Strobes

Jim Kelly wrote:

Has anyone thought to try (very) reflective tape,

Of course. Our club has equipped all gliders with chrome tape. The
opinions vary from "it doesn't hurt" to "we will be able to claim that
we tried everything".

Stefan

Jim Kelly wrote:

Has anyone thought to try (very) reflective tape,

Yes. Reflective tape, and if you repaint a glider,
paint the wingtips white or reflective. It seems I've
seen quite a few with dark wingtips. Sure makes
it easy to hit one's head...

I also wrap my portable ELT in reflective tape. Saves
having a separate mirror...

In article ,
Eric Greenwell wrote:
Mark James Boyd wrote:
Jim Kelly wrote:

I also wrap my portable ELT in reflective tape. Saves
having a separate mirror...

Have you tried to use it? A real signalling mirror is flat, reflective
on both sides, and has a small hole in the center so you can aim it. One
you can't aim might be worthless.
--

This tape actually has a checker pattern and
reflects in all directions. I'd bet the signal mirror
would work better, but might depend on my skill
using it ;-[

Mark James Boyd wrote:
Jim Kelly wrote:

I also wrap my portable ELT in reflective tape. Saves
having a separate mirror...

Have you tried to use it? A real signalling mirror is flat, reflective
on both sides, and has a small hole in the center so you can aim it. One
you can't aim might be worthless.
--
-----
Replace "SPAM" with "charter" to email me directly

Eric Greenwell
Washington State
USA

Mark James Boyd wrote:
In article ,
Eric Greenwell wrote:

Mark James Boyd wrote:

Jim Kelly wrote:

I also wrap my portable ELT in reflective tape. Saves
having a separate mirror...

Have you tried to use it? A real signalling mirror is flat, reflective
on both sides, and has a small hole in the center so you can aim it. One
you can't aim might be worthless.
--


This tape actually has a checker pattern and
reflects in all directions.

I think this makes it worthless unless the other person is very close. A
flat signal mirror has a narrow and therefor much brighter beam.

I'd bet the signal mirror
would work better, but might depend on my skill
using it ;-[

They are very easy to aim, because they are reflective on _both_ sides
and have a hole in the center. You are actually aiming it (using the
hole and the reflective back side), not just waving it in the general
direction of the aircraft or whatever you are trying to signal.


--
-----
Replace "SPAM" with "charter" to email me directly

Eric Greenwell
Washington State
USA

SNIP
A
flat signal mirror has a narrow and therefor much brighter
beam.

I'd bet the signal mirror
would work better, but might depend on my skill
using it ;-[

They are very easy to aim, because they are reflective
on _both_ sides
and have a hole in the center. You are actually aiming
it (using the
hole and the reflective back side), not just waving
it in the general
direction of the aircraft or whatever you are trying
to signal.


--
-----
Replace 'SPAM' with 'charter' to email me directly

Eric Greenwell
Washington State
USA

Eric,
Not ever having seen one, I can't quite get my mind
around how a hole in the centre helps you aim it.
If the sun is 45 degrees left and you aim at the target
aircraft, won't the reflected beam be 45 degrees right
of the target?
I'm not arguing - I'm sure they work, I'd just like
a simple explanation of how!
Rob

On 5 Dec 2003 16:38:12 GMT, Robert John
wrote:
.... text removed...
Not ever having seen one, I can't quite get my mind
around how a hole in the centre helps you aim it.
If the sun is 45 degrees left and you aim at the target
aircraft, won't the reflected beam be 45 degrees right
of the target?
I'm not arguing - I'm sure they work, I'd just like
a simple explanation of how!

This may not be simple, but most of the real signal mirrors I am
familar with have a hole in the backside that is surrounded with a
circle of retroreflective material (like 3M Scotchlite), typically red
in color. The sunlight is reflected off the mirror surface normally.
Where the sunlight hits the Scotchlite, it is retroreflected directly
only the incoming path. A small portion (about 4%) of this reflected
sunlight, now colored red by the Scotchlite, is in turn reflected
backwards again by the front surface of the mirror (toward the user
looking through the backside of the mirror). The usual optics rules
for mirrors (angle of incidence equals angle of reflection) means that
this retroreflected (red) radiation appears to come along the exact
angle as the outgoing reflected sun light. The bottom line is that
when you look outward through the small hole in the backside of the
mirror, all you have to do is put the small red spot you see on the
target you are trying to signal. The Scotchlite properties and the
rules of optics reflection assure that the red spot and the reflected
sunlight are pointing in the exact same direction.

Sorry UseNet does not permit embedded graphics.

Bob

Robert John wrote in message ...
SNIP
A
flat signal mirror has a narrow and therefor much brighter
beam.

I'd bet the signal mirror
would work better, but might depend on my skill
using it ;-[

They are very easy to aim, because they are reflective
on _both_ sides
and have a hole in the center. You are actually aiming
it (using the
hole and the reflective back side), not just waving
it in the general
direction of the aircraft or whatever you are trying
to signal.


--
-----
Replace 'SPAM' with 'charter' to email me directly

Eric Greenwell
Washington State
USA

Eric,
Not ever having seen one, I can't quite get my mind
around how a hole in the centre helps you aim it.
If the sun is 45 degrees left and you aim at the target
aircraft, won't the reflected beam be 45 degrees right
of the target?
I'm not arguing - I'm sure they work, I'd just like
a simple explanation of how!
Rob

You can also buy little stick on convex mirrors for $2.00 or less each
at auto parts stores. Wouldn't the reflected light go out in a cone
shape? After a few hundred feet the cone pattern could be quite
large.

"Slingsby" wrote in message
om...
Robert John wrote in
message ...
SNIP
A
flat signal mirror has a narrow and therefor much brighter
beam.


You can also buy little stick on convex mirrors for $2.00 or less each
at auto parts stores. Wouldn't the reflected light go out in a cone
shape? After a few hundred feet the cone pattern could be quite
large.

...and therefore (by the law of inverse squares) not nearly as bright.

Vaughn