[Elecraft] The Technical Side of Ham Radio

[Alan]

On 10/30/2015 01:59 PM, Jim Brown wrote:
> On Fri,10/30/2015 1:13 PM, Alan wrote:
>> I have a "Signal Hound" USB-SA-44B, which is a 1 Hz to 4.4 GHz
>> spectrum analyzer that uses a PC for power and the user interface.  It
>> currently goes for $919.  I've been pretty happy with it.
>>
>> https://signalhound.com/
>>
>> They also offer an optional USB-TG44A tracking generator for $599,
>> which I don't have.
>
> Interesting. What's the dynamic range -- i.e., how much can you display
> on-screen?
>
> 73, Jim K9YC

You can set the dB/div scale for pretty much anything you want.  40 
dB/div gives 400 dB display range, but of course that's not useful.

With a -10 dBm signal from an HP 8656B signal generator at 18.116 MHz, 
span = 10 kHz and resolution bandwidth = 3.2 Hz, I see that the noise is 
a bit less than -110 dBm at the edges (away from the phase noise near 
the carrier).

So >100 dB dynamic range with those settings.

With a narrow enough span you can set the RBW all the way down to 0.1 
Hz, but at a really slow update rate.  (e.g. 37 seconds with 100 Hz span)

One thing I like about this unit is that it covers all the way down to 
low audio frequencies (1 Hz), which is rare in a microwave spectrum 
analyzer.

Alan N1AL