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I just obtained a really old packet TNC and hooked it up to the computer, and it appears to work.

Is there a standard packet calling frequency on 2 meters? I would like to see if there is packet activity in my area, and if I can start some operation. Also, is there much packet activity on other bands like 1.25 m, 70 cm, 23 cm, 33 cm, etc.?

My QTH is Denver, CO, USA.

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  • $\begingroup$ Interesting answers. Gone are the days of 145.010 for just regular TAPR-2 style messaging. $\endgroup$ – SDsolar Apr 17 '17 at 17:38
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You could tune to 144.390 FM on a 2m rig and see if you can pick up some APRS. This would require some software to decode packets (such as arpx for Linux). Just make sure you're not setting yourself up as a Digipeater until you find out what the network structure is in your area and whether there is a requirement at all.

National APRS frequencies: national APRS frequencies

You should also be able to see APRS activity on sites like aprs.fi for your area.

enter image description here

http://aprs.fi/

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The Colorado Council of Amateur Radio Clubs (CCARC) 2 Meter Frequency Use Plan states that 144.900 - 145.100 MHZ should be used for Packet communications.

144.390 MHZ is also used Nationwide for APRS.

Colorado Council of Amateur Radio Clubs (CCARC) 2 Meter Frequency Use Plan - 144.000 through 148.000 MHz

Frequency (MHz) Usage

  • 144.000 - 144.050 CW/EME
  • 144.050 - 144.100 CW Weak Signal
  • 144.100 - 144.275 CW and SSB Weak Signal
  • 144.275 - 144.300 Propagation Beacons
  • 144.300 - 144.500 Satellite/OSCAR
  • 144.500 - 144.900 FM Repeater Inputs
  • 144.900 - 145.100 Weak Signal, FM Simplex, Digital/Packet
  • 145.100 - 145.500 FM Repeater Outputs
  • 145.500 - 145.800 Miscellaneous and Experimental Modes
  • 145.800 - 146.000 Satellite/OSCAR
  • 146.010 - 146.370 FM Repeater Inputs
  • 146.400 - 146.580 FM Voice Simplex
  • 146.610 - 147.390 FM Repeater Outputs
  • 147.420 - 147.570 FM Voice Simplex
  • 147.600 - 147.990 FM Repeater Inputs
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Have a look at the IARU Region 2 Band Plan. Most of the frequencies marked "all modes" or "DM" (digital mode) may be used for packet radio, although there does not seem to be a single designated packet calling frequency.

Normally a packet radio frequency is coordinated between operators in the area, since one frequency can be shared by several TNCs. In this case the frequency is standardized ad hoc and won't necessarily be the same everywhere.

You should be able to get a good picture of packet activity by listening on these digital-mode bands and seeing what is going on. (A spectrum analyzer or software receiver may help you identify activity visually and allow for faster tuning to frequencies of interest.)

I think most of the packet activity on 70cm and higher bands is point-to-point or "backbone" links between larger sites (similar to a trunked repeater system). This might be due to range issues (APRS uses 2m almost exclusively, if I recall correctly). I have not seen any packet activity in my region (southern Ontario) on any of the higher bands so I can't comment directly on whether packet is really being used on these bands, and if so for what purpose.

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145.010 was the "primary" packet frequency in the 90's

Lee N4TCW

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  • $\begingroup$ Welcome to Amateur Radio Stack Exchange. Please take the tour at ham.stackexchange.com/Tour to get the most out of this site. And you are correct about that frequency. I wouldn't say it was a "calling" frequency, but generally the first PBBS in an area would go there. $\endgroup$ – SDsolar Aug 22 '17 at 4:29

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