Hi Pete,
For a monoband receiving array, you might consider using low impedance
resonant verticals rather than high impedance verticals.
The primary advantages of high impedance verticals are
- very short verticals (but taller verticals produce stronger signals)
- multi-band operation
- no radials
The primary disadvantages are
- reliability issues with outdoor electronics
- lightning susceptibility of outdoor electronics
- higher cost
- much lower signal levels
- extreme care required to suppress common mode signals (buried feedlines are
highly recommended)
- negative effects of nearby trees and buildings.
The primary advantages of low impedance verticals are
- much stronger signal levels
- much less criticality of common mode signal suppression,
- much lower cost
- much higher reliability
- immunity to lightning damage
- much less affected by nearby trees and buildings
The primary disadvantages are
- taller verticals (typically about 24 feet)
- radials (they can be very short if many radials are used)
- mono band operation (switchable matching networks can be used for
multi-band operation).
I highly recommend the DX Engineering Receiving Antenna Phasing System.
Its expensive but well worth the investment especially for a small array.
https://www.dxengineering.com/parts/dxe-ncc-2
If you have 120 feet for a three element array, the YCCC array is a great choice
It can use high impedance or low impedance verticals
Unfortunately its no longer available from DX Engineering
The nine element YCCC array uses only three active elements at any time,
so its really a three element array switchable in many directions.
https://static.dxengineering.com/global/images/instructions/dxe-yccc-switch.pdf?_gl=1*1cv0fc9*_ga*MjEyMDA1Nzc3MS4xNjUyMzAyMjc0*_ga_NZB590FMHY*MTY4MDE5NTk1OC40My4xLjE2ODAxOTYwNTYuNTAuMC4w
https://www.youtube.com/watch?v=dl-crM5Kb6A
https://www.youtube.com/watch?v=lVW1CmrzP7c
A two element array occupies only 60 feet or even a little less.
73
Frank
W3LPL
----- Original Message -----
From: "Pete N4ZR N4ZR" <pete.n4zr@gmail.com>
To: "topband" <Topband@contesting.com>
Sent: Thursday, March 30, 2023 12:54:30 PM
Subject: Topband: 2-element receiving arrays
Thinking ahead to next winter on 160, I'm interested in replacing my
K9AY Loop with a 2-vertical phased array. I'd like to homebrew the
antennas and just buy or build the remote control unit for the shack.
I'm looking for sources of components (antenna-located preamps and an
in-shack controller), and would prefer not to completely homebrew them,
but the prices at the usual suspects are awfully high. Any ideas?
I have pretty reasonably-priced access to 25 and 31-foot fiberglass
poles (used for wind-socks by model airplane enthusiasts). I'm thinking
that one relatively low-cost approach might be to attach, say, #14 wire
to the poles, with preamps at the base, but wonder if there is a
downside to using such small-diameter antenna elements rather than 1 or
1.5 inch tubing? Alternatively, are clones of the DX Engineering 8'
short verticals with preamps a good alternative?
--
73, Pete N4ZR
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