50 Ohm SMB Jack for 4 GHz Signal Paths
The 903-499J-51P2: The gold-plated zinc die cast body and gold-plated brass center contact handle 500 mating cycles with consistent contact resistance — the gold finish prevents corrosion in repeated mate/unmate field service. Insertion loss holds at 0.3 dB across the band, which keeps the link budget clean for a single mated pair in test equipment, telecom infrastructure, or instrumentation.
What Crosses When It's Dry?
The 903-415J-51P is the closest functional peer — same SMB style, 50 Ohm impedance, 4 GHz frequency cap, 0.3 dB insertion loss, gold body finish, and 500 mating cycles. The difference is body material: the 903-499J-51P2 uses zinc die cast, while the 903-415J-51P uses brass. For most RF signal paths the electrical performance is identical; the brass body on the 903-415J-51P is slightly harder, which can matter in high-vibration environments where the snap-on retention sees repeated shock. If the BOM calls for non-magnetic materials, the 903-NM415J-51P with beryllium copper contacts is the path — same 4 GHz and 50 Ohm spec.