Last week I did some repair work at WDDY in Albany NY. It seems the sample line on one of the towers was melted in half by a lightning strike. This station uses sample loops up on the tower for its directional antenna monitoring system.
As it happened, the sample line in question was on the reference tower, which makes everything else meaningless. Before the meltdown, there were several years’ worth of maintenance logs that showed the previous values for current ratio and phase relationship.
With the transmitter turned off and locked out, I removed the damaged section of the line from the base of the tower to the RF choke coil in the tuning house. Where the sample line came off of the base of the tower, there was a UHF-type connector that had been improperly applied. Using spare parts, I fixed that connector, then spliced the line into place. Upon power-up, the transmitter and antenna readings returned to their previous values, which were slightly out of tolerance.
Thus, some phasor tuning was needed. There are not too many people left that can properly tune an AM phasor. All of the control interact with each other; moving the power or phase to one tower will likely affect all of the other towers and possibly the reflected power on the transmitter. This phasor was made in the 1970s by Multronics with what looks like all RCA parts. Multronics, I think, was John Mullaney who is more known for the folded unipole antenna. In any case, after a good few hours of careful hand cranking and a run out to the reference tower to move a coil tap, here are the results:
Oh yeah, that’s right, they were used to attach the RF feed to an AM tower. About ten years ago.
From this view, it looks like whatever tower crew installed this tower could not manage to solder or braze the copper RF connection to the steel tower. The area was then painted, but it looks like there is some corrosion going on between metals.
This is a relatively new tower. Sadly, it is very likely that this station will be going off the air soon. If the station is still on the air come springtime, I will drag the brazing outfit across the field/swamp and fix this. If the station goes dark, then I won’t worry about it.
Emergency! The (AM) Transmitter keeps popping off the air and we can’t figure out why! YOU MUST HELP US!!1!!!
Well, with the ATU mounted about 1/4 inch away from the 90-degree, series-excited tower, I wonder why. It seemed to be especially problematic during rain, snow, and ice storms. When I asked how long this had been going on, I was told “About two years, ever since we put up the new tower!”
You don’t say.
We finally took care of this by moving the ATU back inside the shed after moving the transmitter to a different building. The funny thing is, this was installed by a guy who had a BSEE. I guess he must have been out sick the day they covered this in class.
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, and 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 echoes 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 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 electricity back on after yesterday’s fire, I took a short walk around the WDCD-AM site and took some pictures. The transmitter disconnect thrown, fuses are pulled, it is kind of sad to see the Nautel XL-60 dark:
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.
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.
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.
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.
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 of operation. Now, the bomb shelter has a kitchen and bathrooms. The underground storage tank no longer meets EPA standards and has been pumped out.
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 inline six-cylinder engine with a massive flywheel. When the engine is stopped, it takes about twenty seconds for the generator to stop turning.
National Grid, 3 pot, 480 volt, 3 phase service, original to the 1947 building.