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The original loudspeaker required some work to get it going again, including a patch on the paper cone. The flexible wires that connect the voice coil to the speaker transformer had also been damaged and required replacement. voltage on it. Once again, the cause was simple – an RF (radio frequency) choke in the plate circuit had gone open circuit. Just why there’s an RF choke in this location is a mystery and the circuit certainly doesn’t show one. My theory is that it may have been added to overcome some instability. It was replaced with a small resistor-style RF choke but the receiver still refused to work. It was then found that the earlier “restorer” had wired gangs two and three together at the switch. Once that had been corrected, the receiver came to life and it was possible to tune stations at good volume. A quick check revealed that the IF alignment was close to optimum, as was the alignment of the front-end stages around valves V1 and V2. This is a tribute to the quality of the components used by Airzone in this receiver. All that was left to do was to replace The Fifth National Radio & Phono Fest By KEVIN POULTER In a departure from our usual Photo Gallery feature, this month we are publicising a huge vintage radio and phonograph event. Scheduled for September, it will feature a vast range of collectibles for sale and free workshops. This can be a great opportunity to start or expand your collection, see the best collectables and learn restoration techniques. There is no bigger event in Australia for these collectables. Vintage radio is so popular that this national event is now staged every two years in the nation’s capital. Titled the “HRSA Radio Fest” (previously called the “National Radio and Phono Fest”), it attracts big 92  Silicon Chip crowds of HRSA (Historical Radio Society of Australia) members plus members of affiliated groups and an enthusiastic public to Canberra each spring. In the beginning . . . RadioFest began in late 2000 when Richard Begbie, a relatively new member of the HRSA, attended their meeting in Sydney. He suggested that with the cooperation of similar groups around the country, there might be room for something bigger – a national event. And so the first “National Radio and Phono Fest” was organised for September 2001. A church hall was hired but it soon some defunct dial lamps and fix the volume control. A switch-potentiometer was used for the original volume control and as the on/off switch. However, because the new power supply had its own on/off switch, Marcus decided to fit an ordinary potentiometer instead. The shaft on this replacement unit was still too short and so an extension had to be fitted. A brass extension shaft was scrounged from his spare parts bin while a sleeve to join the two was made from some 16mm-diameter round aluminium bar. This was turned down in a lathe and drilled through with a 0.25-inch hole. Finally, two holes were drilled and tapped along one side to accept the grub screws. At this stage, the technical restoration was complete and the set has now been returned to its owner so that the cabinet can be restored to its former glory. Summary This set’s performance is superb, with distant stations like 5CK (about 750km away from my location in country Victoria) being heard in daylight at a reasonable level. It only has around 350mW of audio output but this is more than adequate due to the efficiency of its loudspeaker and the use of a decent baffle in the large cabinet. In summary, it’s a set that’s wellSC worth having in any collection. became apparent that it wouldn’t be big enough. An adjoining hall was also taken over and by the time the RadioFest doors opened to the public, both halls were jammed with gear for sale. Stallholders and visitors from as far away as Japan were equally enthusiastic about the day and everyone – with the possible exception of the stunned organiser – declared it must happen again. Of course, its ongoing appeal also has much to do with Canberra’s other attractions like the War Memorial, the Film and Sound Archive, the National Museum and the beginning of the capital’s annual garden festival. If you get sick of looking at dusty valve technology, there are lots of other things to see and do. RadioFest offers much more than the usual swap meet. Beyond the large trading halls, there are also workshops by experts on technical, mechanical and restoration matters. A dinner on the Saturday night siliconchip.com.au RadioFest Program • provides the chance for radio enthusiasts to get together and share their knowledge and experience. Because of ongoing space demands, the show was soon moved to University House in the grounds of the ANU (Australian National University) and has since continued to expand. The dinner became a highlight for many, while others eagerly stocked up on rare vintage parts, early phonographs, intriguing radios which tell the story of broadcast radio and must-have sets of the type seen regularly on TV collectors’ programs. In addition, films are made of the various workshops and distributed to enthusiasts around the country. This year it’s on again and the anticipated crowd sizes have dictated yet another siliconchip.com.au change in venue, this time to the Kamberra Wine Centre (yes, the spelling is correct) over the weekend from 18-19th September. Moreover, the HRSA has officially taken over the event for what promises to be a bumper Fest. An added feature this year will be a display of some of the best early radio collectables, including many unique items in Australian radio history. Richard Begbie said the national event had become a huge logistical effort and welcomed the HRSA’s involvement in the organising. “I am delighted that the HRSA has taken over this event”, he told me. “The Society is its natural home and it’s the kind of thing they’ll do well. And besides – there’ll be more people to do the work!” Mike Osborne, president of the HRSA agrees. “I’ve watched the Canberra Fest grow from its beginnings and have personally enjoyed every aspect of its development. It’s a great step forward for the society to be taking responsibility for a national event”. The Kamberra Wine Centre, Federal Highway, Watson ACT is a terrific venue, with good access from the Federal and Barton Highways. If you want to know more, visit the HRSA’s website at www. hrsa.asn.au and click on “RadioFest” for the location map and dates. So how do you secure a place at this outstanding event? If you have something to sell, stall tables are fast running out with just one size left – 1800 x 760mm (6ft x 2.5ft). These are available for $25 each. Stall tables are available to HRSA members and affiliated groups only, however there is still time to Sit-down dinner, Saturday 7pm – great entertainment, including a guest speaker. Preview display over pre-dinner drinks. • Bumper market from 9am Sunday – parts, radios, ephemera. • Genuinely unique historic items in multiple displays. • Professionally-presented workshops, including: (1) The History & Mystery of the Valve. (2) J. G. Balsillie – The Forgotten Australian Radio Pioneer. (3) Timber Cabinets – When And How To Restore. • The HRSA Annual General Meeting (members only) – to be held on Sunday night, with members from all over Australia. join the HRSA, for $35 per year. This fee includes the “Radio Waves” magazine. For stall bookings, contact Richard Elliott on (02) 4846 1096 or email him on lambdas<at> optusnet.com.au The Sunday entry to the event is $5 per person or $10 for a family (stallholders exempt). The dinner function is $40 per person or $75 per couple. The bar opens from 6:15pm. For bookings, contact John Carr on (02) 6226 3230 or Richard Elliott on (02) 4846 1096; email lambdas<at> optusnet.com.au Accommodation options range from camping grounds to five star. For details, including distance from venue, contact Richard Elliott. Other queries can be directed to Richard Begbie on (02) 6238 2246; email rb<at>bordernet.com.au SC August 2010  93