Date: Sat, 14 Nov 2015 17:51:09 +0000
From: Chris Wilson <chris@chriswilson.tv>
Organization: Gatesgarth Developments
Message-ID: <1672997593.20151114175109@chriswilson.tv>
To: Mike Dennison <rsgb_lf_group@blacksheep.org>
In-Reply-To: <56436DA4.32298.17518D1@mike.dennison.ntlworld.com>
References: <1886523092.20151110195707@chriswilson.tv>, <564355D2.23956.1180C23@mike.dennison.ntlworld.com>, <921205756.20151111160715@chriswilson.tv> <56436DA4.32298.17518D1@mike.dennison.ntlworld.com>
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Subject: Re[6]: LF: LF receiver
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Status: O

Hello Mike,

Wednesday, November 11, 2015


Thanks for the detailed replies everyone, I just grabbed a screen shot
of  HDSDR  showing  it  in use with my little Japanese receiver and my
active  whip clone antenna. It's now showing DCF39, and the pointer is
on  the  peak of the carrier. What do you reckon? I have the gain well
down  now, and it seems a little better. But when i look at what G3XKR
receives  and the signal levels I know I have a way to go. Anyone know
what he is using for reception on LF?

http://www.chriswilson.tv/DCF39.jpg


I   am   now   experimenting  with  HDSDR's  AGC settings and a medium
setting  seems  quite  good. Not tried noise blanking yet, but will do
so.


I will make some direct comparisons with the TS-590 and the little Jap
receiver this coming week and log the results, thanks Mike!


> 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


-- 
Best regards,
 Chris  2E0ILY                          mailto:chris@chriswilson.tv