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Of popular trees and telephone poles

This picture reminded me of something that happened early on in my radio career:

WDCD three tower array, Albany, NY

WDCD three tower array, Albany, NY

This is another view, looking across from the roof of the transmitter building before the former studio building was removed:

WFLY STL antenna

WFLY STL antenna, circa 1992

The story dates back to 1990 or so.  In the second picture, one can see two Scala PR-950U Paraflector antennas.  These are the STL and TSL antennas for WFLY.  They are on wooden utility poles because of the WPTR 1540 KHz antenna system is behind the poles, out of the picture to the left.   As you can see in the second picture, these poles were immediately behind the studio building, known as the “Gold Studio, ” the name itself being pure propaganda.

Also, in the second picture you can see behind the poles, a pair of poplar trees.  The reason for the second, taller pole was because across the street, out of the picture to the right, there was a stand of poplar trees which were growing up into the path of the WFLY STL system.

When this was noticed, then General Manager, John Kelly, tactfully approached the property owner and asked if the radio station could cut the “popular” trees down.  Of course, the property owner wanted much money to do this.  There was many telephone calls and discussions on how to kill the “popular” trees and other, not so ethical solutions to this growing problem.  Finally, it was decided that it would be simple and less expensive to install the taller utility pole.

Thus, Northeast Towers found the utility pole and came to install it.  In this area of Albany, the soil is a sandy loam, which required much hand digging and back bracing in the hole before they placed the pole in the ground.  As it is a seventy foot pole, a good 12 feet was placed in the ground and the hole was back filled with concrete.  That is why the pole still stands today.

Naturally, all of this work is taking place on the hottest day of the year.  Also, it stands to reason, the guy in the hole doing the manual labor is the oldest, most out of shape person on the crew.  After lots of grunting and swearing, our man comes out of the hole looking whiter than the driven snow and sweating profusely.  He kind of staggered into the back door of the building and collapsed on the floor just inside the back door.  At this point, he was in full cardiac arrest.  The promotions director, who’s office was closest to the door, called the ambulance.

Fortunately, the board operator on WPTR was an EMT with the local fire department.  After his pager went off, he ran out to his car, got his EMT bag and arrived on scene within seconds.  He was able to start CPR quickly.  In the mean time, a crowd had gathered out in the hallway.  John (the General Manager), hearing the commotion, storms out of his office and down the hallway.  He gets to the edge of the crowd and yells:

“WHAT ARE YOU PEOPLE DOING HERE?  DON’T YOU HAVE JOBS TO DO? AND WHAT IS THAT GUY DOING LAYING ON THE FLOOR?”

The good news is, the guy survived, thanks in no small part to the quick action of the board operator.

Anyway, tales of radio when it was fun.

Hums no more

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

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

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 three

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

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

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

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

Three phase service

National Grid, 3 pot, 480 volt, 3 phase service, original to the 1947 building.

I wonder if it will return.

American Airlines Flight 723

File under: Why we check the tower lights every day (or have an automated tower light reporting system):

56 years ago, on September 16, 1953 American Airlines flight 723 flew between the center and northeast towers of the WPTR antenna system while attempting to land at Albany County Airport.  The plane crashed about 3/10 mile away near NY route 5 (Central Avenue) killing all 28 persons on board.  To date, this is the worst aviation accident in the Albany, NY area.

Several years ago while cleaning out different AM transmitter site, I found a bunch of files about this accident in the trash bin.  It seems that some engineer had moved a file cabinet during the great consolidation of the 1990’s to the wrong transmitter site.  In any case, I rescued the file and for your reading pleasure, have scanned the following documents:

Original telegram to FCC in Washington DC regarding tower/aircraft colision

Original telegram to FCC in Washington DC regarding tower/aircraft colision

Retel WPTR north and center towers struck three hundred foot level 0930 morning 16 September by American Airlines Convair.  Damage inspected afternoon 16 September by representative Zane Construction and afternoon 17 September by engineer Ideco tower used in array.  Both report slight damage to center tower requiring straightening above 300 foot level.  North tower has two legs bent result of wing passing through tower 18 inches above top guys at bolt intersection.  Tower above bent and twisted but all right unless subject to high east wind.  Impact sheered north beacon clevises and shattered glass.  Replacement ordered and beacon restoration expected early next week.  Measurements of directional pattern afternoon 16 September show pattern unchanged and mulls, base currents and loop currents within tolerances except center loop current which reads ten percent low.  Indications are center pickup loop has been jarred and pattern unaffected.  FCC representative Turnbull who arrived noon Wednesday concurred.  No time lost.   Operating at full power

George Wetmore, Assistant Genl Mgr, Radio Station WPTR

This is the statement of the transmitter engineer on duty at the time of the crash.

Statement from the Engineer on duty at the transmitter site

Statement from the Engineer on duty at the transmitter site

I, Robert S. Henry engineer for Patroon Broadcasting Co. would like to make this statement concerning the collision of an American Airlines Plane with our transmitting towers.

On Wednesday morning September 16, 1953 I was on duty alone at the WPTR transmitter when at approximately 9:30 A.M. a low flying plane was heard overhead. The carrier trip circuit which protects the transmitting apparatus from sudden overloads at the antenna almost instantly actuated and a low sound of explosion followed about 3 seconds later. I ran to the back door of the transmitter in time to see what proved later to be aluminum sheets fluttering down through the fog. I estimate the ceiling at the time to have been approximately 75 feet and not sharply defined. The centre (sic) tower of our three tower array swayed violently for approximately for approximately (sic) 1 minute. At the time I knew a plane had hit the tower but it was above the ceiling and invisable to me. I called W. R. David and George Wetmore and the incident was reported to the Albany airport.

Back in these days, the studios were located at the Hendrick Hudson Hotel in Troy, the transmitter site was manned by a licensed transmitter engineer when ever the station was on the air.

What is amazing is that the IDECO towers remained standing after being struck by Convair 240, a pretty good sized aircraft.

Convair CV-240

Convair CV-240

Official report by the International Civil Aviation Organization:

American Airlines’ Flight 723 was a scheduled flight between Boston, and Chicago, with intermediate stops among which were Hartford (BDL), and Albany (ALB). The CV-240 arrived at Bradley Field at 06:57. Weather at the next stop, Albany, at this time was below the company’s landing minimums, but was forecast to improve to within limits by the time the flight arrived there. Departure from Bradley Field was made at 07:14. Because of poor visibility at Albany, several aircraft were in a holding pattern. The special Albany weather report issued at 07:50 indicated thin obscurement, ceiling estimated 4,000, overcast, fog, visibility 3/4 miles. Two aircraft left the holding pattern, attempted to land, but both executed a missed approach procedure. A third airplane landed at 08:16 following an instrument approach to runway 19. Immediately following this landing, Flight 723 was cleared to make an instrument approach to runway 19. Three minutes later the flight advised the tower that its approach was being abandoned because the aircraft’s flaps could not be lowered.
At 08:30 Albany Tower reported:”All aircraft holding Albany. It now appears to be pretty good for a contact approach from the west. It looks much better than to the north.” Flight 723 was then cleared for a contact approach to runway 10. On finals for runway 10, the Convair descended too low. The right wing of the aircraft struck the center tower of three radio towers at a point 308 feet above the ground. The left wing then struck the east tower. Seven feet of the outer panel of the right wing including the right aileron and control mechanism from the center hinge outboard together with 15 feet of the left outer wing panel and aileron separated from the aircraft at this time. Following the collision with the towers, ground impact occurred a distance of 1,590 feet beyond the tower last struck. First ground contact was made simultaneously by the nose and the left wing with the aircraft partially inverted.
The weather reported at the time of the accident was thin scattered clouds at, 500 feet, ceiling estimated 4500 feet, broken clouds, visibility 1-1/2 miles, fog.

PROBABLE CAUSE: “During the execution of a contact approach, and while manoeuvring for alignment with the runway to be used, descent was made to an altitude below obstructions partially obscured by fog in a local area of restricted visibility.”

The above reports notes that the aircraft traveled 1590 feet and struck the ground partially inverted.  I do not know what the flaps up landing speed of a Convair CV-240 is but the cruising speed is 280 MPH.  It would be safe to say the aircraft was traveling in the 120 to 130 MPH range or about 220 feet per second.  At that speed, it was likely airborne for about 7 seconds after it hit the tower.  Enough time to look out the window, realize what was happening and say “Oh, Shit!”

IDECO towers WDCD antenna system

IDECO towers WDCD antenna system, northeast tower is farthest

IDECO stood for the Internation Derrick Company, they build cranes, derricks and bridges as well as radio towers. Apparently they made pretty good stuff because those same towers are still standing today.

Not that checking the tower lights would have averted disaster in this case, it appears to be pilot error compounded by bad weather that caused this incident.  But there have been more recent aircraft/radio tower accidents, some of which have involved possible faulty tower lights.  I wouldn’t want that on my conscience.

My friend, the MW-50B

I began fooling around with radios when I was 10 years old or so. First, I built one of those shortwave radio kits from Radio Shack, which was back when they still sold radios.

Then I bought a small tube type AM transmitter at a garage sale.  The woman there said her son built it several years ago from a kit and it had the instruction manual.  I don’t even know who made the kit.  After some experimentation and changing out some tubes, I got the thing to transmit on about 1600 kHz, although it was a little hard to nail down as it drifted quite a bit until everything heated up.  I don’t know what power that thing put out, but it was certainly less than a watt.

All of this lead to a brief stint in the military as a radioman.  That was an interesting field, albeit different from what I thought it would be when I signed up.  It was during this time that I did some part time work at an AM/FM/TV station assisting the Chief Engineer.  Once it was established that I actually knew something, my responsibilities grew until I was assigned the AM/FM part of the deal.

After a year of that, I moved to a different city for family reasons and took the Chief Engineer job at a local AM/FM station.  The AM station was a 50,000 watt directional in the high end of the band which had a Harris MW-50B transmitter.  My previous station had a Bauer 10,000 D AM transmitter.  What could be so different? Plenty I learned, on my second day.

Harris MW50B transmitter with 50 KW air cooled power supply

Harris MW50B transmitter with 50 KW air cooled power supply

We were subjected to a wicked lightning storm, which, Murphy being present, took out the main transmitter.  The backup was a GE BTA25 which was running at half power because of the age of the 5891  final tubes.

The symptoms of the MW-50 where as follows:  It would run along fine then there would be a big blue flash and a cannon shot boom, followed by the step start relays cycling and it would come back on the air.  There were no overload lights nor any other symptoms leading up to the overload or subsequent to it.

I began by killing the power and shorting out all the high voltage parts with a shorting stick.  I noticed that things inside this transmitter where a little unusual, so I got the manual out and started reading.  The most unusual aspect of this transmitter is the 25 KV isolated box that the PA stage occupies.  25,000 volts DC is a great big potential and what I found over the years is that this transmitter needs to be kept very clean.  Of course, this unit had not been, and that was a part of the problem.

The other unique aspect of this transmitter is the damper diode, which is required by PDM transmitters to conduct voltage during the negative modulation peaks.  If the damper diode breaks down for any reason, the PA supply voltage tries to go to infinity, which is a good deal larger than 25KV and all sorts of problems begin.

To make a long story somewhat shorter, this is the problem I had.  The solid state damper diode had one bad section, which was causing all sorts of corona problems during heavy negative modulation peaks.  It took a call the Harris factory to determine this.  The entire diode assembly needed to be replaced because every section is matched.  That cost a couple of thousand dollars as I recall.

While I was working on the MW-50B transmitter, I was not impressed.  It seemed a little cheap and flimsy.  Later, when I voiced my concerns with the station management, the Harris transmitter salesman stopped by and said I needed to get with the program if I wanted to work in that market.  This was a Harris town you see, if you start bad mouthing our products, you’ll be the one to suffer.  Well, he retired, I kept looking around for other AM transmitters.  Three years later I went to work for the competitor across town.  Today that station has a Nautel ND-50.

The MW50 went off the air once every 6 months for the entire time I worked at this station.  It was always something different, power supply rectifier, bad PDM board, bad directional coupler, arcing insulator on the isolated box, etc.  I began to feel it didn’t like me, and I know I didn’t like it.  In fact, you could say I have never really liked Harris transmitter products ever since.

Update: Okay, I left a few things out of the narrative:

The 50 KW air cooled power supply was the light weight version.  Most MW-50 transmitters had 100 KW oil cooled supplies.  The problem with the 50 KW power supply was it was designed with a zero safety factor.  All of the rectifier were running at or near maximum current and voltage.  It only took one of 144 diodes to go bad, either short or open, and the whole transmitter would crash.  Again, no overload lights or other indications of problems.  We later installed air flushing fans in the power supply cabinet to keep things cool and that helped out quite a bit.

The other thing was a DC feedback sample to the PDM card.  It seems that if the filaments were turned off before the bleeder resistors took the 25 KV supply to zero, the remaining voltage would be routed to the PDM card via the DC feedback sample, blowing the foil off of the circuit card.  We fixed this by installing a gas discharge tube with a series resistor at the connection point for the DC feedback sample.

Then there are the infamous 1N914 diodes in the directional coupler that Dave points out below.

I am sure I am forgetting something else, but you get the idea.

Axiom


A pessimist sees the glass as half empty. An optimist sees the glass as half full. The engineer sees the glass as twice the size it needs to be.

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

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.
~Rudyard Kipling

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.
~Alan Weiner

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