I've looked all over the internet for the type of antenna you built and can't find anything on it.
If you want to make your own I can recommend Mclapps DB4 or DB8. I have made several of the 10 x 9.5 DB4's and can say they just work great for me.
Here is his home page.
http://m4antenna.eastmasonvilleweather.com/index.html
There are also other good designs out there for Gray Hoverman and Yagi styles.
Also the PBS 21 station is not VHF, but UHF real channel 23. Your CBS channel 10 is however a VHF and so is 7 also a CBS.