Ham Radio, my antenna
Antenna etc. I'm interested in and have built
2M antenna tests
Pictures 0.5 to 1Mb in size
RF Bridge, 2x 47ohm surface mount resistors
1) 2m lashup similar to 6m ZL Special on my mini tower - nogo
2) 2m attempt as per HB9CV with thicker wire
3) 2m 5el as built for BMARC, still narrow band
3) 2m 5el as built for BMARC, fixed, broad band
3) 2m 5el return loss 5MHz/cm, broad band
4) back to folded dipole, better BANDWIDTH
With 1 director, 30 ohm reference, -20db return loss, 8MHz BW
5) 2m LP yagi, this really WORKS, over 2+MHz, driven elements brass
5) 2m LP yagi, 5MHz/cm
BANDWIDTH is so important.
Who wants a fantastic 2m beam with 0.5MHz bandwidth on 143.5MHz or even 145.0MHz.
Go for the folded dipole or the LP feed. Or see VK3DIP OWA designs (link below).
Impedance match. (4 above) The director brings the impedance down markedly, hence best match at 30 ohms on the RF bridge. This suprised me.
With the 10mm rod I was expecting about 200 per dipole, paralleled, 100 at the feed. Not so.
My findings are, the HB9CV antenna do not have sufficiant bandwidth to be usefull on 2m. And, I don't believe the RF power presented at each dipole is sufficiantly balanced, because of the 1/8 wave line. Only a 1/2 wave line (or multiples of) presents the same voltage at the other end.
The diagrams here show good gain and Front-to-Back.
HB9CV 2el log periodic, sort of.
HB9CV Will this work, I think not, feed at the wrong end.
Commercial HB9CV, I couldn't get this lovely SWR hear, downunder.
OH4JZJ With a good 20db F/B coming from the feed, why add a reflector?
HB9CV from Asia, I love the english.