SMBs to relieve torsion on coaxes

MCX's are even turnier than SMB's, which can have a lot of retention force. And there is tons of cheap MCX stuff on ebay.

John

Suhweet! I wish the datasheets specified "turniness" though.

I use Hirose x.FL connectors (Digikey). These are very small, good to several GHz, and they latch very well. You can't really make your own cables. I buy 12 inch cables and cut them in half to solder one end into RF prototypes. For disconnect or production test, mount the cheap SMD female recept on the circuit board. Hirose makes several sizes of this style connector, but adapters might not be available for all of them. The SMA adapter is the biggest expense, but they seem to last a long time. Hirose sells a disconnect tool, but a strong fingernail will pop them apart. They spin nicely, but the 12" cable will be so flexible I doubt it will matter. Steve

Dunno what the "very stiff" stuff may be but for test leads I use RG174u coax. It's only 2.8mm and very flexible.

Plenum RG-62U that's been on a reel for 15 years. I need 93 ohm coax so as not to load the tube drivers. Oh man the trouble I went through to get that coax working. As plenum cable, the center conductor was silver-plated steel. So I got some 22AWG silver-plated stranded wire. I managed to strip the Teflon off lengthwise, solder it on the end of the steel wire, and "fish" it through the 4 feet lengths of coax I need. Then I made another jig to score the very stiff outer jacket of the coax. Every three inches I scored the circumference down to the braid. Now I have flexible 93 ohm coax that tests very nice in the real world. But it's still so torsionally stiff it snapped a pin off a vintage Blue Ribbon connector.

I'm a bit anal because I calibrate the plug-ins outside the scope, then when it's in the scope I don't want to have to tweak it because the impedance of my cables was off.

The "real" extender has never shown up on eBay in the four years I've looked.

You've the patience of 'Jobe' 'Job'? :) If it's the 547 'scope, at 50MHz (i.e near DC!) would have thought the cabling would be barely noticeable. But yes, I'm also loathe to let something be if I know I can do something about it.

John Lark>>>MCX's are even turnier than SMB's,

Steve wrote:

Steve, The gold standard in this group (indeed, ALL of Usenet) is BOTTOM-POST. My boiled down version: If previous text is not **important enough** to be ABOVE *your* text just DELETE IT.

I'm crazy. I also need my 1S1 back in service.

Good guess, that's what it is. Nice scope in winter. Now that it's getting warmer, not so much... :)

Yeah it actually wasn't that hard to tweak the cables. I figure since my braided 22AWG has the same O.D. as the steel, I stay pretty close to 93 ohms, as long as I don't mush the dielectric too much out of round.

It's really just a question of having the same results when I take the extender off and jam the plug-in in the scope. Worked until the pin snapped off.

Since plenum conditions do not apply, just get some superflex class coax.