PSN-L Email List Message

Subject: Whip antenna
From: tchannel1@............
Date: Sat, 5 Apr 2008 10:01:11 -0600


Hi Folks, If I had a 36" whip antenna, just a piece of spring steel rod, =
with a small mass on the tip, how much would the tip move during a =
earthquake?
I know that is just a general question, and it would depend on many =
factors.   Let's say the size of the event was 6.0M, 1000 mile away.  =
This event would be recorded by all three of my sensors.  The movement =
of sensor's pendulum or vertical spring during this type of event would =
probably not be noticeable to the eye.  If the event was a large one, =
then surely it would be noticeable to the eye, perhaps even 1/8" or =
more.

I am still trying to come up with a Earthquake Directional Device.   I =
have seen articles on the Chinese versions, and turn of the century =
devices which used a variety of approaches, where a normal pendulum or =
even a  "Wipe Antenna" / inverted pendulum would be set in motion and =
make contact with a circuit.   I know such devices would work in =
California, but I don't know how small or weak events would work. =20

My thinking is, if I just use the motion of a "Whip Antenna" to close a =
contact, it would not record much, unless I could move the two points of =
contact to within the thickness of a human hair.

I know I could use a magnet/coil and the device would work on most all =
earthquakes, presently recordable, but I don't want to dismiss these old =
approaches either.

Just wanted to get an opinion.

Thanks, Ted







Hi Folks, If I had a 36" whip antenna, = just a piece=20 of spring steel rod, with a small mass on the tip, how much would the = tip move=20 during a earthquake?
I know that is just a general question, = and it=20 would depend on many factors.   Let's say the size of the = event was=20 6.0M, 1000 mile away.  This event would be recorded by all three of = my=20 sensors.  The movement of sensor's pendulum or vertical spring = during=20 this type of event would probably not be noticeable to the eye.  If = the=20 event was a large one, then surely it would be noticeable to the eye, = perhaps=20 even 1/8" or more.
 
I am still trying to come up with a = Earthquake=20 Directional Device.   I have seen articles on the Chinese = versions,=20 and turn of the century devices which used a variety of approaches, = where a=20 normal pendulum or even a  "Wipe Antenna" / inverted pendulum = would be=20 set in motion and make contact with a circuit.   I know such = devices=20 would work in California, but I don't know how small or weak events = would=20 work. 
 
My thinking is, if I just use the = motion of a "Whip=20 Antenna" to close a contact, it would not record much, unless I could = move the=20 two points of contact to within the thickness of a human = hair.
 
I know I could use a magnet/coil and = the device=20 would work on most all earthquakes, presently recordable, but I don't = want to=20 dismiss these old approaches either.
 
Just wanted to get an = opinion.
 
Thanks, Ted
 

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