Brentwood FD (3-2-0) dispatches East Brentwood FD (3-3-0) full time.
Both departments are activated on 476.5625 PL 81.9 (Brentwood FD's freq)
Both departments talk to dispatch on 476.800 PL 77.0 (Brentwood FD's freq)
East Brentwood has their own repeater 460.150 DCS 031. They'll use it amongst themselves or Brentwood Dispatch might slide them over to this freq if Brentwood FD UHF is busy with a working fire/mult alarms etc.