"starman" wrote in message
...

The traditional single gang 10-365 cap' was used to tune the oscillator
in a MW radio, not a front-end preselector. The oscillator usually
operated at 455-Khz (I.F.) *above* the desired frequency. This would be
about 995-Khz for the low end (540-Khz) of the band. That's why a
variable cap' with a maximum of 365-pf is not really low enough
(practical) when you want to use it as a tuning cap' for a MW loop
antenna or preselector. This is because it has to tune down to the
actual lower limit of the MW band (540) instead of the receiver's
oscillator frequency (995) at the low end.


The 10-365 pf section of the tuning cap is used to tune the antenna loop
circuit (and/or the RF amplifier circuit if it's a three gang tuner). The
oscillator section usually runs around 5-185 pf or so..