Proper QRO: K4RLC Tours The Edward R. Murrow Transmitting Station

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

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.]

VOA QSL Card showing some of the 38 antennas

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.

Front of VOA Edward R. Murrow Transmitting Station
Wall plaque in lobby explaining the legacy of Edward R. Murrow, who became known while a CBS Radio correspondent in London, broadcasting during the “Blitz” the infamous bombing of London by the Nazis during WW2 (click image to enlarge)
TCI “Curtain” antenna made of 4 dipoles wide & 6 dipoles high, pointed at Cuba. It is controllable in both vertical and horizontal azimuth, depending on the configuration has to up 23dB gain at a 4 degree take off angle

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).

Curtain and Rhombic antennas fed from the antenna switching center
Glenn showing Dale features of the GB-6 transmitter console in the large 8 transmitter control bay
GB-6 Transmitter Monitor & switches
The antennas are well constructed & fed with minimal-loss  open feed line. Note SWR of 1.1:1 at 75,000 watts !
Glenn & Dale studying the transmitter output in the main control room complex
Larger control panel for each transmitter. Note image of “Casper the Friendly Ghost” over the meters for GB-7: There are current problems with the transmitter and, in technical terms, “it’s spooked” !
Antenna switch controller for matching the 8 transmitters with 38 antenna configs.

Glenn & Dale examining the open feedline from Switching station to antenna field; 8 inch coax to Switching station

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.

VOA technician crawling into “guts” of a 500KW Transmitter

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.

Tuning coils for finals – note the entire tube config is on a rotator

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.

Glenn pointing at Modulator Cabinet for the GE 250KW Transmitter
Old fashioned tubes that will fry you; Note Plate voltage of 13 KV
CQK 650-1 Tetrode tube. Final in one 500KW Transmitter. At 100% modulation, produces 2 Million watts PEP. This tube costs nearly $350,000

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.

Bob (K4RLC) (left) with VOA Chief Engineer, Macon (WB4PMQ) (right)

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

15 thoughts on “Proper QRO: K4RLC Tours The Edward R. Murrow Transmitting Station”

  1. Thank you very much, I now know in my next life, I will be using a 600-ohm open ladder line and have that 1.1:1 SWR at 75,000 watts for any antennas that I might have.
    Jeff K9JP

  2. I used to listen to the VOA stations signing on at 1800UTC each evening. WGEO Schnectady WBOU at Bound Brook WDSI at Brantwood Long Island and Greenville which never had it’s own callsign. Overseas relay stations were at Tangier, Monrovia, Berlin and Woofferton. Heady days as a teenaged SWL in the sixties. Yankee Doodle Dandy…. where are you now?

    1. Interesting info about the callsigns, I was not aware of that. Greenville is the one I remember most. I do remember being disappointed when they started using “Yankee Doodle Dandy”. To me it lacked the dignity and seriousness of “Columbia, the Gem of the Ocean”!

      1. I remember VoA transmissions around 1960 which would state , for example “This station is located in Greenville, North Carolina. ” On a few occasions I heard one that stated “This station is located in outer space”. Was this related to the Echo balloon that was put into earth orbit around that time?
        Regards, Ian Brooks, Dorset, UK.

  3. Great article on the “local”VOA site. I’ve lived smack in the middle of all 3 sites since I was a kid, and in the 70s a lot of my best friends’ fathers worked at one of the sites and all seemed to be hams. These fellows ran a very nice club as mentioned, the Brightleaf Club. They taught a Novice class each year and I received my Novice license in ’78. Of course once I turned 16 I got excited about other things, plus I really didn’t have an Elmer to help me out. But I never stopped thinking of myself as a Ham, just an inactive one.
    Now, 40 years later I’m retired and now a full time ham. I’m President of a local club near Site B, the Pamlico Amateur Radio Club, and we appreciate having been near the VOA sites. Site C is now owned by East Carolina University, and they use the building to restore artifacts that their Marine Science students raise off of Blackbeard the Pirate’s ship The Queen Anne’s Revenge, sank off the NC coast.
    ECU gracefully gives us hams access to the remaining Rhombic antennas and we have used them occasionally. In the future there are plans to create a remote operations site with transceivers attached to these gigantic wire antennas. Stay tuned for that!!!!
    73 de NG9T Gary Faust

  4. Bob,

    Thanks for sharing, it’s quite a facility and boy that’s a lot of RF! I had the opportunity to visit the Bethany site in Ohio that you mentioned during the Dayton Hamvention last year and it’s pretty impressive as well.


  5. Thanks to all – really glad you enjoyed our visit. It is an amazing facility and hard to capture in photos. It’s also a Gem that needs protection. According to Senator Tillis, the jurisdiction for this site falls under the Senate Intelligence Committee ! We need to protect its funding going forward. The engineers were great and it’s really a labour of love for them to keep Site B on the air.

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