02-09-2021, 09:41 PM
(01-09-2021, 08:09 PM)colly0410 Wrote: The third harmonic of band 1 channels 4 & 5 in band 1 falls in band 3, ch 4's third harmonic is very close to channel 8, & ch 5's harmonic close to ch's 9/10, I read somewhere this was called the third harmonic trick. My parents who lived just north of Nottingham & received Sutton Coldfield on ch 4, & ITV on ch 8 had an H type band 1 aerial with the rods bent forwards at about 45 degrees, there was no band 3 toast-rack type aerial, but it got ITV just as good as next door's X + 5. How many aerial makers used this third harmonic trick? I presume the third harmonic trick would only work in areas with certain fortuitous BBC/ITV channel combinations...
That might explain why I got a good ghost free signal in south Birmingham on my improvised aerial from Sutton Coldfield (ch4) and Lichfield )ch8) back in the 60s.
Keith
