It has been stated in other threads that there are significant differences in insertion loss among 300/75 baluns, especially at UHF frequencies. I have always felt that many of the dramatic SS gains attributed to the "DBT mod" actually resulted from the removal of the cheapie type with the piercing screws/barrel connector and replacing with a good quality "spade lug" design balun that can be attached directly to the DBT. I made this exact balun change on my attic DBT and SS improved about 10 units on every channel. I have had very good luck with the CM 7281 balun over the years and have 3 of them in use, but it may be discontinued. Winegard makes some good baluns, and I think RS used to have one around $10 in their catalog that tested out well.