21-06-2020, 06:48 PM
Mike Watterson Wrote:The K is much better than the Lissen version of the 5214 I have. But I think it has it's original 1939 valves.
Also running on battery reduces the mains interference.
The loops are a better size, more signal and Q, than the flat coils in the lids of attache models, they outperform a decent ferrite rod...
Now that last bit is interesting!
First, my impression is that the Vidor CN420a (flat coil in attaché case lid) is more sensitive than the Model K (frame aerial), at least for receiving more stations. Though, the K sounds better.
Second, the K has a single coil for its frame, with a (non-receiving) series inductor to bring up total inductance to what's needed for LW. Whereas, the CN420a has extra (receiving) coils in its lid for LW, and the 5214 has a dedicated LW frame aerial, so one would expect a greater signal to the first valve, and better performance overall, on LW for the CH420a and the 5214 if all else is equal.
Last, I have been carrying out experiments with replacing the frame aerial in my K with a 160mm ferrite rod, and my findings are that the rod is better! See here.
