75ohm component cable with 50ohm rca's? (1 Viewer)

[Jeremy Porter]

I am making a 25 foot run of component video cable for HDTV. I will be using Belden 1505 (rg59) or 1694 (rg6) cable.The connectors are made by Nakamichi, but I don't know if they are 50 or 75 ohms. Will there be a problem if they are 50 ohm connectors.

 

[Seth_L]

Unless I really wasn't paying attention in my engineering classes the connectors shouldn't have any impedance. The cable used should determing the impedance.

 

[Chu Gai]

Well they do have an impedance and given that the RCA connector is so easy to deform, that impedance can and does vary under use and stress. Nonetheless, in order for the impedance of the connector to matter, a general engineering rule of thumb is that the distance in question of the impedance mismatch should be less than 1/8 (some say 1/10) of the wavelength of the signal in question. I'll leave it to others to work out the wavelengths if they know the frequency. However, if this is really really going to bug you and you're in the market for connectors just pick up the Canare's. Understand though that their calling them true 75's isn't true. Its just a marketing term. Somewhere in Tweaks, a long time ago, I posted a reply (not very well written) by an engineer from Canare who said as much indicating that their connectors are simply sweep tested to some frequency.