The Ft. Worth NWS SKYWARN Team operate multiple amateur
radio systems, including VoIP systems such as EchoLink
and IRLP. Our VoIP radio systems are
normally dedicated to direct connections with remote SKYWARN spotter radio
stations in affected areas during weather events. We may limit incoming
connections by use of an “allow list” of authorized stations. This helps us
manage connections and limited network bandwidth during weather events.
Periodically EchoLink or IRLP stations find they cannot
connect to the Ft. Worth NWS SKYWARN stations. This memo describes our use of
VoIP systems, and sets forth some criteria and instructions for requesting
access to connect to our stations.
- Stations requesting connect access must be affiliated with a NWS
recognized SKYWARN spotter group in the Ft .Worth NWS CWA, or be affiliated
with a NWS office.
- We require reciprocal access to connect with the requesting
station from our VoIP systems.
- We have two primary VoIP stations, and an EchoLink conference for
weather events.
- EchoLink WX5FWD-L (70938) / IRLP
3786 - This is
a dedicated simplex radio link at the NWS office. This station is only
monitored or in use during weather events. It limits all incoming connections
to those in its allow list.
- EchoLink K5MOT-R (119161) / IRLP
3747 - This is
a link to the K5MOT Motorola repeater in Fort Worth. This station is utilized
during weather events, but otherwise may be available for use at the discretion
of the Motorola North Texas Amateur radio club. This system limits access from
PC EchoLink systems, but otherwise accepts connections from any linked radio
systems.
- EchoLink conference *WX5FWD* (372418) - This is a relatively new
conference, and usage for SKYWARN events is still being developed. We may
monitor the conference before or during certain weather events.
There is an EchoLink chat message capability, which we may also access via a web interface on the conference.
The conference automatically mutes connecting stations to avoid interruptions to SKYWARN events.
Stations that are associated with north Texas SKYWARN groups and the Fort Worth NWS office may request
access without muting.
IRLP nodes may also connect to the *WX5FWD* conference using IRLP node number 0010,
provided the IRLP node owner adds a new optional setting to their
/home/irlp/custom/environment file.
export ALLOW_EXPERIMENTAL_NODES=YES
- WX5FWD (46043) - We also have EchoLink installed on desktop/laptop
computers. The PC connections are only used as necessary. We may also use
SKYWARN team personal EchoLink stations when necessary.
If you believe your VoIP system should be allowed to
connect to our systems, please send your request details, as follows, via email
to requests@wx5fwd.org
The NWS SKYWARN team will respond to your request.
Your name, call sign, and contact
information.
SKYWARN group affiliation.
VoIP Station details, call sign, node number, location, linked radio details
and coverage.
Brief reason for requesting access.
VoIP station operating requirements and etiquette
This is a list of good operating requirements for any linked radio system, not just IRLP or EchoLink. Failure to follow these requirements could result in your station being blocked from accessing our stations.
- Only transmit to the network while receiving a valid local transmission, preferably only when a valid CTCSS code is received. Noise, squelch tails and other undesired transmissions should be prevented to the extent possible, just like you would do for a repeater or RF/wire line linked system design. CTCSS (PL/DPL) squelch is one method to help do this. VOX and noise only squelch is discouraged.
- Do not transmit repeater Drop-out Delay (hang time) over the network. In a simplex network, everyone on the network must wait for the other station to unkey before others can transmit. Although some stations could support full duplex connections, few VoIP ham stations are configured to support full duplex operation.
- Do not send pulse transmissions back to the network after a network station stops transmitting. This is called "pulse-back" on IRLP, and IRLP nodes have a test for this. Two or more stations can send pulse transmissions back and forth, and block others on the network.
- Do not transmit the automatic repeater ID to the network. Exceptions are allowed when the ID is transmitted simultaneously with a received voice transmission.
- Do not transmit courtesy "over" beep tones to the network. Nothing wrong with having them on your repeater transmitter, just don't send them to other repeaters/transmitters on the network.
- Do not connect with conferencing enabled on your station. EchoLink stations have a conference option to allow multiple station connections, including other conference enabled stations. This can defeat access control, and sometimes results in unwanted transmissions and other problems from remote stations in the chain of connected stations.
- Please, set your audio levels correctly. Test them regularly on the EchoLink test conference or IRLP echo test conference. DO NOT assume you sound OK because someone told you so. How do you know the remote system has their levels adjusted properly? You should not adjust radios by asking someone if it sounds OK, so don't do it with link audio level adjustments either. When properly adjusted, it should be difficult to detect any difference between a link transmission and a local repeater or radio transmission.
- This is a network of amateur radio stations, so amateur radio rules, regulations and etiquette will apply.
- Pause several seconds between transmissions. Add a second or two, to allow for the slight additional delay that VoIP systems may add to the PTT/COS exchange. Give others a chance to transmit or break in.
- Pause a second, after pressing PTT, before speaking to avoid dropping first syllable or word over linked systems. This sometimes happens on local transmissions or repeaters too, but may be more pronounced over linked systems.