AJA C10DA: distributing reference and checking termination and gain

Choose a distributor for the signal it receives

Check whether the reference is analog and which inputs need termination. Do not substitute an SDI splitter merely because its connector is BNC.

The AJA C10DA Mini-Converter manual v1.0r1, p. 5describes one analog input and six separately buffered outputs. It lists bi-level and tri-level reference, NTSC/PAL, AES3-id and LTC. The diagram distributes the incoming signal; it does not show reference generation or format conversion. With no signal at INPUT, the C10DA cannot create one.

To choose a device, record the signal type and check what the exact receiving model accepts. Do not select a box solely by its BNC connectors or use settings from an unidentified Blackmagic variant.

Draw three separate paths: program picture, reference and timecode. The C10DA can distribute LTC, but that does not turn LTC into genlock or allow each output to carry a different signal: all six outputs originate from the same input. For reference generation, see the GEN10 guide.

INPUT, outputs and DIP switches: read the labels before connecting

On p. 6, INPUT sits next to OUT 5 and OUT 6; OUT 1–4 are on the other side. OUT 5 and OUT 6 are distributor outputs, not a passive input loop. Follow the labels while wiring and record which BNC feeds each receiver.

The same p. 6 defines DIP 4: left terminates INPUT at 75 ohms; right leaves it open. DIP switches 3, 2 and 1 set gain according to the diagram on p. 7, from –3 to +3 dB in 1 dB steps. Read the switch numbers and orientation on the unit's label; do not infer them from how the unit is mounted in the rack.

The table shows two gain combinations and both termination positions. According to the diagram on p. 5, gain applies to the shared path before the six outputs. If you change it for one camera, check the other branches as well.

The installation procedure on p. 6starts by disconnecting power, then connecting the BNC cables, and finally applying DC power. Prepare the setup off air and record the previous state. The configuration note says this model does not support Mini-Config: its settings use the DIP switches.

This table applies to the C10DA Mini-Converter. The OG-C10DA is a different model; do not carry over these switch positions or the number of outputs. Identify the unit and its power supply before testing.

A camera locks directly but loses reference through the distributor

If a camera locks on a direct path and fails through distribution, the path change is what the comparison establishes. It does not prove that a C10DA setting, DIP position or P/PsF change will repair the fault. The VENICE generation, firmware and full settings of other boxes also remain to be identified.

For a controlled test, keep the format that worked directly and change only the path. Start with one receiver, a verified cable and one C10DA output; record all four DIP switches. If direct works and distributed fails, distribution is the observed difference, but the cause is still unknown. Check INPUT, power, termination, gain and level on that branch.

For a direct generator-to-INPUT path with no loop or other loads, start the proposed test with INPUT terminated at 75 ohms and gain at 0 dB, then check the received signal. This is a test configuration for that path. If there is a T connector or additional loads, identify where termination occurs and how every device is configured; do not copy the manual's open-input example without checking the circuit.

DIP 4 acts on INPUT. It does not configure termination at the camera input or at a downstream Ref Loop. Check each receiver's manual: a passive loop and an already terminated input are different paths. The reviewed C10DA manual does not prescribe an external terminator for every unused output.

If you have a suitable reference-measurement instrument, record the signal at the source, INPUT and destination, identifying the measurement load. Record more than signal presence: capture waveform, level, rate and instrument settings. Do not add unrecorded loads while measuring. A lit power LED does not prove that reference is being received.

Gain: correct a measured level without hiding a connection fault

Before increasing gain, check that INPUT receives the right reference and that cables and loads are identified. If the signal is missing or the receiver needs another reference format, raising the level will not solve that. The VENICE case does not prove attenuation is the fault or that changing a DIP switch will fix it.

Page 7 provides the DIP combinations; p. 8 specifies gain range and tolerance. If a measurement justifies a change, record the old and new settings and the level received on every branch. The 0 dB and +1 dB examples show possible settings; they do not establish what a long cable needs.

If only one camera fails while the others lock, compare that branch and receiver before changing shared gain. If all fail, record what they share: source, input, settings and power. These are proposed diagnostic paths; the worksheet contains no completed test results.

Complete the blank C10DA reference-distribution worksheetwith each comparison and its evidence. Check lock, picture continuity and latency separately; none can be inferred from another.

Connect the distributor, camera and event processor

Use this review alongside GEN10: generation and formats, Canon C400: input, lock and LTC and FS4: format, audio and sync. Keep the model in view when checking controls and termination.

For a conference with LED, recording and streaming, assign a branch and a record to each receiver. That information helps plan video processing and distribution. The VENICE MPC-3610 guide based on manual 2.0 (Spanish guide) documents reference options and states for that edition. Identify the actual cameras, firmware and Evertz or Blackmagic variants in your chain.