SD24 TDR step into SD30

Nice. That ringing is too soon to be the SMA->2.8 mm transition at the SD-30 input, so it could be a slightly battered SMA connector on the SD-24 or the first bend. You sure won't get that measurement quality for anywhere near the price elsewhere!

Cheers

Phil Hobbs

The connectors look like SMA, and that's only guaranteed to 18GHz. They may well represent enough of a discontinuity at 40GHz to explain the ringing you have got - it's about 40psec, too short for the cable between the modules, but about right for the distance from the connector into the module.

I tried some different cables and SD24s and the ringing is similar. It's probably in the SD30 head.

The SD24 step must be in the 18 ps sort of ballpark!

Am 11.03.2013 23:53, schrieb Bill Sloman:

That only looks like SMA.

It could be (A)PC 3.5 that is almost like SMA (to 30 GHz, Precision Connector 3.5 mm, Coproduction of Amphenol and HP) or the 2.8 / 2.4 mm versions. All are somewhat SMA compatible, but if you insert a male SMA with a slightly long pin into an APC, it costs you a few 100$ because the APC center connector is isolated by air and a very thin mica disk. The mica even has

My HP54752A plugin has 2.4mm and 50GHz/9 ps risetime... I have barely used it for fear of killing it.

There is also the W connector (1mm) that goes up to > 100 GHz. I think it was first used on the HP8510XF network analyzer. That one is not even remotely compatible to SMA. I once was allowed to admire a W cal kit, but no way to put it to use :-)

Gerhard

Am 12.03.2013 01:02, schrieb John Larkin:

IIRC, on PicoSecondPulseLabs, there is a comparision of samplers and pulse generators. PSPL wins, of course :-) , at least for the generators ....

Gerhard

PSPL used to make a shock-line step generator and a shock-line based sampling head. I think both are gone now.

There's not a lot of point in doing 100 GHz sort of TDRs and samplers. Signals like that don't go through connectors and cables very well.

Spend $50 on a connector saver, and use it without fear!

Back in the day it was only the female connectors you had to admire from afar. ;)

Cheers

Phil Hobbs

A new 2.4mm female/female is a few 100 already, and it cannot absorb axial pressure.

Those days will come back!

Ouch, Gerhard

Not for us, we are too old and they won't have any interest in us even if we showed up in a red sports car.

Oops, different topic ... :-)

GR874s and APC7s were pioneers in gender equality.

Doesn't the original high impedance mic connector with a threaded lock ring predate both? The Switchcraft 2501 is an example. Unscrew the ring from the female and it's now a male connectors.

It's not the red sports car, rather the green, that interests them. Two 20s are *far* more expensive than one 50, though.

It is?

Plenty of women chasing the old farts at 'The Vilages' That's why it has one of the highest percentages of VD in the US.

Old women chasing old farts, sure. I thought he was talking about those who were attracted to red sports cars.

Plenty of those, and very overpriced red golf carts too. I'll probably had trouble finding an open handicap parking space tomorrow at the VA, because they refuse to park in their own lot. They not only park in the handicap spots, they wont share a spot so they take dozens of prime spots. It's too bad they don't get those $500 fines for illegal parking. The carts aren't street legal, and don't belong where cars & trucks park. One of these days one of them will be run over, or have their cart smashed by someone who doesn't see it in time.

Are you sure they aren't street legal? They are in Alabama and Georgia. I believe they're banned from roads >35MPH, though. At some of the shopping centers here the golf cart parking spaces are closer to the door than the handicapped spaces. Kids as young as 14 drive 'em, too.

why it

you can get street legal golfcarts, like the crazy expensive ones from

-Lasse

They are unlicensed, and can't be driven on public roads. All the roads inside 'The Villages' are private and owned by the retirement community so they are legal on their roads. Some people ignore the law, but drive in the right of way and cross roads after looking for cops. They petitioned the state for the right to cross a busy four lane highway, then demanded and got a private bridge over the highway built at taxpayer's expense.

The worst ar the people with power wheelchairs who ride right down the middle of the street, even those are only legally allowed to cross a road in a crosswalk. I have to dodge them, and even run off the road because they sit sideways to talk to someone on another power wheelchair to talk and block both lanes.

They *are* street legal here (and in AL, AIUI). No registration required. Again, AIUI, they are limited to roads