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The Story of an Old Timer: 1960s

In April 1960, WWVL broadcast began with 1,000 times more stable reception at a distance than WWV or WWVH had been received.

So in 1962 construction began north of Fort Collins, Colorado. The new site would consolidate all NBS continental broadcasts with the VLF (20 kHz) and LF (60 kHz) to be built first.

helix house
A picture of the helix house under construction. Note the transmission feeds brought over on telephone poles. This was later buried.
antenna array
This graphic shows the transmitter building and two antenna systems (WWVL and WWVB) and the helix houses for transmission matching. Note the top hat capacitive load antennas to give a taller effective height. Think about it: 60 kHz = 5 km wavelength; 20 kHz = 20 km wavelength; so 1/4 wavelength antenna would be massive .... so top hat.

And on July 5, 1963, WWVB radiating at 7 kW - soon 13 kW - began broadcasting and in August WWVL began broadcasting.

The time and frequency of the broadcasts were controlled by Boulder Labs with a 50 MHz signal sent from the time scale in Boulder.

antenna parts
Here's a picture of antenna parts prior to assembly.
transmitter building
Here's the transmitter building completed in Spring of 1963.
tower 1
And a view from the top of tower one showing the top hat array.

The new LB broadcast used an amplitude (level shift) modulation and a binary code shift to encode time information.

By 1966, the WWV portion of the Fort Collins construction was complete. And on December 1, 1966, at 0 hour GMT (5 p.m. November 30th local time) all the WWV signals began broadcasting at the new station simultaneously - all signals at Greenbelt, Maryland were shut off.

antenna system
Model showing the antenna system, however, only the smaller system was completed.
WWV signals go live
The moment the signals began broadcasting.
Created March 28, 2017, Updated August 16, 2022