Interference Mitigation on 06

As many members know, there has been an intermittent interference issue affecting the VHF repeater. 

What the committee believes is happening is that two signals are mixing with the product of the two showing up at the link receiver.  This is why members hear the Stadium courtesy tone after the repeater drops. 

One of the two signals mixing is SCARS' own UHF system; the other is unknown. 

The receiver for the link to the Stadium Remote is protected by a CTCSS tone.  Unfortunately, until recently that tone was the same as the tone for the UHF system (141.3 Hz).  Since the new UHF repeater transmits a tone (the old one only required a tone for access), the mixing product was being passed to the controller and repeated on VHF just as if someone was using the Stadium Remote. 

Members of your Technical Committee recently visited both the Main repeater site and the Remote receiver site to change that tone. 

Remember, changing the CTCSS tone at both ends of the link only mitigate the interference issue; the interference was not eliminated.  Since the mixing product is still present at the link receiver, it is possible that members will hear the interfering signal while the
Stadium Remote is in use

Note:  This tone change was done "behind the scenes" - no user changes are needed!