Left: OVRO data vs. MJD. Centre: OVRO (filled squares, black) data and GBI 8 GHz data (empty squares, red) vs. Θ; Θ is the fractional part of (t − t₀) / 1667 with t₀ = JD 2 443 366.775 (Gregory, 2002). Right: OVRO (black) data and GBI 8 GHz data (red) vs. Φ, where Φ is the orbital phase, i.e., the fractional part of (t − t₀) /P₁, with P₁ = 26.496 days (Gregory, 2002). The largest radio outbursts occur around Φ = 0.6. At Φ = 0.23, i.e., at periastron, only a low level of emission is present.