Marine MF/HF SSB Radio HF Antennas & Installation Which SSB?
HF (SSB) Email
Low cost email via shortwave HF SSB radio
Shortwave HF radio SSB email systems offer a
low cost alternative to mobile and satellite phone systems and
offers near global coverage.
Most SSB email service
providers work on an annual subscription basis, so there are no
line-time or number of bits transfer charges as with mobile phone
or satellite systems.
To use SSB Email you require an
SSB transceiver such as the ICOM M710, M801E, M802, M803 and GM800,
a Pactor radio modem and a computer running Microsoft Windows.
HF radio Modem and Transmission Media
Most SSB
email services providers transmit using a transmission media call
Pactor (PACket Text Over Radio) which provides the interface and
control between the HF transceiver and the computer.
The Pactor modem controls the the flow of data across the SSB connection, switching the HF transceiver between transmit and receive. Data is transmitted in short bursts, called packets, after each packet sent is acknowledged back by receiving station that the data has been received without errors. If an error is detected then the packet is retransmitted. If there is an error or corrupted data then the packet of data is re-transmitted until the other station acknowledges that it has been received correctly.
The Pactor modem can also tune the transceiver to the correct station frequency, this saves any manual adjustments of the transceiver by the radio operator.
Pactor modems are manufactured by SCS in Germany who have been producing Pactor modems for over 20 years and today are on their fourth generation Pactor modems.
Pactor modems are designed to maximise the data throughput via the SSB transceivers very limited bandwidth of just 2.4 kHz and cope with variations in HF radio propagation.
In the early days Pactor only achieved a data speed of a few hundred bit per second, but as technology progressed so did the development of the Pactor modem into the few kilo bit per second. (kbps)
The latest
Pactor 4 modems can achieve a data throughput of 5512 bps before
data compression and over 10 kbps with compression.
Inside a DR7400 P4 modem.
Pactor 4 - the fastest way to send data via HF SSB radio
Pactor modem DR-7400 connections
SSB Email Provides
There are a limited number of SSB providers around the world, the best offering near global coverage via HF SSB radio for the marine user is SailMail .
SailMail - Global email provider
Sailmail
is a USA organization offering email compression service to
yachtsmen via satellite and HF SSB radio.
Sailmail uses
a client software package called Airmail3, which is available free
of charge and runs on the Microsoft windows operating system.
AirMail3 is a powerful integrated program which allow for email,
weather (Grib and weather charts) and position reports to be sent
and received via satellite and/or HF SSB radio. Airmail3 is also an
approved application for us the the Iridium GO! Satellite services.
This gives SailMail users the advantage of sharing the data
connection between HF radio or Iridium GO!
Sailmail's
global network of HF SSB stations operates on a mixture of private
and marine frequencies, therefore the marine SSB transceiver may
have to be modified to cover the frequencies used by Sailmail. The
European version of the ICOM M710, M801, M802 and M803, GM800 may
need to be modified.
The
best modem to use with Sailmail is the SCS DR-7400 with Bluetooth
which provides and wireless connection between the computer and
modem.
AirMail
Web site
Brunei Bay Radio - SSB email service
Brunei
Bay Radio providing low cost HF SSB radio communications and HF
radio (SSB) and e-mail services for yachts, charter vessels and
small-craft in the North West Pacific, Asia and Indian Ocean.
The
service area extends in a roughly 4000 NM radius from BRUNEI BAY
RADIO's base, located at approximately 5 degrees North, and 115
degrees East.
For further details on Brunei Bay Radio
visit Brunei
Bay Radio.
Winlink - SSB email service via amateur radio
Winlink is a worldwide radio email service used by radio amateurs, you must hold an Amateur Radio licence to use the service.
There
are several MS Windows software packages that work with Winlink,
the most popular is the Winlink in house software called Winlink
Express. Another is Airmail3, which is the software used by
SailMail. By using Airmail3 it is possible
to have both a Sailmail account and a Winlink running within the
same Airmail3 program, when sending the emails you can select which
service provider you wish to use.
Winlink
being a amateur service is restricted, the service cannot be used
for business or any form of commercial activity
and all messages are freely accessible by third parties.
Winlink 2000 web site.
Email Compression - why email compression
HF SSB radio and some satellite and mobile services were designed for speech as speech uses a very low bandwidth of just 2.4 kHz.
Although it is possible to send data vie these very low bandwidth limited connections, the data throughput is very slow compared to fixed or mobile phone data connections.
Email compression helps by reducing the
amount of data overhead which is used when sending emails. The
compression software sends the email to a dedicated server which
reinserts the overhead data back into the email before sending the
email on its way via the normal public email server for distributed
in the usual way.
The Airmail3 software, which is used
by SailMail provides the user with a number of features:
* Email compression, send and receive email with attachments
* Request and download weather data and grib files
* GPS input for automatic position reporting via email
* Shadow mail allows you to monitor other POP3 email accounts.
* Built in HF radio propagation program
* Support for connectivity via Pactor modem, Internet or satellite phone
* Controls SSB transceiver including setting the station and frequencies.
* Approved application for use with Iridium GO!
Airmail3 only works on Microsoft Windows computers.
