- April 25, 2016 at 6:04 pm #2337
So you’ve gotten on the air and now you want to put up an HF vertical! I listened to the ARRL “The Doctor is In” April 7th Podcast. Here is the ideal ‘Elmering” primer on HF antennas!
1 43 foot vertical is 5/8 wave on 20 meters ideal for maximum gain but due to impedance mismatch it would need a base series inductance to resonate to 50 ohms (or use a tuner). (my own system consists of two 43 foot verticals phased or parasitic for more gain).
2. The 33 foot vertical is 1/4 have on 40 meters and can be fed directly as it is near 50 ohms at the base.
3. Elevated radials: Two will suffice but you would only need three to be effective.
4.Radials on the ground or just below the surface, you need 16 radials minimum for best effectiveness. If you have a large chunk of wire, it is better to have many short radials than a few longer ones. Use any cheap wire but avoid galvanized steel due to it’s magnetic effects.
5. Are verticals noisy? For atmospheric noise such as distant lightning the signal is a higher angles which are less sensitive to high angle reception. For man-made neighborhood noise vertical are not so good due to the low angle reception.
6. A dipole a half wave high has peak radiation at about 30 degrees which is fine if thats the angle you want to radiate and receive from but for good DX you need a 5-10 degree angle which makes a vertical ideal.
For the full podcast, go here:
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