BNC Cable Question

[DaWoofer]

What type of coaxial cable to purchase for connecting to BNC adapters?

[drknstrmyknight]

Depends on what's being connected to what.
Ham might be 50 ohms, a radio/tv antenna 70 ohms.
Arcnet, ethernet, and video terminals use em too.
RG6 is pretty common for video distribution.

[DaWoofer]

Test equipment. 50 ohm.

[mhardy6647]

How about for BNC-terminated digital I/O on a DAC or CDP? 50 or 75 ohm?

[bricktop]

How about for BNC-terminated digital I/O on a DAC or CDP? 50 or 75 ohm?

I believe most commercial video and audio (like the ones on the back of the tv and receiver) cable impedances are 75 ohms, unless specified otherwise.

An interesting read as to why those impedances are common...
http://www.microwaves101.com/encyclopedia/why50ohms.cfm

The most common consumer digital audio standard is S/PDIF (RCA connector), here is a good article on the different standards, including the one that uses BNC connectors.
http://www.sencore.com/newsletter/Apr07/DigAudStdConnect.htm

What type of coaxial cable to purchase for connecting to BNC adapters?

For this, RG-59 for 75 ohms and RG-58 for 50 ohms - is probably a good common one, find a type with stranded center conductor to make it easy on the jacks, since the BNC connector already has a metal pin included in it, you won't need to use the solid core type like with a regular cable F connector.

[drknstrmyknight]

How about for BNC-terminated digital I/O on a DAC or CDP? 50 or 75 ohm?

75 IIRC