We Tried to Not Leave AM Behind

Starting in 1978, nearly all of the station resources and upgrades were going to the FM side, KWWR. But we tried to not leave KXEO entirely out of the picture.

In an earlier post I talked about replacing the ground system for the AM antenna system in 1983 We did that after I found some of the ground radials from the original 1948 tower were disintegrating in the ground. While that did help the KXEO signal, it still wasn't as good as it could be.

The FM got an Optimod 8100A FM processor early in the 80s, a big step up from the processing that dated back to 1966. Orban began marketing the 8100A in 1980 - and it would later become the most popular FM processor in the word.  Two years later Orban unveiled the 9100A for AM, and  KXEO also got updated processing, an Optimod 9100 AM. State of the art processing greatly improved the sound quality of both KWWR and KXEO.

The 400' tower at the studio location was installed in 1966 for KWWR, but that meant the old self supporting 180' tower used by KXEO would have to come down. The new tower was designed to have the FM antenna bays at the top, and use the lower portion of the tower itself as the AM antenna.

Using what's called a bazooka, the 400' tower was connected to electrical ground at a point about 180' from the the ground. By using components to keep that part of  tower isolated from the FM and other equipment on it, allowed the station to use the lower 180' as an AM antenna. The main problem with that is, not only keeping the AM signal entirely out of the FM signal, but a 400' tall tower is larger than 1/4 wavelength electrically (which is what AM requires) so it was an inefficient AM antenna.

The tower also had electricity to feed the tower lights and heaters on the FM antenna for use during icy conditions. While the tower lights ran on 120 VAC, the heaters needed 240 VAC. Keeping that isolated from the AM signal, and keeping the AM signal isolated from that was a marvel itself.

In the late 80s I had read about a new folded unipole AM antenna produced by Nott Ltd. in New Mexico. The Nott system used tower standoffs and copper wire for radiators on the outside of the FM tower structure. The tower itself could then be grounded and KXEO would have a much better AM antenna, particular in terms of RF bandwidth, than the series fed taller structure. The Nott antenna was 180' in length - the perfect 1/4 wavelength electrically needed for the AM.

The Nott folded unipole antenna was a major improvement in the KXEO signal for the Mexico area. But it wasn't the kind of thing you promoted on the air so most people never knew we did that.

In August of 2000 a strong storm brought the 400' crashing to the ground. By then the FM was transmitting from the 1200' tower at Centralia - so 400' was no longer needed. We replaced the destroyed tower with a 200' tower. It, too, got a brand new Nott folded unipole antenna put on it and a microwave dish at 200' to feed the FM signal to the transmitter and tower in Centralia.

With the new ground system in 1983, and the Nott folded unipole antenna a few years later, KXEO got its first physical AM antenna/transmission system upgrade.

So not only was KWWR state of the art, we had brought the little 1 kilowatt KXEO up to state of the art as well.

Today there are probably still numerous small market AM/FM combos with rotting ground systems and inefficient AM antennas - but it was great to get KXEO up to state of the art for the time.

Too bad that most people were only listening to the FM, including the station owner.

KXEO actually sounded better than a lot of FM stations after those upgrades.

So it goes.