WNBZ Transmitter Update

Monday Morning (September 30th, 2013) We spent about two hours on Sunday Afternoon installing a new (sort of) RF Driver Board which allowed us to then pull the Transmitter back up to full power. Over the weekend, we had been operating at low power and this board allowed us to bring the transmitter again to full power. Surprisingly, however, one of the new 833C Tubes was faulty which means it’s going back to the manufacturer for a replacement. At the same time, we’re adding a set of 807s to the order and once these arrive, we’ll re-tune once again to a sound that we’ll be happier with than the current presentation. One of the problems with tubes in the first place is that they waste a lot of energy and weaken over time, so we have to do this project at least once a year, if not more often. The next project will be to raise the funds to install a solid state transmitter which will increase the efficiency to close to 90% from 40% and thus reduce our electric bill, but also require much less maintenance because without tubes, there are very few parts that can go bad. On the other hand, our Workhorse can also tune up to just about any antenna situation, where the newer solid state antennas aren’t happy when things aren’t just so with an antenna..

Friday Morning (September 27th, 2013)

The Transmitter came back on, and while not particularly happy about it’s particular state, It’s on the air. Remember the Power Grid we mentioned previously? That came out of the transmitter again, which is no simple task, so that several of the high voltage capacitors could be replaced. These are 1 kilovolt caps, not particularly easy to find but we did have some that would pass 2kV and while not perfect, mostly because the tuning would be out of sorts, we went ahead and put those in overnight and re-installed the unit back into the transmitter..  At about 4am the transmitter came back to life for the first time in several days. It was a welcome relief, but the fact that it was on didn’t mean we were finished, in fact about a half hour later it was tuned well enough to last the day. There’s a very precarious (finer than fine) line between “Tuned and Locked” and “OFF” and then – the modulation, needs careful attention, so there’s more work to do but hopefully, we’ll be able to accomplish that work overnight so as not to affect the daytime transmissions.. The coverage may be short of maximum for the weekend. Thanks again for your patience as we complete the tuning process..

Thursday, September 26th, 2013

We appreciate your patience while we work through a few troublesome issues with our GATES BC1T Transmitter for 1240 AM.. It’s a powerful transmitter and definitely gets the job done under almost any circumstances but in this case, the primary power grid which supplies the modulation specific to WNBZ’s 1240 AM frequency has failed. About ten years ago, WNBZ’s tower was knocked down by a freak wind storm and typically, AM transmitters are not capable of “Tuning” quickly to a new broadcast antenna, especially an antenna that is close to 180 feet (About 1/4 of the entire AM 1240 Wavelength) but in our case, this workhorse of a transmitter was able to keep going at low power with an emergency antenna we built in less than 3 days..  The transmitter was also plagued with power component failure in 2005 when of all things a major short ahead of the fuse protection reduced one of the transformers to 

833C TUBEcharcoal, even, by the way, as the transmitter plugged along right to the very end..  Parts in short supply, we found a neighboring radio station in Massena with a similar transmitter and most of the components intact. Those components were removed and delivered by hand to us here in Saranac Lake and they’re still operating to this day..  This latest issue, while less troublesome for the transmitter than a lack of power, there is still a component between the intermediate power amplifier (IPA) and the High Power Grid which powers the amplifier for 1240 and subsequently the modulation for the audio. The 833C Tube is essentially an amplifier.. A device which controlls electric current through a vacuum in a sealed container. The 833C is inside relatively thick transparent glass in a roughly cylindrical shape. The simplest vacuum tube, the diode, is similar to an incandescent light bulb with an added electrode inside. When the bulb’s filament is heated red-hot, electrons are “boiled” off its surface and into the vacuum inside the bulb. If the electrode—called a “plate” or “anode”—is made more positive than the hot filament, a direct current flows through the vacuum to the electrode. As the current only flows in one direction, it makes it possible to convert an alternating  current (AC) applied to the filament to direct current (DC) The introduction of a third electrode, a grid between the filament and the plate, yields another function. A voltage applied to the grid controls the current flowing from the filament to the plate.Thus, it allows the device to be used as an electronic amplifier. Our engineer is re-building the driver plate cap today which will allow us to again apply the necessary power to the grid and once that is complete, we will re-install the connection and once again energize the tubes.. This whole process should take us until about 5:00 pm. WNBZ is always available on Time Warner Cable Channel 19. We use the channel to connect our signal with the simulcast and they use the channel for troubleshooting and specific measurments on the cable system which is why you typically see a picture of the oscilloscope on the screen..  On Behalf of all of us at WNBZ we thank you for your patience and your listenership..

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