history – Page 6 – Engineering Radio

How the Cold War was won

This is not really apropos radio broadcasting, but it is about radio and it has a lot to do with engineering. Back in the day, as a young man out to do whatever it was, I ended up being stationed on Guam, working at the Coast Guard radio station there. That was interesting work, to be sure, but every morning and evening, either on my way to or from work, I would drive by this, which looked very interesting:

I had to lift the photo from a Navy Radio history site. Back in my day, aiming or even possessing a camera around this area or building would likely inflict the extreme ire of the Marines, who attentively observed the area and were ready to call down a painful lesson to all not obeying the “NO PHOTOGRAPHY ALLOWED” signs.

Nicknamed “The Elephant Cage” it is a Wullenweber antenna used for high-frequency direction finding (HFDF) and was part of a system called “Classic Bullseye.” There were several of these systems across the Pacific Ocean, and they all worked together using a teletype network. The Army-Air Force version was called a AN FLR-9, which was slightly larger.

There were two concentric rings of antennas, the tallest being the closest to the center building and used for the lowest frequencies. It covered from about 1.5 to 30 MHz. The rings consisted of several individual antennas, all coupled to a Goniometer with coaxial cables cut to identical lengths. The outer ring had 120 vertical-sleeved dipole antennas, and the inner ring consisted of 40 sleeved dipole antennas. The inner ring of towers also contained a shielding screen to prevent the antennas on the other side of the array from picking up signals from the back of the antenna. A radio wave traveling over the array was evaluated and the Goniometer determined the first antenna that received the signal by comparing phase relationships. The ground system was extensive. Immediately under the antennas was a mesh copper ground screen. From the edge of the copper mesh, buried copper radials and extended out 1,440 feet from the building.

The effective range for accurate DF bearings was about 3,200 nautical miles, which equates to about two ionospheric hops with the angle theta between 30 to 60 degrees referenced to the ground.

It was quite effective, it only took a couple of seconds to get a good bearing. If the other stations on the network were attentive, a position could be worked out in less than 10-15 seconds.

AN FRD-10 transmission line diagram — AN FRD-10 ground diagram

It is a little hard to read, but this is the ground layout of the AN FRD-10 CDAA. The transmission lines to each antenna are shown, along with the ground screen and building in the center of the array.

We Coast Guard types used this mainly for Search and Rescue (SAR) and the occasional Law Enforcement (LE) function. I believe we actually saved a few lives with this thing. I found the Navy operators to be very helpful, I think some of them enjoyed the change of targets from their normal net tripping.

The Navy operated AN FRD-10s at the following locations in the Pacific:

Imperial Beach, CA (south of San Diego)
Skaggs Island, CA (northeast of San Francisco)
Hanza (Okinawa) Japan
Waihawa, HI
Finegayan, Guam
Adak, AK
Marietta, WA

The Air Force/Army installed AN FLR-9’s in the following Pacific Locations:

Missawa AB, Japan
Clark AB, Philippines
Elmandorf AFB, AK

Basically, there was no corner of the Pacific Ocean that could not be listened to and DF’d. Some people look back nostagically at the cold war when we “knew who the enemy was,” so to speak. I am not one of those. They either didn’t really know the enemy or have conveniently forgotten some of the less endearing qualities of the Soviet Union.

I believe all of these systems have been decommissioned and most have been taken down and scrapped. The National Park Service studied the Waihawa, HI system as a part of their Historical American Building Survey (HABS HI-552-B2) (large .pdf file) before it was torn down. Good technical description and building pictures. Near the end of the report, it is cryptically noted that:

Beginning in the mid-1990s the NSG (ed: Naval Security Group), noting the absence of Soviet targets and wanting to cut costs and change the focus of its SIGINT collection, began closing FRD-10 sites… Undoubtedly, since the September 11, 2001 terrorist attack on the World Trade Center and the Pentagon, listening posts have gained importance and most likely increased in number and sophistication. The FRD-10 CDAA at NCTAMS Wahiawa ceased listening in August 2004; it can only be assumed the closure occurred because there was a better way to do it.

Indeed.

The Guam site has been stripped out and abandoned, the latest photo I can find is from 2008:

And people think AM broadcasting is expensive…

Incredible Radio Tales

Richard Dillman, who is the driving force behind the Maritime Radio Historical Society (MRHS) has produced a show on KWMR called “Incredible Radio Tales.” This is a show that talks about the various sounds heard on the radio, both natural and man-made. Many of the shortwave frequencies are used for “utility” uses.

He does a great job explaining things like Skyking, numbers stations, and so forth. It is a great show, I can imagine this story being told on Halloween.

You can listen to the first episode here, it’s about an hour long:

http://www.g4aqg.sussex.ac.uk/IRT.mp3

This is a great example of local radio doing local things. I have no idea if the other episodes are going to be put up online.

Radio Ships

Radio London air studio aboard the MV Galaxy

These were broadcast platforms that were usually anchored in international waters broadcasting popular music to several European Countries including Great Britain, Holland, France, and Spain in the late 1960s through late 1980s. The reason for these peculiar operations was strict government control of all broadcast outlets and programming in those particular countries. The BBC was known to be stodgy and repressive of new music, particularly rock music from bands like the Rolling Stones, the Beatles, the Who, the Kinks, and others.

At the time, there was no specific law preventing ships anchored in international waters from broadcasting to shore-based listeners, a loophole in the government control was found and exploited. That loophole has been closed in most places, so as they say, don’t try this at home.

At one time there were several ships out there in the English Channel and coastal Denmark. The first and best-known of these was Radio London or “The Big L.” It broadcast on 1133 KHz from December 16, 1964, to August 14, 1967, using a 50,000-watt RCA ampliphase transmitter. The ship itself was the M/V (motor vessel) Gallaxy, a converted WWII minesweeper formerly known as the USS Density. After Radio London went off the air, the ship was transferred from port to port until it ended up in Kiel, Germany, where it was finally scrapped in the late 1990s.

Radio Caroline was the main offshore competitor, broadcasting on 1520 KHz and several other frequencies off and on from 1964 until 1990 or so using several different vessels to transmit from.

One incident in offshore broadcasting that has always fascinated me was the burning of the Mebo II, then transmitting Radio Northsea International off the coast of Holland (this ship moved around quite a bit) in 1971. Later investigations revealed that the staff of an offshore competitor, Radio Veronica, was responsible for the firing of the ship. Apparently, in those days the competition was brutal.

I like the nice calm music with the increasingly frantic DJ (West, no East). In any case, the ship remained afloat and returned to the air the next day. The final European offshore broadcaster was something called Laser 558 on M/V Communicator. It broadcast using to CSI 25 KW AM transmitters on 558 KHz in 1983, again, off and on for several years until 2004. The CSI-grounded grid transmitters may have been inexpensive to purchase, but I’ll bet they cost a lot to run. This would be especially true if one were using diesel generators as the main electrical power provider. As a result, they were usually run at about 1/2 power. Eventually, M/V Communicator ended up beached in the Orkney Islands off of Scotland.

The only such attempt in the US was Alan Wiener’s MV Sarah, known as “Radio Newyork International” anchored off of Jones Beach on 1620 KHz. The owners figured 4 miles offshore was far enough to be in international waters, but the FCC felt otherwise, I believe at the time, 12 miles was (and still is) the territorial limit for the US. Four miles was not international waters, as the broadcasters claimed. These guys were arrested and sent to trial. After several years all charges were dropped.

Anyway, an interesting bit of radio history. Goes to show the lengths that some will go to when feeling repressed.

The first radio stations

On this, the 98th anniversary of the sinking of the Titanic, some radio history is in order. Before broadcast stations, radio was mainly used by ships at sea sending messages in Morse Code to coastal radio stations. These messages could be routine; we are on schedule, we are carrying such and such cargo, request port clearance, etc. They could also be urgent; the ship is sinking, we need medical advice, etc.

Most of these early radio stations were owned by Marconi Company, which later became RCA. One of the first Marconi Stations was in Wellfleet Cape Cod, the original call sign was MCC (for Marconi Cape Cod) later changed to WCC.

On April 14th about 11:45 pm, the Titanic struck an ice burg and sank about two and a half hours later. The RMS Titanic call sign MGY was equipped with a radio transmitter at a time when ships were not required to be. Sadly, the finer details of distress procedures for radio-equipped ships had not been worked out. After this incident, radio distress procedures were codified and the SOS evolved into an internationally recognized distress signal.

On the night the ship sank, the Marconi employed radio operators were sending routine traffic to Cape Race, Newfoundland radio. Because the radio apparatus used spark gap transmitters and crystal radio receivers, interference from other ship stations often caused problems. Earlier in the evening, a Titanic radio operator had strongly rebuked the operator from the closest ship, the SS Californian, telling him to “Shut up, shut up, I am busy; I am working Cape Race.” At about 11 pm the SS Californian operator retired for the evening and the Californian never received the distress call. Sadly, this incident probably led to the high loss of life because the Californian was just over the horizon to the west and would have likely been able to rescue many of the passengers before the Titanic sank.

Coast Guard radioman Jeffrey Herman has a good SOS story from the late 70s. Being stationed in Hawaii, he was on duty late one night at Coast Guard Radio Station Honolulu, call sign NMO.

John Davies, the radio operator on board the Eriskay also has a story about receiving an SOS while at sea. Fortunately, that one turns out a little better.

I remember one night, hearing an automated SOS on the international lifeboat frequency (8364 kHz). I imagined some poor guy cranking the lifeboat radio not knowing if it was going out or not (I was right, it turns out). We heard him on Guam and DF’d him to off the coast near Australia. We notified the Australian authorities, who diverted a nearby ship that picked 26 survivors up the next morning.

I am sure there a quite a few old CW (morse code) radio operators out there that have similar stories. By the 1990s most maritime communications had moved to INMARSAT, and CW and coastal radio stations became redundant.

The end of commercial Morse Code in the US came on July 13, 1999, when KFS, the last coastal radio station, signed off. Most of them have been scrapped and the valuable coastal land sold off to developers.

The development of broadcast radio was a direct offshoot of these radio stations. AM radio, or rather AM technology was developed by ATT as an adjunct for their long-distance system. ATT used High Frequency (HF) voice circuits to span oceans for several decades, up to about the mid-1960s. Amateur radio operators began fooling around with voice broadcasting, using ATT’s patented AM technology around 1915 or so, after tube-type transmitters and receivers became available. Somebody realized that money could be made with the new-fangled radio contraption and commercial broadcasting was born.