Oh, if only it where so, AM stations would be rich! Rich, I tell you. This dates back to 1987 article in radio world that details how AM stations receiving Cuban interference could submit to the USIA (US Information Agency), the State Department VOA oversight organization, detailed interference reports and requests for reimbursement of lost revenue. In addition to that, the FCC would consider night time power increases and or pattern modifications, so long as no US or Canadian station was adversely effected by the changes.
Prior to about 1980 or so, Cuba adhered to the NARBA of 1950. This allocated broadcast channels in the AM band, including clear channels for the US, Canada, Mexico, Cuba and the Bahamas. Later on, most of the countries in South America joined the treaty and most international interference was mitigated.
Then, for reasons only known to Fidel, Cuba began broadcasting high power on several frequencies. The stations suffering the worst interference were all in Florida; WINZ, Miami, WVCG, Coral Gables, WNWS, South Miami, WEAT, West Palm Beach, WQBA, Miami, WKAT Miami Beach and WSUN, St. Petersburg.
In our neck of the woods, WICC suffered some pretty bad interference from CMKA on 600 kHz. According to treaty, CMKA was supposed to transmit with no greater than 2.5 KW. Sometime in early 1981, they increased power to 150 KW. The path between WICC and CMKA’s transmitter site is almost entirely over salt water. Additionally, CMKA utilizes a fairly tall tower, 130 degrees according to the FCC data base.
The interference was worst in last fall and early spring. Several local newspaper articles were were written about the subject, noting that WICC developed a contest around the interference. The station would drop it’s carrier for 10 seconds at 6:30 and 7:10 pm. Listeners would then try to identify the Cuban songs playing on CMKA and drop a post card to WICC with that information. Winners were picked randomly from the all the correct answers received (CMKA would also be heard on the studio air monitor). Coincidentally, after several months of this, the Cuban station switched it’s programming to English.
In any case, I believe the USIA paid out a total of $500 K to the Florida stations.
The company I work for is in the midst of cleaning out a studio location. Most radio engineers are some form of pack rat. I know I have been guilty of this myself, not wanting to throw something away because tomorrow, it might be needed. That was carried out to the extreme at this location. One of the things that I found in my clean out was a Western Electric 212E vacuum tube.
Western Electric 212E vacuum tube
It is an impressive thing, measures about 12 1/2 inches tall, including the pins. I am thinking this is pretty old, it probably came from a pre-WWII Western Electric AM transmitter. This would make the most sense, as the station signed on in 1926 with 250 watts. Back in the day, Western Electric was the patent holder for AM technology. In fact, there was some talk of suing General Electric for patent infringement after the airing of the world series by WJZ and WGY in 1922. Parent company AT&T was working on radio modulation techniques to implement with their telephone system.
These tubes were used for audio amplification, according to the spec sheet, the plate could dissipate 275 watts. Filament voltages is 14 volts at 6.2 amps, the plate voltage was 3,000 volts, maximum. It is a tetrode. The RF counterpart to this tube is the WE 308A.
From what I am to understand, these have not been made since 1960 or so. I also understand there there is quite a cult following for this tube amongst Asian audiophiles. There are several examples of extremely low distortion class A and AB amplifiers using this tube type. Some prices on Ebay are in the $1,500 to $2,000 per tube range. Unfortunately, I don’t think this one works anymore as there is a loose screw and little bits of what looks like control grid wire in the bottom of it. It does light up with 12 volts on the filament, however.
Yesterday, August 14th, was the 65th anniversary of the end of World War II. Prior to the start of the US involvement in WWII, the Army and Navy had been intercepting and decrypting radio messages between Japanese military units, consulates, embassies and other overseas locations.
Back in the day, most everything was sent via Morse code over HF radio circuits. It was the fastest way to send information from one point to the next. These messages would be encrypted off line, either by hand or special typewriter. The message text would then be altered into 5 number, seemingly random, groups. On the other side, they would be decyphered using a key that matched the encyphering key. There were several different cyphers systems being used, some for diplomatic traffic, several others for military, merchant marine, etc.
Since the messages were transmitted via radio, they were easy to intercept. Everyone knew that the other side was listening. The Japanese assumed that there codes were secure because a “caucasian mind could not possibly unravel the intricacies of a Japanese code.” An assumption the Navy cryptanalysts had different ideas about. Through the 1930′s and early 1940′s they had broke some of these codes, not all of them.
The Japanese diplomatic code was called “purple” by the US cryptanalyists. It relied on a machine called system 97 (by the Japanese) which used telephone stepper relays to generate an ever changing stream of random code groups. It was considered too secure to break. William Friedman, a mathematician working for the Army, studied the purple messages and deduced that it was a machine generated code. He then went to work on duplicating the machine and after a year or so came up with a perfect replica of the Japanese system 97 machine in early 1941. From that point on, almost all of Japan’s diplomatic message traffic was being read by the Army, Navy and state department. This work was top secret and carried out at the war department in Washington. Information gleaned would be sanitized and transmitted to major commands as needed for tactical intelligence.
In early November 1941, the Japanese foreign office came up with the following code to be transmitted to the embassies in the event of the outbreak of war:
HIGASHI NO KAZE AME (East wind rain) = Japan – US
KITA NO KAZE KUMORI (North wind cloudy)= Japan – USSR
NISHI NO KAZE HARE (West wind clear)= Japan – Britain
It is believed that on either December 4th or 5th, East wind rain message was received and decrypted. This was testified to congress in 1945 by the head of the Navy COMMINT section, however, no record of the decrypted message exists. Instead, there is a blank page and a missing message number (JD-7001) in the Japanese diplomatic intercepts file.
The fleet commander at Pearl Harbor knew none of this, as the information was kept under close wraps by the Navy department in Washington. In early December 1941, most everyone figured that war with Japan would happen very soon. Most of the Washington set believed it would start in the Philippines, then a US territory. No figured that the Japanese would steam 3,900 miles undetected and launch a sneak attack on the US military base in Hawaii. The attacking planes homed in on the signal from KGMB (after war reading of Cmd. Fuchida’s (IJN strike leader) diary indicates the actual station was KGMB on 590 KHz, and not KGU as their website claims), to help find Hawaii from carriers still 230 miles away. The station had remained on the air overnight to assist a group of B-17 navigate from the west coast. Unaware of the impending danger, the Hawaii military bases were enjoying a peaceful Sunday morning until 7:48 am, when the first bombs began to fall.
Of course, had the Japanese pressed the attack and launched a third wave to take out the fuel storage and repair facilities, indeed, history might be different. The Pacific Fleet would have had to retire to California, leaving Hawaii exposed and quite possibly invaded.
Most people on the mainland first heard about the attack via radio. At 2:22 pm eastern time, the AP issued a news bulletin and at 2:27 pm CBS broke into their Sunday afternoon programming to announce the attack. Radio played an important part in WWII from start to finish.
This is The Stairway to Heaven for a different decade.
It is so big. She looks like, one of those rap guys’ girlfriends. But, you know, who understands those rap guys?
They only talk to her, because, she looks like a total prostitute, ‘kay?
Ordinarily, I don’t much go in for such things as rap music. But this is entertaining, and somewhat universal.
Hard to believe that it was almost twenty years ago. Almost every lyric in that song is innuendo for some sex act. Like it. Dislike it. No rules were broken when making this song. It went to number 1 on the billboard chart in the summer of 1992 and no radio station anywhere ever received a fine for playing it. It was quite scandalous at the time, of course, we were young and naive then. Things have changed.
To the beanpole dames in the magazines: You ain’t it, Miss Thing!
I occurs to me that part of the reason that the radio industry sucks is because the music industry sucks. The radio and music industry used to have a symbiotic relationship, each benefiting greatly from the existence of the other. Of course, the greed and poor business practices of the last decade have driven every fun and thus entertaining element away from both industries. Leave it to the bean counters, who know the cost of everything and the value of nothing.
Sadly, no hit that I have heard on the top 40 station these days even comes close to the entertainment value of this 18 year old song.
There is a very good blog call Arcane Radio Trivia which publishes interesting tidbits of radio trivia, and a lot of stuff that a reader might not have heard before, hence the name. A post put up last week, when I was out of town, deals with carborundum (Silicon carbide) which is one of the first semiconductors used to produce diodes, and thus detectors for radio.
Certain naturally-occurring minerals can be used to detect radio signals, including galena, zincite, silicon,bornite and others. Carborundum was unique among the early crystals because it was synthetic. It was durable, and at 9 mohs much harder than most available crystals. More here. Also interestingly it requires it requires a negative potential of 1 volt to be used as a diode. Carborundum was not created with this purpose in mind. It was created in the early search for artificial diamonds
Like many things in early radio, there are several plot twists in this story and if one is interested in radio history, it is work a click to read. While you are there, check out “It’s 105 degrees and rising“
I was digging through some old manuals at the shop today and I found this June 1987 memo from Orban to AM stations titled “AM radio CAN sound almost like FM.”
The main purpose of the memo was to get AM radio stations to implement the NRSC standard for pre-emphasis and high frequency roll off to improve the sound of AM broadcasts on ordinary radios.
I am not sure why the receiver manufactures never designed an IF filter that would be compatible with NRSC, it seems like a fairly simple design. Instead, what we have is “digital” AM radio (IBOC) which does not work well, creates many more problems with interference that of pre NRSC broadcasting.
If one were to look at the entirety of AM broadcasting history, one would find some striking parallels with what is happening with IBOC today on both AM and FM.
To start, the NAB began petitioning the FCC to allow more AM broadcasting stations, even as it was known that these stations would create interference with existing stations, especially at night. Still, the NAB persisted and the FCC relented and through the fifties, sixties, seventies, and eighties many more class II and III stations were established on what used to be clear channels (classes I and IA).
Once the AM band was chock full of stuff, they began going to work on the FM band with 80-90 drop ins.
You see, for the NAB, more radio stations means more dues money, greater lobbying power because of the larger size of the industry. Then came deregulation of ownership limits. By this time, Big Group Radio was calling the shots and they wanted more. This led to the great consolidation rush of the late 1990′s from which the radio industry is still reeling. The consolidation rush led to highly overpriced radio stations being leveraged to the absolute maximum, leading to the recent bankruptcies.
Finally, the NAB’s great push toward adopting IBOC digital radio in the early years of the 00′s. IBOC was supposed to save the day, greatly improving quality of both AM and FM and bring radio into the 21st century. Except that the promised technical advances never materialized. IBOC remains a great expensive boondoggle and I am beginning to think that perhaps we should stop listening to the NAB.
The memo itself is a fascinating thing, which were one could substitute AM with RADIO and come to some of the very same conclusions today regarding analog and IBOC digital radio. For example, this paragraph on AM stereo:
AM stereo was thought to be an answer (to improve AM), but AM stereo was embraced with the false assumption that having ‘stereo’ automatically meant having ‘high fidelity’. While AM stereo did provide somewhat better fidelity, it was not comprehensively engineered to get the best fidelity from AM. It was hoped that the gimmick of having two channels would be enough to save AM.
AM stereo could have been an improvement, had it been properly implemented. Unfortunately, the underlying problem of bad sounding receivers was never addressed. About which, the same memo notes:
Receiver manufactures did what they could to reduce listener complaints – - they narrowed the bandwidth (thereby reducing audio fidelity) until the complaints about interference stopped. Listeners clearly indicated, through their buying habits, a clear preference for lower fidelity over continuous irritating static, buzzes, whistles, and “monkey chatter’ from adjacent stations. People accepted this situation for a long time – - until the simultaneous advent of improved receiver technology and the FCC’s anti-simulcasting rules created the FM boom of the late 1970′s. (ed note: I remember listening to FM because there were fewer commercials, not better sounding audio)
Then the memo goes on to stress the importance of implementing NRSC standard for AM broadcasting that included the sharp frequency roll off at 10 kHz, noting that receiver manufactures would design “fine new receivers” that would take full advantage of the new standard, but only if broadcasters first showed good faith by widely and promptly implementing it.
As I recall, NRSC-1 was adopted as rule of law by the FCC in 1989, about two years after this memo was written. One could reasonably expect that receiver manufactures then started producing radios that took advantage of the NRSC pre-emphasis curve with IF filters that did not cut off audio frequencies above 3.5 kHz, but rather rolled them off in a gentle slope until about 7 kHz, more aggressively after that until 10 kHz, where they cut off.
Except they didn’t.
Instead, twenty years later, AM radios universally sound bad, with audio bandwidth of about 3 kHz or so.
I believe that AM receivers could be made with three IF bandwidths, automatically selected based on signal strength. Within the 5 mv contour, full (10 kHz) audio can be reproduced using a high frequency roll off described above. In the 1 – 5 mv contour, a 6 kHz bandwidth and less than 1 mv a 3 kHz bandwidth. The automatic selection could be defeated with a “wide/narrow” IF bandwidth selection switch like the GE superradios have. Of course, if one where listening to stations transmitting AM IBOC, the “narrow” setting would be the best.
Half of me thinks that the ship has already sailed on AM broadcasting. The stations on the air will continue to decline until they are no longer able to broadcast due to expensive repairs or replacement, at which time they will be turned off. The other half thinks that AM radio, as evidenced by the huge public response to WEOK and WALL broadcasting the true oldies channel, can be revived. With the impending inevitable FM IBOC power increases, translator shoe ins, LPFM, etc; the FM band may become worse than the AM band. At which point the public will have to decide whether free radio is important to them, or 3G/4G services will become the new method of broadcasting.
I just found my old copy of the NAB Engineering Handbook, sixth edition. I have enjoyed throughly looking at the AM antenna sections. It reminds me, that while we tend to think we have come up with new answers to old problems, really most of this was figured out a long time ago, this particular edition was copyrighted in 1975.
It is a thick book and covers AM, FM and TV broadcasting technology as it was understood in 1975. There are several chapters about “current” things that no longer apply, there are also many very useful items, such as studio construction, AM and FM broadcast antennas, tower maintenance and so on.
I will keep this on my shelf because it is an interesting primer on AM broadcast antennas with all attendant formulas and charts. It is quite interesting and fun if one is looking for the theoretical efficiency of a 185 degree radiator at 1 mile. I remember WPTR (now WDCD) in Albany had a three tower with 206 degree radiators, 50 KW carrier power on 1540 KHz. It seemed to be quite effective, when I was chief engineer there, we used to get reception reports from South Africa.
Perhaps one day, I’ll put some of that information to good use with an AM station of my own.
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 1960′s through late 1980′s. The reasons 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 minesweaper formerly known as the USS Density. After Radio London went off the air, the ship was transfered from port to port until it ended up in Kiel, Germany, were it was finally scrapped in the late 1990′s.
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.
MV Galaxy with radio mast
One incident in off shore 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 owner’s figured 4 miles off shore was far enough to be in international waters, the FCC felt otherwise, I believe at the time, 12 miles was (and still is) the territorial limits 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.
It just doesn’t have the same ring as Disk Jockey or DJ. However, that would be an apt description of the person who plays the hits on most radio stations these days.
It is mostly just drag and drop the next element into the play deck, if anything needs to be done at all.
Technics SP-15 Turntable
I remember when DJ’s actually jockeyed disks, it was a sight to behold. Back in the day when everything was on vinyl except the commercials, which were on cart, the DJ had his or her hands full. Most of the songs where in the 2:30 to 3 minute range, so while the song was playing, the next song had to be cued up on the platter, the old song needed to be put back into it’s sleeve and shelved (most of the time), check the log to see what was on deck, pull the next commercial stop set, answer the phone and god forbid if the Program Director called on the hot line and it rang more than 3 times. And hopefully the head wasn’t too far away, that coffee went somewhere, after all. While all that is going on, timing, audience interaction, hitting the post and sounding fun. In spite of what Howard Stern says, it was not easy.
Today, of course, if there is even a person in the studio, they may glance up at the computer screen every now and then to see when the next time they need to talk. Otherwise, they would be engaged in talking on the phone with their girl friend, texting, surfing the internet, or watching the baseball game on TV.
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.
RMS Titanic, April 10, 1912
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, original call sign MCC (for Marconi Cape Cod) later changed to WCC.
On April 14th about 11:45pm, the Titanic struck and ice burg and sank about two and a half hours later. The RMS Titanic call sign MGY was equipped with a radio transmitters 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 the internationally recognized distress signal.
On the night the ship sank, the Marconi employed radiooperators 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.” About 11pm 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 70′s. Being stationed on 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, myself hearing an automated SOS on the international lifeboat frequency (8364 kHz). I imagined some poor guy cranking the life boat 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 1990′s most maritime communications had moved to INMARSAT, 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 1960′s. 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 the money could be made with the new fangled radio contraption and commercial broadcasting was born.
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
~1st amendment to the United States Constitution
Any society that would give up a little liberty to gain a little security will deserve neither and lose both.
~Benjamin Franklin
...radio was discovered, and not invented, and that these frequencies and principles were always in existence long before man was aware of them. Therefore, no one owns them. They are there as free as sunlight, which is a higher frequency form of the same energy.
~Alan Weiner
Everyone has the right to freedom of opinion and expression; this right includes the freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers
~Universal Declaration Of Human Rights, Article 19
I just found my old copy of the NAB Engineering Handbook, sixth edition. I have enjoyed throughly looking at the AM antenna sections. It reminds me, that while we tend to think we have come up with new answers to old problems, really most of this was figured out a long time ago, this particular edition was copyrighted in 1975.
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