[Elecraft] Radio Displays

[Fred Jensen]

On 5/9/2012 2:58 PM, Ron D'Eau Claire wrote:
> Rotating the polarized sunglasses 90% makes them ineffective in suppressing
> brilliant reflections and glare. I have never investigated how natural
> sunlight gets polarized, but good quality polarized sunglasses have their
> lens polarity set to be 90 degrees off and so block that glare.

Sunlight reflected at small angles, such as from a chrome strip [or a 
wet road] is "glare" and is polarized in the same plane as the 
reflector.  This is predominantly horizontal, mostly, so polarized sun 
glasses are or should be vertically polarized.  Gas pump LCD's [and 
ATM's and such things] have a predictable viewing angle, so if the LCD 
is polarized vertically, you can read it.  Some other things, like 
perhaps mobile radios, HT's, and TV's in sports bars have less 
predictable viewing angles.  Wearing sunglasses in a sports bar could be 
a bad idea on other grounds, however.

Survival Tip:  If you are ever lost, look through polarized sunglasses 
at the sky while rotating them.  If you are certain you are lost north 
of 23N, the direction which shows the biggest change in brightness is 
north.  Backscattered sunlight from the north is polarized, I'm not sure 
why.  Of course, if the shadows cast by the sun didn't already tip you 
off about north, perhaps you're in more trouble than you first thought. 
If you aren't sure you are north or south of 23N, it's likely hopeless. :-)

I'd like to know if this is reversed south of 23S.  Maybe someone in VK 
or ZL can test this for me.  I've been to both once, didn't have 
polarized sunglasses either time.  Most everything seems to be reversed 
there, up/down, you know.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2012 Cal QSO Party 6-7 Oct 2012
- www.cqp.org