I had a choice of 50khz or 20khz and chose the 20khz spacing. As for "phase
noise", I've heard it discussed for years and I'm still not sure what it
sounds like unless it sounds like the transmitter products emitted by the
Pegasus/Jupiter.
Steve Ellington N4LQ.
----- Original Message -----
From: <al_lorona@agilent.com>
To: <n4lq@iglou.com>; <tentec@contesting.com>
Sent: Sunday, April 07, 2002 1:53 AM
Subject: RE: [TenTec] Rig Chart
>
> In the last few years I have become convinced that the two-tone 3rd order
> dynamic range numbers in ARRL reviews measured with a 20 kHz tone spacing
> are absolutely irrelevant in demanding amateur radio conditions. The two
> tones have to be much closer together in order to get a better idea of
what
> the receiver will tolerate. I'm glad to see that the ARRL is apparently
> getting the message, as I heard recently they were going to start
measuring
> it with something like a 5 kHz spacing. We should publish the 5 kHz specs
> for each of the receivers in Steve's chart.
>
> I define 'demanding conditions' as similar to those in a contest where
there
> are lots of very strong signals very close to the frequency your receiver
is
> tuned to.
>
> I'm going to assume that the rest of the DR specs were all measured with
the
> same receiver bandwidth, although Steve's chart does not explicitly state
> this. If not, the numbers don't mean anything to me.
>
> Every one of the receivers listed has way more than enough sensitivity for
> any of the HF bands. Since about 1980, MDS numbers have been rendered
> irrelevant.
>
> An important spec missing from the chart is that of local oscillator phase
> noise, which is difficult to measure and even more difficult to explain
> exactly what it does to the way a receiver sounds. In general, the more
> phase noise, the more problems that poses to a receiver. One of the
> by-products of phase noise is reciprocal mixing. You can definitely hear
it,
> but describing what it sounds like is hard. That's why during the recent
> thread about which receiver was 'quieter' I kept telling myself one of the
> parameters going into such a qualitative spec has to be the effects of a
> receiving system's phase noise; hence the difficulty in quantifying the
> receiver's 'quietness'.
>
>
>
> > -----Original Message-----
> > From: Steve Ellington [mailto:n4lq@iglou.com]
> > Sent: Saturday, 06 April 2002 8:40 AM
> > To: tentec@contesting.com
> > Subject: [TenTec] Rig Chart
> >
> >
> > I took some data from the ARRL test for these high end rigs.
> > Take a peek at:
> > http://members.iglou.com/n4lq/img/rigs.htm
> > Make of it what you ever you will.
> > Steve Ellington N4LQ.
> >
> > _______________________________________________
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> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
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