[sdiy] Plotting the phase of a filter with FFT or a Phase Comparator?

[Neil Johnson]

cheater00 wrote:
> Given that I only want to do phase and amplitude comparisons, I'm
> wondering if it isn't a better idea to ....

Whatever floats your boat, as the saying goes.

> I wonder how the Tracor and Dranetz work then. Most likely digital.
> You mentioned *mechanical* phase comparators... did I misread that or
> was that a thing at some point in history?

You can play tricks like shifting the input signal up in frequency,
but you still need very narrow filters, which will have long settling
times if you want any useful resolution.

> Why would one buy the 35660A instead of the 3562A?

It is cheaper.  Both will do 100kHz spectrums of a single channel,
only the 35660A drops down to 50kHz in dual channel mode.

> Hmm, I'll check them out. It's been some time since I've ordered from
> good old UK. I know Stewarts, it's a name that keeps coming back. I
> heard good stuff about them but also heard they're a bit pricey. But I
> think at least you get your money's worth, which is not (always?) the
> case with eBay.

I've actually found Stewarts are sometimes *better* than eBay - I
think for some stuff people get carried away.
But I only mentioned them as a data point for comparison so you can
get a rough idea of the relative prices this kind of kit goes for.

Cheers,
Neil
--
http://www.njohnson.co.uk