3B-223 HF 3-Band antenna
HF 3-Band Yagi antenna 3B-223
3B-223 Triband antenna for 20, 15 and 10m band uses a common feed line. Input power limited by feed line only. Low SWR, excelent F/B, excelent F/S ratio. Wind survival speed 170 km/h.
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One of the most important thing on antenna is mechanics. We take special care to make antenna that last longer.
We use 5 mm metal sheet zinc plated and plastic coated (to protect zinc) with 12 mm stainless steel clamps.
Antenna element mounting:
3B-223 Antenna dipole mounting:
Stainless steel screws with electrically large surface transitions.
3-Band antenna 3B-223 common feed line:
Easy to connect coaxial cable with PL-259 connector.
Watertight UV stabilized box.
Common mode balun with Teflon cable.
Measured common mode choke isolation with HP8753ES Network Analyzer:
14.1 MHz = 1.8 kOhm
21.2 MHz > 5 kOhm
28.4 MHz = 1.8 kOhm
Max. power = 2.5 kW
Used RG142 teflon coaxial cable
| Electrical Specifications | |||
| 14 MHz | 21 MHz | 28 MHz | |
| Frequency Range: | 14.0 - 14.35 MHz | 21.0 - 21.45 MHz | 28.0 - 29.5 MHz |
| Free Space Forward Gain: | 6.7 dBi | 6.8 dBi | 7.7 dBi |
| Forward Gain 20m AGL | 12 dBi | 12.9 dBi | 13.6 dBi |
| Front to Back Ratio: | 16 dB | 18 dB | 25 dB |
| 3 dB Horizontal Beamwidth: | 68° | 68° | 62° |
| Number of active elements per band: | 2 | 2 | 3 |
| Maximum SWR at any freq.: | 1 : 1.3 | 1 : 1.4 | 1 : 1.2 |
| Maximum Power Input: | More than 1.5 kW | More than 1.5 kW | More than 1.5 kW |
| Matching Method: | Direct feed through current balun. One cable for all three bands. | ||
| Connector: | SO239 | ||
| Mechanical Specifications | |||
| Boom length: | 4.5 m | ||
| Boom Diameter: | 70 mm or 80x80mm | ||
| Longest element: | 11.6 m | ||
| No. of elements: | 7 | ||
| Turning radius: | 6.0 m | ||
| Surface Area: | 1.1 m2 | ||
| Mounting Mast Diameter: | 43 - 70 mm | ||
| Survival Wind Speed: | 170 km/h | ||
| Weight: | 45.5 kg | ||