3rd Harmonic

[photovision]

I have an old antenna from the 80s. It is basically a dipole cut for low band (40-50). It picks up high band (area of 140-170) quite well. I have been told high band reception is via the 3rd harmonic. What kind of Db loss is there though 3rd harmonic reception?

 

[prcguy]

If you mount the dipole vertical it will have a doughnut shaped pattern with most of the signal at the horizon and little signal up and down at the primary frequency its tuned for.

At three times the frequency the match to 50 ohm coax will be ok but the pattern will have six lobes with one pointing up about 45 deg, one pointing down at 45 deg, both with a little gain and a small lobe at the horizon with less gain than the dipole at its primary frequency.

So, a dipole at 3X frequency does have gain but not where you may want it.
prcguy