I am performing an alignment on a National NC-300 using the manual found on
BAMA. I am having a bit of linearity problems with in the 40m and 20M
bands. That is, once the top and lower frequencies have been set the middle
of the dial scale is off. 80m is right on the money (tracks the band scale
well). I have not finished the rest of the bands yet. It is too late to
focus.

To set the high end a variable cap is used. To set the low end an inductor
is used. To adjust that inductor there is a solid wire or two depending on
the band, inside the ceramic oscillator coil form. The form is about a half
inch ID. You bend (oops-form) the wire like swinging a close line from side
to side.

My attention has been pulled to the coils with two loops. Is one used for
the low end and one for the midband?

Before I dive into all the variables I hope some one has some experience
with linearizing the dial scale on this radio and would share some hints and
tips.

Thanks in advance.

Paul P.