The AM Forum

Band Watch => 6 & 2 Meters => Topic started by: N1WVQ on July 18, 2017, 12:43:02 PM



Title: 2M frequencies: why the OSCAR subband?
Post by: N1WVQ on July 18, 2017, 12:43:02 PM
I am wondering why most 2M frequencies used by AMers are in the OSCAR subband at 144.3-144.5. If that is satellite, shouldn't we go elsewhere? I have a Heathkit HW-17 that I am going to get new crystals for & am choosing 144.9, 145.62, 146.52, 147.42 (I may keep 145.08 which is one of the frequencies in it now, but don't want to mess up packet on 145.07/09. I have read here in Massachusetts there is supposedly a net on 144.425, but again, that's in the OSCAR subband so I don't think I'll get a crystal for that frequency.


Title: Re: 2M frequencies: why the OSCAR subband?
Post by: Pete, WA2CWA on July 18, 2017, 05:11:35 PM
I am wondering why most 2M frequencies used by AMers are in the OSCAR subband at 144.3-144.5. If that is satellite, shouldn't we go elsewhere? I have a Heathkit HW-17 that I am going to get new crystals for & am choosing 144.9, 145.62, 146.52, 147.42 (I may keep 145.08 which is one of the frequencies in it now, but don't want to mess up packet on 145.07/09. I have read here in Massachusetts there is supposedly a net on 144.425, but again, that's in the OSCAR subband so I don't think I'll get a crystal for that frequency.

Your best bet for operating AM and not interfering, or being interfered with, is to operate 144.275 on down a bit, or using the miscellaneous and experimental mode area from 145.5 to 145.8. Operating in the FM repeater and simplex area or the Oscar subband area is just asking for trouble and pain.

The ARRL Band Plan:
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.


Title: Re: 2M frequencies: why the OSCAR subband?
Post by: N1WVQ on July 18, 2017, 11:40:48 PM
That's a relief in that I will be doing the right thing by avoiding 144.425! The New England Spectrum Management Council has allocated 145.5-145.8 to be split between F.M. simplex & packet, due to their plan to change the 146s & 147s into repeater pairs, due to the "need" for more repeater space here in New England. In the 145.5-145.8 subband, they have allocated every 20kc. on the odds to FM/Packet (145.51, 145.53, 145.55, etc.), so I was thinking of operating A.M. on the evens like 145.62. I know the A.R.R.L.'s bandplan is a suggestion & the local spectrum group has final say. Here is a link to the NESMC bandplans for 6m-13cm for the 4 eastern New England states: http://www.nesmc.org/docs/bandplans.pdf.

Long answer short, thank you for affirming my aversion to operating on 144.425 because of the OSCAR subband! I am thinking of getting crystals for 144.27, 144.9, 145.62 & maybe keeping my 145.08.

73,
N1WVQ
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands