[Lowfer] Loop antenna

[Tom Smith]

I built Ralph burhans preamp and a 8' version of the 
shielded loop using 3/4" hardline a year or two after his 
article. It has been in service since that time with the 
only problem being the J310 fet knocked out by lightning. 
It was built using G-10 glass perfboard has performed 
well. I would like to build another larger loop using a 
similiar design and was delighted to find the reference to 
the original articles since I lost my original copy of the 
lowfer. The one thing missing is the values for the trap. 
I think there was either a curve or formula to determine 
the values of inductance/capacitance for a given frequency 
(some local obnoxious am station).

Would anyone happen to have that information handy?

Thanks in advance,

Tom  N5AMA