On Tue, 20 Jan 2009 06:52:36 -0800 (PST), Mike
wrote:

Hello. I have an antenna in my attic and 2 digital converter boxes
and I'm ready for the digital switchover. There are a couple other
channels that I cannot get with my current antenna, and I'm
considering building an antenna as shown in this video and pointing it
in another direction:

http://www.youtube.com/watch?v=EWQhlmJTMzw

My question is this....how do I add another antenna to my existing
system? Is it as simple as just running BOTH antennas into a
splitter? A splitter is generally used to split a signal into 2
signals, but can it work the other way (combining the signals from 2
antennas into 1 signal which will go to my TVs)?

Thanks a lot!

Mike

Yes, you can reverse the splitter to make it combine the two signals
and keep the proper impedance. The only problem is.........the two
antennas may be located far enough apart that the signal induced
into antenna A may be out of phase with the signal induced into
antenna B. When this happens with an analog signal you may
get ghosting or just a reduced signal level that would not justify
using two antennas. With a DTV you may get a inferior signal level.
To reduce the possibility of out of phase antennas you should try to
mount them side by side so that the distance to the transmitting tower
is the same for both. On the upper frequencies a half wave or 100%)
phase shift is only 8 inches. On the lower frequencies it is around
2.5 feet. Keeping the antennas perpendicular and side by side is your
best bet. Signal deflection from mounting the antennas inside could
also cause a out of phase problem. Good luck.