Consult your local band plans and listen for a while to make sure frequencies are not occupied before using any recommended frequencies
144.99 has been used effectively for mobile and portable stations in conjested areas like Dayton Hamvention with high stations that digipete to 144.39.
BBS systems have and may still operate on this frequency in some areas.
We might he wise to use this design for qruqsp relay stations with a 1.25 M frequency to be determined.
See http://www.aprs.org/dayton/dayton.txt
http://www.aprs.org/APRS14499.txt
http://www.txvhffm.org/coordination/bandplan.php
Texas VHF-FM Society Band Plans
6 Meter Band Plan
50.000 - 50.100 CW (50.06 - 50.08 Beacon sub-band)
50.300 - 50.600 Mixed Modes (50.400 AM Calling Freq.)
50.600 - 50.780 Packet and other data modes
53.530 BeaconNet APRS
148 MHz Band Plan
144.000 - 144.100 CW
144.275 - 144.300 Propagation Beacons
144.300 - 144.500 Satellite Sub-Band
144.390 Automatic Position Reporting System
144.900 - 145.100 Packet
145.500 - 145.800 Simplex and Experimental
145.800 - 146.000 Satellite Sub-Band
219 to 220 and 222 to 225 MHz Band Plan
219.000 - 220.000 Secondary Point to Point fixed digital message forwarding see FCC rules Part 97.303(e) for details
222.000 - 222.150 Weak Signal Modes
222.100 SSB/CW Calling Freq.
223.520 - 223.640 Packet
440 to 450 MHz Band Plan
440.000 - 440.500 Digital Wide Band Output (50 or 100 KHz wide)
440.525 - 440.725 Digital Narrow Band Output
441.100 - 441.175 Simplex NB Digital
445.000 - 445.500 Digital Wide Band Input (50 or 100 KHz wide)
445.525 - 445.725 Digital Narrow Band Input
Following frequencies coordinated for digital modes in California source: ncpa.n0ary.org/ncpabandplan.html">http://ncpa.n0ary.org/ncpabandplan.html