aters . ▁For ▁example , ▁a ▁ 1 5 0   M Hz ▁hand ▁held ▁may ▁communicate ▁to ▁a ▁vehicle - mount ed ▁low - power ▁trans ce iver . ▁The ▁low - power ▁radio ▁repe ats ▁transm issions ▁from ▁the ▁port able ▁over ▁the ▁vehicle ' s ▁high ▁power ▁mobile ▁radio , ▁which ▁has ▁a ▁much ▁longer ▁range . ▁In ▁these ▁systems , ▁the ▁hand - h eld ▁works ▁so ▁long ▁as ▁it ▁is ▁within ▁range ▁of ▁the ▁low ▁power ▁mobile ▁repe ater . ▁The ▁mobile ▁radio ▁is ▁usually ▁on ▁a ▁different ▁band ▁than ▁the ▁hand - h eld ▁to ▁reduce ▁the ▁ch ances ▁of ▁the ▁mobile ▁radio ▁transmit ter ▁inter fer ing ▁with ▁the ▁transmission ▁from ▁the ▁hand - h eld ▁to ▁the ▁vehicle . ▁▁ ▁Motor ola , ▁for ▁example , ▁market ed ▁a ▁veh icular ▁repe ater ▁system ▁called ▁P AC * RT . ▁It ▁was ▁available ▁for ▁use ▁with ▁ 1 5 0   M Hz ▁or ▁ 4 5 0   M Hz ▁hand - h eld s ▁and ▁inter fac ed ▁with ▁some ▁Motor ola ▁mobile ▁rad ios . ▁ ▁In ▁the ▁ 1 9 8 0 s , ▁General ▁Electric ▁Mobile ▁Radio ▁had ▁a ▁ 4 6 3   M Hz ▁emer gency ▁medical ▁services ▁radio ▁that ▁featured ▁a ▁ 4 5 3   M Hz ▁veh icular ▁repe ater ▁link ▁to ▁a ▁hand - h eld . ▁ ▁There ▁is ▁a ▁difficult ▁engineering ▁problem ▁with ▁these ▁systems . ▁If ▁you ▁get ▁two ▁vehicle ▁rad