UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Antenna recommendation for 40 and 80M bands

James Duncan · 29th Sep 2019, 5:38 pm

Well done
that is exactly the way a correctly cut dipole will perform ,
20 works well on a 80 meter antenna as it is the harmonic.
if you want 40 just add an extra dipole to your antenna,and all will work well.
as to SWR, it is often overlooked that a dipole has an impedance of 73 ohms and the coax is 50 ohm so 75/50 = near 1.5 to 1 is the best real SWR that should be expected, anything up to 2-1 is fine.

29th Sep 2019, 5:38 pm	#99
James Duncan Pentode Join Date: May 2010 Location: Wick, Scotland, UK. Posts: 227	Re: Antenna recommendation for 40 and 80M bands Well done that is exactly the way a correctly cut dipole will perform , 20 works well on a 80 meter antenna as it is the harmonic. if you want 40 just add an extra dipole to your antenna,and all will work well. as to SWR, it is often overlooked that a dipole has an impedance of 73 ohms and the coax is 50 ohm so 75/50 = near 1.5 to 1 is the best real SWR that should be expected, anything up to 2-1 is fine.