"Paul Keinanen" wrote in message
...
The problem with loop antennas made of ribbon cable (or other
multiconductor cable connected this way) is the stray capacitance
between turns. The self resonance frequency (without external
capacitor) may be below the band of interest, so you can not resonate
such antenna with an external capacitor.

Ob-flippant remark: Sure you can, you just need a negative capacitor! ;-)

I suppose if one actually built a negative capacitor out of, e.g., a gyrator,
the noise performance would be pretty much shot? Might be OK for a
transmitting antenna, though?