[Elecraft] 50 and 75 ohm BNC Connectors

[Richard Kent]

While not an RF application. 75 ohm connector BNC and others are important
to the digital video production environment. It is my understanding that a
50 ohm barrel at the end of the correct length of coax will stop a digital
video signal. I am in the process of installing a new digital switcher and I
am watching connector, barrels, terminators impedances closely.

Rick Kent
WD8AJG K2 5296

-----Original Message-----

I've received a question about compatibility of 50 ohm BNC male 
connectors with the 75 ohm female BNC connectors on Exetron's ADA 6 
300MX video distribution amplifier.

Amphenol makes the following statement about 50 and 75 ohm BNC connectors:

"Two distinct types of 75 O BNC's are available, and both mate with each 
other and with 50 O BNC's. Type 1 is designated 75 O BNC-T1 and provides 
constant 75 O performance with low VSWR DC 4 GHz. Type 2 is designated 
75 O BNC-T2 and is usable with low reflection DC - 1 GHz. For 
applications above 1 GHz, Type 1 is recommended. "

Unlike BNC connectors, however, please remember that 50 and 75 ohm Type 
N connectors are not mechanically interchangeable and that physical 
damage results when a 50 ohm N male connector is inserted into a 75 ohm 
female N connector.

I've added more details on using an ADA 6 300MX to distribute timing 
signals in today's update. http://www.cliftonlaboratories.com/Updates.htm

Jack K8ZOA
www.cliftonlaboratories.com