We (a public high school FM station) are looking to go directional. Due to some rather unfortunate timing, when the school district relocated us, we had to drop power, considerably. This had a serious effect on some of our coverage. We have decided to go directional - by doing so, we go from about 600W to about 5.5kW. A little bit of a jump
The consultant we are working with it still working out the technical details, however we are expecting to go with a 4 bay antenna, with spacing of about 0.8something wavelength (the numbers have not been finalized yet, we have been on the low 0.7 and upper 0.8 with the back of napkin designs thus far). We know about Shively and the quality therein - and the cost. What other manufacturers have you used for FM broadcast antennas? Anyone you would recommend? Anyone you would stay far, far, away from?
It is looking like we are only going to need to replace the antenna (we currently have a 2-bay Shively that was made from a 3-bay that was donated to us, Shively checked and tuned it up for us). The transmission line (1-5/8 air heliax, also donated at the same time at the current antenna) will likely be reused - we are looking at needing somewhere in the neighborhood of 3k from the transmitter, IIRC the line is rated for at least 5k, possibly 10k. Since the feed of the new antenna is expected to be lower than the current one, we will just shorten the line and install a new connector (unless the old one can be reused, but we are planning for a new one, if necessary).
While cost is a factor, reliability is a bigger factor. We do not want to have to address this again anytime soon. Our first antenna served us from the time the station went on the air (October of 1978) until we moved into the new building (January 2007). We still have it in storage.