2012Center Post forum
Cable and connector selection for HD-SDI video installations
14 years old. Gear and prices may have changed since.
DisputedParticipants disagreed and reached no conclusion. Read the findings as positions, not as an answer.
What the thread found
- All HD-SDI cables must have 75 ohm characteristic impedance.
- Belden 1505 stranded cable is suitable for HD-SDI applications in flexible setups like collapsing center posts.
- Belden 1694A is a solid copper HD-SDI cable that is very stiff and less ideal for applications requiring repeated flexing.
- Belden 1694F is a flexible stranded version of 1694A cable but is more expensive and larger than necessary for center post applications.
- Belden 1855A is a smaller solid core HD-SDI cable that provides good flexibility for confined spaces and can be soldered to connectors like lemo plugs.
- Belden 179DT is an alternative HD-SDI cable option.
- HD-SDI cables should be rated for at least 1.5 gigahertz bandwidth.
- 75 ohm rated connectors must be used with HD-SDI systems.
- Crimp connections are the preferred professional method for attaching BNC connectors to HD-SDI cables.
- Soldered BNC connections can work reliably in practice if properly executed with epoxy and shrink tubing for mechanical support.
- Stranded core cable is easier to work with during soldering compared to solid core cable.
Depends on
- The comparison between soldering and crimping for HD-SDI connectors remains unresolved with disagreement among practitioners.
- The claim that soldering changes the 75 ohm resistance characteristic is unverified speculation.
- Using smaller gauge stranded cable may require compensation to match transmission capabilities of larger gauge solid copper cable.
- The 1694F cable's larger size may not be practical for center post installations.
- All advice is based on practical experience rather than formal engineering analysis.