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Amateur Radio Quiz: Getting One’s Bearings

11/20/2010

By H. Ward Silver, N0AX
n0ax@arrl.net

Hams need to point their antennas accurately, but how can you do that if you don’t know the words used to describe direction? Ready, fire, aim!

1) For two different stations to have short-path bearings that are exactly reciprocal -- that is, 180 degrees apart -- which of the following conditions must be true?
a. Both must be at the same latitude.
b. Both must be at the same longitude.
c. They must be at longitudes 180 degrees apart.
d. One must be on the equator.

2) For two different stations to have identical short-path bearings to each other -- that is, the same numeric value -- which of the following conditions must be true?
a. Both must be at the same latitude.
b. Both must be at the same longitude.
c. They must be at longitudes 180 degrees apart.
d. One must be on the equator.

3) What is the difference between geomagnetic north and true north?
a. Precession
b. Declination
c. Equatorial anomaly
d. Dip angle

4) Which of the following are true?
a. Heading is the direction in which an antenna is pointed.
b. Heading and bearing are the same.
c. Bearing is the direction to another point in degrees from north.
d. Bearing is the reciprocal of heading.

5) How much delay occurs between the arrivals of short-path and long-path signals?
a. The Earth’s circumference divided by the speed of light.
b. One-half of the value given by (a).
c. The signals arrive simultaneously.
d. It depends on the relative location of the transmitting and receiving stations.

6) What is a skew path between two stations?
a. The path halfway between short and long path.
b. Any path not directly along the great circle path.
c. The path that supports both vertical and horizontal polarization.
d. A path at high vertical angles.

7) What does an azimuthal projection map show?
a. True size of all land masses.
b. Rectangular latitude and longitude grids.
c. True distance and azimuth from the central point to any location.
d. True azimuth between any two points.

8) On what are the aurora borealis and aurora australis roughly centered?
a. North and South Geomagnetic Pole
b. Arctic and Antarctic Circles
c. Tropics of Cancer and Capricorn
d. North and South Pole

9) What does the elevation pattern of an antenna show?
a. The radiation pattern at different heights above ground.
b. The azimuth at which the antenna’s peak radiation occurs.
c. The azimuth at which the antenna’s highest front-to-back ratio occurs.
d. The radiation pattern at different angles above the horizon.

10) When communicating via auroral reflections, where do you aim your antenna?
a. True north
b. Wherever the transmitting station’s signal is received best.
c. Geomagnetic north
d. Halfway between the short-path and long-path bearings to the transmitting station.

Bonus: What famed radio company was named for the point directly overhead?

 

Answers
1) b
2) c
3) b -- Magnetic declination is noted on topographic maps for use with magnetic compasses.
4) a and c
5) d
6) b -- Propagation along skew paths is common as bands are opening and closing.
7) c -- These maps show the great circle path between two stations.
8) a
9) d
10) b -- The aurora shifts over time and has variable reflectivity, so you must continually re-aim for best reception.

Bonus Answer: Zenith -- “Where the quality goes in before the name goes on!”

Zenith got its start in 1918 when two wireless-radio operators -- Ralph H. G. "Matty" Mathews, 9ZN (SK), later W9ZN, and Karl Hassel -- set up the Chicago Radio Laboratory on a kitchen table and began making radio equipment for other amateurs. By the early 1920s, the infant radio industry began to grow as did the business, which sold radios under the name “Z-Nith.” This was the origin of the Zenith trademark, derived from Mathews’ call sign. Zenith Radio Corporation was incorporated in 1923.

As 9IK in 1916, Mathews was appointed manager of the central US area in the ARRL’s then-new trunk line system. This relay operation spanned the country and matched or exceeded the commercial wire services in speed of handling messages. He was appointed an ARRL Director in 1917 (this was before election by the membership) and also became a Central Division Manager, a sort of “super SCM.” At the first ARRL Board meeting after World War I, Mathews was named an ARRL Vice President. Since assets were scarce, he joined his fellow directors in putting up a $100 kitty to finance the first postwar issue of QST. He was a kingpin in relay activities after the wartime ban was lifted, with the coast-to-coast circuit of 1AW (Maxim)-9ZN-LF (Louis Falconi in New Mexico)-6EA (the Seefred brothers). Mathews largely organized and was chairman of the first ARRL National Convention in 1921 in Chicago. He was elected Central Division Director in 1937 and served two terms.

Mathews was active in the Naval Communications Reserve, achieving the rank of Lieutenant Commander and serving as the Executive Officer of the Ninth Naval District. After retiring, he moved to Mexico, where he passed away in 1982. Mathews was buried with military honors at Fort Sam Houston in Texas.  -- Thanks to the Zenith Corporation, Tom Roscoe, K8CX, and the March 1983 issue of QST for the information



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