Many thank to Bob (K4RLC) who shares the following guest post:

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Visiting VOA Site B: The Edward R. Murrow Transmitting Station

by Bob (K4RLC)

Two week sago, Dale (W4AUV) and I were treated to a “under the hood” visit to the last remaining Voice of America transmitting station in the United States. It is located in eastern North Carolina, and officially known as the “Edward R. Murrow Transmitting Station” part of the “Office of Cuba Broadcasting” in Grimesland, North Carolina. Also, known as “VOA Site B.” This type of shortwave broadcast station is only one of a few remaining worldwide.

[Note: Click on images to enlarge.]

This VOA site has been on the air continuously (24/7/365)  since the 1963 on-site dedication by President John Kennedy, broadcasting up 8 transmitters at a time on the short wave bands. There are three 250,000 watt and five 500,000 watt GE, Continental and Telefunken  transmitters feeding 38 possible antenna configurations, with an Effective Radiated Power of 2,000,000 watts. (There is also a 39th antenna, that is a Dummy Load that will handle 500,000 watts).

The antenna field covers over 6,000 acres of flat, costal plain wetlands, not far from the  Atlantic Ocean, so it has a minimal absorption factor and a salt water boost.

The antennas are fed by over 26 miles of 300 Ohm open line “ladder line” with a minimal SWR and minimal signal loss. The largest antennas are called “Curtain” antennas, given their configuration, of matched horizonal and vertical dipoles suspended between large towers, giving the visual impression of huge curtains.

There are also  rhombics, each 6 wave lengths long. The rhombics are not used as often, given their narrow bandwidth and narrow beamwidth. The Curtains can bathe a large geographic area (such as part of a continent) with a very strong signal. The primary broadcast areas for this station are Cuba, Central and South America, and Africa (although the antennas could reach out and touch Russia and eastern Europe, when needed).

Many of the engineers are hams, including Macon (WB4PMQ), the chief engineer. Gary (N2AD) transferred to Greenville when the VOA in Bethany, Ohio closed. (The Bethany VOA site operated during WW2 into Germany, and was referred as the “Ohio Liars” by Hilter !)

Glenn (W7GSW), a US Navy communications vet, has been at the site many years and conducted much of the tour for Dale and I.

As the transmitters are no longer manufactured, the ham engineers fortunately  have the ability to repair components or make them from scratch. When we visited, in the tech Lab, Macon was tweaking a relay switch he made. On another table, was the original “bread board” layout of the switch. In addition to an electronic shop, there is a full mechanical shop with lathes and grinders for fabrication of mechanical components.

The transmitters are so large that you can walk inside them….with care. For one, Glenn made sure the 13,000 plate voltage was cut and the capacitors had been discharged with a “dead man’s wand.” There were multiple fail safe lock sequences before one could enter the final stage of the transmitter. Above is a photo of one of the technicians crawling inside the transmitter to make repairs. In addition to heavy voltage, the components can weigh a few hundred pounds and require a mechanical lift for disassembly. And, as one can imagine with voltages this high, temperatures are extremely high and require a water cooling system, as well as a very cold transmitter room.

There is also a huge machine shop, as mechanical components have to be repaired or fabricated. Below is a photo of Glenn with a lathe in the well-equipped  machine shop.

External weather in eastern North Carolina adds to problems, given the high temperatures and high humidity levels in the summer. Also, this area has been plagued by hurricanes, but the antenna system has a wind rating of around 250 MPH, and has never been bothered by a hurricane. If the high voltage lines feeding the plant were to come down, there are back up Diesel generators that can run the station.

The entire area is a nice RF field, possibly exceeding RF limits, but multiple signs warn of this. Gary has been at the facility since it opened and is not showing signs from RF, nor is Glenn (maybe RF is good for one’s health). As a test, the ham operators may have brought in  an Elecraft K2 QRP rig and loaded to one of the 15dB gain antennas. Excellent results, as would be imagined. Glenn cautioned that the RF field there is so strong that it would overload popular SDR radios, like the IC-7300.

While our focus was on the technical details of the station, it is worth nothing the purpose of the station. In the words of Wilford Owens, station manager, it is to “…provide reliable news and information about America and the world to our foreign audiences.”

Some question the relevance of shortwave broadcasting in a time of sophisticated technology.

Here are some answers: first, radio is a proven medium and still the primary information and entertainment medium in undeveloped parts of the world. In fascist and totalitarian countries, the internet is blocked and those who try to access it are monitored and threatened. Radio has no limits, as it is an electromagnetic wave, transversing oceans and penetrating artificial political boundaries. Finally, the Voice of American Jazz Hour (playing cool, “Blue Note” Jazz) was credited with helping bring down the “Iron Curtain” as the Russians loved American Jazz and felt the freedom in this form of music.

After the lengthy visit, we left with admiration for the engineers and ham-engineers who use their technical expertise to keep this aging behemoth station running 24/7/365. And you can easily tell it’s not just their technical expertise, but their love of the equipment and radio that keeps it going.

Thanks to Macon WB4PMQ, Gary N2AD and Glenn W7GSW for such a personal and educational tour of the technical complexities of VOA Site B.

(PS-I posted a previous article on “Activating the VOA.” Site A was unfortunately decommissioned, and the 24 antennas destroyed. It is now a Game Land area owned by the North Carolina Wildlife Commission, and a POTA Site: K-6964. I was also able to “activate” VOA Site C, a receive only “spy” station, with the local Brightleaf Radio Club for the NC QSO Party, about 25 years ago. Site C has  4 massive Rhombic antennas; we loaded up the one that had a name plate at the feed point stating it’s aimed direction as  “Moscow.”

73 de K4RLC Bob 01.28.24