[Premium-Rx] Racal RA 3701

[acyg]

Dear Clemens,

Michael makes excellent points below especially the DK-43 tuning unit.
A very simple but extremely effective unit useful for AM, FSK, CW tuning and
gives a somewhat analogue feel to what could otherwise be a 'flashing digit'
syndrome.

Just as point of interest if you like the RA370x series, then I think the
next progression for you to try out is the RA379x model. DSP IF, the front
end is still analogue, the panel is much the same as the RA3701 and the
general operational feel of both these sets is very very similar.
Audio recovery is excellent on these DSP sets. I have not detected any of
the usual DS processing artefacts.
Build quality is perhaps not as solid as the RA3701 but certainly better
than many others of similar vintage.

The RA3791 is my personal favourite of (I think) most Racal HF sets.

Gud luck - 73 - Andrew - G7JQL




-----Original Message-----
From: premium-rx-bounces at mailman.qth.net
[mailto:premium-rx-bounces at mailman.qth.net]On Behalf Of Michael O'Beirne
Sent: 09 September 2011 20:39
To: Clemens Ostergaard
Cc: PREMIUM-RX
Subject: Re: [Premium-Rx] Racal RA 3701


Dear Clemens

The LCD displays on the RA1792 are very much older and suffer from smudging,
like tear drops, and then become useless.  It may be the damp geiing inside
the glass "sandwich" of the display.  That's why there have been some
alternative designs.

Frankly with my deteriorating eyesight I mush prefer big bright LEDs to
ordinary LCDs.

The displays on my RA3701 have given me no problem.

As for extra modules - this is dificult.  I know of only one sub-octave
filter unit, which was on a set owned by Pat G3YFK, but he did not like the
radio and sold it abroad.  He suspected that few of those modules were made.

I acquired the 100kHz IF output module so that I could use the set with the
superb DK-43 tuning bargraph display, which needs a 100kHz input -
 ex-GCHQ - and much superior to the Racal MA1105 bargraph.

I have never seen the FSK module.  It is a lot easier to use a standard
audio terminal unit or a PC.

I actually like the 3701 a great deal.  The recovered audio is of excellent
quality and very smooth and easy to listen to.  There is a bit too much
hiss - the antidote is to fit a resistor in the input of the headphones jack
plug and increase the AF Gain, and all sounds most sweet.  I think that the
AGC response on my RA1792 is slightly better, but I am being fussy.

The tuning feel with the lovely weighted knob is so much better than pretty
much anything else bar the 1772.  Why anyone would want to tune around with
a R390 for long period baffles me when the RA3710 requires just a gentle
stroking with a finger tip.

The logic of the front panel is excellent, even diving down 5 levels of
display.  Logical brain power has been applied here, or maybe my brain is in
synch with the designer's.  I once owned a VHF scanner and I just could not
make head or tail of all the dozens of tiny buttons and soon got rid of the
wretched thing.  You know the old saying that any fool can make  a simple
thing complicated, but it takes genius to make a complicated thing simple.
73s
Michael
G8MOB

----- Original Message -----
From: "Clemens Ostergaard" <clemenso at gmail.com>
To: <Premium-Rx at mailman.qth.net>
Sent: Friday, September 09, 2011 8:28 AM
Subject: [Premium-Rx] Racal RA 3701


> Recently an RA 3701 has been competing (successfully) for my attention. It
> is a great analog radio, fine audio recovery, and the mechanical
> construction a pleasure in itself (a bit like it is in the R390a or
> EK-07). The panel assembly is an early s/n 099, while other modules range
> up
> to s/n 1942. Perhaps this is why one of the three LCD display cannot be
> viewed from a low angle. Adjustment of the display angle via the menu has
> no
> effect. It is not a problem now, but I note that there is available on the
> market substitute LCD-displays for the RA 1792 which seems to need it. I
> wonder if there are spares around for this display, and if other members
> of
> the list have encountered problems. Is there a source for individual
> modules, like the A1, Sub-octave one for instance?
>
> I am guessing this list is the most relevant for this Rx, the Racal list
> seems fairly sleepy.
>
> All the best,
>
> Clemens S.Ostergaard
> Aarhus, Denmark

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