Anthony and Kayla Schaefer's Blog » TV Antenna http://akschaefer.com A technology and personal blog. Sat, 21 Aug 2010 03:48:43 +0000 en hourly 1 http://wordpress.org/?v=3.0.1 DB2 Antenna Modification to include VHF http://akschaefer.com/2010/06/21/db2-antenna-modification-to-include-vhf/ http://akschaefer.com/2010/06/21/db2-antenna-modification-to-include-vhf/#comments Tue, 22 Jun 2010 03:38:29 +0000 tonyscha http://akschaefer.com/?p=1243 So back when the whole TV transition was just starting and I didn’t have a clue what I was doing, I bought an antenna that I thought would cover my needs. Its an Antenna Direct DB2 antenna. Its a nice Multi-directional UHF antenna and at the time it worked great because there wasn’t any VHF stations. However after the final transition, two of the major stations switched back to VHF to the channels 7 and 9. So when the world cup started on TV, I decided I needed ABC which was on channel 9. So I researched what I needed to do, and obviously I needed a VHF antenna, but I didn’t want to get rid of my current DB2 antenna. In basic I needed a simple half dipole antenna to add to my UHF antenna at the center.

Since I wanted channel 7 and 9, I found out which freq the channels broadcast in.
VHF HIGH 07 174-180 Mhz
VHF HIGH 09 186-192 Mhz

Found the calculations to get length of wire for frequency from this website here.

Formula: Length of wire = 468/frequency
Example: Length of wire = 468/180.000 Mhz (upper range of channel 7)
Length of wire = 2.6ft feet or approx 30″

I think the exact length was about 30.5″

The material I used for the antenna was some aluminum wire rod I picked up at Menards. I forgot to get the exact size but it was slightly larger then the original wire. I flattened the ends with a hammer and drilled a hole so I could mount it to the balun.

Here is the finished product. I would like to mention it picks up channel 7 and channel 9 now!!! So I would say this has been successful.

Here is the finished product.

Here is the back side and how it mounts to the balun.

Maybe after the two antenna projects I have done, maybe I should take an Electromagnetic fields Class from school…

I would like to note this may be unsafe to modify your antenna! NO guaranteed results!

]]> http://akschaefer.com/2010/06/21/db2-antenna-modification-to-include-vhf/feed/ 0 DIY 4-Bay UHF Antenna http://akschaefer.com/2009/12/28/diy-4-bay-uhf-antenna/ http://akschaefer.com/2009/12/28/diy-4-bay-uhf-antenna/#comments Tue, 29 Dec 2009 02:42:01 +0000 tonyscha http://akschaefer.com/?p=640 I decided to try and make a TV antenna from many different online resources I have read. The Antenna I made was a 4-Bay bow-tie antenna. You will see this called a coat hanger antenna also, because you can make the whisk out of coat hangers easily. I first read about this antenna from this website, but I am sure its been on the internet long before this. My goal was to get some vhf channels in ( channel 7,9 and 12) , and since this antenna is mostly UHF, I found some modified designs by mclapp that help produce a small gain in the VHF-HI range.

http://www.frontiernet.net/~mclapp/Antennas/4baystuff/4%20bay%209%201-2%20element%20layout.pdf

http://www.frontiernet.net/~mclapp/Antennas/4baystuff/4%20bay%209%20inch%20phase%20line.pdf

Unfortunately the antenna didn’t work as well as I was hoping it would. The antenna worked for 12,51 (2-1), and 20 in my area, even though there is channel 48 and 28 which it was missing. My guess is I did something wrong.

The antenna was fairly cheap to build from all store bought parts. It was under 9 dollars from my local Menards.
Wire ( I used 14 gauge galvanized steel)
#6 wood screws
#6 washers
Board from the scrap bin ( 15 cents !!! )
Balun – Converts it over to coaxial cable.

If anyone has any suggestions on why it doesnt work as well as my DB2, let me know :)

I would like to note: I am not an antenna expert, just a beginner. Just going off what I have read online for information.

]]> http://akschaefer.com/2009/12/28/diy-4-bay-uhf-antenna/feed/ 0