Suburbia’s once-ubiquitous rooftop antenna — a familiar sight in the 60’s — appears to be making a comeback, although in a newer, 21st-century form. Antennas are now being marketed as designed specifically for the 2009 digital conversion. With the analog TV cutoff now just seven months away, consumer interest groups and some Congressmen have been increasingly concerned that real-world difficulties of the transition will be insurmountable for too many people. In some regards, I think these difficulties are overblown and will have the same impact as the much-feared Y2K transition.

Aldo Cugnini
Analyst

But one element of the transition does need more improvement — practical and user-friendly antennas for the over-the-air (OTA) viewer. In addition to performing well, OTA antennas will have to be attractive and easy to install if they are to provide a viable solution. Some antennas are claimed to have a range of up to 30 miles and a wide-enough beam-width that would allow them to capture signal from multiple broadcasting towers. And specifications will need to avoid inflated numbers, such as stating gain over an isotropic radiator, which adds about 2 dB over the more common dipole (think rabbit ears) reference.

However, in urban environments, the more important characteristic is often directivity (front-to-back ratio), which is a measure of an antenna’s ability to favor desired signals and reject undesired multipath. With about 15 - 20 dB of directivity, an antenna can offer protection against multipath, especially if (big if) some deeper nulls can be oriented carefully.

I had a chance to evaluate one recently and can say that anecdotally that an attractive 10" x 20" antenna with about 8 dB of gain (and a pre-amplifier) was able to pull in a station 60 miles away — from the top of an 800-foot ridge. However, I had no interfering stations or multipath with which to contend.

Interestingly, some of these antennas seem to be cosmetic changes to the old-standard "bowtie" or double bowtie antennas. A 4-bay bowtie UHF TV antenna, with 8-13dB of gain across the UHF band, can service suburban to fringe reception areas with medium signal strengths. Still, with MSRPs of $59 - $79, it would seem to be a low-risk proposition to see how well such an antenna performs in a particular situation. And a return guarantee would make the risk even lower.

Antennas are viewed by many as the best way to receive HDTV signals. Not only are they free, but most stations that broadcast OTA use much less compression than cable or satellite providers. That makes for a better picture.

While antennas continue to be improved, certain characteristics are exceedingly difficult (or expensive) to achieve in small form factors. As Scotty said in Star Trek, "You can’t change the laws of physics…," but certainly, making an attempt will keep enterprising ventures (sorry about that) busy for a long time.