Miniature coax test connectors, which one is best?

I like SMBs, because they mate and unmate quickly without needing finger clearance. But maybe too big for you. I sometimes use edge-launches in what would be the manufacturing keepout on the edge of a board, with connectors installed by engineering only. That effectively takes no board area.

It's really handy to pull out a clock for a scope trigger.

The U.FL and such are really hard to mate and un-mate.

Murata SWF/SWD series ? Available from Digikey with connector cables. The cables usually require mechanical support, though.

U.FL is also a pain and the cable connectors don't survive too many connections.

MCX as commonly found on most external GPS antennas.

Surface mount:

If those are too big, the next size smaller is MMCX, which is found on later and smaller GPS receivers: However, I think they're too small and flimsy.

SMB seems a bit large, so try the smaller SSMB:

Are you sure cost is not an issue? Gold plated and precision machined connectors tend to be pricy. Would a stamped tin coax connector be acceptable? Or maybe just a coaxial solder pad and a coaxial pogo pin for the test fixture?

If cost is not an issue then put in the best ones. Put in the ones that feel great when you connect and disconnect them. Put in the ones that scream " Joerg is all quality"

Good to 18GHz too :)

You're thinking of SSMB.

Clifford Heath.

But they have to use that really tiny coax, which is very lossy.

I think it's the MMCX that has a vicious detent, hard to mate/unmate.

There is/was a common verticle bnc board mount, thru hole type connector. Has 4 pins on the periphry for ground and one at the center for signal. I don't have any numbers handy, though.

Hul

Joerg wrote:

MMCX has a split ring on the male connector. Some examples: The degree of retention is influenced by machining tolerances and the width of the gap in the split ring. I've seen a few odd connectors that require brute force to mate, especially when they're dirty. However mostly they're acceptable. They're not as easy to mate as the spring fingers of the MCX connector.

Size comparison of MCX and SMA female:

Size comparison of MMCX and SMA female:

Looks nice but I could not find any cables for that.

That's exactly my concern. It doesn't have to be high frequen=cy stuff, VHF is fine.

Unfortunately I do not have the space for a side-out connector .

Yup, hence my post.

Within reason. Like $5 isn't a problem, $50 is. MMCX looks good though I do not like beryllium copper but I can place a warning.

Best of all there are off-the-shelf cables. For some reason SMA, others and even bulky N-tupe but no BNC. Oh well, there are adapters.

Thanks!

We like to use "test points", which are just plated-through vias that a scope probe will sit in. Small and cheap. Surface mount!

Those are ok to scope stuff but in this case we need to make tricky SNR measurements in a potentially radio-hostile environment. Similar to your Sutro tower.

On Mon, 22 Jan 2018 14:18:25 -0800, Joerg wrote: (...)

Also, look at SMP connectors: They're designed for PCB to PCB interconnection, but I think they might work as a test connector. Unfortunately, berillium copper in the female center pin.

Google image search seems to find MMCX to BNC cables: Mostly Alibaba, AliExpress, and custom cable vendors.

Also found all over eBay. From US vendors:

What is the problem with Cu-2%Be contacts? It is an incredibly good alloy for making connector spring contacts - probably better than anything else - and is widely used in RF and ordinary electrical connectors such as BNC and even mains sockets.

The two main advantages are that 1) it is mostly copper, so it is a good conductor and 2) it can be machined in a soft state and then precipitation hardened to make it springy by baking it for a short time.

It is very hard to expose yourself to significant amounts of Be from the alloy unless you grind it and inhale the dust. John

Digikey 490-4982-ND ?