[mythtv-users] OT Question About OTA Antennas

Brian Wood beww at beww.org
Thu Sep 20 15:44:00 UTC 2007

James Oltman wrote:
> I just purchased an HDHR.  Very cool device BTW.  I currently live in
> the country of Central Illinois.  There's an antenna on the top of a
> mast attached to the house.  It's probably above the tree line.  The
> antenna is on a rotor however, the rotor is broken.  This is what the
> antenna looks like.
> Top View:
> | | | | | | | | 
> | | | | | | | |  || || || || ||
> --------------------------->
> | | | | | | | |  || || || || ||
> | | | | | | | |
> That's kinda how it looks.  Anyways.  The pointy, narrow tip is
> currently facing North.  I need to turn it South West.  However, I don't
> know if the smaller end faces that direction or the larger (wider) end. 
> Which way should it face?  The way that I'm judging the signal strength
> is by hooking up the antenna feed (which runs through an amplifier,
> can't remember model or make) into the VCR and tuning to the analog
> channel and if that starts to come in better, then I'm assuming the
> digital will come in better as well (since they come from the same
> transmitter).  This is all assumptions and hopes and dreams at this
> point.  AntennaWeb says I should only receive my local FOX station
> (which I do just fine), but it didn't say anything about the religious
> channels which I also get.  Any help with the antenna anyone could
> provide would be helpful.  Thanks!

The smaller/shorter elements face towards the direction you wish to
receive signals from (generally the transmitter site unless you have
HORRENDOUS reflections to deal with.

The basic element of this type of antenna (a "log periodic", which is a
modified "yagi") is the "driven element". This is the one the signal is
received from ("driven" refers to when the antenna is used for

Passive elements are used to increase the directionality of the antenna.
A "reflector" is larger than the driven element, and is placed behind
it. A "director" is smaller than the DE, and is placed in front if it.

Usually a combination of many directors and reflectors is used, to
increase the directionality (or "front-to-back ratio") of the antenna.

(This is an extremely simplified explanation)

So, to answer your question, point the smaller elements towards the signal.


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