Radio Shack used to make a combiner for all 3 TV bands, the 15-1236:My tower is at 100 ft with 3 UHF , 3 VHF high and one VHF Low antenna.
Three tower mounted Preamps that feed into three RG11 runs. to the base. ....I have no problems with the VHF high and the UHF coming into my headin however, I can't find a combiner that will let me add in the VHF-low into the mix. .
You can do the same thing by using a UVSJ (UHF/VHF Separator-Joiner) and a HLSJ (VHF-High/VHF-Low Separator-Joiner). This is one way to do it:
With this method there is only one insertion loss for UHF, and you can insert a preamp for UHF only (if desired) between the UHF antenna and the UVSJ if the UVSJ can pass DC on the UHF side.
UVSJs and HLSJs are also known as Diplexers. They can combine or separate two different bands.
Calaveras uses a similar method for his TV antennas: