Topband: Broad band antenna approach for 160 Contesting

[John Harden, D.M.D.]

I have been using a shunt fed 45G tower for many years with around 50 radials. It is top loaded with a mono stack from 80 to 10 meters. It works extremely well on 160 using an Omega match. There is a 1000 pfd vacuum variable in series with a motor driven 1000 pfd vacuum variable to ground. The motor is a reversible 1 RPM, 12 VDC motor that is tuned remotely from the shack. The SWR is always 1.3/1 or better. The tower is 100 feet high. I can usually work anything I can hear.

The receiving antennas are a Hi-Z 8, Hi-Z 2, NW BOG, and a Waller FLAG on a 40 ft boom at 93 feet. The FLAG shines on the long path.

73,

John, W4NU 
K4JAG (1959 to 1998)
Atlanta

Sent from my iPhone

> On Feb 28, 2021, at 10:41 AM, Grant Saviers <grants2 at pacbell.net> wrote:
> 
> The nice thing about switched serial caps (if same values) for tuning upwards from a low resonance is the voltages are all the same. Plus caps and appropriate relays are cheap, easy, and small.
> 
> Rick, I think you might have suggested this to me, and my implementation was published in QEX May/June 2019.
> 
> Grant KZ1W
> 
>> On 2/28/2021 07:10, Richard (Rick) Karlquist wrote:
>>> On 2/27/2021 2:23 PM, Artek Manuals wrote:
>>> Rick et all
>>> 
>> he feed, The taps are relay selected .  Taps selected for a dip
>>> at 1816, 1840 , 1860, 1880, 1900 and 1920. SWR 1.3:1 from 1.8 to 19.5 which the my KPA1500 and Alpha 9500 both love.
>>> 
>>> Dave
>>> NR1DX
>>> manuals at artekmanuals.com
>>> 
>> Thanks for posting this suggestion.  Perfectly reasonable design.
>> I use an alternative design using switched mica capacitors.
>> I also use a 2.25:1 matching transformer, but the "windings"
>> are implemented using coax.  Not sure if Sevick does this.
>> 73
>> Rick N6RK
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