If a designated repeater is off the air, use the output frequency on simplex. Relay traffic if necessary. When the repeater comes back on the air, it will be obvious by the tone. When choosing additional simplex frequencies to use, choose the highest frequency practical for your needs. The higher the frequency, the greater need for line of sight transmission.
Directional antennas can be very helpful.
This frequency is used for the Monday ACS Net and many public service events. This frequency is often used for personnel and equipment requests and tracking. 7245 KHz LSB - Primary Daytime 40 Meter frequency. Listen on the hour if phones are down. 3915 KHz LSB - Primary Nighttime 80 Meter frequency.