Last weekend, I finished installing the T-loaded vertical antena using the
18m Spiderbeam fiberglass pole. It has 3 wire spokes for top load, each at
15 meter long. Also, 3 elevated radials at 1/4 wavelength long in the height
of 3 meters each. The elevated radials are still bended here and there
according to my limited land-lot area. The SWR 1,6:1 at 1825 kHz. The lowest
1:1 is at 1800 kHz. I think I must pull out radials in straight-and-level
form to obtain the SWR match and resonance (at 1825 kHz) and will see if the
radial wires would need trimming.
I am using coax Andrew 7/8 inch about 21 meters in length as feeder line. My
shack is in the first (not ground) floor. So, both (coax and radials are
elevated). I am using home-made UNUN dual impedance (12.5 & 24 Ohms) a la
W2FMI
This is my first time to build vertical antenna for TX on topband. Would be
very grateful to hear any advises on what to do best to optimise the
antenna. TIA. Also, I'd like to express my gratitude to Bjorn, SM0MDG, for
his suggestions and guidance in making this antenna.
I hope I can continue to present YC-land on topband. 73 de Jo, YC0LOW
_______________________________________________
Topband mailing list
Topband@contesting.com
http://lists.contesting.com/mailman/listinfo/topband
|