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@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@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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