Best type of connection to maintain 75ohm

john dozier · 26th February 2013, 07:27 PM

When using BNCs, what is the best type of connection to maintain true 75ohm empedence, crimp, compression, or solder? Thanks

Harleyjon · 26th February 2013, 07:35 PM

A BNC connector is 50 Ohms.

john dozier · 26th February 2013, 07:42 PM

There are two types of BNC, one 50 and one 75ohm. Regards

cliffforrest · 07:47 PM

Hmmm!

BNC comes in 2 flavours, 50R and 75R. They are slightly different size, physically and mate best with different cables.

There is much room for confusion here! Some would say that for the very low speed in digital audio it would make not a jot of difference.

All conection types are designed to maintain the correct impedance, as far as it goes. Crimping is the neatest and easiest, but does mandate the matching cable to the connector.

Harleyjon · 26th February 2013, 07:45 PM

My appologies, we use BNC for 50 Ohm aerials on shipping. 75Ohm is usually a Coax Connector.
As long as the connection is good, the housing maintains the impedance. Personally I prefer solder but if carried out correctly, it makes no difference.

Speedskater · 12:20 AM

As "cliffforest" wrote:
Some would say that for the very low speed in digital audio it would make not a jot of difference.
I'm one of those people.

I would also add "the short length of our connectors & cables"

counter culture · 27th February 2013, 12:42 AM

Quote:

Originally Posted by john dozier

crimp, compression, or solder?

It makes no difference to the impedance. BNC are often a combination of solder and compression, but you get crimp types too. Crimp is probably better for production line assembly and solder/clamp better for DIY.

Bibliophile · 27th February 2013, 01:06 AM

Quote:

Originally Posted by john dozier

There are two types of BNC, one 50 and one 75ohm. Regards

The 50 Ohm ones have a thicker centre pin.
Be sure not to use them with 75 Ohm sockets as you could spread the socket centre and make it unreliable for 75 Ohm connectors.

DF96 · 27th February 2013, 10:55 AM

The 'thicker central pin' claim is often made, but many deny it. There was a long debate about this a few years ago. I can't remember whether it was on here or a UK vintage radio site. I think the concensus was that the pins are supposed to be the same size, and the change in impedance is obtained by using less dielectric in a 75 ohm socket.

Bibliophile · 27th February 2013, 04:46 PM

I have seen the thicker pin variety but this Wikipedia article supports what you are saying.

BNC connector - Wikipedia, the free encyclopedia

26th February 2013, 07:27 PM	#1
john dozier diyAudio Member Join Date: Dec 2010 Location: columbia sc	Best type of connection to maintain 75ohm When using BNCs, what is the best type of connection to maintain true 75ohm empedence, crimp, compression, or solder? Thanks __________________ Evil looms. Cowboy up. Kill it. Get Paid.

26th February 2013, 07:42 PM	#3
john dozier diyAudio Member Join Date: Dec 2010 Location: columbia sc	There are two types of BNC, one 50 and one 75ohm. Regards __________________ Evil looms. Cowboy up. Kill it. Get Paid.

26th February 2013, 07:44 PM	#4
cliffforrest diyAudio Member Join Date: Sep 2004 Location: UK	Hmmm! BNC comes in 2 flavours, 50R and 75R. They are slightly different size, physically and mate best with different cables. There is much room for confusion here! Some would say that for the very low speed in digital audio it would make not a jot of difference. All conection types are designed to maintain the correct impedance, as far as it goes. Crimping is the neatest and easiest, but does mandate the matching cable to the connector. Last edited by cliffforrest; 26th February 2013 at 07:47 PM.

27th February 2013, 12:18 AM	#6
Speedskater diyAudio Member Join Date: Sep 2002 Location: Lakewood, Ohio	As "cliffforest" wrote: Some would say that for the very low speed in digital audio it would make not a jot of difference. I'm one of those people. I would also add "the short length of our connectors & cables" __________________ Kevin Last edited by Speedskater; 27th February 2013 at 12:20 AM. Reason: added content

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26th February 2013, 07:35 PM	#2
Harleyjon diyAudio Member Join Date: Dec 2012 Location: England	A BNC connector is 50 Ohms.

26th February 2013, 07:45 PM	#5
Harleyjon diyAudio Member Join Date: Dec 2012 Location: England	My appologies, we use BNC for 50 Ohm aerials on shipping. 75Ohm is usually a Coax Connector. As long as the connection is good, the housing maintains the impedance. Personally I prefer solder but if carried out correctly, it makes no difference.

27th February 2013, 10:55 AM	#9
DF96 diyAudio Member Join Date: May 2007	The 'thicker central pin' claim is often made, but many deny it. There was a long debate about this a few years ago. I can't remember whether it was on here or a UK vintage radio site. I think the concensus was that the pins are supposed to be the same size, and the change in impedance is obtained by using less dielectric in a 75 ohm socket.

27th February 2013, 04:46 PM	#10
Bibliophile diyAudio Member Join Date: Nov 2011	I have seen the thicker pin variety but this Wikipedia article supports what you are saying. BNC connector - Wikipedia, the free encyclopedia

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