[time-nuts] Phase noise measurements on the cheap with an Agilent E4406A VSA Transmitter Tester?

Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby at kirkbymicrowave.co.uk
Sat Jun 18 17:25:33 EDT 2016

On 18 June 2016 at 21:01, John Miles <john at miles.io> wrote:

> > and looked at what was used to make the phase noise measurements. It was
> an
> > Agilent E4406A. The noise floor is nowhere near as low as the more
> > expensive instruments, but the E4406A is available for under $500, which
> is
> > more than two orders of magnitudes cheaper than an E5052B.
> It appears that Leo's using a notch filter to remove the carrier before
> measuring it with the E4406A, so it's not quite a plug-and-play sort of
> measurement.  But yes, the E4406A is a really cool piece of gear given the
> prices they sell for.  It's not meant to be a general-purpose spectrum
> analyzer -- and Agilent went well out of their way to make sure of that --
> but it can still handle many common SA measurement tasks including SSB
> noise.

Thank you. In which case it may or may not be better than  the HP 70000
series SA I have, consisting of:

* 70004A display,
* 70905A 50 kHz to 22 RF GHz front end
* 70902A (10 Hz to 300 kHz) IF
* 70903A (100 kHz to 3 MHz) IF
* 70310A precision frequency reference.
+ some irrelevant bits.

I was not looking for a general purchase SA, as I have one of them already.

> The plot on that page came from my freeware phase noise app from
> http://www.ke5fx.com/gpib/pn.htm , which is a (very) distant ancestor of
> TimeLab.  The last two FAQ entries at http://www.ke5fx.com/gpib/faq.htm
> offer some hints for suppressed-carrier measurements that can be used with
> the E4406A and other analyzers.  There's nothing special about the E4406A
> with respect to this type of measurement, except that it's an unusually
> cost-effective way to get the job done.

I note your software works with the HP 70000 too. As I say, I already have
one of them, but was thinking the E4406A would be a worthwhile addition.
But perhaps not in that case. Although maybe it will outperform my 70000
system for phase noise measurements. I expect you will know the answer to

BTW, the link to the  "Wenzel Associates, BluePhase 1000 Phase Noise Test
System Operations Manual
<http://www.wenzel.com/pdffiles1/BP1000Manual/BP_1000_v101_2_.pdf> (30
pages, 1.3 MB)" PDF is broken.

> The E5052A/B's most immediate predecessor was probably the HP 4352A/B.
> They were made specifically for VCO and PLL transient analysis and noise
> measurement, and they've been selling in the $1K-$3K

It seems the HP 4352Bs are available for a little under $1000 now, but are
but still twice the price of a E4406A.

neighborhood for several years.  Their measurement floor is better than a
> conventional spectrum analyzer, but still not adequate for "time
> nuts"-class measurements on 10 MHz sources.

OK, I will give this idea a miss. I was actually looking to compare 116 MHz
oscillators. but I guess the same principles apply.

Cheers John.

> -- john, KE5FX
> Miles Design LLC

Dave, G8WRB

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