Another idea:
4. Channel Master used to make a device called a JoinTenna to join two antennas. You might be able to find one for CH23. One input would pass only the FOX CH23 signal and reject all others. The other input would pass all other channels and reject CH23. The output combines both.
http://www.warrenelectronics.com/Ant...Jointennas.htm
http://www.avsforum.com/t/1152566/th...tenna-exchange
Google search
If you can't find a CH23 JoinTenna, Tin Lee Electronics in Canada can make a custom filter, but it would cost more than $100.
http://www.avsforum.com/t/945821/alt...e-to-jointenna
Google search
http://www.tinlee.com/index.php
http://www.tinlee.com/MATV_headend.p...IGNALINJECTORS
http://www.tinlee.com/PDF/AC7-custom...kup%20Info.pdf