If you happen to find yourself strolling through the bustling grounds of the Iowa State Fair in Des Moines—past the butter cow, the livestock barns, and every imaginable food served on a stick—there is a quiet haven of vintage communications history waiting for you: the Telephone Museum.  The building dates to 1915 as the Harper, Iowa, central exchange, and has been on the grounds of the State Fair since about 1980.

This year, the fair runs for eleven days, from August 13 through August 23, 2026. We had the opportunity to visit the museum on Saturday, and it proved to be an absolute delight for anyone who appreciates classic electromechanical engineering.

Staffed by dedicated volunteers and telephone pioneers, the building is packed with artifacts tracing the growth of telephony, from early wooden magneto wall sets and manual patch cord switchboards to the sleek plastic desktop phones of the mid-20th century.

Without question, the centerpiece attraction of the exhibit is a fully functional, live-action demonstration of automatic switching equipment wired between two rotary dial telephones.

The setup features open-frame electromechanical switching racks—specifically classic stepping switches (often known as Strowger switches). The equipment is positioned so visitors can stand right next to the gear and see every mechanical action unfold:

• A visitor picks up the handset of the calling phone and hears the continuous tone of a vintage dial tone.
• As they wind the rotary dial and let it spring back, direct-current dial pulses trigger the relay coils on the switch rack.
• With a rhythmic, unmistakable clack-clack-clack, the vertical shaft steps upward and wiper contacts rotate into position, hunting across the bank until establishing the connection.
• The real electromechanical ringer inside the second telephone rings out across the room, and someone at the other station can pick up and talk.

It is pure hands-on educational fun. For younger visitors who have grown up exclusively with smartphones and touchscreens, it is a fascinating lesson in how numbers used to be dialed—and where everyday terms like “dialing,” “ringing,” and “hanging up” originated. For older visitors, it offers a rare, behind-the-scenes look at the intricate machinery that quietly routed phone calls inside local central office buildings for generations.

If you’re heading to the fairgrounds before the gates close on August 23 (or next year), take a few minutes to step into the Telephone Museum. It is a wonderful, living tribute to the pioneers of wire communications.  It’s located at the corner of East Grand Avenue and Hoover Avenue, just down the road from the Pork Tent.

And a trip to the Iowa State Fair isn’t complete without a visit to WHO Radio, which takes it’s history seriously, and has a display of some of the highlights of its past century plus of service.

Related Reading & Vintage Tech on Amazon

If you’re fascinated by the history of telephony and electromechanical switching, check out these interesting books and retro gear:

• The Idea Factory: Bell Labs and the Great Age of American Innovation by Jon Gertner – An outstanding history of Bell Laboratories and the engineers behind the modern communications age.
• Exploding the Phone: The Untold Story of the Teenagers and Outlaws Who Hacked Ma Bell by Phil Lapsley – The definitive history of telephone network mechanics, phreaking, and early network security.
• Classic 1950s-Style 500-Series Rotary Desktop Telephone – A fully working reproduction of the iconic Western Electric Model 500 rotary telephone for retro home setups.

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