Hi Guys,
Hope you can give provide some wisdom on an antenna problem I'm having on
40-meters. I'm operating at a temporary QTH and mounted a Hustler 5BTV
vertical up on the rooftop at 30' above ground. Using two 1/4 wave radials
for 40-m. and four 1/4 wave radials for 20m. the SWR across 40-m. was 1.3 to
1.5 to 1. The antenna radiated pretty well for what it is. ( a simple GP)
Since I'll be at this QTH for another month and I'd like to work
12-17-30m. I took the Hustler 5BTV down today and replaced it with a Big
SteppIR
vertical. Using the same radials at with the Hustler... my SWR on 40-m. is
now a terrible 5 to 1 and it doesn't hear well either. I'd say the reception
is down about 4 S-units.
On 10-30 meters the Big SteppIR Vertical is resonating aprx. 2 Mhz from
the norm:
Transmit Freg SteppIR Resonance
28mhz 24mhz
21mhz 18mhz
14mhz 12.5mhz
10mhz 8mhz
7mhz ? (unfortunately I cannot add add'l length
on 40-m. to find resonance but the SWR is 5 to 1)
Since I can vary the antenna length I can make the SteppIR work on 10-30
meters. But I'm wondering what I can do to make it work on 40-meters? The
SteppIR instructions say you can adjust a ground planes resonance by
changing the radial length. I'm wondering if you think increasing the length
of
the 40-meter radials would lower the SWR on 40-m?
I'd appreciate ideas on how to reduce the SWR and increase the antennas
efficiency on 40-m. Such as: adding more radials to the GP or increasing the
radial length, etc.
Thanks & 73,
Dick K9OM/9
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