[Elecraft] [P3] How to measure bandwidth of RX signal

[David Cole]

Hello,

Between Vic's, and Alan's answer I have what I need, thank you all!!!  I
can now measure bandwidth, and tell how many db down a signal is vs.
it's width.  Thank you gents!

Peak hold, then measure!  :)

-- 
Thanks and 73's,
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On Mon, 2014-04-28 at 08:37 -0700, Vic Rosenthal K2VCO wrote:
> 'Bandwidth' is measured by specifying some number of dB that a signal is 
> down at a particular offset from the center frequency. A measurement in 
> Hz alone is therefore meaningless.
> 
> I suspect that the number of dB needed to make the waterfall display of 
> a signal disappear depends on various things, like the gain setting. So 
> this is not an accurate way to measure it.
> 
> What should work is to use the spectrum display of the P3. If you want 
> to know, for example, the bandwidth of a signal at 30 dB down, you just 
> find the points where the 'skirts' of the signal are 30 dB below the 
> peak. This is easy to do on the P3 which can display the signal strength 
> in dBm.
>