[Elecraft] Why noise generator?

[George, W5YR]

I have run dozens of spectra of the IF/Audio response of the PRO and my 765
using SpectroGram and have always used either band noise or receiver noise,
whichever was more appropriate.

One trick here is to average a very large number of spectral estimates, in
the order of 60 to 100, in order to effectively average out the presence
and effect of occasional static bursts or signal fragments, etc.

I have been tempted to build Tom's noise generator, but thus far the band
gods have smiled and given me adequate excitation.

Incidently if you would like to see a comparison of the digital IF DSP
filters of the IC-756PRO on a one-to-one basis with the crystal filters in
the IC-765 (with Icom's top-of-the-line filters installed in all slots), go
to Adam Farson's Icom website where the spectra are on display. All the
spectra were obtained using band noise only, usually on the ten meter band
late at night in the absence of any band activity.

Adam's URL is

			http://www.qsl.net/ab4oj/


72/73/oo, George W5YR - the Yellow Rose of Texas         
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe   
Amateur Radio W5YR, in the 56th year and it just keeps getting better!
QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771
Icom IC-756PRO #02121  Kachina #91900556  IC-765 #02437

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"Bob Lewis (AA4PB)" wrote:
> 
> > Why do I need a noise generator when aligning the filters with
> > Spectrogram?
> 
> No difference *provided* that the received noise is clean with no
> static or other signals present.