Hi Jerry,
One fellow suggested that could be a contributor. I am not a big DSP noise
reduction fan as I found it to be nearly useless with my Omni VI+; granted
that was an early DSP application in amateur radio. Therefore, the original
noise issue I described with the Eagle was observed with noise reduction (NR)
turned off.
Thank you, Thomas
---- "Dr. Gerald N. Johnson" <geraldj@weather.net> wrote:
> The DSP noise blanker may be as susceptible to nearby strong signals as
> the hardware noise blanker.
>
> 73, Jerry, K0CQ
>
> On 2/4/2011 10:07 AM, Thomas wrote:
> > All,
> >
> > Thank you for your helpful responses. Indeed it appears that it is my
> > unfamiliarity with a DSP-based radio that resulted in the CW-note noise
> > and raspiness that I described yesterday. The DSP-based radio is a
> > different bird than the mostly analog radios I've used the past 42 years.
> >
> > Here is what I learned about setting the Eagle audio:
> >
> > 1) Keep the RF gain, in the Eagle's case the IF gain, at a minimum. As the
> > person responding said that prevents the ADC before the DSP from being
> > overloaded. I should have know that, I work for a company that designs and
> > manufactures ADCs. However, we in the trade always take it for granted that
> > we usually won't be over driving the ADC input. Use the AF gain instead to
> > control the volume. That is different than what I tended to do with my
> > analog radios. Also, something very different about the Eagle's RF gain
> > control is that setting it to minimum doesn't completely cut off the RF
> > traveling through he signal chain. It has a very usable, sensible range.
> > That had the greatest affect on the noise I described.
> >
> > 2) Use the attenuator. I found using the attenuator nicely reduces the
> > level at the front-end which of course further strengthens an already
> > strong front end. That was key in the listening to the pile-ups. The Eagle
> > has plenty of gain and I have always been a big fan of using an attenuator
> > instead of the RF gain control. I usually ran my Omni VI+ with the
> > attenuator on during the entire 160m CW contests. I found it had little
> > affect on the super weak DX stations and further helped attenuate the
> > fellow a few miles away running serious power.
> >
> > 3) Keep the noise blanker turned off. I don't have the noise blanker
> > option, so that may not be applicable in this case. When I used my Omni VI+
> > I recall a a broad-band noise being generated over tens-of-kilohertz when
> > a strong CW station was operating near by. As a rule I always kept it
> > turned off. The Eagle has the DSP noise reduction which should be adequate
> > for home use.
> >
> > There were other good tips as well and I will relate them as I learn the
> > radio better. All I can really say for now is the Eagle is really cool! The
> > ergonomics, size, and utility of the radio are perfectly suited for my
> > uses. Wow.
> >
> > '73, Thomas - AC7A
> >
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