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Date: Thu, 03 May 2012 11:57:34 +0200
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From: "Roelof Bakker" <roelof@ndb.demon.nl>
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Subject: Re: LF: Re: Basic LF understanding
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Hello Alan,

> The DSP waterfall is so usefull for identifying problems it should
> not be avoided in the early satges and even if the QRM is bad and the
> receiver deaf it will probably aid you to hear something. One of the most
> difficult part is finding a receiver that has any performance down there  
> out
> of the standard Amateur range. A lot that advertise they go from DC to
> 1300MHz are very deaf below 500kHz or even 2MHz.


The best option is to go for a direct sampling SDR; e.g. the SDR-IQ.
I have owned a PERSEUS for four years now and besides an excellent it is  
also a piece of test gear.
It can be used as a high resolution 0 - 40 MHz spectrum analyzer and also  
as a selective level meter.
It has been very useful in observing noise problems.
Instead of searching in the dark, the noise picture can spotted at a  
glance.

A cheaper option is a "Softrock" type direct conversion SDR.
Though not as useful as the direct sampling type, performance as a  
receiver are excellent.
Most use a SiLab Si570 as local oscillator, which has already excellent  
phase noise figures.
The Si570 will work down to 3.5 MHz, so for use at LF the signal must be  
divided down, which improves the phase noise even further.

73,
Roelof, pa0rdt