E-mail over HF radio

archived information

Last updated: 12 May 1998


Any and all feedback please to ben@ocha.unon.org. I am trying to re-do this page without the use of tables to it can more easily be e-mailed and faxed.  Thanks to the many people who have helped me with information on this topic. I will endeavour to keep it up to date. Of course all this information is subject to change, and any errors are mine alone.


You have a remote place without telephone and you want to connect via Internet e-mail. You want to use HF e-mail. You will need a radio transceiver, antenna, modem, as well as a computer, cables and software. You will also need agreed frequencies, probably some kind of license to operate radio equipment and compatible HF modems at each end. A number of service providers can provide this service already. Some I have found are listed below.

When considering options in this area, it would be wise to at least consider e-mail over satellite phone - phones now cost about $4,000 and calls are $2.50 per minute. Also Inmarsat has announced e-mail services on their C-terminal range. In ranges of less than 50km, VHF radio is an option and is probably cheaper and faster. New GPMCS systems like Iridium and Globalstar may offer data services too.

Service providers (in no particular order)

Fastest comm mode Client software Gateway / hub software Minimum hardware costs Software costs Monthly costs Traffic costs

Non profit providers

WFP (Uganda) (private, non-profit) Codan 9002 cc:mail cc:mail about $6,000 ? n/a n/a
MAF (non-profit) Pactor-1 cc:mail cc:mail+"Mlink" ? ? ? ?

Commercial providers

RadioMail (Wilken Uganda) Clover 2000 Barrett 923 Barrett 923 about $7,500 full base station  about $7,500 full base station  Signup: $250 $150 per month $0.24 above 100kb per month
Bushnet (Uganda) Codan 9002 cc:mail "bushpoll" $6,300 ? different options (from $0.30 per kb) to $500 per month unlimited about $0.30 per kbyte
Bushlink (Tanzania) SCS PTC-II Pegasus mail + PMFIDO FIDO node+Bushlink PTC-II modem: $985 $250 $40 $0.20 per kbyte sent/received
DTS (Benin) Clover-2000, Clover-500, Pactor-1 and Pactor-2 DTS DTS $4,000 $50 unlimited
Sistec (Angola) Colver-2000, Pactor-1, SITOR SISDATA 2000 derived from DTS $50 unlimted
Globe Wireless (USA) Clover
P-SeaMail SITOR? $149.95
Message Center, Inc (USA) SITOR
Bernradio (Switzerland) Clover-2000, Pactor-2, Pactor-1, SITOR DTS + fax, telex, snail mail gatway DTS: CHF 500 10 CHF low traffic, 50 CHF per month high traffic 0.30 CHF per 100 chars
Pinoak (USA) "Podlink f" modem looks like a PTC-II? Podlink F  $1,720 hardware and software $1,720 hardward and software $275 per year $0.95 per kilobyte

Modem and "mode"  choices

As a very crude guide, you will need at least Pactor 1 to do any reasonable amount of e-mail. Pinoak has a description of various HF data modes at http://www.pinoak.com/p_tech.htm. A very basic summary of that paper is that PACTOR 2 outperforms PACTOR 1, CLOVER, G-TOR and AMTOR. I haven't yet found a clear comparison of CLOVER-2000, Codan 9002, and other faster modems. However, many other factors come in including performance under bad conditions, medium distance compared to inter-continental distances, long files compared to short files, lenght of handshaking, external/internal compression, binary files vs ASCII files etc etc. A comparison of Clover 2000 and Pactor 2 is at: http://www.halcomm.com/clvr2k.htm

As you might imagine, the perfomance of the modes is somthing of considerable importance, if not controversy, between the vendors. Any modem to be used with "normal" e-mail software will obviously benefit from built-in compression in the protocol, although external compression can be used before transmission as is commonly done in fidonet.

The confusing number of open/licensed/other "standards" is, I venture, a pity, and holds back the potential of the technology. At the risk of getting ripped apart by the experts, I try a list here. Most of these speeds are those provided by external experts, checked against what the vendor claims.

Mode Maximum speed and comments
SITOR ARQ 100 bits/second Open standard, upper case only, no error correction
CCIR-476 Same as SITOR
PACTOR-1 200 bits/sec
G-TOR 300 bits/sec
PACTOR 2 508 bits/sec
Clover-400 600 bits/sec
Clover-500 750 bits/sec
Clover-2000 3000 bits/sec (minus overhead: 1936 bits/second uncompressed)
Codan 9002 2400 bits/sec + built-in compression = 6000 bits/sec or 1475 bits/sec uncompressed
Mil-std-110 open standard
Stanag 4285???
Rohde & Schwartz 2700 bits/sec

All speeds quoted not considering compression where possible.

Popular modems

Modem prices usually include software.

There is a difference between the SCS PTC-II Pactor-2 and the Swiss PTC-II Pactor-2 modes from Schuemperlin. The Swiss version is somehow encrypted, leading to the mode being known as "private" mode (also known as UN(DP) mode, thanks to adoption by parts of the UN). I have not listed SITOR compatibility, which many of these modems have, as it would be a pretty unsatisfactory mode for any serious amount of e-mail.

Model Price Pactor 1 Pactor 2 Clover-500 Clover 2000 Codan Suitable transceiver
SCS-PTC II $985 yes yes no no no
Codan 9002 see note no no no no yes Codan 9360
Swiss-PTC-II 2850 CHF yes yes no no no
SCS PTCPlus yes no no no no
Barrett 923 see note 
yes no yes yes no Barrett 550 (base station $3395)
HAL DSP-4100/2K  $1795 yes no
HAL DSP-4000/2K (internal card) $1495 yes yes yes no
HAL DSP-4000/2K with FSK (internal) $1620 yes yes yes no
http://www.halcomm.com/p38.htm HAL P38 (internal card) $350 yes no yes no no
Kantronics Kam+ $350 yes, also G-TOR no no no
Datron/Transworld ? yes no


Swiss-PTC may offer AT-commands like the Codan 9002 in an upcoming version. Refer to a Codan dealer for exact prices, but a complete base station including modem, transceiver and antenna would start at no less than $6,300 Barrett 923 complete base station withj modem comes at about $7,500

Do it yourself software options

These packages may allow you to put together your own HF radio - Internet e-mail service just for your own organization or as a service provider.

Software: Wavemail
Compatible with: Swiss PTC-II
Comments: new, internet mail gateway called wavenet expected soon
Further info: http://www.schuemperlin.com
Software: DTS/EURAF
Compatible with: Most modes
Comments: $4,000 per client
Further info: http://dtsdata.intnet.bj
Software: F6FBB
Compatible with: Packet and Pactor II
Comments: Freeware BBS (DOS/Windows/Linux) - internet gateway?
Further info: http://www.f6fbb.org
Software: Any
Compatible with: Codan 9002
Comments: modem takes AT commands
Further info:
Software: UN/OCHA/UNOG GL-Plus+Perl scripts
Compatible with: Swiss PTC-II
Comments: Used in Central Africa - gateway in Geneva
Further info: Contact sjacobson@unog.ch
Software: Barrett 923
Compatible with: Clover 2000, Pactor 1
Comments: Client and hub/gateway, derived from DTS
Further info: e-mail: aburt@dial.pipex.com
Software: Winlink/Netlink
Compatible with: Pactor 1 and 2
Comments: BBS + internet gateway (freeware/shareware)
Further info: http://www.win-net.org
Software: Airmail
Compatible with: SCS PTC-II, Kam+
Comments: BBS + internet gateway (freeware/shareware)
Further info: http://www.win-net.org
Software: KA9Q/TNOS/JNOS
Compatible with: Pactor 1?
Comments: Complex OS-based idea, mainly used for packet radio
Further info:
Software: Rhode & Schwartz Message Handling Software PostMan
Compatible with: R & S XK2000 transceiver with built-in GM2100 modem
Comments: TCP/IP over HF
Further info: http://www.rsd.de/PRODUKT/239a.htm

Further Information




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