What do you want to receive? If you want the LOS (line of sight) I would try a 2 bay UHF bowtie even though the PBS is VHF. For under $30 you should have a selection of small low cost antenna.
Do a Google for Eagle Aspen DTV2BUHF antenna price should start in the $19-12 area. I've used it out to 60 miles with an amplifier.
tvfool is wrong. Looking at the stations website CW is on channel 35 RF32 (KMYS) and MY Network is on KCWX 2. Yeah it looks weird.
In the 2009 annual report for Sinclair Broadcasting Group released in March 2010, that company disclosed that it had made an agreement to carry CW programming for the San Antonio area via KMYS beginning on September 1, 2010. The affiliation change was eventually moved up to August 30; at that time, MyNetworkTV, which had been carried on KMYS, moved to KCWX.