Why are VHF antennas just so darn big?

One of the nice things about digital broadcasting is that a lot of it takes place on UHF frequencies. That lets you use UHF antennas, which tend to be fairly compact when you compare them to their VHF/UHF counterparts. Unfortunately, there are a lot of television markets that still have at least one VHF station, and that means you’re still using a VHF antenna. And, that does lead to the question, why do VHF antennas end up being so darn big?

There are several reasons for this, but the biggest issue is that VHF antennas tend to be designed to cover the entire spectrum from channel 2 to channel 13 while almost all VHF broadcasting today only takes place on channels 7 through 13. New antenna designs are expensive to create and the FCC keeps talking about eliminating VHF broadcasting altogether, so most designs are just slight modifications from what was available on the market prior to 2006 when the digital broadcasting transition started. In theory a newer VHF antenna could be a little smaller.

Another really important distinction is that different frequencies respond well to different size antennas, and the higher the frequency, the less picky you have to be with an antenna. A UHF antenna tends to work well for all UHF broadcast frequencies, while for VHF, you really want a separate antenna for every 2-3 channels. That’s the whole point of having all those antenna elements on a VHF antenna… each one specializes in picking up a different set of frequencies, and actually each element of a “Yagi” antenna is actually an antenna all by itself.

Indoor VHF antennas tend to not have all those elements because they can rely on you to reposition the antenna. Repositioning the antenna actually changes its size relative to the broadcast tower, making more or less of the antenna usable for reception and therefore tailoring it for different frequencies. That sort of finagling isn’t necessary with UHF antennas because a single antenna does a fairly good job of picking up all broadcast frequencies.

If you live somewhere where you need an outdoor VHF antenna and you don’t have the room for one, you can at least take heart that most UHF antennas don’t actively block VHF signals. There is a possibility that with some fancy positioning, and if you’re close enough to the towers, that you’ll get VHF reception from a UHF-only antenna. It’s obviously not what it’s designed for but it’s worth a try. Usually you’re just talking about one channel, and it’s possible that one channel isn’t as important to you. You can also set up an indoor antenna just for VHF and use a combiner like this one to use only VHF signals from one antenna and UHF signals from the other.

If you’re not sure which channels are on VHF or UHF, we’re happy to help, or you can consult a site like tvfool.com or antennaweb.com. Remember that the channel number on your TV is different from the actual broadcast channel so what you see as channel 4 might actually broadcast on channel 42.