Stepping back from ANR

On Sat, 02 Sep 2006 20:50:46 +0100, wrote:

On Sat, 02 Sep 2006 14:25:05 -0400, "Roger (K8RI)"
wrote:

On Sat, 02 Sep 2006 18:22:41 +0100, wrote:

On Thu, 31 Aug 2006 21:19:11 -0400, Roger
wrote:

snip

I've been looking at headsets recently and came to the conclusion that
the QFR XCC clone is a good compromise at $240. Compared to other ANR
headsets it has some of the highest passive attenuation though only
~10db electronic. If the electronics fail it should still be very
good.

By the way Roger you mentioned in a previous post that 3db was
half/double. I think you're still thinking of power not volts.
I assume ANR refers to volts so think 6db = half/double, or am I
getting rusty with all this?

Sound (and our hearing) is logarithmic so I'm pretty sure that the 3
db holds for sound as it does for power.




David
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Roger, now you've got me thinking:-) As you say it's logarithmic but
if I'm not mistaken 10w to 100w =10dbw, 10v to 20v = 20dbv. I don't

That is correct, but sound is analogous to power not volts.


know how ANR is measured so I'm guessing dba but it looks like double
= 6db. In an expample I found on the web and you compare say the Rifle
& Threshold of Pain there's 6db difference. That would suggest
headphones with say 26db passive attenuation would reduce the sound
level by a factor of 40. If you use 3db then it would be a factor well
over 500 which I think would be unrealistic.

Source of sound Sound pressure Sound pressure level
pascal dB re 20 µPa
=============================================
Rifle being fired at 1 m: 200 Pa = 140 dB
Threshold of pain: 100 Pa = 134 dB
Hearing damage during short term effect: 20 Pa = approx. 120 dB
Jet, 100 m distant: 6 – 200 Pa = 110 – 140 dB
Jack hammer, 1 m distant / discotheque: 2 Pa approx. 100 dB
Hearing damage during long-term effect: 6×10-1 Pa = approx. 90 dB

When I had a two blade prop on the Deb is was measured at 93 db at a
distance of one city block and full RPM. So you can see why the
neighbors off the end of 18 complained when I'd go over at roughly 300
feet on climb out at full power. :-))

David (GM3RFA)
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

On Mon, 04 Sep 2006 05:14:25 -0400, Roger
wrote:

On Sat, 02 Sep 2006 20:50:46 +0100, wrote:

On Sat, 02 Sep 2006 14:25:05 -0400, "Roger (K8RI)"
wrote:

On Sat, 02 Sep 2006 18:22:41 +0100, wrote:

On Thu, 31 Aug 2006 21:19:11 -0400, Roger
wrote:

snip

I've been looking at headsets recently and came to the conclusion that
the QFR XCC clone is a good compromise at $240. Compared to other ANR
headsets it has some of the highest passive attenuation though only
~10db electronic. If the electronics fail it should still be very
good.

By the way Roger you mentioned in a previous post that 3db was
half/double. I think you're still thinking of power not volts.
I assume ANR refers to volts so think 6db = half/double, or am I
getting rusty with all this?

Sound (and our hearing) is logarithmic so I'm pretty sure that the 3
db holds for sound as it does for power.




David
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Roger, now you've got me thinking:-) As you say it's logarithmic but
if I'm not mistaken 10w to 100w =10dbw, 10v to 20v = 20dbv. I don't

That is correct, but sound is analogous to power not volts.


know how ANR is measured so I'm guessing dba but it looks like double
= 6db. In an expample I found on the web and you compare say the Rifle
& Threshold of Pain there's 6db difference. That would suggest
headphones with say 26db passive attenuation would reduce the sound
level by a factor of 40. If you use 3db then it would be a factor well
over 500 which I think would be unrealistic.

Source of sound Sound pressure Sound pressure level
pascal dB re 20 µPa
=============================================
Rifle being fired at 1 m: 200 Pa = 140 dB
Threshold of pain: 100 Pa = 134 dB
Hearing damage during short term effect: 20 Pa = approx. 120 dB
Jet, 100 m distant: 6 – 200 Pa = 110 – 140 dB
Jack hammer, 1 m distant / discotheque: 2 Pa approx. 100 dB
Hearing damage during long-term effect: 6×10-1 Pa = approx. 90 dB

When I had a two blade prop on the Deb is was measured at 93 db at a
distance of one city block and full RPM. So you can see why the
neighbors off the end of 18 complained when I'd go over at roughly 300
feet on climb out at full power. :-))

David (GM3RFA)
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

I'm not qualified to comment further on this topic so will let it lie
and await somebody better qualified to chip in.

Ok on the Deb, it sounds much louder than the PA28 I fly. Perhaps you
need some 'Stealth bomber paint' so they don't know who you are?

David

On Mon, 04 Sep 2006 10:57:37 +0100, wrote:

On Mon, 04 Sep 2006 05:14:25 -0400, Roger
wrote:

On Sat, 02 Sep 2006 20:50:46 +0100, wrote:

On Sat, 02 Sep 2006 14:25:05 -0400, "Roger (K8RI)"
wrote:

On Sat, 02 Sep 2006 18:22:41 +0100, wrote:

On Thu, 31 Aug 2006 21:19:11 -0400, Roger
wrote:

snip

I've been looking at headsets recently and came to the conclusion that
the QFR XCC clone is a good compromise at $240. Compared to other ANR
headsets it has some of the highest passive attenuation though only
~10db electronic. If the electronics fail it should still be very
good.

By the way Roger you mentioned in a previous post that 3db was
half/double. I think you're still thinking of power not volts.
I assume ANR refers to volts so think 6db = half/double, or am I
getting rusty with all this?

Sound (and our hearing) is logarithmic so I'm pretty sure that the 3
db holds for sound as it does for power.




David
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Roger, now you've got me thinking:-) As you say it's logarithmic but
if I'm not mistaken 10w to 100w =10dbw, 10v to 20v = 20dbv. I don't

That is correct, but sound is analogous to power not volts.


know how ANR is measured so I'm guessing dba but it looks like double
= 6db. In an expample I found on the web and you compare say the Rifle
& Threshold of Pain there's 6db difference. That would suggest
headphones with say 26db passive attenuation would reduce the sound
level by a factor of 40. If you use 3db then it would be a factor well
over 500 which I think would be unrealistic.

Source of sound Sound pressure Sound pressure level
pascal dB re 20 µPa
=============================================
Rifle being fired at 1 m: 200 Pa = 140 dB
Threshold of pain: 100 Pa = 134 dB
Hearing damage during short term effect: 20 Pa = approx. 120 dB
Jet, 100 m distant: 6 – 200 Pa = 110 – 140 dB
Jack hammer, 1 m distant / discotheque: 2 Pa approx. 100 dB
Hearing damage during long-term effect: 6×10-1 Pa = approx. 90 dB

When I had a two blade prop on the Deb is was measured at 93 db at a
distance of one city block and full RPM. So you can see why the
neighbors off the end of 18 complained when I'd go over at roughly 300
feet on climb out at full power. :-))

David (GM3RFA)
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

I'm not qualified to comment further on this topic so will let it lie
and await somebody better qualified to chip in.

Ok on the Deb, it sounds much louder than the PA28 I fly. Perhaps you
need some 'Stealth bomber paint' so they don't know who you are?

And unfortunately I have those great big numbers on the side. sigh

One *hot* afternoon, the wind was out of the SSE and gusty. That
meant even the high performance stuff was using 18. Unfortunately that
same subdivision fought lengthening 18/36 so *everyone* was going over
their houses at 200 to 300 feet. I made three takes offs and
landings that afternoon. We had a pair of Navions, a 310, two 210s, a
couple of Bonanzas, some 182s and I don't remember what else.

It was a busy day at the airport and I have no doubt they were telling
the truth when they said they couldn't even carry on a conversation
when one of us went over. To the non flying we all sound alike and
the one guy wrote down my N number. He said I went over every five
minutes. I can't take off, fly the pattern, land, taxi back and take
off again in less than twice that. Fortunately he lost sympathy and
credibility when accusing one plane of doing all that when the pattern
was full most of the afternoon.

I wasn't one of those paint jobs that changes color depending on your
angle to the viewer and sun. That way no two people will give the same
story. :-))

When we took off, loaded to gross for the day and I could see the
grass under the picnic table through the gaps in the top I told my
passengers "I'll bet we hear about this one!":-))

Which reminds me. That subdivision just popped up. One day I was on
final for 36 and some guys were putting up a tall TV antenna. I
noticed it was gone the next day. I had the gear down and full flaps
with lots of power when I went directly over the top of it. I'll
bet it was a bit drafty on top of that tower. Apparently they didn't
know they are not allowed to go above the tree line around there.
Actually I think it may be less than that.

If you ever visit 3BS and land using the VASIs on 36 you'll know what
I mean. Take a look just south of the expressway.



David
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

On Wed, 06 Sep 2006 03:39:17 -0400, Roger
wrote:

- snip -

I'm not qualified to comment further on this topic so will let it lie
and await somebody better qualified to chip in.

Ok on the Deb, it sounds much louder than the PA28 I fly. Perhaps you
need some 'Stealth bomber paint' so they don't know who you are?

And unfortunately I have those great big numbers on the side. sigh

Foiled!

One *hot* afternoon, the wind was out of the SSE and gusty. That
meant even the high performance stuff was using 18. Unfortunately that
same subdivision fought lengthening 18/36 so *everyone* was going over
their houses at 200 to 300 feet. I made three takes offs and
landings that afternoon. We had a pair of Navions, a 310, two 210s, a
couple of Bonanzas, some 182s and I don't remember what else.


Don't tell me the airfield was built first, then they built houses,
then they complained of the noise :-(

Would you believe in the UK a new resident in a farming area
complained of early morning noise from a farmer's cockerels. What's
more he went to court and won despite the farm having animals for many
many years. Perhaps they should have supplied ANR headsets?

It was a busy day at the airport and I have no doubt they were telling
the truth when they said they couldn't even carry on a conversation
when one of us went over. To the non flying we all sound alike and
the one guy wrote down my N number. He said I went over every five
minutes. I can't take off, fly the pattern, land, taxi back and take
off again in less than twice that. Fortunately he lost sympathy and
credibility when accusing one plane of doing all that when the pattern
was full most of the afternoon.

I wasn't one of those paint jobs that changes color depending on your
angle to the viewer and sun. That way no two people will give the same
story. :-))


Never heard of that but it sounds good. We have the lower half of the
aircraft dark red and the half upper white. Hopefull so it looks dark
against the sky and light against the ground. Doubt it makes as much
difference as the strobes.

When we took off, loaded to gross for the day and I could see the
grass under the picnic table through the gaps in the top I told my
passengers "I'll bet we hear about this one!":-))


Oops!

Which reminds me. That subdivision just popped up. One day I was on
final for 36 and some guys were putting up a tall TV antenna. I
noticed it was gone the next day. I had the gear down and full flaps
with lots of power when I went directly over the top of it. I'll
bet it was a bit drafty on top of that tower. Apparently they didn't
know they are not allowed to go above the tree line around there.
Actually I think it may be less than that.


Last time I read my amateur licence I think it said antenna maximum of
50 ft within about half or 1 mile of an aerodrome in UK. I think
anything else like kites are 200ft??? With low flying Military
aircraft authorised to 200ft and some 50ft that could be a problem.

If you ever visit 3BS and land using the VASIs on 36 you'll know what
I mean. Take a look just south of the expressway.


Doesn't look too bad using Google Earth but I guess flying gives a
different perspective.



David
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

David

On Wed, 06 Sep 2006 15:13:45 +0100, wrote:

On Wed, 06 Sep 2006 03:39:17 -0400, Roger
wrote:

- snip -

I'm not qualified to comment further on this topic so will let it lie
and await somebody better qualified to chip in.

Ok on the Deb, it sounds much louder than the PA28 I fly. Perhaps you
need some 'Stealth bomber paint' so they don't know who you are?

And unfortunately I have those great big numbers on the side. sigh

Foiled!

One *hot* afternoon, the wind was out of the SSE and gusty. That
meant even the high performance stuff was using 18. Unfortunately that
same subdivision fought lengthening 18/36 so *everyone* was going over
their houses at 200 to 300 feet. I made three takes offs and
landings that afternoon. We had a pair of Navions, a 310, two 210s, a
couple of Bonanzas, some 182s and I don't remember what else.


Don't tell me the airfield was built first, then they built houses,
then they complained of the noise :-(

You've been here?


Would you believe in the UK a new resident in a farming area
complained of early morning noise from a farmer's cockerels. What's
more he went to court and won despite the farm having animals for many
many years. Perhaps they should have supplied ANR headsets?

At least here in the states the answer to that is usually *to bad* or
something a big more pointed. He should be happy the farmer doesn't
take up pig farming. I was raised on a farm, but that was in the days
before the honey wagons made it from Europe to the States. I never
knew that stuff could spoil until the advent of the honey wagon. There
is a large pig farm about a half mile to the SE of us. It seems like
the wind is *always* out of the SE when he empties the tank. OTOH he
is required to work it into the ground within two days.


It was a busy day at the airport and I have no doubt they were telling
the truth when they said they couldn't even carry on a conversation
when one of us went over. To the non flying we all sound alike and
the one guy wrote down my N number. He said I went over every five
minutes. I can't take off, fly the pattern, land, taxi back and take
off again in less than twice that. Fortunately he lost sympathy and
credibility when accusing one plane of doing all that when the pattern
was full most of the afternoon.

I wasn't one of those paint jobs that changes color depending on your
angle to the viewer and sun. That way no two people will give the same
story. :-))


Never heard of that but it sounds good. We have the lower half of the
aircraft dark red and the half upper white. Hopefull so it looks dark
against the sky and light against the ground. Doubt it makes as much
difference as the strobes.

I've never seen it on a plane, but there was a custom truck over at
the neighbors a while back. I was one color coming toward me and a
different one going away. It went through the spectrum as he went by.
Really pretty, really expensive, and probably impossible to touch up.

When we took off, loaded to gross for the day and I could see the
grass under the picnic table through the gaps in the top I told my
passengers "I'll bet we hear about this one!":-))


Oops!

Which reminds me. That subdivision just popped up. One day I was on
final for 36 and some guys were putting up a tall TV antenna. I
noticed it was gone the next day. I had the gear down and full flaps
with lots of power when I went directly over the top of it. I'll
bet it was a bit drafty on top of that tower. Apparently they didn't
know they are not allowed to go above the tree line around there.
Actually I think it may be less than that.


Last time I read my amateur licence I think it said antenna maximum of
50 ft within about half or 1 mile of an aerodrome in UK. I think
anything else like kites are 200ft??? With low flying Military
aircraft authorised to 200ft and some 50ft that could be a problem.

I'm 4 1/2 miles directly off the end of 06 and on the centerline. My
tower is 97' with the top UHF/VHF array at 130 feet. I think I could
have gone to about 190 feet without permission, except my lot isn't
large enough to go that high.


If you ever visit 3BS and land using the VASIs on 36 you'll know what
I mean. Take a look just south of the expressway.


Doesn't look too bad using Google Earth but I guess flying gives a
different perspective.
We seldom see any one dragging it in over the express way and those
trees like they do on final for 24. OTOH I don't know of any
one..yet...that has pranged one on 36, but we've had several dragging
it in on 24 get too low, apply too much power, over correct and turn
it into a lawn dart. So far all have survived and one guy even did it
*twice*. We did have a guy force a 172 down on 18, porpoise and put
shoulders in the wings.

Try the same city and 521 North Clyde road. They have me on the
corner which is in the wrong place, but mine is the second drive on
the west side with the black satellite dish in back and the white car
just in front of the garage. My shop where I'm working on the G-III is
just north of the house. You can only go another half mile west before
they go into very low resolution on the map.




David
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

David
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

On Wed, 06 Sep 2006 23:15:36 -0400, "Roger (K8RI)"

Don't tell me the airfield was built first, then they built houses,
then they complained of the noise :-(

You've been here?

Sadly, haven't we all?

I've never seen it on a plane, but there was a custom truck over at
the neighbors a while back. I was one color coming toward me and a
different one going away. It went through the spectrum as he went by.
Really pretty, really expensive, and probably impossible to touch up.

Interesting

I'm 4 1/2 miles directly off the end of 06 and on the centerline. My
tower is 97' with the top UHF/VHF array at 130 feet. I think I could
have gone to about 190 feet without permission, except my lot isn't
large enough to go that high.


What you need is a site like the amateur may tens of years ago.
His entire installation was up a mountain and remote controlled with a
10GHz link.

Try the same city and 521 North Clyde road. They have me on the
corner which is in the wrong place, but mine is the second drive on
the west side with the black satellite dish in back and the white car
just in front of the garage. My shop where I'm working on the G-III is
just north of the house. You can only go another half mile west before
they go into very low resolution on the map.

Are you sure your white car is still in the drive or was that somebody
driving it away :-)

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

david

On Thu, 07 Sep 2006 11:55:46 +0100, wrote:

snip
What you need is a site like the amateur may tens of years ago.
His entire installation was up a mountain and remote controlled with a
10GHz link.

There's one down in Tennessee who purchased a mountain top that was
once a military/government communications installation. He got it
towers and all and is still active.

What I need is the mountain top, towers and an airstrip.


Try the same city and 521 North Clyde road. They have me on the
corner which is in the wrong place, but mine is the second drive on
the west side with the black satellite dish in back and the white car
just in front of the garage. My shop where I'm working on the G-III is
just north of the house. You can only go another half mile west before
they go into very low resolution on the map.

Are you sure your white car is still in the drive or was that somebody
driving it away :-)

Try the first place north of where they say I am. The car is right in
front of the garage. However the resolution isn't all that great.
There area few spots including one in the Sahara desert where you can
tell what color shoes a guy has on. One area in NJ has 2"
resolution.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com