DB2 Antenna Modification to include VHF

June 21st, 2010 | Posted by tonyscha in Personal | Technology

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!

You can follow any responses to this entry through the RSS 2.0 You can leave a response, or trackback.

4 Responses

  • Pingback: Trying to find and understand how to pick the right Antenna

  • Paul Orsini says:

    yes this is correct it connect to both-sides of the 300 to 75 block and you are done and your math seem correct so people could go to lowes and get alum strips and cut to each vhf channel u need normally only one and avoid teh huge VHF antenna outside

    I did teh same thing with 2 yard sticks and 21/16 x 1/2 flat aluminum and a indoor 300 to 75 ohm cut to channel 10 28.36 each side and hung with velco on teh back of teh tv rememebr to keep tehm from touching each other or anything else that conducts paint metal

  • Paul Orsini says:

    that was 2 @ 1/16 x 1/2 flat alum cut to the channels lengths

  • James Robbins says:

    Worked great. I cut mine for channel 11. I am 16mi from the antenna farm and needed two UHF ganged

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>