Auxiliary Communicators of Tennessee – on Facebook

There is a Facebook page called “Auxiliary Communicators of Tennessee.”  It is a closed group in the sense that you must be a licensed ham radio operator to join.  Many thanks to Elizabeth St. Vincent (K4KTG) for organizing it.  It is a great place to share information of interest to all Middle Tennessee hams interested in emergency communications.

Global Eavesdroppers
In World War II, dozens of radio operators in Scituate dialed into enemy conversations worldwide.

W4PHS Hamnet Presentation (9/20/14)

Click on this link to access Phil Sherrod’s Hamnet presentation, given at Chew and Chat on 9/20/14

Note: The presentation can also be found at under the link for Hamnet MESH Networks.

Hamnet: A Broadband MESH Network

From Phil Sherrod, W4PHS:

I just got home from a meeting with two other Winlink developers. We spent most of one day discussing the Hamnet MESH network, and I had a chance to learn a lot and play with the Hamnet software.

Hamnet is a broadband MESH network providing speeds about the same as a Comcast cable connection (or much faster if you use more expensive equipment). Since it is a MESH network, as long as a node has a connection to any other node, it can reach anything in the network. You can simultaneously stream feeds from multiple 802.11 video cameras, do high-speed file transfers, set up an iGate, use VoIP phones or do anything else you could do through a TCP/IP LAN. You can access the Internet through the mesh if one of the nodes has an Internet connection (optional). It would be very cheap to set up Hamnet drop kits as long as we can get the coverage across the county. You only need a Technician license to be part of it.

One of my Winlink colleagues helped set up a country-wide Hamnet network in Chester Co, PA that provides broadband coverage for nearly all locations in the country. They have a hilly county like Williamson.

Texas is big into Hamnet – especially around Dallas and Austin which have almost complete coverage. Hamnet is spreading like wildfire across Europe and developing countries. It now covers many countries in Europe. We are working with them to set up an interconnection with Winlink through the Wien CMS.

The only equipment we need are a collection of Linksys WRT54G routers of versions 1.1 through 4 or the WRT54GL (Linux); I just ordered several WRT54G on eBay for about $25 each.

Note that you don’t have to have a computer at a node. Just plug in a WRT54G, and it’s instantly part of the network, and it can provide coverage to other stations further away. No on-site software configuration is needed. If you put a WRT54G on a hill with a battery, you would have an instant relay across the hill and coverage for anyone with a LOS location around the hill.

Here’s the main page for the Hamnet organization:

An even better device than the W4T54G is the Ubiquiti Bullet BM2HP or one of their other devices:

The Bullet is available in several frequencies, but I think we should stick with 2.4 GHz to be compatible with other 802.11 devices except for long-haul links where 800 MHz would have better penetration through foliage.

For long-haul, line-of-sight links (10-20 miles), you can use 20+ dB antennas that only cost about $10, such as:

The Fall TEMA/AuxComm exercise is Oct. 10-11, and it’s being held at the Independence High School in Franklin. My plan is to set up and demonstrate a Hamnet covering the exercise.

If you want to get going with Hamnet, here are the steps:

Register your callsign at
Read this page to find out which versions of the Linksys WRT54G are compatible with Hamnet.
Find or buy a suitable WRT54G, and load the Hamnet firmware into it:
You may want to consider replacing the antennas on the WRT54G with a mag mount or better. Note that at 2.4 GHz, feed line loss is severe.
If you want to set up an outdoor installation or build a good drop-kit for field operation, this is the recommended equipment including a Ubiquiti Bullet that mounts outside and requires only a CAT5 cable to run inside:
Total cost: $107.41


Ideas for Field-Expedient Antennas

Visit the following website for ideas on field-expedient antennas, many of them applicable in a military-type setting:

Online Weather Spotter Training

Online Webinar NWS Spotter Classes!!
Here is the webpage to visit if you want to sign up:

Remember, to attend the webinar, you will need to complete the two modules on this same page first.
Any questions, just let me know..
Scott Unger
NWS Nashville

Software Defined Radio

Apps for the Emergency Services community

From Richard, WB4TNH:
Website for apps for the Emergency Services community. ReadyTN is one of the apps listed. Looks like it has a lot of potential.

AppComm is APCO’s Application Community forum where first responders can learn about existing apps, rate and comment on apps, and share thoughts about these new tools.

Learn Winlink!

This is the greatest development in years! It is easy to get started. And there are many RMS sites, VHF and UHF, in our immediate area. This mode should be a mainstay for us, especially in emergencies when the internet may be down. Best source of information:

Additional information (from K4IDK):
Anyone wishing to check-in using Winlink is encouraged to do so when not available at 7PM for the regular net. All you have to do is send me, K4IDK, an email using Winlink by way of any RF mode (packet, winmor, pactor). When doing so, include your power source and the mode that you used when checking in. I will acknowledge receipt of your check-in at some point during the day as I’ll be signing in periodically to check for email, and following the repeater net I will send out an email on Winlink with any/all announcements. This way you will be able to check-in at a time convenient for you and still get any information that was given out during the regular net. The only catch is that you must use an RF mode, meaning that Telnet will not count as a check-in, and you must check-in prior to 6:30 PM so that we will have time to get the roster set for net control.
If you are still learning about Winlink, then please feel free to send me an email via Winlink using Telnet as a training tool and I’ll be more than happy to send you a reply while you gain proficiency in the use of RMS Express. Phil, W4PHS, has an excellent paper that he’s written and kept up to date on Winlink at You can download it and read through it at your leisure. Getting involved in using Winlink using an RF mode is not difficult or expensive, costing about $100 or so for a basic 1200 baud modem for VHF, such as a Tiny Trak 4, or a TigerTronics Signalink sound card for use with winmor when using HF. The same sound card is useful for other modes as well, such as PSK-31 or RTTY. If I can do it, you can as well, as I’m far from a computer guru. Winlink provides us, as an ARES group, the ability to send message traffic in real time devoid of any errors that can occur when passing traffic from station to station using voice and is therefore critically important in emergency communications.

NWS Radar and APRS in Google Earth

Today I was thinking about how great it would be if I could overlay National Weather Service alerts, radar, and APRS objects on top of Google Earth. After searching to find out if this is possible, I quickly found this great article from a fellow ham. I’m sure it will be of interest to many of you. Enjoy!




Below you’ll see a screenshot I took over Williamson County on the morning of July 22, 2015 as a storm is rolling through. You can see here that I was able to query the weather stations that are in our area to track rainfall levels, pressure, temperature, and wind speeds. If I needed information from people on the ground, I could look for mobile stations transmitting in the area and call them on the frequency that they listed in their APRS position report.

APRS and NWS in Williamson County Google Earth

Dallas Clements