@ M0BEW Station 21 element 432MHz LFA-LN Yagi

@ M0BEW Station 21 element 432MHz LFA-LN Yagi

My current 70cm antenna here @ M0BEW
Performance, details, construction and comments.

Performance.
Gain: 18.81dBi @ 432.200MHz
F/B: 40.75dB @ 432.200MHz
Peak Gain: 18.97dBi
Gain 10m above Ground: 24.77dBi
Peak F/B: 42.32dB
Power Rating: 3kw
SWR: Below 1.1.1 from 432.00MHz to 433.00MHz
Boom Length: 5.210m
Stacking Distance Vertically: 1.36-1.7m (best trade-off 1.622m)
Stacking Distance Horizontally: 1.37-1.8m (best trade-off  1.710m)
Following figures calculated at 432.200MHz
2 Stacked Vertically 10m up @ 1.622m spacing - Gain: 27.47dBi
2 Stacked Vertically 10m up @ 1.622m spacing - F/B: 37.83dBi

2 Stacked Horizontally 10m up @ 1.710m spacing - Gain: 27.65dBi
2 Stacked Horizontally 10m up @ 1.710m spacing - F/B: 37.95dB
4 Antennas 1.622m V x 1.710m H Gain (corrected): 24.41dBi, F/B: 36.24dB (free space)
Sky Temperature (corrected): 25.45 Kelvin @ 432.200MHz
G/T Figure (corrected):  10.35dB @ 432.200MHz

Construction.

Comments:
Well built antenna. Very solid.
One or two little issues but were sorted very quickly.
I first tested the antenna in a RSGB 70cm activity contest and it appeared to perform as expected.
I gather the overall conditions were not very good so it'll be intresting to test it again next month.
Seemed good towards the north and poor towards the south east.

Fed the driven from around the rear and back around the boom underneath.
Needed some very exact measuring while assembling as the elements weren't marked and within 0.5mm of each other. ie. 272.5mm, 273mm, 273.5mm and 274mm.
Testing with a 10 year old piece of Ecoflex on a flat band I'm hearing GB3FNY, GB3UHF, GB3MCB and PI7CIS consistantly.  There are others that come in/out of the noise during an evening if I monitor long enough.

The pattern is as sharp as a torchlight. Quite an eye opener compared to some VHF yagi patterns im used to. Checking performance, pattern and swr in  heavy rain appears to have no effect. Good news.

All in all very pleased so far. Be nice to set up a box or a 4 stack for contesting. But be rather an expensive luxury for my current uses.... we will see.

Tim M0BEW.

@ M0BEW 5 element 50MHz LFA-VR Yagi (4.35m)

@ M0BEW 5 element 50MHz LFA-VR Yagi (4.35m).

My current 6m antenna here @ M0BEW
Performance, details, construction and comments.

Performance.
Gain: 10.63dBi @ 50.150MHz
F/B: 29.52dB @ 50.150MHz
Peak Gain: 10.68dBi
Peak F/B: 30.02dB
Power Rating: 5kw
SWR: Below 1.1:1 from 50.00MHz to 50.700MHz
Stacking Distance: 3.9-5.1m ( 4.70m recommended)
2 Stacked Gain @ 4.70m spacing: 13.45dBi
2 Stacked F/B: 27.53dB
2 Stacked Gain @ 4.70m Spacing 10m above ground: 18.67dBi
Boom Length: 4.354m
Weight: 4.73Kg / 10.43LB
Turning Radius: 2.667m / 8.78ft
Wind Loading: 0.20 Square Metres / 2.16 Square feet
Wind Survival: 253KPH / 157MPH

Specification.
Named after Kerry G8VR who uses 3 x 5el 50MHz LFA-VR antennas.
Boom is 1.25 inch square aluminum.
12.7mm centre elements and 9.525mm outer elements.
Fully insulated elements.
A direct 50 Ohm feed-point. No matching.
Boom to mast bracket to fit upto 50mm masts.
Marine grade Stainless Steel Fittings.

Construction.

Comments.
I have used this antenna now for around a month and feel very happy with the performance.
I choose this particular boom length as a trade off between gain and beamwidth for general use.
For this purpose it's perfect.

Tim M0BEW.

@ M0BEW 10 element 144MHz EME Yagi OWL-G/T

@ M0BEW 10 element 144MHz EME Yagi OWL-G/T.

My current 2m antenna here @ M0BEW
Performance, details, construction and comments.

Performance.
Gain: 15.27dBi @ 144.3MHz
F/B: 28.49dB @ 144.3MHz
Peak Gain: 15.29dBi
Gain 10m above ground: 21.07dBi
Peak F/B: 28.87dB
Power Rating: 5kw
SWR: Below 1.2:1 from 144MHz to 145MHz
Boom Length: 5.83m
Weight: 4.1kg/9lbs
Safe Wind Speed: 204Kph/127Mph
Turning Radius: 2.29m/7.52ft
Vertical Stacking: 3M

Specification.
12.7mm and 9.525mm diameter tube OWL loop.
12.7mm elements with a wall thickness of 1.2mm. 
Boom is 3/4 inch.
A direct 50 Ohm feed-point. No matching.
Boom to mast bracket to fit upto 50mm masts.
Marine grade Stainless Steel Fittings.

Construction.

Comments.
Very tidy and well constructed.
More to follow.

Tim M0BEW.