+ or - Question on 2 meter

[67roadster]

Does anyone know on 2 meter repeaters what is meant by +/- . Example: a repeater's frequency is listed as 144.895 and the offset is + or 145.200 with an offset of -.

Thanks.

 

[n5ims]

Transmit frequency is either + or - (as indicated) .600 from the frequency indicated. For example, if a repeater is 147.00 MHz with a + offset, the transmit frequency (your transmit frequency, not the repeater's transmit frequency) would be 147.600 MHz. If it was 147.00 MHz with a - offset, the transmit frequency would be 146.400 MHz. Most 2 meter radios manufactured for amateur use (vs commercial radios programmed for amateur band use) use the + or - offset notation and default to .600 MHz, although most will allow the default to be modified.

 

[kb2vxa]

To put it much more simply; when the output is below 147MHz it is -600KHz, above it is +600KHz and if it is 147 exactly it could go either way.
Here's the rub, in some areas where they have a "repeater glut" they ran out of standard offsets so they snatch up simplex channels. When the output is in the bottom end of the band the input is +1MHz and when it's in the top end the input is -1MHz.

 

[n5ims]

To put it much more simply.

Perhaps that put it a bit too simply based on this chart Standard 2-Meter Amateur Radio Repeater Input Frequency Offsets and the ARRL bandplan here Band Plan (2 meter portion copied below)

2 Meters (144-148 MHz):
144.00-144.05 EME (CW)
144.05-144.10 General CW and weak signals
144.10-144.20 EME and weak-signal SSB
144.200 National calling frequency
144.200-144.275 General SSB operation
144.275-144.300 Propagation beacons
144.30-144.50 New OSCAR subband
144.50-144.60 Linear translator inputs
144.60-144.90 FM repeater inputs
144.90-145.10 Weak signal and FM simplex (145.01,03,05,07,09 are widely used for packet)
145.10-145.20 Linear translator outputs
145.20-145.50 FM repeater outputs
145.50-145.80 Miscellaneous and experimental modes
145.80-146.00 OSCAR subband
146.01-146.37 Repeater inputs
146.40-146.58 Simplex
146.52 National Simplex Calling Frequency
146.61-146.97 Repeater outputs
147.00-147.39 Repeater outputs
147.42-147.57 Simplex
147.60-147.99 Repeater inputs

Notes: The frequency 146.40 MHz is used in some areas as a repeater input. This band plan has been proposed by the ARRL VHF-UHF Advisory Committee.