This hand built radio designed by the donor clearly demonstrates their continued development as a radio circuit designer and desire to understand the new technology of transistors and its application to radio circuit design.

Included with the radio are handwritten notes by the donor that detail the original design of the radio and a commentary on the developments in the circuit design as they occurred, the conditions that engendered these developments and expressions of their feelings regarding the results and achievements.

These notes hand written by David Hain in 1995 are included here:

'02 April 1995. Notes about this radio by D.W.H.

Unfortunately I do not have ready access to dates etc about this radio, so must rely on my memory.

Originally I built this set in the early 1950s or perhaps the late 1940s as a 5 valve battery operated portable using the 'new' 7 pin miniature 1.4 volt series of valves (IT4, IR5, IS5 and 3V4). It was based upon a Radio and Hobbies (now Electronics Australia magazine) design and used the chassis and cabinet produced for the R&H design. It worked very well and was kept in service until transistor portable superseded valve sets in the 1960s.

Rather than dispose of it I used the chassis etc to experiment with transistor circuits.

When silicon RF transistors became available at modest prices in the mid 1960s or thereabouts I decided to design and build some 'way out' unconventional circuits which I knew would not be commercially viable and probably not very good from a performance viewpoint. The tuner of this set is the result. The Audio output section with germanium TO3 transistor is earlier in its origin.

Not a good performing set but it helped me to gain a better understanding of the transistors of those times.'

Designed and built by David Hain in the early 1950s or the late 1940s as a 5 valve battery operated portable using the 'new' 7 pin miniature 1.4 volt series of valves (IT4, IR5, IS5 and 3V4). Based on a Radio and Hobbies (now Electronics Australia magazine) design and used the chassis and cabinet produced for the R&H design.

David used the chassis etc. to experiment with transistor circuits in order to develop a better understanding of this new technology and its application to radio circuit design. Handwritten notes by David Hain explain that 'when silicon RF transistors became available at modest prices in the mid 1960s or thereabouts I decided to design and build some 'way out' unconventional circuits which I knew would not be commercially viable and probably not very good from a performance viewpoint. The tuner of this set is the result. The Audio output section with germanium TO3 transistor is earlier in its origin.'

Designed and built by David Hain around 1950. David's notes indicate that 'it worked very well and was kept in service until transistor portable superseded valve sets in the 1960s.' and 'Rather than dispose of it I used the chassis etc to experiment with transistor circuits.' David then set about redesigning various parts of the radio circuit using the new transistor.

Radio receiver, mantle radio, and documents, wood / glass / electronic components / metal, designed, made and modified by David Hain, Sydney, New South Wales, Australia, 1950-1970

Wooden radio with brown mottled vinyl covering, two bar speaker grille and oblong frequency dial. Frequency dial has horizontal white needle and brown plastic moulding surround. Three control knobs below dial. Swinging handle on top, hinged back board.

Three handwritten circuit diagrams and four hand written notes.

Made: Hain, David; Sydney; 1945 - 1955

2007/17/13

1945 - 1955