GartFarfunkel

Piggie

In nutshell VHF are channels 2-13 and UHF are channels 14-51

However there are only a few stations still using 2-6 so there are VHF antenna that only cover 7-13 also. But all the UHF's typically do cover all of UHF, 14-51.

If you would like a an analysis of your recerption, go to TV Fool, put in your address and how high the antenna is and copy the link back here. Then we can give you a better idea of what type of antenna you need.

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DTVuser2009

If you saw a UHF/VHF Combo antenna, it will have two dipoles that are extendable and a circular ring in between. those extendable dipoles are for VHF reception and the ring is UHF. that means such an antenna is a combo UHF/VHF antenna. on recent sets, the circular ring is now replaced with a plastic square that swivels.

A VHF-only antenna is basically your 'rabbit ears' or two extendable poles only, no ring and used to ship with new TVs in the late 80s-90s. some TVs of that era also sport a slot for such an antenna.

A UHF-only antenna is not so common but is usually a ring only, some people even 'create' a UHF only antenna by removing the two extendable poles and leave the ring, and then combine it with a set of VHF-only rabbit ears with an antenna 'combiner' since for some, having them set on one unit causes interference, so they 'separate' them and put the two newly-seperate antennas in different locations so they can get better reception, such as adjusting the VHF side independently without affecting already good reception on the UHF side.

Roof-mounted antennas are almost always combo UHF/VHF since their dawn of existance.

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TonyT

Just for a reference, as DTVuser2009 explained, here's a UHF (loop/ring part of the antenna) and VHF (Dipole/bunny ears portion of the antenna). Outdoor antennas can be a bit different and not easily as distinguishable, but this picture should give you a good idea of what we're talking about too.

divxhacker

It's all elementary, my dear GartFargunkel. Basically, the length of the element is directly prportional to the power of the frequency itself. VHF frequencies, being weaker have the best reception on larger elements, especially telescoping ones. They don't call 'em "rabbit ears" for nothing.

UHF signals are stronger, sharper, and have the best reception on small elements, the basic shape is the short bar, bowtie or loop. Some inexpensive antennas have UHF shape attachments suspended over the VHF elements.

The more elements an antenna has, the better the reception. For tough to receive signals, it's best to have separate UHF and VHF antennas, so there's no interference crossing between the two signal bands. So if you have the space to put it, build or buy a good big one.

For building your own, pant-stretchers make a great base, especially when you're planning to go on a diet. Put large VHF elements on one, and small UHF elements on the other. If you only have the target signals in the UHF band, the VHF sections may be omitted.

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Piggie

The length of the element is inversely proportional to the frequency. The higher the frequency the shorter the antenna elements, having no correlation to power. VHF has the best reception on larger elements because it's wavelength is longer, taking a longer element for resonant reception, not because they are weaker.

UHF is actually a weaker signal and why the stations on UHF have always run a lot more power then VHF to make up for the fact. UHF penetrates indoors which makes it appear more powerful. (Divx I don't want to totally pick this apart but trying to keep some basic RF and antenna facts straight. ) That said TV signals are for the most part sine waves and sharp doesn't apply to reception.

Exactly!


Ok, this is just my curiosity. Who is building antennas our of pant-stretchers?

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Don_M

The best way to visualize this is by looking at a traditional, full pipe organ in a church. The pipes producing the lowest bass notes -- the ones that seemingly make the whole place vibrate -- are several inches in diameter and many feet long; several octaves higher, at the top of the scale, the pipes are just a few millimeters across and mere inches in length. The same principle holds true for antennas: A dipole tuned to receive channel 2 is about 8 feet long; at channel 52, the correct length is less than 8 inches. That's why indoor antennas have two whip elements for VHF and a single loop for UHF.

Piggie

As an interesting aside Don, I was watching a TV game show a month or more ago.
The question was if a trombone extends the slide does the note go higher or lower?

They got it wrong

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DTVuser2009

Speaking of game shows, there was one on nickelodeon once called 'Get The Picture' which i thought this was funny:

"Name the Actor who played Steve Urkel on Family Matters"

**Silence**

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