history – Page 11 – Engineering Radio

Higashi no kaze ame

Or “East wind rain,” which was the Japanese code words transmitted to their embassies indicated hostilities with the United States were imminent. While the Navy intercepted the first message to the embassies, outlining the various code words and instructions on what to do when or if they were used, they never actually intercepted the code word messages themselves.

This is not all that unusual, as the Japanese were using several different diplomatic, army, and naval codes at the outbreak of the war. Many different stations and frequencies were in use, and it is quite possible that the message was sent and never intercepted. According to the NSA, many, but not all of the Japanese Codes had been cracked and were being read regularly. The diplomatic code, known as Purple as well as a similar code, J-19, and a lesser version, JNA-20 were being intercepted and forwarded to Washington for decoding. Only JN-25 was intercepted and decoded at Pearl Harbor prior to December 7th.

In 1979 the NSA declassified over 2,000 intercepts. They declassified more in 1994. Those decrypts paint an interesting picture of the lead-up and aftermath of Pearl Harbor. A good book is “And I was There,” by Edwin Layton. It was completed in the late 1980s before the 1994 document dump. Layton was indeed at Pearl Harbor on the morning of December 7th. Layton does not come out and directly say that Washington knew of the attack, but rather that they should have known, warned Pearl Harbor but didn’t.

By the first week of December, the Japanese tipped their hand several times.

A bomb plot message was transmitted to the Naval Attache in Pearl on September 24th. This message was sent in J-19 and requested information on shipping and locations within Pearl Harbor-based on a grid. No other locations around the Pacific required such detailed analysis by the Japanese Navy. This was intercepted in Pearl but sent to Washington for decoding. No information from this message was shared with the military commanders in Hawaii.
Several spies (Russian, British, Korean) and diplomats (Germany, Peru, Mexico) warned the US that the Japanese intended to attack Hawaii before the end of the year
The Japanese striking force did not maintain radio silence during its transit from Japan to Hawaii, they sent 663 messages, many of which were duly intercepted by Hawaii and the Navy intercept stations in the Philippines and Guam. The National Archives contains about 100 of those messages, however, the direction-finding information attached to each message has been removed or remains classified. In addition to this, most of the JN-25 messages sent between December 1-7 remain classified.
All PYB (long-range flying boats) patrols from the Aleutians were discontinued in early December. Their patrol area covered at least part of the northern route from Japan to Hawaii.
On the evening of December 6th, Roosevelt was shown the first of 13 parts of a Japanese Diplomatic message which was a declaration of war on the US. The US code breakers and translators finished the decrypt and had it in the hand of the President hours before the first bombs were dropped on Pearl Harbor, even before the Japanese envoys had read it.

It is also well known that Roosevelt wanted Japan to attack the US as justification for the entry of the US into WWII. In early 1941, Roosevelt sent a gunboat up from the Philippines nosing around the Chinese coast to see if it could stir up any trouble. The Japanese failed to take the bait on that and several other occasions.

There is still quite a bit of controversy as to who knew what and when. Whether information was deliberately withheld, or not transmitted due to some concern of compromised intelligence or some bumbling bureaucracy is hard to tell. Certainly, the powers that be in Washington knew more than they let on. The military commanders on Hawaii took the fall and several thousand lost their lives that morning. Many more would die in the coming months and the Japanese tide rolled over the western Pacific basin.

By the end of World War II, over 74 million people had died, most of them civilians. History, do not repeat thyself.

At a crossroads

This is a situation that is and will be playing out over and over throughout the country as the decay advances. W*** signed on the air in March 1963. I believe this is the original tower:

As you can clearly see from this picture, this tower has several problems. Aside from the loose guy wires, the rust, and general structural decay, it is bent in several places. Currently, the forces are in equilibrium, but for how long, no one knows. It is certainly not safe to climb. At 144 feet, it is no longer required to be marked or lit, thus, over the years, the paint peeled, the weep holes filed up, and the guy wires rusted and loosened, which leaves us with the situation today.

At the transmitter building, there are other issues with the basement flooding, mold, etc. Truth be told, this station makes no money on its own. It would cost several tens of thousands of dollars to fix all these issues, and for what; a high end of the broadcast band class D AM station which has not shown up in the ratings for fifteen years. Once upon a time, it was a surviving, perhaps not thriving, local radio station. Those times have long since passed.

The question is; what to do with it? Sign it off and surrender the license? Fix all the problems and continue to broadcast? Donate it? If so, who would take it? Or, more likely, wait until the tower collapses and deal with it then.

I’d imagine that there are many others just like it dotting the country. On the whole, the AM broadcasters that are viable would be better off if this dead wood was cut away and discarded.

The Nautel AMPFET 1

The Nautel AMPFET series transmitters date from the early ’80s through early ’90s. They were Nautel’s first attempt at MF Broadcast transmitters and were quite successful. This particular transmitter was installed in early 1990 at WBEC in Pittsfield, MA:

Nautel AMPFET 1 AM broadcast transmitter

I believe Nautel got started making MW transmitters for Marine Radio stations, Aeronautical and Marine radio beacons, and similar equipment. Their early equipment is very rugged and designed for rough/continuous service. The early solid-state broadcast transmitters like the AMPFET were not hot pluggable but who cares, they almost never break. The design is simple, and efficient and it sounds good on the air.

Early transmitters were housed in racks that were much shorter. In later versions, the racks became larger to standardize the transmitter size with comparable units of the day. Inside this cabinet, there is a lot of empty space.

The design is modular, RF modules and power supplies can be removed from the transmitter for repair, unlike the Harris AM transmitter products of the same or later periods.

There later AM transmitter versions built on the AMPFET experience.

Conet Project

Perhaps one of the more intriguing uses for radio broadcasting is spying. Covert radio stations broadcasting coded number or letter groups have been the interest of SWL and others for years. The Conet Project sought to gather several of these recordings and make a CD out of them. What they ended up with is a rather spooky 4 CD set of various spy numbers stations throughout the world conducting their business which dates back to 1997. Since that date, samples of those recordings have been used in several movies and by recording artists.

While stationed on Guam doing important work for the government, we would often come across these numbers stations in the late 1980s. An East German numbers station was only 1 KHz away from one of our working frequencies, thus around 2 am local time, an East German lady would regale me with half an hour of five number groups in German, which is slightly off frequency, was utterly delightful. We knew where it came from because of this and others like it.

Sort of like that. That recording sounds like a computer-generated voice, ours was a real operator that would occasionally screw up.

The two most famous numbers stations are Cherry Ripe and Lincolnshire Poacher, so named after the songs they use for interval signals.

Both are allegedly off the air now, surely replaced with something else. When pressed as to the purpose of these stations, a British information minister replied “They are what you think they are.”

The numbered groups are coded groups meant to be received by agents in the field. The use of unique interval music helps to identify the broadcast. Once those field agents have written down the coded groups, they use a one-time pad to decode them. The one-time pad is then destroyed. In all, it makes for a system that is almost unbreakable by any currently known analytical system.

In March 2003 on the eve of the Iraq war, also known as Operation Iraqi Freedom, NY radio station WFMU played the entire 4 CD set, appropriately freaking everybody out.