Sometime, just for fun, I'd like to get a Tek sales 'engineer' in to demo his latest, hideously expensive, digital toy and compare the display to a 453 from 1965 on a WW II LORAN-A simulator that works with- gasp- vacuum tubes.
Just for laughs, of course. -John ============== > On 4/17/12 7:15 AM, Robert Darlington wrote: >> I need lots of memory on scopes. A buddy of mine I worked with in the >> ultrasound world actually yelled at the Tek product management and >> asked if they actually *use* oscilloscopes. The answer was a sheepish >> no, and yet they felt qualified to develop the products for the >> company. >> >> The cheap Aktakom scope I have has plenty. 10 million samples (you >> can select less if you want) and will write out to usb thumb drives. >> It's definitely a toy scope with lots of noise, but it's useful for >> some things. >> >> What we do is send out pulses or chirps and look at what returns. >> There are tens of millisecond delays between what we send out and what >> we receive and the echos. With traditional low memory scopes we >> simply can't get by. Thankfully Tek is learning that memory is cheap >> and 2500 samples was hardly sufficient in the 70s, let alone now! > > > Yes, just like in the radar world (really, ultrasound and radar are > really similar.. same kinds of pulse compression and signal processing) > > > Back in 1998-1999, I was buying digitizer cards from Gage Applied > Sciences (since acquired by Tek, as it happens), and one of their big > markets was for ultrasound. Same for Signatec (another mfr of fast > digitizer cards for PCs) > > Another case where deep memory is nice is when you don't know exactly > when the signal is going to arrive, it's very low SNR, so you want to > record a long time, and then go look for the signal later. But that's > more a data capture problem than a bench oscilloscope problem. > > say you were recording off-the-air GPS signals. You want to record a > couple milliseconds, at least (so you get at least 1 code epoch), and > you need to record at least 10 MHz bandwidth. That's only, say, 64,000 > samples, but you might want to record a whole 50 bps nav message bit, so > then you need ot record 40-50 milliseconds, and the record length starts > to grow. > > Again, that's more of a data recording problem than an oscilloscope > problem. > > It's the wideband pulsed waveforms where you want to compare pulse to > pulse is where deep memory in an oscilloscope is nice. The digitizer > cards are ok, but "real oscilloscopes" tend to have better input > amplifiers and such. > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.