5/8 over 1/4

[wa1knx]

I was reading about 5/8 antennas and found this article..

2-Meter EchoLink Antenna 5/8 over 1/4 » VE3NCQ

..an interesting idea of homebrewing a 5/8 antenna over a 1/4 ground plane. here sloping radials would work and could help hone in matching. his model claims 5.71dbd. it would be a big antenna on 11 but a more elegant coil could be wound and it looks plausible and good gain. the
antenna pattern he models is really nice.


also found this youtube of a diamond gh62 5/8 over 5/8 for 6mtrs..

http://www.youtube.com/watch?v=K_5hX4MGmck

its 21'+ on 6mtrs. probably would be 39'-40+' scaled to 11mtrs. I am not sure how
this one feeds (?)

73 dean

 

[M0GVZ]

It actually has validity and is similar to methods used in high gain commercial VHF vertical antennas. Antennas such as the high gain ones from Amphenol aren't just a straight wire running up the middle of a PVC tube but something similar to the above usually using two or three or more 5/8 sections connected by phasing sections all with a PVC tube to make it look neat and tidy as well as provide support.

 

[wa1knx]

5/8 over 1/4 or 5/8 over 5/8

The 5/8 over 1/4 looks really nice as presented by ve3ncq. I started
looking into this, after sketching out the W58 I just got, made by workman.
I can see why sloping radials don't work on 5/8 antennas. the matching
device is on the last 1/8 wave after the 1/2 wave phase reversal point.
thus sloping radials would radiate out of phase with the top 1/2 wave. with his
design one also could lengthen the top into a .64 wave and put it over the 1/4.

Anyone know how the 5/8 over 5/8 diamond GH62 works? it is still on the market as a model CP62. 22' high on 6mtrs. from the video I just see coax into the base and aluminum up to the only coil (in sight) somewhat near the middle. it has 3 full size radials at 90 degrees on it.