HAM Bands

High Frequency (HF) Bands:

160 meters (1.8 - 2.0 MHz)

Pros:
Good for night-time communication due to skywave propagation.
Low noise levels compared to higher bands.
Cons:
Large antennas are required for effective operation.
Limited daytime range due to absorption by the D layer of the ionosphere.

80 meters (3.5 - 4.0 MHz)

Pros:
Excellent for local and regional night-time communication.
Useful for NVIS (Near Vertical Incidence Skywave) communications.
Cons:
Similar to 160m, requires large antennas for efficiency.
Can be noisy during electrical storms.

40 meters (7.0 - 7.3 MHz)

Pros:
Good balance between day and night-time propagation.
NVIS communication is effective, useful for regional contacts.
Cons:
Band can be crowded during peak times.
Antenna size still significant for best performance.

20 meters (14.0 - 14.35 MHz)

Pros:
Often open for worldwide communication during the day.
Good for both short and long distances.
Cons:
Propagation can be variable; band might close unexpectedly.
Can be quite crowded, especially around contests.

15 meters (21.0 - 21.45 MHz)

Pros:
Excellent for long-distance (DX) communications during solar maximum.
Less crowded than 20 meters in some regions.
Cons:
Band can be closed during solar minimum, limiting use.

10 meters (28.0 - 29.7 MHz)

Pros:
Can provide spectacular DX during high solar activity.
Allows for satellite operation and can be used for FM voice communications.
Cons:
Very unpredictable; can be closed for long periods during solar minimum.
Bandwidth shared with CB radio, leading to potential interference.

Very High Frequency (VHF) and Ultra High Frequency (UHF) Bands:

6 meters (50 - 54 MHz)

Pros:
Sporadic E propagation can provide long-distance contacts during summer.
Good for local communications with modest antennas.
Cons:
Propagation is typically line-of-sight, except during sporadic E events.

2 meters (144 - 148 MHz)

Pros:
Excellent for local communications, including repeaters for extended range.|
Good for mobile operations with small, portable antennas.
Cons:
Limited by line-of-sight, though can benefit from tropospheric ducting.

70 cm (420 - 450 MHz)

Pros:
Even better for local communications; smaller antennas; less interference.
Good for satellite communication.
Cons:
Propagation is very much line-of-sight; less effective for long distances without repeaters or satellite use.

General Considerations:

Antenna Size: Lower frequency bands require larger antennas for efficiency.
Propagation: HF bands are dependent on ionospheric conditions for long-distance communication; VHF/UHF are more line-of-sight but can benefit from certain atmospheric phenomena.
Crowdedness: Popular bands like 20 meters can be very busy, especially during contests or major events.
Regulation: Band plans vary by country, and there might be restrictions or shared usage with other services.
Equipment: Different bands might require specialized equipment or transceivers capable of multi-band operation.

Choosing which band to use can depend on your communication goals, the time of day, current solar conditions, and the equipment at your disposal. Each band has its niche, and many operators enjoy experimenting across them to understand their unique behaviors.