Keysight E4406A question

[rhb]

How suitable for use as a general purpose spectrum analyzer are these?  They're quite cheap on eBay.

They look as if they'd be very good for general RF work, but I'm nervous that there's a gotcha I don't know about.

[chriswebb]

Found some stuff on keysight's forums. Didn't do much reading, but may be helpful:

https://community.keysight.com/thread/1777

[KE5FX]

There's a reason they're so cheap.  There are a lot of drawbacks to the E4406A when used as a general-purpose spectrum analyzer.  Limited span width, no front-end RF filtering, lots of controls and features are disabled, and deliberately-crippled usability for the ones that are provided -- e.g., the knob tunes at the same rate regardless of span.

But they're still very nice instruments.  If your application involves characterizing a known signal source (as opposed to hunting spurious signals, doing EMC precompliance, or otherwise looking at sources with unknown characteristics), they're very capable.  They're especially well-suited for use in automated test applications.

[rhb]

Thanks.  I felt sure there was a reason they were so cheap.  It looks as it it would make a hell of an SDR with the I/Q output option. Rather larger than my SDRplay RSP2 though.  I'll have to search around to see if they can be hacked into something more capable.