[SECC] Cushcraft A3 Dimensions

[Bill Savage]

Our FD group acquired a used Cushcraft A3 yagi. We downloaded the manual for the A3S from the Cushcraft/MFJ web site, and dimensioned the yagi elements for mid-band resonance. We temporarily assembled it atop a 35 foot wooden scaffold/tower to measure SWR and bandwidth. Despite dimensioning it for mid-band, the antenna shows lowest SWR at the very bottom of 20M and 15M (14.01 and 21.07 MHz respectively) and at 28.15 MHz on the 10M band. The feedline was a 42-foot length of RG-8X, with a W2DU-style "choke balun" at the feedpoint.

What we noticed when we dimensioned the elements of the A3 was that the overall length of each element was not what the A3S manual said it should be, despite each band's measurement being double-checked and verified as spot on. I'm guessing that the length of the trap housing is different between the two antennas, but that's just a guess.

So, does anyone have a manual for the A3 (not
 A3S) and can you
 provide me with the dimensioning info from it? Many thanks.

K3AN