[Elecraft] The Technical Side of Ham Radio

[Alan]

On 10/31/2015 09:32 AM, Wes (N7WS) wrote:
> I should have added, read the manual too, especially sections 2.2 and 2.3:
>
> http://signalhound.com/sigdownloads/SA44B/SA44B-User-Manual.pdf
>
> This thing has some major limitations that turned me off.

The limitations are due to the fact that it uses software algorithms 
rather than hardware for image rejection.  Basically it takes two 
measurements with different local oscillator frequencies and figures out 
which spectral components are real and which are images.  It works quite 
well.  Other than slowing down the sweep speed somewhat (for span > 200 
kHz), I have never noticed any effects in normal operation.

The main effect is it doesn't work correctly on transient signals, like 
pulse-modulated or swept.  If you need to measure one of those you can 
always turn off image rejection, at the risk of seeing spurious responses.

Also it can't be used for wideband signals greater than 42 MHz.  Maximum 
resolution bandwidth is 250 kHz, so you can't demodulate an analog TV 
signal (although you can display the spectrum).

But for the types of measurements typically needed for ham radio it acts 
just like a conventional spectrum analyzer.  I doubt you'd ever notice 
the difference.

Alan N1AL



> On 10/30/2015 7:56 PM, Wes (N7WS) wrote:
>> Before springing for this I would suggest reading the RSGB review.
>>
>>
>> On 10/30/2015 1:59 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
>>