Zener Noise (was: 1N4007 varactors)

Nice touch, Bill.

I've used noisecom for some years, but they are hard to buy in onesie-twosies and are rather expensive in quantity when you only need one.

They USED to sell seconds that didn't meet spec, but I don't see that offer on their current website.

Jim

Is it a General Radio noise generator? I have an old GR noise generator, and the manual talks about moving the magnet around to optimize something.

John

We had this already yesterday in '97 and '98. The internet does not forget anything, so watch your mouth :-)

But, my final solution was to buy an Agilent 346c.

regards, Gerhard

Ah, had a feeling it was something about a manufacturer...

Unfortunately(?) no, it appears to be Elgenco, and I also now remember not finding much info on this device after I picked it up. It's a rack mount unit BTW.

Tim

-- Deep Fryer: a very philosophical monk. Website:

For the record, that was Roy McCammon, not me.

Roy Lewallen, W7EL

Just ask for samples, I got five of them a few years ago.

Wouldn't a zener running in (or near) the (easily seen on curve tracer) negative resistance mode have lots of noise?

In article , Robert Baer wrote: [...]

There's noise and then there's noise. Any signal we don't want we call noise. A noise source for instumentation needs to have a flat spectrum. The noise on a zener is a good example of the former and poor example of the latter.

You use one of the circular-gap plugs, run it to a HV supply via a 10M resistor, and just discharge the capacitance of the plug--you get a nice irregular relaxation oscillation. It isn't the absolute most beautiful pulse, but (a) it's easy to shield so you get rid of the pickup, (b) it's surprisingly bright, and (c) the rising edge is way under 1 ns, which should be fine for the VHF to low UHF range. I might stick one on my sampling scope sometime and find out more about its actual performance, but this is a pretty common trick.

There are femtosecond lasers around here--my fastest one is about 20 ps, but it's continuously tunable from 420 nm to 10 microns, when it's working.

Cheers,

Phil Hobbs

Why sure. Can you red Chinese tech manuals?

Funny how my Made-In-China keyboard with its @#%^$}# sticky "a" key laid that out. :-\

Ah, Bruker, my arch-enemy. I make the gradient drivers and temperature controllers for Varian. I've also had bad experiences with Bruker AXS in Madison. They both seem to be very NIH and very PhD oriented, so they're hard to deal with and especially sell to.

John

depends upon the resistance and temperature of the filament

a small grain of wheat bulb will work to 500 MHz..

Mark