Tivo's have Known issues with Digital Broadcast Tv Signals that not perfect.
--> ALL Digital Broadcast Tv Transmission and Reception is Less Then Perfect<--.
Tivo's tuners do not deal well with multi-path reception.
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Most Digital Tv's have tuners that do a good job with multi-path reception.
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Also Digital Broadcast Tv tuners can develop - Digital Glitches - that are not cleared out with simple channel scans.
Do Double Rescan.
http://www.wchstv.com/DoubleReScanAlert.pdf.
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If combining the 2 UHF antennas use a Isolation transformer type combiner.
http://www.winegarddirect.com.
Model CC7870.
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http://www.solidsignal.com.
http://www.amazon.com.
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