Coax modelling question

I don't have a problem. Both of mine are ruby red.

If you say so. Too expensive and too many people. I lived in Dutchess county for almost 20 years. What a dump.

Using a regular scope, 100 MHz or so, it wouldn't be useful for measuring PCB traces or such. It would be mostly a transmission-line learning tool.

Eliminate the box, sell it as a board, and cut the cost by 3:1.

You could run it from batteries, too. A couple of AAs maybe.

My TDR, the one I haven't built, is more complex but would be ballpark

70 ps, good enough for PCB traces. I got the PCB from MyroPCB, and the pads tend to fall off when you solder it, so I'll have to re-order boards if I want to build one. That would ultimately be USB, with some PC software.

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John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com

I agree that Dutchess isn't the same at all. I've spent a fair amount of time in Fishkill back in the day.

I lived in Putnam for awhile, which was OK but much colder than Westchester. It's partly elevation and partly microclimate, I expect.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

Put a voltage-controlled time delay (comparator and one of your fast ramp circuits) and a sampling head on it (HSMS-286x diodes fast enough?) so you don't need a fast scope, and you'll sell thousands to hobbyists.

Clifford Heath.

SMBs pop on and off instantly, easier than BNCs even. A heap better than torquing SMAs. SMBs are pretty fast:

I use SMA-SMA connector savers on my sampling scopes, to protect the threads.

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics

We spent a fair amount of time in Westchester. Didn't like it at all. Too crowded and the taxes are outrageous. SWMBO was watching a HGTV show the other day. They were looking at a $500K house and the taxes were $24K per year. Ya' gotta be kidding!

At least Westchester had shopping. Duchess was the sticks.

Elevation couldn't have had much to do with it. It's not like the "mountains" are 10K'. I don't doubt your microclimate differences. We used to live about 70mi SW of here and it was a *lot* hotter in the summer. Most summer nights were unbearably muggy. It's hot here, too but not at all unbearable at night.

A fast CML part, like NB7V52 or ADCMP580, makes a good 50 ohm step source. The fast sweep isn't bad, with an analog ramp and an ECL comparator. The sampler is more challenging.

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics

I did an SRD + dual-diode sampler a long time ago, on FR4, the classic Tek/HP architecture. I got about 7 GHz bandwidth. I'd do something easier nowadays.

Agoston Agoston showed me a 20 GHz sampler, surface-mount on FR4. I think he had a contract with Tek that limited him to 20 GHz.

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics

I'd like to sell it to PCB fab houses and engineers developing fast boards. They have more money.

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics

Here, the gradient up into the Sierras, Auburn to Truckee, is about 3F per 1000 feet.

Leaving SF horizontally, the gradient is commonly 1F per mile.

It was comfortable, almost warm, when I left work today. When I got home, about 3 miles away, it was uncomfortably cold. That run averages over 2F per mile.

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics

Am 16.09.2016 um 01:29 schrieb Clifford Heath:

I do not use toner transfer but optical contact copy with mild UV light. If it needs to be REALLY exact, I go to the next print shop and have them make me an offset film at real 2400 dpi for ?8. The interface format is .pdf :-) I need to mirror when printing to .pdf so that the toner / silver faces to the pcb.

That is the same like JL's picture of the sampler above.

No. It was for a dual ramp time-to-digital converter. I finally had to use sth. slower that I could get space-qualified.

regards, Gerhard

nt

.

Well, if you don't like the sticks, you're going to have more people around .

My property tax rate is about half of what you quote. Still on the high sid e, but at least it isn't Florida.

Cheers

Phil Hobbs

Me too, except on the HP 70820A, which has 2.4 mm->SMA adapters for the same job. Those are ridiculously expensive.

Cheers

Phil Hobbs

Not really true. I live in the "sticks" (small rural city) but there are 4.5M people within 60-70 miles. Everything is within easy driving range (if there is such a thing in any city) but it's far enough away that we avoid 99% of the problems.

And mine is a quarter of that.

Red is the most likely to be followed by a police car. I couldn't leave my house in my red '66 GTO without the local cops following me to the edge of their territory. I've had officers tell me that the drivers of red cars were more likely to speed, or drive recklessly.

It was the same with the 'Chinese Red' '84 Toyota pickup truck.

--
Never piss off an Engineer! 

They don't get mad. 

They don't get even. 

They go for over unity! ;-)

In my experience the worst colours are "orange" and "BMW".

Cheers

--
Syd

I one got pulled over for speeding in the Mustang Convertible when we were on the way back from a movie at midnight. The cop thought he had a drunk kid. When he saw the white hair he calmed down a few notches and just gave me a warning. ;-)

Red has been known to attract cops but I don't think it's true anymore. As John said, the vast majority of cars are somewhere on the black-silver line.