Hi Ed. You make a valid point, but I think at these relatively low frequencies you may be worrying unnecessarily.
I have just checked the capacitance between two adjacent tracks on the 4"x3" piece of 0.1" matrix Veroboard on which I propose to build this project, and measured just 2pF. As the tuning capacitors for both oscillator and output stage are 270pF, this will swamp any stray capacitance introduced by the Veroboard, and the range of variable inductance available from the specified coils should be more than sufficient to compensate.
In his original article, Ian did say that construction wasn't critical and Veroboard or other methods could be used, so I'm not anticipating obtaining an output signal on Long Wave or the 49 metre band...!
