[ICOM] IC-7000 AGC

[cj_bonde at netidea.com]

Adam:
Awhile back you helped me greatly with me learning how to operate my new
rig.  Now I am wondering if you would compare that with another.

That is, my rig is a IC756PRO (one of the first in Canada by the serial
number)  Now I am wondering how it would compare to the new IC7000.  The
main reason is I am not that active, am unable to reach Europe because of
the mountains to the NE (also ON and east)  However, on 80m WAS on 40m
most.  So I have been think of the IC7000 plus an auto tuner.

What sayest thou?

Chris opr VE7HCB






> Hi Scott,
>
> In the IC-7000, both the AGC and the NB are DSP processes. I suspect that
> the NB process is inside the AGC loop, so it should be possible to adjust
> the NB so as to remove fast-rising noise impulses which might -
> theoretically - trigger a fast AGC response.
>
> The NR process is post-AGC, so it will not be of too much help in this
> case.
>
> You may be able to generate a test signal if you can borrow an RF signal
> generator with a pulse-modulation input, and modulate it with a
> square-wave.
>
> Cheers for now, 73,
> Adam VA7OJ/AB4OJ
>
>
> -----Original Message-----
> From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net]
> On
> Behalf Of Scott Honaker
> Sent: Friday, June 08, 2007 09:29
> To: icom at mailman.qth.net
> Subject: [ICOM] IC-7000 AGC
>
>> http://www.sherweng.com/documents/Dayton2007w.pdf
>
> I do wish I'd attended this talk.  It's not clear to me what real-world
> conditions cause this to happen.  At home I have to deal with an electric
> fencer that creates ~S5 broadband noise.  I find the IC-7000 noise blanker
> to be incredibly effective removing this impulse noise and haven't noticed
> side effects.
>
> The implication is that the impulse noise has to be <1mS to be troublesome
> to the AGC.  I suspect the difference between the impulse noise and
> desired
> signal strengths would have to approach the dynamic range of the ADC
> before
> it would be an issue.  I don't have a shack full of toys to test this but
> am
> interested in duplicating it.
>
> He mentions "Same problem on unblankable line noise".  That implies there
> might be a feature in the DSP to reduce/eliminate this problem (noise
> blanker, noise reduction, AGC response time, filter width, auto/manual
> notch, etc.).  I'd like to try that out.
>
> I don't have a good way to measure the pulse width of a fencer but
> intuitively I'd say it's pretty short.  I could move an antenna closer to
> the fence to exaggerate the intensity relative to incoming signals.  Any
> other suggestions for real world duplication scenarios?
>
> Thanks,
>
> Scott N7SS
>
>
>
>
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