn't quite as 
> > elegant in
> > writing.  The only part where I might disagree, in regards to radio
> > reception, is under the situation where next channel interference 
> > is
> > high enough, and the receiver has variable bandwidth filtering, so
> > that the higher audio frequencies are filtered out.  Depending on 
> > the
> > depth and shape of the filters, one could strip out most of the 
> > higher
> > audio frequencies, of a high pitched female announcer, and yet
> > still pass the lower frequencies of a heavy-bass announcer.  Under
> > this unique set of circumstances, you could make a case for
> > the lower audio frequencies.
> > 
> > Pete has a nice explanation of the speed of sound, but I think what 
> > he
> > overlooked is the attenuation factor of higher audio frequencies
> > vs lower audio frequencies.  I believe that was part of your 
> > concern,
> > wasn't it, range, not velocity.
> > 
> > Sheldon
> > 
> > "Duane Fischer, W8DBF" wrote:
> > 
> > > Sheldon,
> > >
> > > First, the human ear is trained from before an infant is born to 
> > listen in a
> > > specific frequency range for vocal patterns. Hence, humans focus 
> > on certain
> > > frequency ranges and filter out others without even realizing they 
> > are doing
> > so.
> > > A higher pitched voice tends to be heard above the general din of 
> > noise
> > > pollution we all experience in our daily comings and goings.
> > >
> > > The best example of this filtering I can think of, is that of a 
> > mother hearing
> > > her child several rooms away with a TV set going, people talking 
> > and all sorts
> > > of other racket. She hears the child whimpering and nobody else in 
> > the room
> > > hears a thing.
> > >
> > > The low note carries the greater distance because it has a longer 
> > wavelength.
> > > For instance, the kid down the street with the kickers in his 
> > trunk. You can
> > > hear the bass a quarter mile away, but nothing else.
> > >
> > > It was said that a female announcer on a radio station could be 
> > heard at a
> > > greater distance because of her high pitched voice. I disagreed. 
> > The radio
> > > signal carries only so far, regardless of what sex is doing the 
> > talking.
> > > However, because her voice is generally of a higher pitch it may 
> > be easier to
> > > hear because it is above the area of the general noise. So it 
> > 'appears that
> > she
> > > is heard farther away simply because the frequency of her voice is 
> > higher than
> > > the background noise.
> > >
> > > Your thoughts?
> > >
> > > DBF
> > >
> > > ----------
> > > From: Sheldon Daitch <sdaitch@ibb.gov>
> > > To: vintage-audio@mailman.qth.net
> > > Subject: Re: [Vintage-Audio] Re Frequency Behavior
> > > Date: Monday, January 12, 2004 3:42 PM
> > >
> > > Duane,
> > >
> > > Maybe we are trying to compare apples and oranges here.
> > >
> > > In general, lower audio frequencies are attenuated less than
> > > higher frequencies, thus, you can hear the rumble of the loud
> > > bass much further away than the higher frequencies from the
> > > same boom box.
> > >
> > > When you get into the second part of your question, which
> > > announcer would be "heard" at a greater distance, assuming
> > > no interference, one would think there should be no
> > > difference in radio range, if that is the intent of your 
> > question.
> > >
> > > Now let's subject the signals to some interference, and
> > > then it becomes a little more difficult to answer, as the 
> > filtering
> > > necessary to reduce or eliminate the interference  might also
> > > be the same frequency range as the announcers voice.
> > >
> > > So now, at the RF side of the equation, I am at a loss for
> > > a definitive answer, as I think it might be a lot more
> > > subjective and related to the skills of the listener.
> > >
> > > More thoughts?
> > >
> > > Sheldon
> > >
> > > "Duane Fischer, W8DBF" wrote:
> > >
> > > >
> > > > Is it true that a higher note is often easier to hear, but a 
> > lower note
> > > travels
> > > > a greater distance?
> > > >
> > > > Now leaving the length of the sound wave out of the discussion 
> > momentarily,
> > > > given a male and a female announcer for a radio station, 
> > speaking at the
> > same
> > > > volume into the same mike, which signal will be heard at the 
> > greatest
> > > distance?
> > > > The one with the highest voice pitch or the one with the longest 
> > wave
> > length?
> > > >
> > > > Duane W8DBF
> > > >
>
> ________________________________________________________________
> The best thing to hit the internet in years - Juno SpeedBand!
> Surf the web up to FIVE TIMES FASTER!
> Only $14.95/ month - visit www.juno.com to sign up today!
> _______________________________________________
> Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer@usol.com ** 



From vintage-audio@mailman.qth.net  Tue Jan 13 20:08:00 2004
From: vintage-audio@mailman.qth.net (bob)
Date: Tue Jan 13 20:08:00 2004
Subject: [Vintage-Audio] Re Frequency Behavior
In-Reply-To: <200401131710.i0DHA8e18442@hades.usol.com>
References: <200401131710.i0DHA8e18442@hades.usol.com>
Message-ID: <40049610.9070009@csnsys.com>

I didn't pay much attention to this thread until today. Man what a bunch 
of missinformation. I don't even know where to start.

Hearing is a highly processed sense. Not only is the ear itself a highly 
developed processor, but a goodly portion of the brain further processes 
the data. Much of the confusion here is involved with the brain and its 
processing.
In the pure physical transmission of sound, the audio frequency range 
from 20 to 20kHz travels with about the same efficiency in free space 
(free air..there is no sound in space). In the real world, the higher 
frequencies bounce off of things and get absorbed in things and tend to 
get time delays and losses that the low frequencies don't get.  But in 
general, they all get there about the same.

In hearing there are two effects that come into major play. The first is 
that the preceived frequency response is a function of sound level (the 
famous Fletcher Munson curves). For very low level audio, the human 
hears only a  narrow band centered around the voice frequencies. This is 
not trained or learned but is in the very nature of the construction of 
the ear and the firmware in the brain. You can demonstrate the 
processing power of the ear-brain by recording a conversation you are 
having in a crowded room, a noisy party. You have no trouble listening 
to those that are talking to you and understanding what they are saying. 
Take the recording into the quiet of you expensive sound room and play 
the tape. You won't hear anything but the crowd noise. Your brain is 
using visual (sorry Duanne), directional, tonal and other cues to 
decipher the speech. This is the mechanism that allows a mother to hear 
her child crying 10 miles away. This is why if you rip a concert from 
the audience on your pocket DTR you end up with garbage. You can hear 
the concert well, but the mic's don't have 20 lbs of processor working 
the problem.

The second effect of interest is masking. The brain has a strange 
ability to not hear some things. You won't hear a quiet tinkle in the 
presence of a crash. You can see it on the scope, well in the loudness 
range where it should be heard, but you cant hear it. The brain will 
ignore stuff on nearby frequencies to large sounds. Effect is really 
wierd, but is the mainstay of much of the perceptual coding that is used 
on MP3, MD and video sound CODECs. they hide much of the digital crap 
under big sounds where you cant hear them.

The concept of understanding speech is a very well studied field. The 
exact bandwidth and shaping that provides the best comprehension of the 
spoken word hidden in noise is manifest in our modern communication 
receivers. Hide the spoken work in something other than noise (like a 
cocktail party), and it is another issue. No electronic gadget can keep 
up with the brain in pulling intellegence out of a cocktail party, in 
spite of the liquid refreshments.

The female voice is not more comprehendable just more shrill and 
grating.  High frequcnies take less energy to create the same sound 
level so for the same amount of energy, the higher frequencies are 
louder. You are juse moving less air at the higher frequencies.. In you 
100 watt amplifier, 90 watts are of use below 200 Hz and the other 10 
watts take care of the rest of the spectrum.

WBob



Duane Fischer, W8DBF wrote:

>Sheldon, 	
>	
>Yes, on all points. 	
>	
>Pete was having some fun throwing math equations around, but Pete, I have a
>minor in mathematics from the University of Michigan, so be careful! You might
>have to buy some new batteries for your calculator OM! (chuckle)		
>	
>Because I am blind, I know far more about what people hear, listen to, filter
>out and so forth than anyone who is sighted. I use it every single day. A
>sighted person learns 92% of everything visually. That means all of the other
>senses, and there are far more than the five people think of, only 8% get used.
>What is the greatest sense organ anyhow? The skin! What do we do? We cover most
>of it up so its functionality is severely limited. Before we go down the path of
>nudists ... Ha Ha.  	
>	
>Bob? If you want to debate hearing, write me off list. Who was it that said:
>"Everybody is talking, but nobody is saying anything?" 	
>	
>DBF	
>  
>	
>
>
>----------
>From: Sheldon Daitch <sdaitch@ibb.gov>
>To: vintage-audio@mailman.qth.net
>Subject: Re: [Vintage-Audio] Re Frequency Behavior
>Date: Tuesday, January 13, 2004 8:39 AM
>
>Duane,
>
>I think we may be in total agreement.  Maybe I wasn't quite as elegant in
>writing.  The only part where I might disagree, in regards to radio
>reception, is under the situation where next channel interference is
>high enough, and the receiver has variable bandwidth filtering, so
>that the higher audio frequencies are filtered out.  Depending on the
>depth and shape of the filters, one could strip out most of the higher
>audio frequencies, of a high pitched female announcer, and yet
>still pass the lower frequencies of a heavy-bass announcer.  Under
>this unique set of circumstances, you could make a case for
>the lower audio frequencies.
>
>Pete has a nice explanation of the speed of sound, but I think what he
>overlooked is the attenuation factor of higher audio frequencies
>vs lower audio frequencies.  I believe that was part of your concern,
>wasn't it, range, not velocity.
>
>Sheldon
>
>"Duane Fischer, W8DBF" wrote:
>
>  
>
>>Sheldon,
>>
>>First, the human ear is trained from before an infant is born to listen in a
>>specific frequency range for vocal patterns. Hence, humans focus on certain
>>frequency ranges and filter out others without even realizing they are doing
>>    
>>
>so.
>  
>
>>A higher pitched voice tends to be heard above the general din of noise
>>pollution we all experience in our daily comings and goings.
>>
>>The best example of this filtering I can think of, is that of a mother hearing
>>her child several rooms away with a TV set going, people talking and all sorts
>>of other racket. She hears the child whimpering and nobody else in the room
>>hears a thing.
>>
>>The low note carries the greater distance because it has a longer wavelength.
>>For instance, the kid down the street with the kickers in his trunk. You can
>>hear the bass a quarter mile away, but nothing else.
>>
>>It was said that a female announcer on a radio station could be heard at a
>>greater distance because of her high pitched voice. I disagreed. The radio
>>signal carries only so far, regardless of what sex is doing the talking.
>>However, because her voice is generally of a higher pitch it may be easier to
>>hear because it is above the area of the general noise. So it 'appears that
>>    
>>
>she
>  
>
>>is heard farther away simply because the frequency of her voice is higher than
>>the background noise.
>>
>>Your thoughts?
>>
>>DBF
>>
>>----------
>>From: Sheldon Daitch <sdaitch@ibb.gov>
>>To: vintage-audio@mailman.qth.net
>>Subject: Re: [Vintage-Audio] Re Frequency Behavior
>>Date: Monday, January 12, 2004 3:42 PM
>>
>>Duane,
>>
>>Maybe we are trying to compare apples and oranges here.
>>
>>In general, lower audio frequencies are attenuated less than
>>higher frequencies, thus, you can hear the rumble of the loud
>>bass much further away than the higher frequencies from the
>>same boom box.
>>
>>When you get into the second part of your question, which
>>announcer would be "heard" at a greater distance, assuming
>>no interference, one would think there should be no
>>difference in radio range, if that is the intent of your question.
>>
>>Now let's subject the signals to some interference, and
>>then it becomes a little more difficult to answer, as the filtering
>>necessary to reduce or eliminate the interference  might also
>>be the same frequency range as the announcers voice.
>>
>>So now, at the RF side of the equation, I am at a loss for
>>a definitive answer, as I think it might be a lot more
>>subjective and related to the skills of the listener.
>>
>>More thoughts?
>>
>>Sheldon
>>
>>"Duane Fischer, W8DBF" wrote:
>>
>>    
>>
>>>Is it true that a higher note is often easier to hear, but a lower note
>>>      
>>>
>>travels
>>    
>>
>>>a greater distance?
>>>
>>>Now leaving the length of the sound wave out of the discussion momentarily,
>>>given a male and a female announcer for a radio station, speaking at the
>>>      
>>>
>same
>  
>
>>>volume into the same mike, which signal will be heard at the greatest
>>>      
>>>
>>distance?
>>    
>>
>>>The one with the highest voice pitch or the one with the longest wave
>>>      
>>>
>length?
>  
>
>>>Duane W8DBF
>>>      
>>>
>  
>



From vintage-audio@mailman.qth.net  Tue Jan 13 22:18:01 2004
From: vintage-audio@mailman.qth.net (Duane Fischer, W8DBF)
Date: Tue Jan 13 22:18:01 2004
Subject: [Vintage-Audio] Re Frequency Behavior
Message-ID: <200401140316.i0E3Gwe04637@hades.usol.com>

This is the 'manual man' I have recommended to people for the past five years as
being a first class person taking cheap shots like these? You can not judge a
book by its cover nor the character of a person by the number of framed
documents upon the wall. I sure misjudged your character Peter. 	
	
Duane Fischer, W8DBF	
  

----------
From: Robert    J. McKee <mckee137@mindspring.com>
To: vintage-audio@mailman.qth.net
Subject: Re: [Vintage-Audio] Re Frequency Behavior
Date: Tuesday, January 13, 2004 7:24 PM

Easy there Peter, thin skin can bring lurkers out of the woodwork.
Think how much damage can be done with a 15 K Hz "tone"
the same amplitude as say a 32 Hz.  Iz it real or iz it; what wuz
the brand of that tape, oh yeah, Memorex?


> [Original Message]
> From: Peter Markavage <manualman@juno.com>
> To: <vintage-audio@mailman.qth.net>
> Date: 1/13/04 6:01:07 PM
> Subject: Re: [Vintage-Audio] Re Frequency Behavior
>
> Ok, I'll dance with you one more time.
> I wasn't having fun. I thought you were asking about the speed of sound
> at various tones and I told you. The speed of sound is not dependent on
> the frequency of the sound wave. Given the same starting point of the
> sound, the same amplitude, the same medium, and the same temperature, a
> 100 Hz tone, 1000 Hz tone, or 5000 Hz tone will all travel the same
> speed. Given that they travel the same distance, they all should hit the
> receiver at the same time. Obviously, the farther they travel, all tones
> will be proportionally weaker by the time they get to the receiver. How
> the receiver interprets these sounds, the receiver limitations, etc.
> would determine ultimately whether all tones would be heard. If you guys
> believe that  some frequencies, traveling the same distance, through the
> same medium, the same temperature, etc. are attenuated (high or low), I
> want to see the math for that
>
> Since you want to throw some credentials around, I  have a Master's in
> EE, major in physics, and minors in business and math. (chuckle, chuckle
> to you too)
>
> Pete, WA2CWA
>
> On Tue, 13 Jan 2004 12:07:24 -0500 "Duane Fischer, W8DBF"
> <dfischer@usol.com> writes:
> > Sheldon,         
> >         
> > Yes, on all points.         
> >         
> > Pete was having some fun throwing math equations around, but Pete, I 
> > have a
> > minor in mathematics from the University of Michigan, so be careful! 
> > You might
> > have to buy some new batteries for your calculator OM! 
> > (chuckle)                
> >         
> > Because I am blind, I know far more about what people hear, listen 
> > to, filter
> > out and so forth than anyone who is sighted. I use it every single 
> > day. A
> > sighted person learns 92% of everything visually. That means all of 
> > the other
> > senses, and there are far more than the five people think of, only 
> > 8% get used.
> > What is the greatest sense organ anyhow? The skin! What do we do? We 
> > cover most
> > of it up so its functionality is severely limited. Before we go down 
> > the path of
> > nudists ... Ha Ha.          
> >         
> > Bob? If you want to debate hearing, write me off list. Who was it 
> > that said:
> > "Everybody is talking, but nobody is saying anything?"         
> >         
> > DBF        
> >   
> >         
> > 
> > 
> > ----------
> > From: Sheldon Daitch <sdaitch@ibb.gov>
> > To: vintage-audio@mailman.qth.net
> > Subject: Re: [Vintage-Audio] Re Frequency Behavior
> > Date: Tuesday, January 13, 2004 8:39 AM
> > 
> > Duane,
> > 
> > I think we may be in total agreement.  Maybe I wasn't quite as 
> > elegant in
> > writing.  The only part where I might disagree, in regards to radio
> > reception, is under the situation where next channel interference 
> > is
> > high enough, and the receiver has variable bandwidth filtering, so
> > that the higher audio frequencies are filtered out.  Depending on 
> > the
> > depth and shape of the filters, one could strip out most of the 
> > higher
> > audio frequencies, of a high pitched female announcer, and yet
> > still pass the lower frequencies of a heavy-bass announcer.  Under
> > this unique set of circumstances, you could make a case for
> > the lower audio frequencies.
> > 
> > Pete has a nice explanation of the speed of sound, but I think what 
> > he
> > overlooked is the attenuation factor of higher audio frequencies
> > vs lower audio frequencies.  I believe that was part of your 
> > concern,
> > wasn't it, range, not velocity.
> > 
> > Sheldon
> > 
> > "Duane Fischer, W8DBF" wrote:
> > 
> > > Sheldon,
> > >
> > > First, the human ear is trained from before an infant is born to 
> > listen in a
> > > specific frequency range for vocal patterns. Hence, humans focus 
> > on certain
> > > frequency ranges and filter out others without even realizing they 
> > are doing
> > so.
> > > A higher pitched voice tends to be heard above the general din of 
> > noise
> > > pollution we all experience in our daily comings and goings.
> > >
> > > The best example of this filtering I can think of, is that of a 
> > mother hearing
> > > her child several rooms away with a TV set going, people talking 
> > and all sorts
> > > of other racket. She hears the child whimpering and nobody else in 
> > the room
> > > hears a thing.
> > >
> > > The low note carries the greater distance because it has a longer 
> > wavelength.
> > > For instance, the kid down the street with the kickers in his 
> > trunk. You can
> > > hear the bass a quarter mile away, but nothing else.
> > >
> > > It was said that a female announcer on a radio station could be 
> > heard at a
> > > greater distance because of her high pitched voice. I disagreed. 
> > The radio
> > > signal carries only so far, regardless of what sex is doing the 
> > talking.
> > > However, because her voice is generally of a higher pitch it may 
> > be easier to
> > > hear because it is above the area of the general noise. So it 
> > 'appears that
> > she
> > > is heard farther away simply because the frequency of her voice is 
> > higher than
> > > the background noise.
> > >
> > > Your thoughts?
> > >
> > > DBF
> > >
> > > ----------
> > > From: Sheldon Daitch <sdaitch@ibb.gov>
> > > To: vintage-audio@mailman.qth.net
> > > Subject: Re: [Vintage-Audio] Re Frequency Behavior
> > > Date: Monday, January 12, 2004 3:42 PM
> > >
> > > Duane,
> > >
> > > Maybe we are trying to compare apples and oranges here.
> > >
> > > In general, lower audio frequencies are attenuated less than
> > > higher frequencies, thus, you can hear the rumble of the loud
> > > bass much further away than the higher frequencies from the
> > > same boom box.
> > >
> > > When you get into the second part of your question, which
> > > announcer would be "heard" at a greater distance, assuming
> > > no interference, one would think there should be no
> > > difference in radio range, if that is the intent of your 
> > question.
> > >
> > > Now let's subject the signals to some interference, and
> > > then it becomes a little more difficult to answer, as the 
> > filtering
> > > necessary to reduce or eliminate the interference  might also
> > > be the same frequency range as the announcers voice.
> > >
> > > So now, at the RF side of the equation, I am at a loss for
> > > a definitive answer, as I think it might be a lot more
> > > subjective and related to the skills of the listener.
> > >
> > > More thoughts?
> > >
> > > Sheldon
> > >
> > > "Duane Fischer, W8DBF" wrote:
> > >
> > > >
> > > > Is it true that a higher note is often easier to hear, but a 
> > lower note
> > > travels
> > > > a greater distance?
> > > >
> > > > Now leaving the length of the sound wave out of the discussion 
> > momentarily,
> > > > given a male and a female announcer for a radio station, 
> > speaking at the
> > same
> > > > volume into the same mike, which signal will be heard at the 
> > greatest
> > > distance?
> > > > The one with the highest voice pitch or the one with the longest 
> > wave
> > length?
> > > >
> > > > Duane W8DBF
> > > >
>
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_______________________________________________
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From vintage-audio@mailman.qth.net  Wed Jan 14 16:40:01 2004
From: vintage-audio@mailman.qth.net (Sheldon Daitch)
Date: Wed Jan 14 16:40:01 2004
Subject: [Vintage-Audio] Re Frequency Behavior
References: <200401131710.i0DHA8e18442@hades.usol.com> <40049610.9070009@csnsys.com>
Message-ID: <4005B66B.287DB563@ibb.gov>

Bob,

I think you essentially answered part of Duane's original
question.  Low audio frequencies will travel
further.

But then Duane makes the question more complicated,
by asking would a female radio announcer be more
audible than a male announcer, I would assume due to
"interference."  I would submit that interference to a
radio signal is going to be of a different nature than
the "interference" to conversations at a cocktail party,
plus we also have electronic filtering aids for
radio reception that we would not normally bring to
a cocktail party, unless yours are radically different
from those I usually attend!

But you have brought into the discussion much more
technical information.  Thanks,

Sheldon



bob wrote:now where to start.

>
> In the pure physical transmission of sound, the audio frequency range
> from 20 to 20kHz travels with about the same efficiency in free space
> (free air..there is no sound in space). In the real world, the higher
> frequencies bounce off of things and get absorbed in things and tend to
> get time delays and losses that the low frequencies don't get.  But in
> general, they all get there about the same.
>


From vintage-audio@mailman.qth.net  Mon Jan 26 17:22:04 2004
From: vintage-audio@mailman.qth.net (Roy Morgan)
Date: Mon Jan 26 17:22:04 2004
Subject: [Vintage-Audio] Akai Recorders: Value?
In-Reply-To: <40049610.9070009@csnsys.com>
References: <200401131710.i0DHA8e18442@hades.usol.com>
 <200401131710.i0DHA8e18442@hades.usol.com>
Message-ID: <5.0.0.25.2.20040126172021.035de650@mail01.amdiac.net>

Audio folks,

A friend has for sale two Akai recorders and wonders what their value might 
be.

Akai GX-630D   (stereo dolby with 7 or 10" reels) and Akai GX-270D-SS 
(quadraphonic recorder!).  These have very little wear on the heads.  They 
are operating and working very well.

Thanks for any opinions.

Roy
- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
7130 Panorama Drive, Derwood MD 20855
Home: 301-330-8828 Work: Voice: 301-975-3254,  Fax: 301-948-6213
roy.morgan@nist.gov --


From vintage-audio@mailman.qth.net  Mon Jan 26 18:19:01 2004
From: vintage-audio@mailman.qth.net (Duane Fischer, W8DBF)
Date: Mon Jan 26 18:19:01 2004
Subject: [Vintage-Audio] Akai Recorders: Value?
Message-ID: <200401262318.i0QNIJe15760@hades.usol.com>

Roy, 	
	
Let's be candid. Have you heard them to know for sure they work as they should?
Has the owner been using them or just gotten them out of storage, powered them
up for the first time in eight years and did a test recording? 	
	
Getting parts for either of these tape decks is nigh onto impossible Roy, as you
know. Before he asks for a price, find out from the seller how good they truly
are. Then get back to me and I will give you prices.	
	
Duane W8DBF	


----------
From: Roy Morgan <goodguy3@amdiac.net>
To: vintage-audio@mailman.qth.net
Subject: [Vintage-Audio] Akai Recorders: Value?
Date: Monday, January 26, 2004 5:21 PM

Audio folks,

A friend has for sale two Akai recorders and wonders what their value might 
be.

Akai GX-630D   (stereo dolby with 7 or 10" reels) and Akai GX-270D-SS 
(quadraphonic recorder!).  These have very little wear on the heads.  They 
are operating and working very well.

Thanks for any opinions.

Roy
- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
7130 Panorama Drive, Derwood MD 20855
Home: 301-330-8828 Work: Voice: 301-975-3254,  Fax: 301-948-6213
roy.morgan@nist.gov --

_______________________________________________
Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
List Administrator: Duane Fischer, W8DBF
** For Assistance: dfischer@usol.com ** 

From vintage-audio@mailman.qth.net  Mon Jan 26 18:23:01 2004
From: vintage-audio@mailman.qth.net (Duane Fischer, W8DBF)
Date: Mon Jan 26 18:23:01 2004
Subject: [Vintage-Audio] Re Stereo To Mono
Message-ID: <200401262321.i0QNLke16047@hades.usol.com>

Courtesy of KO6BB: 

	
First, you really "don't" want to cut those cords on modern headsets to try
to rewire them as it is nearly impossible to do anything with those fine
wires and have them at all reliable.

Secondly, most of them have earpieces that are pretty close to 8 Ohms, some
as high as 30 Ohms each.  What this means is that even if you do rewire them
and put them in series about the highest impedance that you're going to see
is in the area of 16-60 Ohms, nowhere near a good match to the 600-2000 Ohm
output impedance of many of the old receivers.  (headphone jacks on some
receivers such as the cheapie S-120 actually are tied into the speaker lead
and are already low impedance).  This usually means a transformer or small
amplifier is needed for optimum sound anyway.  (I often use a active audio
filter between headset and radio to match things up).

To adapt a stereo headset to mono in itself is pretty easy as there are
adapters that can be bought that are a stereo jack to mono plug, just plug
the headset into one of these. I may even have one around here somewhere
yet.  Lacking that you can tape a 1/4 inch mono plug and put on one end of a
cable and a stereo jack wired in parallel on the other end.  Insert between
headset and radio.



