The RACAL RA1217

The much maligned RA1217 (the rack-mounting variant of the RA217) was Racal’s first transistorised HF receiver and is for all intents and purposes an RA117 in everything but looks (and perhaps performance). I had been looking for one of these for over a year, to complete my collection of Racal HF receivers from the 50s through to the 90s. I first saw one close up when myself and two others put on a demonstration of Racal receivers for a local radio society. I was mesmerised by the mechanical digital readout to the extent that I was determined to add one to my collection. The first one that came up on Ebay was being auctioned simultaneously with the R1155 that I was fortunate to ‘win’. Then the one pictured above came up for auction. Actually it was one of two, both described as faulty. I was very fortunate to get this one for less than half the price of some that I have seen over the years! The RA1217 is actually rather rare.

It arrived very well packed and after a few safety checks I confirmed that it was indeed faulty, as described. Actually, there was a sticker on the top cover which declared that it was working but with a faulty Calibrator ... But that was over 20 years ago! It was rather grubby, so I set about giving it a good clean. The knobs and front panel cleaned up nicely with soap and water. The BFO shaft (top RH corner) was bent and duly straightened. It had also been ‘dropped’ on its end at some time and the RF input BNC socket was at a strange angle. So that too was straightened. As you can see from the photograph, the MHz Dial Lock lock is missing. The KHz Dial Lock had no effect. These locks are very clever and work like car drum brakes. When the lever is moved down into the lock position four ‘shoes’ (for want of a better description) extend from the hub. However this was having no effect since there should be a rubber band around the hub which is pushed against the inside of the knob. I simply fitted two suitable elastic bands, one on top of the other to achieve the correct thickness around the hub and the brake now works perfectly. I’m not too concerned about the missing MHz brake since the MHz tuning mechanism has natural detents and as such is not easily knocked ... See the photograph below.

 It is true to say that when Racal produced the RA17 they gave us a receiver that more than made its mark on the market and more than likely paved the way for the company as a manufacturer of high specification communications equipment. Unlike manufacturers like Collins, Racal was actually new to the game, technology was advancing at a fast pace and it was inevitable that transistors were bound to replace thermionic valves. The RA117 was not as some believe the successor to the RA17L. The RA117 was conceived to satisfy an Admiralty requirement and was actually built alongside the RA17L. At the end of the day, Racal really only made one valve-based receiver, albeit in many ‘flavours’.

 The successor to the RA117 was the RA1217 and it is debatable if there were actually any performance improvements in the design. When you lift the lid the first thing that strikes you is the modular construction. Each module can easily be identified with its predecessor counterpart. It is clear that Racal simply took the ‘elements’ within the RA117 and designed transistor-based versions. However the RA1217 still retains some of the aspects of its predecessor in that the chassis is still largely of cast aluminium which offers a modicum of rigidity, although this chassis is now surrounded by a steel frame. Hats off to Racal for going for a digital frequency readout! The implementation of which is a masterpiece of engineering. The KHz mechanism is similar to that in the RA117, but I really love the way the drive cog on the MHz tuning shaft interfaces with teeth on the inside of the main gear. The outside of this gear is machined so as to produce a ‘natural’ detent per MHz.