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From: "Alan Melia" <alan.melia@btinternet.com>
To: <rsgb_lf_group@blacksheep.org>
References: <010101c6403b$8b692610$90a24054@MLB>
Date: Sun, 5 Mar 2006 12:15:24 -0000
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Subject: LF: Re: What's the best receiver?
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Status: O

Hi Martin, as Dave says the most cost effective way would be Albertos mod,
even if you have to pay someone to do it for you.
The Lowe receivers HF 150 and 225 are good I dont know the 125 but i think
that is probably in the same class. I have a 150 and used it some quite a
while. Its main difficulty is lack of a narrow IF filter, but an external
audio filter can get round some of that problem. The other difficulty is the
lack of an RF gain control and an AGC off switch, essential for waterfall
watching I find. The AOR 7030 (or 7030plus) are excellent performance
receivers, the only niggle from "operators" being the rather contorted menu
system to change things, but they are not cheap and mostly require the
addition of CW filter for best performance.

SLMs can be useful,but they have drawbacks in that they are intended for for
line measurements, and are not designed for the sort of dynamic range needed
on a radio receiver. They have no front-end preselection so can suffer from
IMD problems if you have strong local BC stations. This can be solved with
the use of a bit of passive filtering or an "out-of-box" soltion in a G0MRF
filtered 136kHz preamp. My SLM does not have an audio output and requires
extra hardware of software (Alberto's program?) to produce an audio signal.
Then for general listening they do not have AGC at all so it is a bit hard
on the ears. For weak signal work the stability of the "unsynchronised"
versions is generally inadequate.

Usually the problem is not the reciever, several epople have used Direct
Conversion and simple TRF set-ups, it is the aerial and the local noise
level that determines what you can hear. Local geography is not so much of a
problem on LF though, ground sloping down to the sea in a prefered direction
is obviously superb. The two secrets of LF receive aerials are height, and
spacing from habitation. In the latter case even increasing the distace of
an aerial by a few extra feet away from the EMI radiated by dimmers, and TV
SMPSUs can make a big difference.

Good Luck we could do with a an active LF station in Wales again. As for
general experimentation, eyesight may not be a problem. I regard it as a
croc-clip, and choc-block breadboarding area, and many of the first
experimental TXs seen in pics were spread of the bench "in Kellogs packets".
And DX can be worked on relatibely low powers I have had a report from
700kms on a 2W DC input "PA" stage.

Cheers de Alan G3NYK


Cheers de Alan
----- Original Message -----
From: Martin Evans. <books@mollies.freeserve.co.uk>
To: <rsgb_lf_group@blacksheep.org>
Sent: 05 March 2006 09:59
Subject: LF: What's the best receiver?


> Good morning all.
>
> I'm Martin, GW3UCJ, located in the Swansea Valley in South West Wales.
It's
> a very poor radio location, surrounded by hills.
>
> I've been interested in 136 for several years, listened on and off as
> workload permits, but had very little time to get properly involved.
>
> I've been subscribed to this newsgroup for a while.
>
> I have a Kenwood TS950 and have also used a couple of W & G SLMs - I
> currently have a SPM-14. I also had a Datong converter for a while.
>
> I know that the 950 is recognised as being stone deaf on 136 - I've only
> ever heard - or should I say seen - a few UK stations, nothing more - and
I
> don't like using the selective level meters.
>
> Bearing in mind that price is important, what would you suggest for a good
> receiver on 136?
>
> I know that the TS850 is good, but that's too expensive at the moment.
>
> Are such things as the Lowe HF125/150/225 etc any good?  Or the AOR 7030?
>
> Your comments will be much appreciated.
>
> Regards,
> Martin Evans                 email: info@molliesloft.com
> Mollie's Loft Books
> 31 Cilmaengwyn
> Pontardawe
> Swansea                   Tel UK: 01792 863 556
> SA8 4QL                 From US: 011 44 1792 863 556
> UK
>
> Website: www.molliesloft.com
>
> Specialising in Welsh interest, the Sciences & Technology.
>
>
>