March 19 2000
receiver is less known in Finland than it's precedessors RA17
and RA117. The RA1217 is an example of first-generation transistorized
receivers. The receiving equipment shown here has been used on
the icebreaker "Tarmo" as a map plotting receiver. The RA1217 has been
reviewed and tested in the "Funk" 4/96 and "Weltweit
Hören" 9/96 magazines.
shown includes a VLF/MF converter, enabling reception from 3 kHz
upwards. Due to more modern technology, the receiver is much smaller
than earlier models. The height is only 9 cm. It seems that another
version also exists, which is a narrower and higher table-top
receiver. A picture of this verison is also shown on this page.
principle of the RA1217 is on the traditional Racal line, using
a Wadley loop. Perhaps due to the wide first IF bandwidth or the
first mixer using 2N918 transistors, the RA1217 seems unable to
handle large signals as well as it's precedessors did.
here you'll see part of the first mixer schematics.
international SW bands this will not be a problem, but on the
tropical bands the signal must be attenuated more than what's
desirable, bringing up the receiver's internal noise to a disturbing
level. When listening to a strong signal, the attenuator does
not have an adverse effect.
even on the lower frequencies is very good. Unfortunately, it
cannot be fully exploited, due to the poor large signal handling
digital frequency display is much more accurate than the film
scale used in older models.
differing from the previous models, the RA1217 is equipped with
crystal filters on the next to last IF. Unfortunately, the filter's
shape factors are not published. The selectable bandwidths are
0.2, 3 and 8 kHz. Of these, the 3 kHz filter is the most usable;
2 and 4 kHz filters would be desirable though. Otherwise, the
front panel functions are very much the same as in the RA117,
although the controls are packed closer together.
inside the receiver is a pleasure, if you've mostly seen lightly-constructed
modern gear. The receiver is modular, with easily exchangeable
and well-shielded modules. The modules use D-connectors, with
integral coaxial connectors where necessary. The covers are properly
RF-tight. Mechanical parts, axles, gears etc are of high-quality
metal workmanship. The RA1217 still has many solid die-cast parts,
although fewer than in older models. The crystal filters are physically
about the same size as the mechanical filters in a Collins 51-J4.
detail is a toolset under the receiver's top cover, containing
the necessary hex drivers and tuning tools - this is a feature
often found in older commercial radio equipment. This enables
small repairs even when no servicing equipment is at had.
elsewhere complained about the unprofessional use of screws at
service depots. Opening up an RA1217, I found that a serviceman
had lost a screw from the 1 MHz oscillator and forcibly used a
wrong (millimeter) size screw, resulting in the screw snapping
when I tried to unscrew it.
reading this needs screws for the Racal, please contact the webmaster.