The television antenna is designed to be mounted horizontally to get TV signals that broadcast sending signals that are horizontally polarized. Radio signals from police, fire, aircrafts are mainly vertical polarization. Like the previous post above, it will drastically cut your reception. You will have to drill holes in the antenna main beam 90 degrees and mount it .
The elements on the TV antenna are cut originally for the VHF-low (54-76Mhz) VHF High (approx 170-220Mhz) and UHF (approx 500-800 Mhz).What this means is that out of band signals like pagers, etc will come over the regular signals causing lots of interference, ghost images , etc. The antenna would also be very directional and pick up signals only in one area.
The hobby is really for experimenting so if you want to try the antenna go ahead. Radio Shack sells a matching transformer that has two separate leads (300 ohms) that screws on the antenna and another side that terminates as an F connector. From here you can buy adapters from F to BNC or F-PL259, etc.
I would prefer to get a dedicated antenna that would be much smaller, less wind resistance/damage, and one that would really pick up signals in the scanner bands without the interference.