Stupid Antenna Questions

[Mags]

I have a couple of antenna questions that are probably pretty easy for most of you, so I'm hoping you can help me....

Given that most antennas are shaped like  <<<<<<  (as I just showed)....

Which end points towards the antenna farm (which I'll designate as "*")....

I'm pretty sure it should be like:

a)  *    >>>>>>   this way it kinda looks like a baseball glove and "catches" waves

or is it like:

b)  *  <<<<<<   so basically the antenna "points" at the antenna farm?

I'm pretty sure it is "a", but wanted to make sure...

The 2nd question is:

How much does putting an antenna in the attic rather than on the roof limit it's effectiveness?  I've learned that all antennas are color coded, which gives an approximation of how much they receive (which coupled with antennaweb.org is all you need).  Does putting it in the attic effectively "reduce" the color of the antenna down one notch?  Does it have any effect at all?

Thanks for your help, guys!

[Gilbert]

I have a couple of antenna questions that are probably pretty easy for most of you, so I'm hoping you can help me....

Given that most antennas are shaped like  <<<<<<  (as I just showed)....

Which end points towards the antenna farm (which I'll designate as "*")....

I'm pretty sure it should be like:

a)  *    >>>>>>   this way it kinda looks like a baseball glove and "catches" waves

or is it like:

b)  *  <<<<<<   so basically the antenna "points" at the antenna farm?

I'm pretty sure it is "a", but wanted to make sure...

The 2nd question is:

How much does putting an antenna in the attic rather than on the roof limit it's effectiveness?  I've learned that all antennas are color coded, which gives an approximation of how much they receive (which coupled with antennaweb.org is all you need).  Does putting it in the attic effectively "reduce" the color of the antenna down one notch?  Does it have any effect at all?

Thanks for your help, guys!

Smart questions for a new guy to ask! Answer to question 1 is indeed "a",
you are correct. You need to catch those waves! The "Pac Man" shaped fins should want to swallow the broadcast tower.    BTW, that is the UHF
signal reflecting part of the antenna.

As for #2...putting the antenna in an attic, assuming wood and shingles on the outside, reduces the signal by---hang on tight---an average of 20 dB. OK, in english, that means...roughly 90%! That means that unless you are close to the towers, you may need a signal amplifier. If you are withing 50 miles of the Milwaukee towers with an outdoor antenna, no amplification is generally needed.
P.S. If you have aluminum siding, that signal reduction goes to nearly 100%!  :eek:

[jkane]

Think the same as a dish.  The widest element goes to the back and the smallest towards the signal.  They are spaced like that so the last (widest) element reflects the signal back forward so you get gain by receiving the signal both on it's way towards the antenna, and then again as it's reflected by the back element.  Each element on most TV antenna's are for a different frequency.  They are tied together and you only pick up on the second from the last element.

Usually the UHF (smallest) part should be closest to the signal source.

It will work on the backside too, but you get a lot of loss.  The worst way to point it is sideways.  It rejects almost all of the signal from the sides.  The best way is to point at the "farm" like an arrow head.

[foxeng]

Smart questions for a new guy to ask! Answer to question 1 is indeed "a",
you are correct. You need to catch those waves! The "Pac Man" shaped fins should want to swallow the broadcast tower.    BTW, that is the UHF
signal reflecting part of the antenna.

Actually not.

What you appear to have described is what is called a yagi antenna. It is a directional antenna where the shorter elements are called the director elements, the element that has the cable connected is called the driven element and the longer elements beyond the driven element are called reflector elements.

You point the shorter elements (directors) toward the transmit antenna since they "direct" the signal in to the driven element and where the reflector elements act as a kind of "backsplash" so to speak. It is a little more complicated than that, but it is a good layman's explaination.

Many VHF/UHF yagi antennas are actually two antennas built on to one boom. The very short group of elements at the front is the UHF antenna, where the longer grouped antenna elements are the VHF antenna.



With this antenna you aim the short end toward the transmit antenna.

[Mags]

I appreciate all the help!

[Gilbert]

Actually not.

What you appear to have described is what is called a yagi antenna. It is a directional antenna where the shorter elements are called the director elements, the element that has the cable connected is called the driven element and the longer elements beyond the driven element are called reflector elements.

You point the shorter elements (directors) toward the transmit antenna since they "direct" the signal in to the driven element and where the reflector elements act as a kind of "backsplash" so to speak. It is a little more complicated than that, but it is a good layman's explaination.

Many VHF/UHF yagi antennas are actually two antennas built on to one boom. The very short group of elements at the front is the UHF antenna, where the longer grouped antenna elements are the VHF antenna.



With this antenna you aim the short end toward the transmit antenna.

FOXeng is definitely correct. I got confused as to what you meant by the ">>>"
and which way they pointed. Mea culpa.

[JohnRacine]

I don't disagree with the other posters one bit regarding their explanation of which way to point a Yagi antenna.  However, you will likely receive a strong signal off of the back as well.  I live on the Racine/Kenosha county line.  I keep my small, $20 antenna from Radio Shack permanently pointed towards Chicago.  All Milwaukee stations come in just fine off of the back.  I do not use any kind of an amplifier, just the little antenna and some coax.  I do have the antenna mounted on a rotor but never have to use it...turned out to be a waste of my money.  Good luck with your antenna selection/mount.