Do cellphones, the internet, and ham radio repeaters ever go down?

Yes, they did during the Great Texas Freeze of February 2021. To practice for similar outages, join our ham radio VHF simplex net which takes place twice month.

Greater Houston Simplex Network



1st and 3rd Thursdays of the month (7pm Central)

  • 146.540 MHz (primary)
  • 147.540 MHz (backup)


As needed (as new neighborhoods are added)

Geographic coverage

  • Currently, our coverage is strongest on the west side. The pins on the map denote stations checking into the simplex net, and the colors denote nets held during different weeks.
  • We'd like to expand our footprint. If you live adjacent to our area of coverage and would like to serve as a net control or relay, please email Mark Brantana at
Coverage map for Houston Simplex Net

Extend your simplex range

Simplex is the most basic radio setup — it's radio-to-radio, antenna-to-antenna, without any infrastructure like repeaters.

Furthermore, VHF propagates by line of sight, so without repeaters, your range is limited by the curvature of the earth – that is, the distance to the horizon. There are only three ways to increase that distance to the horizon:

  1. Raise your antenna as high as possible.
    • If you have a two-story house, an antenna in the attic is better than one in a second-story window. Likewise, the second-story window is better than a ground-floor window.
    • If you mount your antenna outdoors on a mast, the higher the better.
  2. Make sure there are as few obstacles as possible. An antenna facing your neighbor’s brick wall will not be as effective as one facing an open area like your back yard or front yard.
  3. Use a mobile radio (50 watts) as opposed to a hand-held radio (5 watts). The extra wattage will give you a little more oomph. Five watts may not be enough to hit the horizon.

Best operating practices

  • Turn off the squelch on your radio! This will enable you to hear weaker, more distant stations.
  • Write down callsigns you can hear. If net control does not acknowledge them, please relay them in.
  • Over time, determine which stations you can hear. You all may end up serving as relays for each other.

Monitor check-ins with NetLogger

The nature of simplex nets is that you will not be able to hear everyone due to line-of-sight issues. During the practice nets, we will be continually taking check-ins. To avoid frustration when you cannot hear other stations, you can see who’s checking in by using NetLogger. NetLogger is an application you can download to your computer. It’s very simple to use and there are several benefits.

Learn more about NetLogger

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