Adding another antenna to my existing antenna set-up wrote:

Andy comments: A very good answer .
One caveat..... The phase difference into the splitter from each antenna will be not only spacing dependent, but ALSO frequency dependent.... In other words, what will work fine at , say, 200 Mhz may cause a deep null at another frequency, like ,say 300 Mhz. And this will occur at multiple places in the VHF and UHF bands. This may not be a problem, depending on where the stations are located, frequency-wise.....
The best answer is to use a switch between antennae to select the best signal. However, a splitter/combiner will save having to throw the switch, IF it doesn't have phasing problems. You just have to give it a try for your own specific location.
For the record, a properly designed splitter (2way) has an internal resistor that is only effective if one of the outputs is not terminated properly. If both outputs are terminated properly, the resistor does nothing. The signal will be halved (3db) to each output, PLUS about a half db of internal loss.
To learn more about splitters, go to a MINI-CKTS LAB website, (you can google the address). They manufacture these components, and have many tutorial papers on how they are built, and how they should be used.
Andy in Eureka, retired RF engineer from Raytheon.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.