The ‘NHS’ SW/MW Vintage Crystal Set 

Victor Brand, G3JNB, reports on a unique example of traditional amateur adaptation skills.

 For the ‘Old Timers’ such as myself, it did our hearts good to see the variety and the ingenuity of the work ranging from simple lash-ups and kits to advanced microwave systems and a worthy return to complex ‘metal bashing’!  The best of these gained the appropriate awards but one item in particular was outstanding and, naturally, won the ‘Novice Trophy’ for a first time entry by a new member.

 The ‘NHS SW/MW Crystal Set’ designed and built by Sydney Smith, M0ZAR, sat there on one of the three tables for this category and was soon surrounded by an intrigued membership.  The very idea of such a vintage ‘repro’ set and a short wave version to boot, caught the imagination of all.

This breadboard-style set was lovingly presented with straight-line wiring, the coils had permeability tuning pistons and the front panel was reminiscent of the glory days when listeners were invited to ‘Hear what the Wild Waves are saying’!   Old hands gazed in rapture at this vision from the past that, nevertheless, seemed to still be relevant in the 21^st century.  The ‘solid state’, new kids on the block were in awe of this example of their art that harked back to their great-grandfather’s concept of a cutting-edge broadcast receiver. However, they were quietly pleased to see that a small LM386N had crept onto the board to help boost audio output.

‘A triumph of construction work’ you may think,
‘but what is so unique about it?’  Well, many of the components did not come from an amateur junk box or, indeed, the Maplin’s catalogue.  They were ‘liberated’ from the uncontaminated waste bins of the operating theatres at Bedford Hospital where Sydney is a Maxillofacial and Oral Surgeon. He spends his whole life reassembling badly injured people.  He had noticed the ‘handy’ looking tubes and plastic items that ended up in the rubbish bins. As any true amateur, who habitually says ‘what could I make out of that’, Sydney confounded his nursing staff and colleagues by retrieving some of these items and wandering off with a knowing look on his face.  

“Sydney, just what did this stuff do in its previous existence” I asked and “just how did you come to build such a delightful repro radio?”

“I have always loved the idea of the crystal set and it seemed such a waste to see those high quality ‘coil formers’ going begging.  I thought that I would just try to recycle some of the stuff, using it to construct a particular circuit called ‘The Mystery Crystal Set’ by Proton that had been published in Australia.  The very idea of presenting my colleagues with a radio made from hospital rubbish was attractive and the possibility of a medium and short wave radio set that was so ‘green’ that it used zero power (before I added the IC) was bound to cause a laugh.

 “The outer tubes of 50ml theatre syringes were obvious coil formers and their plungers made ideal permeability tuning controls. Endotracheal air filters and small specimen jars (with a little surgery) became dials and I used some cellophane from a surgeon’s visor in the MW coil as a guide for its ferrite core! “Another specimen jar serves as a ‘Pacent’ detector and dial pointers are made from scrub finger nail cleaners and odd theatre cable ties.” “Sydney, the wiring is so neat and the presentation a joy to behold. Just how did you achieve that veteran look without compromising performance?” “Victor, it is really a con! I just used stiff diathermy wire and superglued it to the base!  The effect, however, is of a 1930 broadcast set and certainly rang a few bells at our club meeting!”

At this point, I just had to ask the obvious question….”Does it work?”  “Oh yes” he replied, and described how, with a 30m wire aerial, he has heard Dutch and German AM stations on SW and most of the local MW broadcasters.  Apparently, the switched coils permit coverage from 530 kHz right up to 9 MHz!

“So what about the circuit itself?” I asked.

 Proton’s design was actually published way back in 1932 in the Brisbane ‘Sunday Mail’.  A Mr. Ken Harthun modified it for short wave reception and I adapted it to suit my own thoughts.  It seemed to me that the very idea of SW listening with such a set had been much neglected and, so, I got to work, making changes as I went along.  It really has been a wonderful experience developing the set and to see the reaction of the Bedford Hospital team when I walked in with it and re-introduced them to their discarded junk!”

 Now, G3JNB has been involved with home-brew club contests for over sixty years.  I can honestly say that in all that time I really have not seen anything like Sydney’s creation.  For sheer ingenuity and the creative use of pure junk, resulting in such an attractive and viable receiver, the ‘NHS’ surely is an all time winner in my book.  But, then, perhaps Sydney’s rather special professional skills do account for the meticulous way he presented his little masterpiece?  The SADARS people obviously thought so too and unanimously awarded him the ’Novice Trophy’

It is good to find that the true ‘amateur’ spirit is alive and doing well at one’s own club. 

“Nice one Sydney..HI!”