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Re: Re[4]: LF: LF receiver

To: [email protected]
Subject: Re: Re[4]: LF: LF receiver
From: "Mike Dennison" <[email protected]>
Date: Wed, 11 Nov 2015 16:32:36 -0000
In-reply-to: <[email protected]>
References: <[email protected]>, <[email protected]>, <[email protected]>
Reply-to: [email protected]
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Hmmm. Interesting. You don't show DCF39 (I wrongly called it DCF38 
before) as it is outside your passband. However you show HGA on 
135.42 at 40dB above noise. I see it at 59dB above noise and that 
could illustrate your problem. However. the beauty of using HDSDR is 
that you can accurately compare before and after settings. We have 
different receivers (I use an Afedri SDR) but at face value it looks 
like you may have too much RF gain. 

If you can adjust the receiver gain, or perhaps attenuate the input, 
see how various settings affect the signal/noise on a fixed station 
such as HGA. It is not obvious to me (as you are using HDSDR at 
audio) but can you apply AGC or noise blanking? If so, compare the 
results.

Listen to the audio. Does it sound 'clean'? If not, you may have 
noise from out of band products - adjusting the gain should affect 
this. Try going back to the E-field antenna - how does the 
signal/noise compare? 

If none of that helps, perhaps the receiver is simply not up to the 
job. So how does your HF transceiver compare?

Mike, G3XDV
==========

> Wednesday, November 11, 2015
> 
> I  just took a screen shot of HDSDR as of about 4.00PM with averaging
> set to 16. http://www.chriswilson.tv/band.jpg  This is with the active
> antenna and the little Japanese receiver.
> 
> 
> > Chris, 
> 
> > You should not need to use the 's' meter on HDSDR when taking 
> > relative readings. The (wideband) waterfall display is already in
> > decibels - just place the cursor at the position you want to
> > measure. If that doesn't work, go to
> > Options/Visualisation/Informations on Mouse position. For noise
> > readings I would increase the averaging (Avg) function to perhaps 16
> > or more to get a flattish line.
> 
> > As a guide, I find that DCF38 is typically 63dB above daytime noise.
> > You are a little further away from DCF, so you should get a slightly
> > lower figure.
> 
> > Mike, G3XDV
> > ==========
> 
> 
> 
> 
> 
> 
> 
> -- 
> Best regards,
>  Chris  2E0ILY                          mailto:[email protected]
> 
> 
> 
> 
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