Envelope-to: dave@picks.force9.co.uk
Delivery-date: Sun, 29 May 2005 13:24:17 +0100
Message-ID: <002301c56449$31f11300$ecac8351@w4o8m9>
From: "James Moritz" <james.moritz@btopenworld.com>
To: rsgb_lf_group@blacksheep.org
References: <E1Dc3W1-0000Fe-5L@post.thorcom.com> <4298D673.7020308@usa.net>
Date: Sun, 29 May 2005 13:23:16 +0100
MIME-Version: 1.0
Subject: LF: Re: RE: RA1792
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Dear Alberto, LF Group,

While I would agree with most of the comments made about the RA1792, I have
to say I have been using it for nearly 5 years now, and have done all my
"best" LF reception with it, and have also found it good for MF and HF
reception. The problems that have been described are annoying, but none of
them actually prevent you receiving signals!

 I wouldn't really reccomend the RA1792 for the dedicated CW operator,
because the controls and display are particularly "user-unfriendly" when you
are tuning around for signals. There is some leakage past the filters, but
this is easily eliminated with a simple audio filter for aural reception,
and is outside the passband when receiving QRSS, etc. The LCD displays are
"first generation" and have rather poor contrast and viewing angle, but mine
have not apparently deteriorated even after several years continuous
running.. Some later examples have backlit displays, which are better. It
does have pretty good RF performance at HF and LF, and is usable down to
about 10kHz. At 136kHz and 300Hz bandwidth, a 0.1uV signal gives you about
12dB SNR. The synthesiser uses an OCXO standard that maintains a few parts
in 10^8 over an extended period, so frequency errors are rarely significant.
It has no preselector at all, which does not matter for LF, since you
normally have to provide one anyway. It has features like IF output and
reference frequency input/output that you don't usually get on amateur-type
equipment, and are useful for the experimentally minded, as is the fact that
all the components are full-sized through-hole types, so poking around
inside and modifying it is easy.

These receivers are now about 15 - 25 years old, so being realistic you will
have to repair them from time to time. Having said that, the only thing I
have had to do to mine is re-align the BFO VCO. I see that Telford
Electronics are selling these RXs for 500 GBP + VAT, or 650 GBP for the
backlit LCD model.

Cheers, Jim Moritz
73 de M0BMU

----- Original Message -----
From: Alberto di Bene <dibene@usa.net>
To: <rsgb_lf_group@blacksheep.org>
Sent: Saturday, May 28, 2005 9:37 PM
Subject: LF: RE: RA1792


> Dave, Laurie and Tracey,
>
>   thanks indeed for your considerations about the RA1792. I had thought
> it were indeed a "premium receiver", as owning it qualifies you for
> membership in the premium-receivers discussion group... but apparently
> its performance is less than stellar... this fact and the potential
> problems it can have, probably will make me saying "no thanks" to that
> offer.
>
> TNX
> 73  Alberto  I2PHD
>
>
>
>