- 40Meter delta loop -
2009.12.12 - Recalculated and adjusted each side to 13,59 meter. Made a new run with the miniVNA. The Loop works fine on 40/20 Meter band, and is 'usable' but not optimal on 15Meter.
Here are the results:

DeltaLoop @ 40meter BAND

DeltaLoop @ 20meter BAND

DeltaLoop @ 15meter BAND

2009.10.14 - Made a run with the miniVNA vector analyser, it seems that the loop is a bit to long, resonant frequency is now @ 6778KHz. Need to recalculate the delta-loop.

Click on image to enlarge

About wave propagation speed 'Velocity factor' @ Wikipedia

-Calculation -
Since i know the resonant frequency and lenght of the 'faulty-loop' i'm able to calculate velocity factor of the wire used.

# Calculation of velocity factor in faulty-loop
 6,778 x 42,96 = 291,18
291,18 / 299,8 = 0,97

# Recalculation of loop
[Wave Speed] / [MHz] x [Velocity Factor] = [Wave length]
[c] / [F] x [VF] = [λ]

Wave Speed [c] = Universal constant, speed of light in total vaccum (299,8 km/s)
Velocity Factor [VF] = Ratio of [c] and acctual wave speed in conductor.

299,8 / 7,13  x 0,97 = 40,78 meter

# One side of loop
40,78 / 3 = 13,59 meter

2009.10.13 - The delta-loop antenna is up and tested, less noise on all bands (HF 40-10Meter) compared with the Carolina windom 160. Made first couple of QSO's into PA and GI, it locks as it's working, need more QSO's to be able to determine directional pattern a.s.o.

2009.10.05 - Made some plans for putting up this delta loop antenna. Using 1:4 air-core balun with 50ohm coaxial feed.

Drawing of complete delta-loop

In the table is given lengths (Recalculated) for other amateur band's - I'm using the measurement's given for the 40M band. Wire length 40,78m (all sides) 13,59m (one side)

Wire length given for different amateur bands (Recalculated)

- Making the 1:4 Balun -
An 1:4 Ratio air-core balun with bifilar windings.

Using 2pcs of 2,4mm OD (4,5mm2) plastic insulated Cupper wire (Single Solid Wire) This type of wire is normaly used for electrical installations - Made 13 turns of each wire onto the 32mm PVC-Plastic tube-core. (Refer to illustration below)

Balun schematics and layout - Click on image ta enlarge

1. The Winding A and B is electricaly connected in series (Wire end A2 to B1)
2. Shield from coaxial feed is connected to wire end A2 and B1 (Center of winding A and B)
3. Center lead from coaxial feed is connected to wire end A1 and to one side of balanced line.
4. The wire end B2 is connected to other side of balanced line.

Bifilar windings on 32mm PVC Tube - Click on image ta enlarge

- Making the antenna -
I'm using Swedish military DL-1000 Telephone wire, This is a very strong and lite weight wire with 4x piano-wire parts and 4x cu parts. The images show some simple means to make weather proof connections to the balun or balanced feed-line.

Balun corner and 2x support rope corners - Click on image ta enlarge

Balun connection and Screw terminals used - Click on image ta enlarge

Building silicone used - Click on image ta enlarge

- Technical data -
Total lenght ......... 40,78m (all sides)(Recalculated)
Lenght one side ...... 13,59m (one side)(Recalculated)
Center frequenzy ..... 7,130MHz
Balun ................ 1:4 HomeBrew 50ohm SO239
Antenns wire used .... Swedish military DL-1000
                       Telephone wire 4x steel 4x cu parts

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©2009 SM2YER Goran