This past July I was fortunate to be able to visit the island of Oahu in the state of Hawaii. My step-daughter Ilia left home for Oahu in the spring of 2016 to join her husband who at the Pearl Harbor base where he is serving with the Navy. My YL and I started saving for a chance to go visit not long after. Moving to Hawaii was especially exciting for the young couple as Ilia is part Hawaiian on her father’s side. She had visited twice before, and now gets to live in a place where she can really connect to her Polynesian heritage. Most of our time on the island was spent hanging out with the kids, meeting their friends in the military, hiking, swimming, checking out sites, and learning more about Hawaii’s rich history. I also kept my perked for anything I might learn about radio while I was there.
While thinking about different trails to hike my son-in-law told me about a spectacular hike and what was once the amazing site of a Naval radio station. That hike, called the Ha’iku stairs, or the Stairway to Heaven. Unfortunately that hike is currently illegal to go on. Folks who sneak on it early in the morning before the guards arrive may be rewarded on the way back down with an arrest or heavy fine, and I wasn’t willing to pay those prices, as it might have put a cramp in our vacation. While not being allowed to take in the views at the top of the 3,922 stairs saved my legs from cramping, it did give me a research project for back home. I did get to see Pu’ukeahiakahoe mountain and drive through the Hai’ku valley a number of times. The fact that there had once been a center fed dipole antenna strung between two mountains with the transmitting station nestled in the valley below filled me with wonder. The Stairway to Heaven trail took hikers, when they were allowed to go, up to the top of the 2,000 foot mountain where one side of the 7,500 foot long antenna was anchored.
In 1942, as WWII raged in the Pacific, the U. S. Navy needed to communicate with fleet members active in distant theaters of operation. After the attacks on Pearl Harbor the existing station had proved to be highly vulnerable. The main radio station was only 4,000 yards from the shoreline with power supplied from overhead lines. Nor was the 600 foot tower at Lualualei deemed high enough to reach the desired destinations. A giant VLF sending station had to be built that could reach the waters of Australia, the Indian Ocean, and most crucially every submerged Allied submarine, especially those lurking in the bottom of Tokyo harbor.
Antenna-anchor-sitesSo began construction of a top-secret high-powered experimental radio facility in the Ha‘ikü valley. The natural amphitheater surrounded by 2000-foot-high ridges was considered an optimal spot. To gain access to the spot where the antenna was anchored a ladder-like stairway was constructed with much grueling and painstaking effort. Other anchors were also placed on cliff ridges, with wires running to the transmitter. A copper grid system was installed on the floor of the valley to help conduct signals. After more than a year of this work, the station was commissioned in 1943 where it served as the primary long-range communication system to the end of the war.
Even with a badass antenna system the Navy needed a similarly capable transmitter to get their signals to the destination. They needed something that was more powerful than the vacuum tube technology of the time was able to give. What they decided on was a bit of older tech in the form of the Alexanderson alternator a rotating machine that generates high frequency alternating current invented in 1904. It was one of the first devices capable of creating the continuous radio waves needed for amplitude modulation. At the beginning of WWII the Navy had taken control of the of RCA’s American Marconi Station at Marion, Massachusetts, where there were two Alexanderson alternators. One of these was purchased and shipped to the Hawaii.
With everything in place the Ha’iku VLF station operated at a frequency of 22.3 kHz and wavelength of 13,443 meters. It’s powerful signal was capable of long distance travel and could penetrate obstacles such as mountains and water. The site continued to be of use in military communications until 1958. Besides the anchor to the antenna a Communications Control Link was used there by the military for VHF communications on the island, and the Air Force had a microwave relay station there until 1963.
After five years of dormancy the site was eventually repurposed as part of the Omega navigation system. Following on the heels of other radio navigation systems such as LORAN, Omega was the first truly global-range radio navigation system. It was operated by the U.S. with six partner nations. Ships and aircraft were able to determine their position using VLF signals in the range of 10 to 14 kHz that were transmitted by a network of beacons to onboard receiver units. The Ha’iku valley station was reopened and retooled by the Coast Guard in 1968. The whole system became operational around 1971 until it was shut down in 1997 with the advent of GPS. (For satellite buffs the U.S. Air Force Space Command operates a satellite tracking station on another side of the island. I saw some dishes and domes while hiking along the coast in that area. Having no clearances I didn’t try to go up through the guarded gate!)
The closing of the Stairway to Heaven to the public seems to be mostly a matter of funding, politics, and environmental concern. Posted on the friends of Hai’ku website (haiku.org) was the folliowing: “April 23rd 2017 that the Honolulu Board of Water Supply (BWS) announced in an Environmental Impact Statement Preparation Notice (EISPN) that it plans to tear out the Haʻikū Stairs. This notice (see link) triggers a 30-day comment period, during which time the public can express their opinions on the project. Of particular importance is identifying issues not mentioned in the EISPN that you feel should be discussed in the EIS. The BWS is required to address in the EIS all relevant issues brought up during this comment period.” etc. etc.
While the access to this historic radio site remains uncertain a good deal of further information about the operations have been preserved. Much of the preserved information is thanks to silent key Thorn Mayes who worked under the following call signs W6AX, W9AX, 6BDQ, 6AX, K6BI, K2CE, and W1CX on the west coast in the early days of our hobby. After retiring from his a manage position with GE, Mayes became an avid collector of antique electronic gear (prior to 1922), books and magazines, as well as recording the history of early wireless in the United States. Before his death he had compiled a good deal of information about the Hai’ku stairs, some of which can be The Perham Collection of Early Electronics at History San José, and also in the following article on radio ops in Hawaii: http://www.navy-radio.com/commsta/todd-hawaii-01.pdf
History is all around us. We just have to pay attention and keep the aerials of optimism raised and ready to receive the signal.
This article was originally published in the August 2017 issue of the Q-Fiver.