Date: Wed, 20 Apr 2016 08:04:48 +0100
From: Chris Wilson <chris@chriswilson.tv>
Organization: Gatesgarth Developments
Message-ID: <186935535.20160420080448@chriswilson.tv>
To: LineOne <rsgb_lf_group@blacksheep.org>
In-Reply-To: <5716079B.30004@lineone.net>
References: <5713E677.6040003@lineone.net> <1071555453.20160418034309@chriswilson.tv> <5716079B.30004@lineone.net>
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Subject: Re[2]: LF: Alex (R7NT) reports
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Status: O

Good morning Hugh,

Tuesday, April 19, 2016

Thanks  for  the  detailed reply, I have some good info to try there, I
need to improve my reception, for sure


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


> For LF reception there's no great secret. A decent communications 
> receiver tuning down to 30kHz combined with a wire  aerial broadly (or
> sharply) tuned to 136kHz, a correct loading coil should do the same job,
> this reduces broadcast signals to more acceptable levels.
> The receiver should have no attenuation below (say) 550khz, most of them
> have a bandpass filter on the front end, the older ones with a tuned 
> front end were good but not stable enough. If you can get a circuit of
> the front end and re-draw it in a software program such as Tina it will
> display the frequency response and allow modifications to be set. I 
> altered one inductor only. Beware of the remaining stations on Long 
> Wave, it may require a notch filter, this is where software helps again.
> I think many transceivers for Amateur use have very poor, mediocre or 
> just average receiver response at LF so I'm not sure if a preamplifier
> would help unless it's tuned.
> A notch filter on the receiver is essential and a good USB filter as 
> well. It's worth buying extra filters according to the receiver as 
> supplied. There is some choice but an internet search may help.

> Hugh, M0DSZ