We have this certain transmitter which has been on the same tube since June 6, 2001. Come to think of it, the transmitter itself has been on the air for the same amount of time without failure. A testament to its designer…
According to my calculations, that is 151,691 hours or 17 years 3 months and 22 days. The tube is the original EMIAC 4CX15000A that came with the transmitter.
I am a little nervous about turning it off to clean the cabinet.
We have a spare on the shelf for the eventual replacement of this tube, but I really want to see how long this thing will last. This is also one of the last tube transmitters we have in main service. There are several backup tube transmitters still around.
I was at the WEBE transmitter site recently and took the time to look over transmitter we installed last year:
Overall, I would say that this transmitter has been very reliable. We had to install a UPS for the exciter and HD Radio exporter, but that is not a big deal. During the first power outage, the exciter went dark first. It took longer for the transmitter controller board to lose power, in the interim the controller turned the transmitter power all the way up. When the generator came on line 10 seconds later, the transmitter returned to operation at 41.5 KW. This, in turn, caused one of the other field engineers to freak out and nearly lose his mind (stay away from the brown acid, FYI).
I installed the UPS a few days later.
Transmitter power output is 35.3 KW, which is getting into the semi-serious range. The reflected power goes up when it gets warm out and goes down in colder weather. Over the winter, it was running about 50 watts. Even at 138 watts, that represents 0.004% reflected power. The TPO forward goes to the 6 bay, 1/2 wave spaced antenna side mounted, 470 feet (143 meters) AGL. The station covers pretty well.
Overall, I would give the liquid cooling system an A grade. The transmitter still dumps a fair amount of heat into the room from the RF combiners and PA power supplies. Most of the heat, however, ends up outdoors. Previously, we had two Bard 5 ton AC units running almost full time. Now, only one AC unit cycles on and off except for the hottest days of the year. Outside temperature when this picture was taken was 81 degrees F (27.2 C).
Next year, we will have to send a sample of the coolant off to be analyzed.
I have had good experiences with the GatesAir FLX/FAX series transmitters. I would recommend this to a friend.
I do not particularly like these. I know, they are relatively inexpensive, easy to come by, easy to install, etc. However, a shipping container was not designed to house a transmitter, they have certain drawbacks. These are, in no particular order:
Air conditioning. Using a traditional Bard type equipment shelter HVAC unit requires cutting through a lot of fairly heavy gauge steel. What’s more, the steel walls are uneven, requiring filler.
They are by necessity, fairly narrow. Arranging racks and transmitters along the length of the unit restricts access to either the front or the back of the equipment. Meeting NEC clearance requirements for electrical panels, transfer switches and disconnects can pose problems.
They are not very tall. Mounting overhead equipment can be problematic as one does not want to drill through the top of the container. Crosswise unistrut is one solution, but it lowers the overhead considerably.
Electrical work is slightly more dangerous. Doing any kind of electrical work, trouble shooting, repairs, etc is a little more nerve-racking when everywhere around you is a metal surface at ground potential.
They are difficult to insulate against cold and heat.
The door latching mechanisms bind, wear out or otherwise fail over time.
All of those things being said, I am now rebuilding a transmitter site in one of these shipping containers.
Fortunately, the original electrical work was not bad. The transmitter is a twenty year old BE FM10B, which will be retained as a backup. The new transmitter is a Gates Air FAX-10. We have installed several of these Gates Air transmitters in the last two years or so and they seem to be pretty solid units. This is the second 10KW unit I have installed.
We decided to install the FAX-10 in a Middle Atlantic rack, since we did not have a whole bunch of extra room for a separate transmitter rack. The 1 5/8 inch coax switch is installed in the top of the transmitter rack along with a Tunwall TRC-1 switch control unit. The other rack will have the STL and all other ancillary gear. My idea is to have nothing in between the door and the FM10B so it can be easily removed when that day comes. Something, something about planning ahead since it will be likely myself removing the FM10B.
They don’t think so. A small class A FM station, one of many that signed on in the early 1990’s as part of the 80-90 drop ins (FCC docket 80-90, for those unfamiliar). Many of these stations did not fair too well and ended up being absorbed by larger stations and groups starting with the first wave of ownership deregulation in 1993.
WHXC has remained under the same ownership since it signed on in 1991. Eves Broadcasting is a family operation, employing maybe half a dozen people. Their studios and offices are on the third floor of the Bank of Niagara right in the center of town. The facility is very nice. Like any successful radio station, their focus is the community they serve. The format is “Oldies” but they also broadcast high school football, Syracuse sports and so on. They host a yearly Blue Grass festival on the village green.
The air studio has an Arrakis console and uses BSI Simian automation software. They have live DJ’s from 6am to 6pm, local news, weather, sports, etc.
The production room has a BE Spotmaster 8S200A console from 1978. Aside from needing some power supply capacitors, it still works relatively well. However, as the owner’s son said; that thing belongs in a museum.
BE Spotmaster line input card. Probably can still get all these parts if we wanted to.
I forgot to take pictures of the transmitter site when I was there. Next time.
We will be working on several projects for these folks, so I will keep you posted on the progress.