Reflecting the state of the economy in Detroit, WDTW went silent on January 1st. Less than two weeks later, the towers come down:
Thanks, Chris R for the video link.
The license has been donated by Clear Channel to MMTC (Minority Media and Telecommunications Council), but not the land or towers. It remains to be seen whether the station will return to the air, however, given the costs involved and the economic conditions in Detroit, that is unlikely.
The station signed on in 1946, moving to 1310 KHz with full time operation in 1948. Back in the day, it was a flame throwing top 40 station and is purported to be the source of the “Paul is dead” rumors that surrounded the Beatles in the late 60′s. Much more history at Keener13.com.
Take pictures of your favorite AM stations now because tomorrow, they and all their history may be gone.
I found a 1981 Continental Electronics equipment catalog at an old transmitter site. These finds are great if one is interested in history and looking at the way things used to be done. This particular transmitter is a 2,000 KW (2,000,000 watt) medium wave unit:
Continental Electronics D323C, Circa 1981
I believe most units like this were destined for use by government broadcasters either the middle east or western Europe. I know there were several 1,000 KW medium wave stations in West Germany at one time. The Continental transmitter is basically two 1,000 KW units (323C) combined. They used a modified version of Doherty modulation, that is called “Screen and Impedance,” which accurately describes how it works. More information from the Continental Catalog can be found here: Continental D323C. The tubes (or valves depending where you are located) used in the D323C were 4CW25000A tetrodes as modulators and IPA the final was a pair of X2159, which is an impressive tube.
EIMAC X-2159 water cooled power tetrode
The tube sat anode up. The filament, grid and screen connections are underneath. Cooling water was pumped through the two connections on the top at about 130 gallons per minute depending on the plate dissipation. With a 30° C rise, that equals about 96,000 BTU per minute. The D323C had a dissipation of 400,000 watts for the carrier tube and 240,000 watts for the peak tube (640 KW total) under 100% modulation. That equals about 2 million BTU per hour. Notice the lifting hook, this tube weight in at 175 pounds. Tube date sheet here.
Continental no longer makes medium wave transmitters, their closest high powered broadcast product now is the 418/419 and 420 HF (shortwave) transmitters. The 420D does a wimpy 500 KW using a solid state modulator section.
I remember in the early 1990′s when I was at the Harris plant in Quincy, they were working on a 1,000 KW solid state DX series AM transmitter for Saudi Arabia. It had to be liquid cooled, which added another layer of complexity to an already complex system.
I don’t know if there is much call for 2 MW medium wave transmitters anymore as there are more efficient ways to reach remote populations and I can’t even imagine what the electric bill would be like.
This is a trip down memory lane. Someone has taken the time to preserve and document Radio Shack, its founding, history and all of the catalogs printed from 1939 to 2005. The website archive is Radio Shack Catalogs.
I remember reading these very catalogs cover to cover, when they came out in the mid 1970′s. At that time, this stuff looked expensive and in relative dollar terms compared to today, it was. We had one of these computers in our “Math Lab” in 9th grade:
Radio Shack catalog, TRS-80
In fact, when I found one of these computers stashed away in the corner of a transmitter site, I had a flash back of Mr. B scowling as yet another student made a mistake plotting x/y coordinates on the backboard.
Historic VLF (Very Low Frequency) station SAQ Grimeton will be on the air to celebrate United Nations Day on October 24th at 10:30 UTC (6:30am EST) on 17.2 KHz CW. This station was established in 1922 and is the last radio station in the world employing an Alexandersontransmitter. More information at their website.
This is a great 2011 video of a tour of the station, including transmitter start up:
It is great to see that old gear come to life and transmit a message. The electric motor/generator sounds like a jet engine spooling up.
Before solid state or even hollow state rectifiers, motor generators were used to create the DC voltages needed to transmit high power radio signals. This method was used by high powered Naval shore stations through WWII and beyond.
By way of comparison, an average CW operator can send and receive Morse code at about 20-25 words per minute. A good CW operator, about 30 words per minute and a Russian CW operator, somewhere near 50 words per minute. This was the main wireless data transmission method until Radio Teletype came into widespread use in the 1950s. Here is a comparison of data speeds through the years:
75 Baud/100 WPM
100 Baud/133 WPM
Switched 56 (Switchway)
The Morse Code (CW) and Radio Teletype data rates are not a direct comparison, as most radio teletype systems use 5 bit Baudot code instead of 8 bit ASCII. Morse code varied in length from one to five bits, if one thinks of each dot or dash as a data bit. Back in the day, before “Netcentric” mindset, we used mainly radio teletype to communicate from ship to shore. A premium was placed on brief, concise, operational communications. Everything else was sent via the mail.
It is quite amazing to see the increase in data speed, which directly correlates to information exchanged (or the ability to exchange information) in the last 90 years.
To receive SAQ Grimeton, one needs a VLF receiver or converter capable of receiving 17.2 KHz and a very quite receiver location. There are many VLF hobbyists that will be tuning in.
I have covered numbers stations before. This is a radio program from BBC Radio 4 first broadcast in 2005. It is an interesting look what is known and not known about various numbers stations around the world.
Somebody working to preserve a record of past work:
Some of these have familiar looking cabinets and tube arrangements. They all look like classics to me and it is good that they are being saved. I noticed at the end of the video there is a Harris MW10A. As for the RCA Ampliphase transmitters; I maintained a BTA5J in Harrisburg PA on 580 KHz. It was reliable enough, but I could never keep it sounding good for more than a couple of days.
Every year on July 12, the Maritime Radio Historical Society (MRHS) commemorates the end of commercial Morse code use in the US. I have a soft spot for Maritime Radio, as that is where I began my radio career. For nearly one hundred years, ship board radio operators, “sparks” communicated with land based stations using Morse keys and relatively simple low powered transmitters. The skills gained by a good CW operator could only be attained by time spent sitting watch.
In order to remember those who did that service, several former coastal radio stations fire up transmitters once a year on July 12th. This year’s frequencies are:
Festivities begin at 8pm eastern time. In addition to those frequencies, K6KPH will be on the air on 3550, 7050 14050 and 21050 KHz.
KPH, KFS and KSM are all operated from Point Reyes National Park, transmitters are on Bolinas. This is a video of the transmitter gallery in Bolinas:
Other video of Bolinas Facility:
Former KPH receiver site, Point Reyes National Park:
This is a former coastal station site in Cape Cod, which was torn down:
My first job as Chief Engineer was at WPTR and WFLY in 1991. I was young and it was a learning experience. The WPTR transmitter was a Harris MW50A, which reliably went off the air every six months. The transmission lines going out to the towers had fallen off of their wooden support posts, trees were growing up in the antenna field, sample lines were going bad. In short, it was a mess. Even so, the station was well known and well liked in the community. One could still see echos of greatness that once was.
When Crawford Broadcasting purchased the station in 1996, they put much money and effort into renovating the facility. Replacing the Harris transmitter with a solid state Nautel, replacing the phasor and transmission lines, cutting the trees from the field, painting the towers, renovating the old transmitter building into a new studio facility and finally removing the old Butler building that formerly housed the “Gold Studios.”
Then the depression of 2008-20?? hit. Once again, the place has fallen on hard times. WDCD-AM has been silent since last April. The cost of running the 50 KW AM transmitter being too much to bear in the current economy. Formatically, the station drifted around for several years. According to the the STA to go silent:
WDCD WILL SUSPEND OPERATIONS FOR A PERIOD DURING WHICH IT WILL DEVELOP AND PREPARE TO DEPLOY A NEW PROGRAM FORMAT AND REPOSITION ITS VOICE AND IDENTITY IN THE COMMUNITY.
They may need to do something slightly non-religious to survive.
While we were waiting for the utility company to turn the electric back on after yesterday’s fire, I took a short walk around the WDCD-AM site and took some pictures. Transmitter disconnect thrown, fuses are pulled, it is kind of sad to see the Nautel XL-60 dark:
Nautel XL-60 AM transmitter. WDCD Albany, NY
I apologize greatly for the blurry picture, it was taken with my cellphone camera, my good camera being back at home on my desk. Radio stations, when they are on the air, seem like they are alive. Machinery hums, fans move air, meters move, and there is a sense of purpose. Silent radio stations give me a sense of foreboding, like something is terribly wrong.
WDCD three tower array, Albany, NY
View of the towers without Butler Building. The towers are 340 feet tall, which is 206 electrical degrees on 1540 KHz. The site was constructed like this to suppress skywave signals toward ZNS, Nassau, Bahamas. ZNS is the only clear channel station allotted to the Bahamas by NARBA. The other station WDCD is protecting is KXEL, Waterloo, IA. During the 90′s, I received many QSL requests from Norway/Finland and even a few from South Africa. I know that the station had a large following in most of New England.
WDCD tower base, tower one (furthest from building)
Tower one tower base. This IDECO tower had to have the top 60 feet replaced after it was hit by an airplane in 1953. The tower base also had to be replaced in the late 1980′s as it was crumbling and falling apart. To do this, Northeast Towers used railroad jacks and jacked the entire tower up off of the base insulator. They re-formed and poured a new base, carefully letting the tower back down on a new base insulator about a week later.
WDCD towers looking back toward the transmitter building
Antenna field looking back at the transmitter building. If you work at radio transmitter sites, I encourage you to take pictures of all these things, as someday, they will all be gone.
WDCD bomb shelter
The “bomb shelter” and 220 KW backup generator, constructed by FEMA in 1968 as part of the BSEPP. This used to have an emergency studio and enough diesel fuel for fourteen days operation. Now, the bomb shelter has a kitchen and bathrooms. The underground storage tank no longer meets EPA standards and has been pumped out.
WDCD Onan generator
The Onan generator is conservatively rated at 220 KW, surge rating 275 KW. These things were way over constructed, so it is likely it would easily run 225 KW all day. It has an in line six cylinder engine with a massive fly wheel. When the engine is stopped, it takes about twenty seconds for the generator to stop turning.
Three phase service
National Grid, 3 pot, 480 volt, 3 phase service, original to the 1947 building.
So sent wireless operator John “Jack” Phillips on the night of April 14th, 1912, and likely sealed the fate of some 1,514 passengers and crew of the RMS Titanic, radio call sign MGY. That message was sent in response to the radio operator on the SS Californian/MWL, who was attempting to report icebergs nearby.
RMS Titanic side view
Of course, it would be a gross error to blame the sinking of the Titanic on the radio operator, he was but one small link in a long chain of events that unwound that fateful night one hundred years ago. Beginning with the ship’s design and ending with the Captain of the Titanic, Edward Smith, many seemingly unconnected decisions lead up to the ultimate disaster that befell the Titanic.
After about four days at sea, during the late morning/early afternoon of April the 14th, the Titanic began receiving wireless messages indicating “growlers, bergs and ice fields” were in the area. The Captain decided to alter the ship’s course to the south, out of the supposed ice fields.
In spite of numerous reports of nearby ice, the Captain did not order the ship to reduce speed. It continued on at 22 knots (41 kp/h) up until the time it struck the berg. Lookouts were posted in the crows nest, near the bow, to spot icebergs. This was considered normal operating procedure at the time, but is the most significant factor in the collision. A number of nearby ships had spotted ice and had greatly reduced speed or stopped for the night. Further exacerbating the situation, the lookouts on the Titanic did not have binoculars, which was due to a mix up before they sailed from England.
Some of the ice reports received later in the day and evening did not make it to the bridge. Wireless operator Jack Phillips was either repairing a malfunctioning spark gap transmitter or was sending messages from passengers to Cape Race Radio/MCE, Newfoundland. At the time, the (wireless) radio operators were not a part of ship’s company, but rather were employed by the Marconi Company for the purpose of sending messages for profit. Any notion of safety or distress communication was an afterthought.
The SS Californian, closest ship to the Titanic at the time it sunk, was attempting to broadcast another ice warning to all ships in the area at about 10:30 pm. The message was broken off by Phillips with a terse: “SHUT UP! SHUT UP! I AM WORKING CAPE RACE” At about 11:30 pm, Cyril Evans, the Californian radio operator closed station and went to bed. Ten minutes later, the Titanic struck the iceberg.
5 KW synchronous rotary spark gap transmitter
The Titanic used a 5 KW synchronous rotary spark gap transmitter, which was state of the art at the time. The power is measured at the input of the DC motor. Considering the efficiencies of the motor and generator, the ability of the spark gap to generate RF and the efficiency of the tuning circuits and antenna, the actual power radiated by the transmitting antenna would have been significantly less, on the order of a couple of hundred watts. The above schematic is not exactly the same as the unit installed on the Titanic, as the meters and additional controls for motor speed and generator voltage have been omitted. Additionally, some sources report the transmitter as a 1.5 KW non-synchronous unit. The difference between the two would be very apparent in the sound of the received signal; a synchronous transmitter had a tonal quality to it versus a non-synchronous or simple spark gap, which sounded like hissing. Wireless operators from shore stations and other ships who worked the Titanic reported that they were using a synchronous unit.
The transmitter used two frequencies; 600 meters, or 500 KHz and 300 meters, or 1,000 KHz. Because of these frequencies, maximum range during daylight hours was about 200-400 miles (322-644 km). Night time, the ranges were considerably more, 1,000-2,000 miles (1600-3200 km), which is typical for medium frequencies, including the AM or standard broadcast band in use today. Thus the effort by the Titanic radio operators to clear the backlog of message traffic out during darkness, when Cape Race was about 374 miles (602 km) away.
Another part of the problem was with the transmitting and receiving apparatus itself. The transmitters were crude and generated broad harsh signals. The receivers were also very broad, and nearby transmitting stations could easily wipe out all frequencies on early receivers. That is what likely prompted Phillips’ outburst, something termed today as blanketing interference. Vacuum tubes (aka valves) had yet to accepted for wide spread use as amplifiers and most receivers were simple tuned circuits connected to a detector of some type. As such, receivers were far less sensitive and selective than they are today.
Interestingly, the Titanic had both types of receiver on board. The main receiver was a tuned circuit with a Marconi Magnetic detector (aka “Maggie”) and a valve receiver as a backup. The valve or vacuum tube was likely a simple diode detector connected to a tuned circuit.
After the collision, Jack Phillips stayed at his post sending out distress messages and communicating with other ships en route to assist. Long after the Captain told the radio operators they were dismissed, Phillips persisted until power was lost and the radio room began flooding. He perished shortly after in the 28° F (-2°C) water, however, assistant operator, Harold Bride, survived.
There is also some bit of discussion about the rudder commands given after the iceberg was sighted. Most accounts say First officer, William Murdoch, gave the command “Hard over starboard” which would be the equivalent of right full rudder, effectively turning the ship to the left.
As rudders work, the amount of water flowing over the rudder determines its effectiveness or loading (resistance to water flow). With the center screw turning at full speed, the rudder would have quickly loaded and pushed the rear of the ship away from center line by re-vectoring the water coming from the propellers. There is no way to know if this would have changed the outcome as not enough is known about the maneuverability of the Titanic. Her sea trials consisted of about seven hours of sailing time before passengers were embarked.
The next commands issued were “full astern,” on the engine room telegraph. Because of the design of the ship, it took about thirty seconds to engage the rudder and backing engines. The ship continued straight ahead at 22 knots (11 meters per second), traveling 372 yards (340 meters) before beginning to turn. The center screw had no reverse, so it was simply stopped. Once the engines were reversed, the rudder lost much of its effectiveness due to turbulent flow and stalling. The ship could not maneuver around the iceberg, striking it in a glancing blow springing the hull plating in five forward compartments on the starboard side.
As it was the Titanic’s maiden voyage, the first officer did not have much deck time and was likely less familiar with the maneuvering characteristics of the ship versus other ships he had conned. On most other ships of the time, including the SS Californian, which had just completed the identical maneuver, that combination of rudder and engine room telegraph commands would have been appropriate to stop and swing the ship around the berg.
The SS Californian was within sight of the Titanic as it sunk, observing several “rockets” (as many as eight) being fired. When informed of the rockets, the Captain of the Californian asked their color, but did not move to investigate or waken the wireless operator. According to some of Californian bridge crew, the Titanic looked strange in the water, like something was wrong. The Californian attempted to signal the Titanic with blinking light, which was not acknowledged. Inexplicably, the Californian never attempted to investigate further until 5:30am the next morning when wireless operator Evans was back on duty and reported the sinking to the bridge.
Therefore, the entire chain of events that led up to the disaster include:
Too few life boats for passengers and crew
Not enough training in deployment of life boats
Very short sea trail period for the ship’s crew before passengers were embarked
Over confidence in the water tight door system in keeping the ship afloat
Binoculars for lookouts not procured in time for sailing
Ship’s rate of speed too fast for conditions, with numerous reports of ice in the area
Ship’s radio operator dismissing ice report from nearest ship (almost within view at the time) so he could continue to send paid message traffic
Combination of helm and engine room telegraph commands did not produce optimum maneuvering
Failure of nearest ship to recognize distress flares (or rockets) as such and render assistance
Change any one of those nine things and the outcome might be entirely different. Something to ponder.
The result of this disaster was the formal codification shipboard safety requirements known as SOLAS or Safety Of Life At Sea. Those standards include the transmission of distress signals, distress communications, numbers of life boats, radio watches, fire suppression systems, and training for passengers and crew. Currently the distress communication system is known as the Global Maritime Distress Safety System or GMDSS.
Originally signed on as WMNB in 1947, it is a Class C AM station on 1230 KHz, one of thousands in the country. Initially, it had a power of 250 watts, upgrading at various times to its current power of 1,000 watts.
WNAW-WUPE-FM, North Adams, Ma circa 2012
What is different about this station is the studio building. It is located in it’s original place on Curran Highway on the south side of North Adams. The studio is a late Art deco design, complete with small glass atrium in the lobby. Like many older radio stations, this installation was built on a raised floor. The walls and doors are all well constructed for maximum sound attenuation. The doors are large, heavy and solid wood.
WNAW news room, formerly the performance studio
Inside, the original studios are laid out with a control room, a broadcast studio and a live performance room. At one time, the live performance room had a grand piano. Several times per week, live music shows were broadcast on the station. There was a large news room, a big corner office for the General Manager and sales managers.
WNAW studio monitor speakers
WNAW studio, looking into the control room. Back in the day, the announcer, who’s only concern was announcing, worked in a separate studio from the engineer on duty, who worked console in the control room. The audio level limiting consisted of turning down the level on the console if the announcer started speaking loudly. They often communicated with each other with hand signs through the windows.
At the time that WMNB was signed on, the Adams/North Adams Massachusetts area was in the heart of the north east manufacturing belt. Sprauge had a capacitor plant in Adams, GE was making plastics in Pittsfield, There where many textile mills still in operation and so on. The population was predominantly working middle class.
WNAW control room console
Obviously, the console has been changed since those days. The current console is a Audio Arts R-60. This serves as the control room for WNAW and WUPE-FM. The programming for WUPE-FM comes from Pittsfield on a T-1 line. From here, it is relayed to the transmitter site on a 950 MHz STL. WNAW transmitter is located about 2/10 of a mile south of the studio building on Curran Highway. It consists of a skirted self supporting tower with a Gates 1 solid state transmitter.
WNAW-WUPE-FM equipment racks
Equipment racks containing the T-1 equipment, modulation monitors and STLs. Note the very old Moseley TRC-15 remote controls. We have been unwiring these at the transmitter sites and disconnecting the TELCO lines. The transmitter sites now have Sine Systems dial up remote controls.
In 1961, WMNB-FM (now WUPE-FM) signed on the air from a tower north east of down town, off of Mohawk Trail (MA route 2). It broadcast on 100.1 MHz with an ERP of 1,000 watts using a Gates FM1B transmitter.
WNAW continues on today as a community based radio station and is well liked and supported.
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.
The individual has always had to struggle to keep from being overwhelmed by the tribe. To be your own man is hard business. If you try it, you will be lonely often, and sometimes frightened. But no price is too high to pay for the privilege of owning yourself.
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
...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.