I was inspecting a customer’s TV antenna installation recently and noticed that the bowtie was still folded up.  I see this problem often enough that it is worth going over the details.

Most combo VHF/UHF antennas are designed to fold up so that they can fit in a smaller box for shipping.  For example, a typical VHF/UHF antenna is 90″ x 110″ x 19″ unfolded, but ships in a box only  6.5″ x 6.5″ x 101″.  You unfold the antenna after taking it out of the shipping carton and then install it.  I have noticed that the unfolding instructions that come with most antennas aren’t very clear about the process.  They have a black and white line drawing showing the unfolded antenna, but the small details aren’t very clear.  One very important element that needs to be unfolded is the bowtie.  This is a folded dipole that is the focus of the signal.  It is easy to find because that is where the coax cable attaches to the balun and the balun attaches to 2 wing nuts.  If it is not unfolded, the energy is focused onto empty air, and most of the signal is lost.  If you loosen the wing nuts it may be a little easier to unfold.  Retighten the wing nuts after unfolding.

Here is a picture of the bowtie in the folded position for shipping:

 

 

This is an unfolded bowtie, correctly unfolded and ready for installation:

 

You would be amazed how much more signal you get when this one small element is in the right configuration.   I measured a 12 dB increase on some UHF channels after I unfolded the bowtie.
I mentioned this to my customer, and asked him if he had installed it himself.  He said that he had paid Best Buy to install the antenna!  Even an antenna installer can make this mistake it seems.  This was 2nd one I have seen this year.  Go check your bowtie!