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Old 14-Jul-2015, 6:33 PM   #4
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,355
Quote:
but I'd have to use a 2-way splitter to bring both uhf antennas into one side of my UVSJ. The other uhf antenna gets all my other local uhf channels.
No, don't use a splitter in reverse as a combiner for your test, it doesn't always work. The CPF will pass 20 and reject the rest, but you also need to block 20 from the other UHF antenna. This is what Channel Master Jointennas do and what the AC7 does. They both contain a bandpass and a band stop filter for the same channel.

For a test just try the second antenna with the CPF and an amp if needed to see if it will work.

I agree with your evaluation on co-channel and 2nd adjacent (Taboo 2-away) channel interference.

ATSC Recommended Practice:

Receiver Performance Guidelines
Document A/74:2010, 7 April 2010

RECEIVER PERFORMANCE GUIDELINES

5.4.1 Co-Channel Rejection

Quote:
The receiver should meet or exceed the following thresholds for rejection of co-channel interference at the following desired signal levels (Table 5.1).


5.4.3 Taboo Channel Rejection

Quote:
The receiver should meet or exceed the following thresholds for rejection of taboo-channel interference at the desired signal levels (Table 5.3, 5.4)


http://www.avsforum.com/forum/25-hdt...xchange-3.html
http://www.warrenelectronics.com/Ant...Jointennas.htm
http://www.channelmaster.com/JOIN_TE..._p/cm-0583.htm
Attached Images
File Type: jpg Co-Channel Rejection Thresholds2.JPG (42.3 KB, 1454 views)
File Type: jpg Taboo Channel Rejection2.JPG (64.0 KB, 1525 views)
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Last edited by rabbit73; 14-Jul-2015 at 7:26 PM.
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