[time-nuts] Query about insulated coax panel connectors?

[Robert LaJeunesse]

If panel and connector sizes permit a small single hole panel mount connector can be insulated with a fiber shoulder washer and a flat fiber washer.
https://www.keyelco.com/category.cfm/Shoulder-Washers-Bushings/Fibre-Shoulder-Washers/id/813
https://www.keyelco.com/category.cfm/Washers/Nylon-Fibre-and-Steel-Washers/p/448/id/712/c_id/714

Alternately a piece of PCB material with copper removed can become an insulating mount, with the connector poking out through an oversize panel hole. Yes, now you need to mount the PCB somehow (2-4 screws?). But one piece of PCB stock can hold multiple connectors, making that a bit easier.

Bob L.


> Sent: Saturday, October 24, 2020 at 2:24 PM
> From: "AC0XU (Jim)" <James.Schatzman at ac0xu.com>
> To: time-nuts at lists.febo.com
> Subject: [time-nuts] Query about insulated coax panel connectors?
>
> Time-nuts:
>
> Having recently run into major ground loop noise issues, I have begun reworking some of my homemade pieces of equipment using insulated coax connectors. My goal is to have one ground connection only in the cases, and that is at the power entry point, either a power cord or the outer terminal of a DIN. I am also installing isolation baluns on inputs and/or outputs.
>
> Insulated BNCs are readily available. Others not so. In some cases, there is not room to install an insulated BNC. I am not finding any insulated SMA, SMC,  SSMA, or SSMC despite googling and searching catalogs.
>
> Does anyone know of a source for insulated small threaded coax panel connectors?
>
> Another option would be a compact insulating bushing that an SMA panel connector, for example, could be mounted in. I am not finding anything like that either...  In fact the ideal solution would be an insulated SMA with an integrated 1:1 balun.
>
> And I am not thinking about using plastic cases - that would introduce a whole other set of problems. I think about my lab area at work where a bundle of dozens of gigabit ethernet cables run through the roof directly over the lab bench - the ambient noise level is quite high.
>
> Suggestions???
>
> The only idea I have some up with is to design something myself, possibly 3-D printed...  Any suggestions about how to get started on something like that?
>
> Thanks in advance-
> Jim