The **48AV-2CHD-R** is a high-density, professional-grade **BNC Patch Panel** manufactured by **Canare**. It is primarily used in broadcast studios, post-production facilities, and telecommunications racks to manage high-definition video signals. --- ## 1. Technical Specifications The "48AV" designation refers to the 48-port configuration (2 rows of 24), and "2CHD" refers to the specific normaled/video jack type. | Feature | Specification | | :--- | :--- | | **Rack Units (RU)** | 1RU (1.75 inches) | | **Total Ports** | 48 (2 x 24) | | **Format** | 3G-SDI / HD-SDI Compatible | | **Impedance** | 75 Ohms | | **Return Loss** | >20dB @ 1.5GHz / >10dB @ 3.0GHz | | **Connector Type (Front)** | Dual Video Jacks (Wecco Standard) | | **Connector Type (Back)** | BNC Female | --- ## 2. Key Electronic Components ### A. Internal Video Jacks (Normaling) The core "electronic" logic of this panel is the **Normaling Mechanism**. Unlike a simple coupler, these jacks contain internal switches: * **Normalled (Normal-Through):** The top jack is internally wired to the bottom jack. No patch cable is needed for the signal to flow from source to destination. * **Breaking the Normal:** Inserting a patch cord into either the top or bottom jack physically breaks the internal connection, allowing the signal to be rerouted. ### B. Gold-Plated Contacts To maintain signal integrity for 3G-SDI (2.97 Gbps), the internal switch contacts are typically **Gold-Plated**. This prevents oxidation and ensures low contact resistance over thousands of insertion cycles. ### C. BNC Interface (Rear) The rear of the unit features 48 BNC connectors. These are precision-engineered to maintain a consistent **75-ohm impedance**. Any deviation in impedance would cause "ghosting" or signal reflections, which are critical in digital video. --- ## 3. Physical Layout The unit is designed for high-density environments where space is at a premium. 1. **Front Panel:** Houses the patch points and a designation strip for labeling. 2. **Chassis:** Constructed of cold-rolled steel with a powder-coated finish for durability and EMI shielding. 3. **Cable Management:** Often paired with a rear support bar to prevent the weight of BNC cables from straining the internal connections. --- ## 4. Signal Application The 48AV-2CHD-R is rated for: * **SD-SDI:** Standard definition. * **HD-SDI:** 720p/1080i. * **3G-SDI:** 1080p (This is the upper limit for this specific model series).