For best results, dipoles should be at least 1/2 wavelength above ground level. For the lower bands, especially 160-40 meters, this can become impractical–place your dipole as high as your situation allows.
What is the length of a 40 meter dipole antenna?
Read more about . . . . Dipole Length Calculations.
| Approximate Lengths for HF Ham Band Dipole Antennas | ||
|---|---|---|
| Band (MHz) | Length (Feet) | Length (metres) |
| 7.0 MHz (40 metres) | 68.5 | 21.1 |
| 10.1 (30 metres) | 47.5 | 14.7 |
| 14.00 (20 metres) | 34.3 | 10.6 |
Will a 40m dipole work on 15m?
It has long been known that a 40m antenna will also work on 15m. It will have a decent SWR “somewhere” within the 15m band. The 40m antenna needs to be about 15cm (6″) longer on each side to bring the resonance down to about 21.150 MHz.
Can you use a 40 meter dipole on 20 meters?
MFJ-17754 40/20M Dipole Antennas are shortened, coaxial-fed, 42 ft. long dual-band resonant antennas. While functioning as a full-size dipole on 20-meters, it’s also an ultra-efficient end-loaded dipole on 40-meters. You may operate these dipoles at up to 1,500 watts!
What frequency is 40m?
The 40-meter or 7-MHz band is an amateur radio frequency band, spanning 7.000-7.300 MHz in ITU Region 2, and 7.000-7.200 MHz in Regions 1 & 3. It is allocated to radio amateurs worldwide on a primary basis; however, only 7.000-7.100 MHz is exclusively allocated to amateur radio worldwide.
How long is a 20m dipole?
20 Meter Dipole at 42 feet.
What band dipole for 40m?
Dual band dipole for 40m (7 – 7.3 MHz) and 15m (21 – 21.45MHz) bands at my previous residence in Melbourne, Victoria in 2004 For my first HF antenna I selection a basic 40m band dipole primarily as a simple antenna that provided access to one the most versatile amateur HF bands.
How do you calculate the length of a dipole antenna?
This antenna is cut for 7.150 MHz. To calculate a different frequency, you can recalculate the length in feet use the formula “Length feet = 468/frequency in MHz”. Divide the answer by 2 and this will be the length for each element of the dipole.
What is the typical HF dipole configuration?
Figure 1 Typical HF dipole configuration complete with 1:1 balun and 50ohm coax cable to transceiver. Half wave length of copper wire, fed at the centre with a 1:1 balun and coax cable to the transceiver.
What is the impedance of the dipole in the graph?
The MS Excel graph shows how the impedance components R + jX vary as the feed point moves away from the centre of the dipole at the 0.5 position. On the graph at the 0.18 position the impedance is 300Ω on the Y axis.
