RA3712 is a relatively hard to come by professional
receiver. It was widely used by the Royal Navy, but
certainly found several further areas of use.
Unfortunately there is little specific documentation
available describing the RA3712 fields of application.
The RA3712 is a dual HF receiver. This means that two
independent receiver modules are mounted in the chassis.
Switching between the receivers is done via keypad
Here the most important facts and figures:
Frequency range RX1: 500khz - 30Mhz
Frequency range RX2: 10khz - 40Mhz
100 memories with scan functions
Slow > 1Hz
Medium > 50Hz
Fast > 1Khz
Variable > 1Hz > depending on the turning
rate of the tuning knob with flywheel
Pass band tuning
Modes: AM, USB, LSB, CW, FM, FSK & ISB
Filter bandwidths: 0.3 - 1.8 - 2.7 - 12khz
(roofing filter) LSB only 2.7Khz
AGC: slow, medium, fast & manual.
Additionally, the gain control auto / manual
can be combined. A special AGC setting is
reserved for the "Link11" military radio
Various BITE functions (self test)
Very good strong signal performance
professional RX, the RA3712 were custom fitted. This
means the receiver will only in very few cases be
equipped with appropriate filter bandwidths for SWL use.
The AM filter of this specific unit is 12 kHz wide. Much
too wide for reasonable AM reception. This leaves only
the 2.7khz and the 1.8khz filters. So AM stations can
only be heard reasonably by switching to SSB mode.
I've been comparing the RA3712 with the legendary
AEG/Telefunken E1800/3. The RA3712 has installed more
suitable SSB filters for our needs compared to the
E1800/3. But this has to do only with the width of the
filters, not their selectivity. The E1800/3 uses
mechanical filters that are incredibly sharp! The RA3712
uses quartz filters of comparable selectivity. Both
receivers perform almost on the same level. The RA3712
audio is quite similar with a treble-dominated tendency.
A clear benefit of the RA3712 is its pass band tuning!
Signals can be "edited" for better intelligibility which
is not possible with the E1800/3. Unfortunately, the
pass band tuning is a bit complicated to use. First
select PBT in the menu, then select the filter, and only
then you can use PBT. Although the RA3712 has a flexible
AGC, it can best be used in manual gain control. So
noise can be handled elegantly. In terms of reception
the RA3712 plays in the top league. In a low noise RF
environment, the RA3712 is a wonderful shortwave
receiver. Like the E1800/3, the Racal RA3712 is a top
Also for the RA3712 applies: Be careful when buying!
Some of these receivers have been in continuous use for
years and can suddenly cause problems. Repairs can be
costly. Additionally, such receivers are not primarily
intended for SWL use.
RA3712 in Action (HD Video)