K7DAV Digital Operations

This is an overview of the digital operations at K7DAV.

K7DAV maintains 24/7 packet and pactor operation backed by a generous UPS system, and diesel generator capable of keeping the station up 72 hours at a minimum.

VHF/UHF Packet Operations

The RMS Packet station shown here is an Icom V8000 on 145.070 MHz with the antenna up about 45 feet. The 1200 baud Winlink packet station has been operating continuously since 2004, reaching most of Davis County. Power output is 75 watts. Here is a screen shot of the RMS Packet program. Information on the left part of the screen indicates the packet channel events (radio), and the right screen shows the telnet channel events (Internet). RMS Packet is a VHF/UHF packet gateway program, in that it receives packet connections via VHF at 1200 baud, and packet connections via UHF at 9600 baud. The program will then open a direct telnet connection to one of four random CMS Stations (Central Message Server). Winlink (WL2K) messages are sent and received in this manner. There can be up to 10 simultaneous radio connections open at any given time, on each channel. RMS stands for Radio Message Server.

K7DAV has 9600 baud capability on 431.450 MHz. The radio used is a Yaseu FT-7800 and the antenna is up about 35 feet and the power used is 35 watts. Both packet channels use the call K7DAV-10. The TNC (Terminal Node Connector) is a Kantronics 9212+ dual port TNC. Both radios share the same TNC.

HF Pactor Operations

Beginning in 2008, K7DAV has added RMS Pactor to the 24/7 operation of Winlink 2000. This means that we now have HF coverage region wide, nation wide, and world wide. RMS Pactor is intended to provide HF Pactor radio infrastructure (access ports) for the Winlink 2000 system and uses the B2F protocol that supports attachments, multiple addresses and tactical addresses.

Information related to Pactor, and the SCS PTC-II modems can be found at this link: http://www.scs-ptc.com/pactor.html

The HF radio used for RMS Pactor is a Kenwood TS-480SAT, with an LDG Z-11 Pro antenna tuner. The radio feeds a dipole cut for 40-80 meters, up about 65 feet. RMS Pactor scans three frequencies, 7.105, 3.592, and 7.066. Pactor III occupies a wide bandwidth of about 2.4 KHz, and on 40 meters, it is restricted to operation between 7.100 and 7.105 MHZ. 7.066 is available for Pactor I and II connects only.

The main screen of the RMS Pactor program is identical to RMS Packet. Pactor channel events are on the left, Telnet channel events on the right. The grey box on the far left opens a radar screen showing the station connected, and the distance/direction relative to K7DAV, when a Pactor station connects.

RMS Relay

RMS Relay is a program that pr ovides local store and forward message handling in emergency situations when no internet access is available to connect to a CMS site. It is normally used in conjunction with RMS Packet, and or Paclink, located on the same computer or local area network.

Here’s how it works. In times when there is a connection to a CMS, RMS Relay acts as a simple repeater, forwarding all packets between a local packet user and a CMS site. If the CMS becomes unreachable, then RMS Relay intercepts connection requests and mimics the CMS telnet port to provide access to a temporary local message database. When access to one or more CMS sites is restored, RMS Relay transfers all stored message to the CMS site and clears the local database. Local WL2K clients can send messages to other local clients only. All traffic not local will be held in the database until a CMS site is available. A later version of RMS Relay will include the ability to exchange messages with a CMS site using HF radio when Internet is not available.

A user who connects to the K7DAV-10 RMS Packet server normally would see something like this:

Welcome to K7DAV-10 RMS Packet Server - Farmington, UT (DN40BX)
[WL2K-1.6.1.6-B2FIHM$]
Washington CMS via K7DAV-10 >

When the user connects to the server and RMS Relay is storing messages to the local database, the user sees:

No CMS connection available - using the local K7DAV database
[WL2K-2.0.0.0-B2FIHM$]
K7DAV Relay >

If RMS Relay is not running, and there is a loss of the internet the user will see the following:

Welcome to K7DAV-10 RMS Packet Server - Farmington, UT (DN40BX)
Connection to CMS lost - disconnecting

The user will be unable to connect, and the TNC will revert to a basic TNC with digipeating capability via K7DAV-10, and K-Net node capability via WL2K:K7DAV-5. If there is an RMS Packet server somewhere within the node system, the user can connect to the other RMS Packet station via that station’s call. The only other Utah RMS Packet station is in Logan, N7UWX-10, and it’s unclear if that station is connectable via the DAV 9600 backbone.

Paclink

Paclink is a client program that uses the B2F protocol, supporting attachments, multiple addresses, and tactical addresses. K7DAV runs Paclink to support emergency communications at the Davis County Sheriff’s EOC, and it interfaces with popular email clients such as Outlook, and Outlook Express. Think of Paclink as an emergency email server that interfaces alongside your normal email accounts. If the Emergency Services Director needs to send an email message out of the EOC, he can use a Paclink account to send the message via Telnet, VHF/UHF Packet, or HF Pactor. One computer acts as the master, running the Paclink program, and each computer in the LAN must be configured with an account name (Amateur Radio Callsign or Tactical Callsign).

There are five levels of priority that can be assigned. The various channels, (Telnet, Packet, and HF Pactor) can be assigned a different priority level 1 to 5, with level 1 tried first, if that channel fails, level 2 and so on.

Paclink is a favored multi-client Winlink 2000 tool, and it is also favored by single users because it can be used with the AGWPE packet program. Airmail can only directly connect to a TNC thereby limiting the number of TNCs one can use. With AGWPE, there are lots of possibilities, including computer sound cards.

K7DAV supports three Paclink accounts in the EOC at this time, used as test models.

Because there are so many different devices using COM ports, a practical solution was found to operate all the equipment on one computer. An Edgeport USB connecter is used to supply all the radios, and modems. Up to 8 comports including the one built into the computer, for a total of 9 COM ports are being used. Each program usually requires one COM port for communication with the modem, and another COM port to communicate with the controlling radio. This can consume resources in a big way. The Edgeport USB connector allows everything to fit on one computer. Fortunately, the WL2K programs do not require a lot of processor power to perform their job.

This is a quick overview of the digital operations at K7DAV, and how I believe a good WL2K infrastructure will benefit Davis County into the future.

Please see links to reference WL2K, and training:
Winlink 2000 http://www.winlink.org
WL2K For Dummies http://www.winlink.org/node/23
Winlink – WL2K FAQ http://home.earthlink.net/~k7bfl/WL2K_FAQ.pdf