Should I disconnect or terminate my SL-2 MCX to SMA cables when not in use?

[WaterlooNorm]

I'm looking forward to your advice here.

 

I've utilized the convenient auxiliary MCX antenna outputs from the Sound Devices SL-2 for distributing my antenna signal to a third receiver. When I don't need a third receiver, it would be nice if I could leave those two MCX-to-SMA cables connected to the SL-2 and the SMA ends unconnected.

 

If I leave them connected to the SL-2 and not connected to a receiver, am I creating RF issues by doing so? If so, do I have to disconnect them, or could I terminate them somehow?

 

Thanks all.

 

[DanieldH]

I'd try it out and if I'd run into issues, I'd try if a 50Ohm terminator helps.

[fieldsound]

Not sure about the SL-2 but Christian at BSRF recommended that I terminate all unused ports on my RF distro. I would imagine it would be considered best practice for all RF distros.
 

I asked Christian if I could use a termination on the end of my coax cables to make swapping out receivers easier and he said it would work fine. I have been using these to do so with no issues: 

 

https://www.digikey.ca/en/products/detail/amphenol-rf/132361/1011929?utm_adgroup=&utm_source=google&utm_medium=cpc&utm_campaign=Pmax_Shopping_Product_Toronto_CDI&utm_term=&utm_content=&utm_id=go_cmp-21024044764_adg-_ad-__dev-m_ext-_prd-1011929_sig-Cj0KCQjw4Oe4BhCcARIsADQ0cslKE009Rpy73b3-nReHQYo9yHkDlPlcADasVHGrxlTdE3JknSjnZvUaAuC6EALw_wcB&gad_source=1&gbraid=0AAAAADrbLliYBtBIbA-W6bV4W8vniH6xT

cheers!

[WaterlooNorm]

On 6/16/2025 at 11:01 AM, DanieldH said:

I'd try it out and if I'd run into issues, I'd try if a 50Ohm terminator helps.

Thank you.

On 6/16/2025 at 12:58 PM, fieldsound said:

Not sure about the SL-2 but Christian at BSRF recommended that I terminate all unused ports on my RF distro. I would imagine it would be considered best practice for all RF distros.
 

I asked Christian if I could use a termination on the end of my coax cables to make swapping out receivers easier and he said it would work fine. I have been using these to do so with no issues: 

 

https://www.digikey.ca/en/products/detail/amphenol-rf/132361/1011929?utm_adgroup=&utm_source=google&utm_medium=cpc&utm_campaign=Pmax_Shopping_Product_Toronto_CDI&utm_term=&utm_content=&utm_id=go_cmp-21024044764_adg-_ad-__dev-m_ext-_prd-1011929_sig-Cj0KCQjw4Oe4BhCcARIsADQ0cslKE009Rpy73b3-nReHQYo9yHkDlPlcADasVHGrxlTdE3JknSjnZvUaAuC6EALw_wcB&gad_source=1&gbraid=0AAAAADrbLliYBtBIbA-W6bV4W8vniH6xT

cheers!

Thank you. Appreciate the link to the terminators as well.

FYI - here is what Sound Devices recommends:

 

" Unterminated cables from the Aux Outs become antennas. If you can terminate the cable, that can help mitigate this, but you should scan your environment to confirm.

Normally we do not recommend leaving them connected since the cable will become an antenna. Since the Aux is just passing the filtered and incoming frequencies from the antennas, you could be affecting the RF integrity/quality, and signal-to-noise.  "