May, 2023 Blog

We are approximately one month away from Field Day, 2023 ( June 24-25. Field Day is ALWAYS the fourth full weekend, beginning at 1800 UTC Saturday and ending at 2059 UTC Sunday.). This is our club’s premier event for the year and this year we are going all out, post Covid, to make it a welcoming event for all of our members. Whether you are new to ham radio or an experienced Elmer, there is something for everyone. We are going to have a catered social on Saturday afternoon (4 pm onwards) from Lou Malnati’s Pizza with a spread of food that will have you remembering this event for many years to come. Our Field Day is family and friend friendly so please invite your significant other and your children as well. I hope to see everyone of our members show up to this once a year event at Clarkson Park in Northfield, IL.

When you were a child, did you ever wonder what would happen if you could dig a hole straight down through the center of the earth? Wouldn’t be cool if instead of transmitting radio waves around the world, they would be capable of penetrating the earth’s crust and travel directly to the opposite side? OK, this is nonsense, but now that I have you’re attention, have any of you every made contact with our antipode city via HF?

What the Heck is an Antipode?

The antipode of any place on the Earth is the place that is diametrically opposite it, so a line drawn from the one to the other passes through the center of Earth and forms a true diameter

The antipodal city to Chicago is Port-aux-Français. This means that, among all the populated locations in the world, the farthest city from Chicago is Port-aux-Français.

Port-aux-Français is the main settlement of the Kerguelen Islands, and French Southern and Antarctic Lands, in the south Indian Ocean . The settlement is located on the shore of the Gulf of Morbihan.

The distance from Chicago to Port-aux-Français is about 18,000 kilometers. A direct flight would take around 20 hours, but there aren't commercial routes between these cities

How to calculate the antipodal point?

The antipode can be calculated by understanding the geographic coordinates and applying simple formulas. We will use the following variables:

LatO: Latitude at the origin point.

LngO: Longitude at the origin point.

LatA: Latitude at the antipodal point.

LngA: Longitude at the antipodal point.

Step 1: Obtain the geographic coordinates of Chicago 

The DMS coordinates are: 41°51'0.1'' N 87°39'0.2'' W. 

Calculations are easier by using the decimal format, hence:

LatO = 41.85003°

LngO = -87.65005°

Step 2: Calculate the latitude

LatA = - LatO = -41.85003°

Since the latitude is positive (north direction), the antipode must be negative (south direction).

Step 3: Calculate the longitude

LngA = LngO ± 180° = -87.65005 + 180° = 92.34995° 

Since the longitude is negative, we sum 180° to ensure the final value lies between (-180, 180). If it were the other way around, we would subtract 180° for the same reason.

Result:

The antipode of Chicago is located on coordinates: (LatA, LngA) = (-41.85003, 92.34995) 

In DMS format: 41°51'0.1'' N 87°39'0.2'' W.