N2HJD REPEATER MEGAPLEX, TECHNICAL INFO
Build a low cost dual band antenna for VHF/UHF (ARRL Feb 2003, written by Edison Fong, WB6IQN):
Download Article (theory, design & performance), 850K pdf
Build the improved "RRRA" dual band antenna for VHF/UHF (Design by Pete Schuch, WB2UAQ):
RG-8/U Dual Band J-Pole, 465K gif
The following is a table of common coax charactistics:
Attenuation ( dB ) / 100 Feet
| Coax Type | VP in % | 50 Mc | 100 Mc | 200 Mc | 400 Mc | 1000 Mc | Max. P @ 400 Mc |
| RG 174 | 66 | 5.8 | 8.5 | 12.5 | 19 | 34 | 12 W |
| RG 316 | 70 | 5.6 | 8.3 | 12 | 17.5 | 29 | 240 W |
| RG 58A/U | 66 | 3.3 | 4.9 | 7.3 | 11.5 | 21.5 | 75 W |
| RG 58U | 66 | 2.9 | 4.2 | 6 | 9.1 | 16.5 | 85 W |
| RG 142 | 70 | 2.7 | 3.9 | 5.6 | 8.2 | 13.5 | 1100 W |
| RG 8X | 78 | 2.5 | 3.7 | 5.4 | 8 | 13 | 200 W |
| RG 8U | 66 | 1.5 | 2.2 | 3.2 | 4.7 | 8.2 | 350 W |
| RG 213 | 66 | 1.5 | 2.1 | 3.2 | 4.6 | 8.2 | 350 W |
| RG 9U | 66 | 1.4 | 1.9 | 3.0 | 4.1 | 8 | 350 W |
| RG 214 | 66 | 1.3 | 1.9 | 3.0 | 4.1 | 8 | 350 W |
| RG 8 FOAM | 78 | 1.2 | 1.8 | 2.7 | 4.2 | 7.1 | 250 W |
| 9913 | 84 | 0.9 | 1.3 | 1.8 | 2.7 | 4.5 | 400 W |
| FLEXI 4XL | 84 | 0.9 | 1.3 | 1.8 | 2.7 | 4.5 | 350 W |
| 1/2" LD HARD | 84 | 0.5 | 0.68 | 0.92 | 1.5 | 2.3 | 1200 W |
| 7/8" LD HARD | 84 | 0.16 | 0.24 | 0.66 | 0.8 | 1.4 | 1500 W |
