N6MW
Antenna Matching Stuff
Problem with ARRL Gamma Matching Code
Gamma Matching Discussion
As mentioned in notes above, the ARRL ON4UN's Low-Band DXing Fourth Edition Section 3.8.1 on The Gamma Match is often incorrect and anyone attempting to use specifics from there will be led to gamma
grief. Here is a better version of 3.8.1 that removes the errors, updates some text and replaces two tables of examples. The ARRL has noted this and placed the revision on their website under "A
Revision to Section 3.81. of Low Band DXing." See Below
Low Band DXing 3.8.1 Gamma Match Fix
Improved Gamma Match Code
Posted somewhere on ARRL website after vetting
Gamma Match Spreadsheet
If the file is called ' gammaMW9aXLS.pdf" change to gammaMW9a.xls due to allowed file types on this free site. The spreadsheet gammaMW9a.xls can solve for Gamma Match parameters, needed Capacitance and Length, using inputs of Frequency, Feedline Impedance, Ro, unmatched antenna impedance of Ra(resistance) and Xa(reactance) and conventional Gamma Match quantities D(antenna rod dia.), d(gamma rod dia.) and S(spacing between rod centers). If either of two cells have a Red background, no solution is possible requiring a change of input parameters.
Hairpin Matching Discussion
This led to a QST article June 2013
A Version of Hairpin Article published in June '13 QST