[Premium-Rx] Racal RA 3701

[Michael O'Beirne]

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