2023 Club Competition
The 2023 Club Competition will be a construction competition using type 5676 miniature valves provided for entrants.
The Rules
- Club Vice President, Ray Creighton, will provide for free:
- a kit of four 5676 valves
- a data sheet for those valves
- a sheet showing a typical application of those valves
- Applicants must attempt to construct any electronic device using one or more of the supplied valves.
- If more than four valves are required they can be purchased from Ray Creighton at $5.00 each.
- There is lots of information on line about uses for 5676 valves/tubes.
- Prizes will be awarded for 1st, 2nd and 3rd place getters, plus Certificates of Participation for all other entries.
- The only condition is that recipients of the kits must present their attempt at the judging. Ray is not providing the valves for free for members to simply store them.
- Peter Gofton has confirmed the RF front end of the typical application circuit provided (below) works. He has also constructed a two valve VTVM using these valves. So the possibilities are limited only by your imagination.
- A typical circuit showing the use of 5676 valves is shown below.
The Contestants
Ches Bassingthwighte for his use of the valves to replace the (almost) unobtainable WD-11 valves used in the early 1920's Westinghouse and Radiola receivers.
The WD-11 triode was introduced by the Westinghouse Electric corporation in 1922 for their Aeriola RF model radio and found use in other contemporary regenerative receivers (used as a detector-amplifier) including the Regenoflex and Radiola series. The WD-11's design was somewhat ill thought out, as when the filament burns out it has a tendency to flop against the plate, feeding high B+ voltage back through the heater circuitry and burning out the filaments on the remaining valves. Because of its rarity it has become one of the most valuable valves in the world. New-old-stock units have sold for as much as US$180 and used units for over $100, more than the original price of the radios that used them. Collectors rarely, if ever use these valves for fear of burning them out.
Dan Bedford entered a 1950's style hearing aid, inspired by the trials and tribulations he witnessed as his father's hearing failed following service in the artillery during WWII. Dan constructed his aid in a cigarette tin and had the battery pack housed in a "bum bag" style belt pack.
Rob Walker entered a superhet circuit supplied and fitted it into a small multimeter case with a tape recorder cover. Rob added a small transistor amplifier. He is waiting for an output transformer to complete his project.
The Winners
Judging took place at the Club AGM and Auction at Wynnum State School on the 3rd September 2023. Three entries were presented, and judging was decided by a show of hands.
- First Prize went to Dan Bedford for his 1950's style hearing aid
- Second Prize was awarded to Ches Bassingthwighte
- Third Prize went to Rob Walker
Prizes
Dan chose the slim Dual Mode Detector and Multimeter as his prize.
Ches Bassingthwighte chose the Diamond Files for his reward.
Rob Walker chose the Smart Multimeter as his prize.
