Offset

Offset is the difference between the transmit and receive frequencies of a radio channel. Most commonly it refers to the frequency separation between the input and output frequencies of a repeater or other type of full duplex system.

Certain bands and frequency ranges in the United States have fixed offsets.

Standart US Offsets

Band	Frequency Range	Offset	Notes
10m Ham	29.5-29.7	-100 kHz
VHF Low Band	30-50	No standard offset
6m Ham	50-54	-500 kHz or -1 MHz	1
2m Ham	144-148	+600 kHz or -600 kHz
VHF High Band	138-174	No standard offset	2
220 MHz	220-222	+1 MHz
1.25m Ham	222-225	-1.6 MHz
380 MHz	380-400	+10 MHz
Federal UHF	406.1-420	+9 MHz	3
70 cm Ham	420-450	+5 MHz or -5 MHz	1
UHF	450-470	+5 MHz
UHF T	470-512	+3 MHz
700 MHz	769-806	+30 MHz
800 MHz	806-896	-45 MHz
900 MHz	896-940	-39 MHz
1.2 GHz Ham	1240-1300	-20 MHz or -12 MHz	2

Notes

• 1. Ham radio offsets can vary in certain areas of the country.
• 2. There are some paired channels in the VHF high band (paging, taxi, old RCC mobile phone channels) but not standard offset.
• 3. The 406.1-420 federal land mobile band began changing to a +9 MHz offset a few years ago. Some older systems still remain with non-standard offsets.