Unlikely you will find a single channel notch filter for sale, though one can easily be built. Without looking up the present TV channel frequencies, a Band Pass filter (probably Low Pass) may work. Possible sources:
Morgan Manufacturing http://www.morganmfg.us/
The standard list:
-Re-orient the antenna
-move the antenna further away/higher
-Tidy up: straighten out (TV) cables, power cords, don't overlap, coil up unused lengths, attach chokes close to TV (that appropriate Mix for the frequencies in question).
-place covers or even aluminum foil over any cable F type connectors not in use.
-Simplify your setup for troubleshooting. Remove the second TV antenna. Work with only one antenna.
-Borrow a different TV and see if it has the same interference.
Realistically, a 1w HT shouldn't cause interference to a TV. If all else fails you may need to get a different TV, or coordinate your hamming so as not to bother the family.