The "Amateur Six"


A fairly complex homebuilt set of the late 1920`s was found in a very sorry state amongst a box of junk. It consisted of the baseboard and ebonite front panel, but miraculously also most of the components.It was all there apart from an intervalve transformer and (perhaps)an HF choke. Needless to say,it had no valves! The oscillator cicuit in particular was difficult to follow, being sealed in a copper can with it`s own built-in rotary switching for three wave bands.Only two of these were used -Medium and Long. A "Blue Spot"moving armature speaker in a rather shabby cabinet was also found. The speaker case and it`s mechanical unit were renovated and a period type cabinet made.The whole is now in good working order.


The IF of this set is around 100kHz which allows ample opportunity for stations to appear at more than one point on the tuning scale, also the use of separate tuning capacitors for RF and Oscillator makes this set a "two hand" tuning job. The combination of this and the low IF frequency effect almost turns tuning into an art form.Volume control is by varying the voltage on the screening grids of the first and third Screen Grid valves and is quite touchy.




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