Re: Simple spectrum analyzer for pre-compliance

Phil Hobbs <pcdhSpamMeSenseless@xxxxxxxxxxxxxxxxxx> writes:

John Devereux wrote:
John Larkin <jjlarkin@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> writes:

On Thu, 20 Sep 2007 18:23:16 +0100, John Devereux
<jdREMOVE@xxxxxxxxxxxxxxxxxx> wrote:

John Larkin <jjlarkin@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> writes:

[...]

If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.
Says the guy with 10 identical old scopes he bought off ebay :)
In that case, the older gear is just about as good as the new stuff,
at about 1% of the price. Besides, I like scopes!

Yeah, me too. (I have a couple of older Tek analog scopes, which I
bought *after* the more modern TDS3054).

Anyone used a higher-end modern digital scope?

<http://www.tek.com/products/oscilloscopes/dpo7000/>
<http://www.tek.com/products/oscilloscopes/dpo4000/index.html>


I have a 20 Gs/s Tek (7 GHz BW) that I use occasionally...but those
sorts of things just aren't as trustworthy as slower ones. They have
to sweep a lot of stuff under a huge DSP rug in order to make a nice
display. Of course the Agilent ones are smoother looking, but that
makes me more suspicious rather than less. One of these times I'll
try it out with my 11801C and see if it's telling the truth.

Actually one of the things I dislike about my TDS3054 is that it does
*not* do this much. The trace can be a bit noisy. I see no reason not
to have an option to do averaging of its 5Gs/s sample rate, at the lower
sweep speeds.

--

John Devereux
.

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