If you have to turn the volume up 100 percent to hear it, why worry about
it? How many of us run our radios at 100 percent volume?
I bet if you ran your car at 100 percent you'll hear some strange noises
too.
----- Original Message -----
From: Duane Grotophorst <n9dg@yahoo.com>
To: dslosty <dslosty@pipeline.com>; <tentec@contesting.com>
Sent: Tuesday, June 26, 2001 10:44 PM
Subject: Re: [TenTec] ARRL product review test change
>
>
> I would like to see the ARRL add a product review test
> where they show the audio output spectrum of the RX
> audio passband with a 50-ohm load on the RX input.
>
> With today's digitally based radios (DSP IF or
> otherwise) there is a potential for, and frequently
> is, extraneous noises and other artifacts in the RX
> audio signal.
>
> At the risk of re-opening old heated debates here on
> the reflector, I have also seen the persistent tone in
> the middle of the RX filter passband the Larry, VA3LK
> saw with the Pegasus. It is actually quite easy to
> see, I used SR5 Spectrum Analyzer program (from
> www.ar5.com) to look at the audio passband. I can also
> see it on the waterfall display of the PSK31 program I
> use. In fact both of the Peg's I have exhibit the
> exact same behavior. That tone is actually audible if
> you crank up the volume 100%. For what its worth
> though, the fact that you can turn the volume up all
> the way and not be driven out of the room by white
> noise is a testament to what Ten Tec has done well
> with their RX design.
>
> Anyone who is already wired up to do PSK31 or any of
> the other "sound card" modes, can simply download any
> number of freeware spectrum analyzers and look at the
> audio signal of you RX. I've used both SR5 and
> Spectrogram for my tests; I'm sure there are others.
>
> I haven't turned the audio spectrum analyzer loose on
> my other radios yet, but I do expect to find some
> interesting things. Bottom line is that whatever
> internally generated noises or other artifacts that
> may appear in the RX audio passband are actually every
> bit as important as all of the dynamic range and phase
> noise measurements that product reviewers are so
> focused on.
>
> 73,
> Duane
> N9DG
>
> --- dslosty <dslosty@pipeline.com> wrote:
> >
> >
> >
> > I don't know if this has been mentioned on the
> > reflector but I
> > found the changes announced in July's QST
> > interesting.
> >
> > The League is now going to use a 5KHz standard
> > spacing versus the
> > former 20 KHz spacing while testing receiver dynamic
> > range
> > and intercept points. This should better
> > characterize crowded band conditions.
> >
> > On page 80 of July's QST is a listing of several
> > current HF
> > transceivers. According to the new tests, the
> > Elecraft K2 and
> > the Ten-Tec Omni 6+ have far better figures than the
> >
> > IC-756PRO, FT-1000MP, etc.
> >
> > Of course, most of us already knew this.....
> >
> >
> > 73,
> > Doug/WA1TUT
> >
> >
> > --
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> > owner-tentec@contesting.com
> >
>
>
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