Articles for Amateur Radio Newsletters aimed at new hams
 written by Gerry Crenshaw, WD4BIS, Rowlett, Texas

 

 

NHP #12: VHF and UHF Band Plans

One of the frequent items of discussions on the repeater is what frequency to go to and its offset, + or -. As many of us grew up with the VHF and UHF band plans as they emerged, this presents no mystery to many of us. To someone new to the VHF/UHF spectrum this spectrum plan can be confusing.

First, the 144 to 148 MHz Spectrum is broken up by the FCC into two major portions. These have to be followed. The frequencies from 144.000 to 144.100 are considered CW or Morse code only, and the frequencies above 144.100 are can be used for any mode. In addition the FCC has limited Repeater Operation to two major sub-bands, these sub bands are in the 146 to 148 region of the two meter band.

Repeater sub band 1:

146.01 to 146.37

Repeater Inputs

146.61 to 146 97

Repeater Outputs

For this reason repeater pairs below 146.999 MHz are all minus offset

Repeater sub band 2:

147.00 to 147.39

Repeater Outputs

147.60 to 147.99

Repeater Inputs

For this reason, repeater pairs above 147.00 are positive offset.

Remember, when you plug in a frequency pair to your handi-talkie, the frequency displayed is the receive frequency, not the transmit frequency. That's where the offset comes in: it will transmit up or down 600 Khz from the receive frequency

The holes in-between the input and output repeater frequencies (146.40 to 146.58 and 147.42 to 147.57) are used as simplex frequencies. This explains why the simplex frequencies we use on 'thons are usually frequencies like 146.52, 146.54, 147.52, and 147.54.

By the way, 146.52 is considered the National Simplex Calling Frequency, when you get the party you are calling, take the conversation off of ‘.52 to something else.

Please notice that 146.38 to 146.39 and 147.40 to 147.41 are NOT used as simplex frequencies. These frequencies are not used in order to protect repeater inputs and outputs from interference. These frequencies are sometime called a "Guard Band". That's what the FCC says, now what about the other modes you sometimes here about such as OSCAR (Orbiting Satellite Carrying Amateur Radio), EME (Earth-Moon-Earth or Moon Bounce), SSB and Packet. and meteor scatter and Sporadic-E.

The ARRL and others have established a plan for the entire 2 meter spectrum. These band plans are semi-formal agreements or gentlemen's agreements between all parties concerned. The simply make operation easier for everyone with minimum interference.

The Band plan has changed a little recently, so the current band plan is listed below.

Two Meter ARRL Band Plan

Frequency

144.00-144.05

144.05-144.10

144.10-144.20

144.200

144.200-144.275

144.275-144.300

144.30-144.50

144.50-144.60

144.60-144.90

144.90-145.10

 

145.10-145.20

145.20-145.50

145.50-145.80

145.80-146.00

146.01-146.37

146.40-146.58

146.61-146.97

147.00-147.39

147.42-147.57

147.60-147.99

Activity/Mode

EME (CW)

General CW &Weak Signal

EME& weak signal SSB

National SSB Calling Frequency

General SSB Operation

Propagation Beacons

NEW OSCAR Sub-Band

Linear Translators Inputs

FM Repeater Inputs

Weak signal and FM simplex. (Note 145.01, .03, .05, .07,.09 are widely used  for packet operation)

Linear Translators Outputs

FM Repeater Outputs

Misc. and experimental modes

Existing OSCAR Sub Band

FM Repeater Inputs

Simplex (146.52 National FM Calling Freq.)

FM Repeater Outputs

FM Repeater Outputs

Simplex

FM Repeater Inputs

The band plan is fluid. You don't write it, publish it, and never change it. As new modes and services are developed such as Packet, and APRS, the band plan has to change to accommodate them. Remember to check the band plan once in a while to see if something is different. Two meters is a shared resource, there's room for everybody, and all the modes.

73's & GL

Gerry WD4BIS

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Copyright 2005 Gerald Crenshaw WD4BIS. All rights are reserved.

Permission in advance is granted to those who use this for non-profit Amateur Radio club newsletters as long as it is used unmodified including this copyright notice and that notice is given to the author via email (wd4bis@arrl.net). In addition, please forward a copy of any newsletter this appears in to: Gerry Crenshaw WD4BIS, c/o GARC, 1027B W. Austin St, Garland, TX, 75040

Web site maintained by Janet Gobeille Crenshaw (WB9ZPH)