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[Russell Ault]

Hi all!

Really quick question: I just noticed that Neutrik only sells 75-ohm (and not 50-ohm) D-series BNC panel connectors, and I'm wondering if they would cause problems with IEM transmitters. My research suggests that 75-ohm and 50-ohm BNC connectors manufactured in the last 25 years are mechanically compatible. I also know, from reading posts on this forum, that impedance mismatches on IEM transmit lines are a much bigger problem than they are on RX lines. So should I be seeking out 50-ohm pass-through connectors for IEM lines? What to people use in the real world?

Thanks!

-Russ

[Pete Erskine]

Hi all!

Really quick question: I just noticed that Neutrik only sells 75-ohm (and not 50-ohm) D-series BNC panel connectors, and I'm wondering if they would cause problems with IEM transmitters. My research suggests that 75-ohm and 50-ohm BNC connectors manufactured in the last 25 years are mechanically compatible. I also know, from reading posts on this forum, that impedance mismatches on IEM transmit lines are a much bigger problem than they are on RX lines. So should I be seeking out 50-ohm pass-through connectors for IEM lines? What to people use in the real world?

Thanks!

-Russ

You should use 50 ohm if that is the cable you are using, 75 ohm if your cable is 75 ohm

see digikey

http://www.digikey.com/product-search/en/connectors-interconnects/coaxial-connectors-rf-adapters/1442775?k=BNC+Jack-Jack&pv1340=13&pv60=92&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

[Jens Palm Bacher]

Hi all!

Really quick question: I just noticed that Neutrik only sells 75-ohm (and not 50-ohm) D-series BNC panel connectors, and I'm wondering if they would cause problems with IEM transmitters. My research suggests that 75-ohm and 50-ohm BNC connectors manufactured in the last 25 years are mechanically compatible. I also know, from reading posts on this forum, that impedance mismatches on IEM transmit lines are a much bigger problem than they are on RX lines. So should I be seeking out 50-ohm pass-through connectors for IEM lines? What to people use in the real world?

Thanks!

-Russ

http://www.canford.co.uk/Products/20167/49-280_D-SERIES-Recessed-BNC-double-sided-50-ohm-black

[Russell Ault]

You should use 50 ohm if that is the cable you are using, 75 ohm if your cable is 75 ohm

That's what I thought. Guess I was just surprised that Neutrik doesn't make a 50-ohm version.

http://www.canford.co.uk/Products/20167/49-280_D-SERIES-Recessed-BNC-double-sided-50-ohm-black

Oh how I wish there was a Canford dealer in Canada. They have so much good stuff, but so often it isn't worth the shipping (then again, sometimes it definitely is...).

Thanks!

-Russ

[Russell Ault]

To anyone who finds this and (for whatever reason) has their heart set upon having an Neutrik D-sized 50-ohm BNC pass-through, it turns out that the Neutrik part is actually just a D-sized metal shell with a separate 75-ohm pass-through connector threaded through it, and finding a similarly-sized 50-ohm connector turned out to be pretty trivial (in that I did so accidentally).

(The part I used was Digi-Key part number 367-1150-ND, but I'm sure there are others.)

-Russ

[Scott Holtzman]

To anyone who finds this and (for whatever reason) has their heart set upon having an Neutrik D-sized 50-ohm BNC pass-through, it turns out that the Neutrik part is actually just a D-sized metal shell with a separate 75-ohm pass-through connector threaded through it, and finding a similarly-sized 50-ohm connector turned out to be pretty trivial (in that I did so accidentally).

(The part I used was Digi-Key part number 367-1150-ND, but I'm sure there are others.)

-Russ

Impedance is determined by the aspect ratio of the center conductor to the outside shield.  It's not a question of mechanical compatibility.

[Aaron Becker]

I'm fairly certain that the IEM transmitters usually come with the appropriate pass-through connectors if you are rack mounting. You could swap these out in the D-sized mount as others have mentioned. I'm sure the manufacture of the IEM would also have the spare part number that would include the BNC connector, also, but it would likely be more expensive than buying the part directly from a vendor such as Digi-Key.

[Pete Erskine]

Impedance is determined by the aspect ratio of the center conductor to the outside shield.  It's not a question of mechanical compatibility.

Actually mechanical size is different.  50 Ohm BNC connectors have a thicker pin than 75 ohm connectors.  Where this will bite you is if you are using 50 ohm cables for your Riedel coax panel connections and then switch back to 75 ohm the female on the panel will have been spread and will be intermittent now.

[Russell Ault]

Actually mechanical size is different.  50 Ohm BNC connectors have a thicker pin than 75 ohm connectors.  Where this will bite you is if you are using 50 ohm cables for your Riedel coax panel connections and then switch back to 75 ohm the female on the panel will have been spread and will be intermittent now.

Hi Pete!

Okay, now you're making me a little nervous: my understanding (given to me by Canford) was that IEC 169-8 (and now IEC 60169-8) required 50 and 75 ohm BNC connectors to mate non-destructively, and that this has been generally true for a while. Are there any other known exceptions?

Thanks!

-Russ

[Pete Erskine]

Hi Pete!

Okay, now you're making me a little nervous: my understanding (given to me by Canford) was that IEC 169-8 (and now IEC 60169-8) required 50 and 75 ohm BNC connectors to mate non-destructively, and that this has been generally true for a while. Are there any other known exceptions?

Thanks!

-Russ

Maybe it's older 50 ohm connectors but we were burned about 10 years ago on a job where ALL of our panels were 50 ohmed by another client and almost destroyed our show.

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