David,

With an MFJ-259B I just ran a test using an air-wound coil
resonating with a series combination of 820pF and 100pF at about
44MHz, all strapped across a 4.7K resistor. The figures came out
as follows -

Inductor (calculated) = 146nH

Real part of Zin (with 4.7k) = 14 ohms (tuned for X = 0)

With perfect components, and the capacitor tap chosen, this
should have been 55 ohms. Disconnecting the 4.7k (again tuned for
X = 0) the real part of Zin increased to 20 ohms. This, if my
maths are correct, means the inductor's equivalent shunt loss
resistance was about 1.6K giving an inductor Q of around 40.

Due to the similarity of component values used, these then are
the sort of figures you should have obtained. Obviously the
limiting factor here is the circuit Q but I supposed you had
intentionally chosen this to meet a specific bandwidth target.


Cheers - Joe