Free - Amateur Radio Contest Logging Software

Updated : 19 April 2024

What's New

HF Contests Supported


Download SD

For Windows

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SD Manual
English PDF
Italiano PDF - I7ALE, Settembre 2023

Remote Operation

Vranyo. Look it up

Latest DXCC.CTY & CQWW.CTY files

FTx and Ham Radio

Did Joe Taylor K1JT destroy Amateur Radio?

The SD-User Mailing List - Get help from other users.

WA7BNM's Contest Calendar.

T32C - 213,000 QSOs
World #1 DXpedition
3B7C - My Story
The ARRL at 100
Hunting in Africa
What I don't like
Excessive Bandwidth
The Internet of Things
DXCC and the AIRL
Hybrid Contesting
The Wild West
New RBN Servers
Far, far away
A Bitter Pill
Remote Contesting
Internet Propagation
Clicking & Pouncing
CW Skimmer
New Technologies
Remote Control
Put the wires back
Remote Contesting
Hybrid Communications
Reality Check
Remote Operation
Parallel Radio
Ceased to Exist
We should not be here
Digital Mode One
Copy by Ear
I'd recommend Skype
Just Another Digital Mode
Allow all Technology
QSOs & Thoroughbreds
Field Day & the Internet
SD Updated April 2010
New Contest Categories
Remote Control 2009

SD is written in PowerBASIC

Conor O'Kane
A 3D-printable cello - the O'Cello
and Thingiverse
DroneSwarm for iPad
Fossil Swap for iPad

Dermot O'Kane

SCP Super Check Partial files.

ARRL's Logbook
of the World

USA/Canada International paper sizes.

IRTS - Irish Radio Transmitters Society

Begali HST Mk II - my single-lever paddle.

Begali HST Mk II

Birds of Saint Brandon 3B7C

Fairy Tern - EI5DI

"A great program. Keeping it simple is both the hard part and its greatest virtue." K1CTT

SD is a free and unrestricted HF contest logger, with more than 280 templates supplied.

SD sets the standard for fast, simple logging and editing in the major HF international contests and in hundreds of others worldwide. It is intended for single-op unassisted entries, on both SSB and CW. There is no easier way to get started in HF contest logging - the manual (included) has only 17 pages.

SD helped me to World #1 for SO LP 80m CW in CQWW 2015.

SD runs on all versions of Windows from 11 back to XP, with a character-based display.

How to install SD


Here is the logging line for CQ WW, with W3LPL typed in the callsign field.

  • We're logging on 40m, and the time is 15:14z
  • This is QSO #646
  • If logged, W3LPL will be a country mult (C), and a zone mult (Z)
  • This will be our third (3) QSO with W3LPL
  • The received report defaults to 599
  • The zone previously logged (5) is pre-filled
  • Our data entry mode is OVR, and mode is CW
  • The band/mult analysis shows that -
    • W3LPL has been worked on 10 and 20m
    • He is needed on 15m, but will not be a mult on that band
    • He is needed on 80 and 160m, and would be a double mult on both bands

SD supports rig control, serial and parallel keying - and integrates with WinKey to eliminate CW timing issues caused by Windows.

SD offers instant "full-screen" editing of any QSO in your log. All SD's files, including the log, are standard ASCII text files and can be viewed with any text editor.

Following any QSO edit, no matter how complex, SD checks your complete log for consistency, and instantly updates all relevant QSOs.

This includes setting and unsetting dupe and multiplier flags, and updating area codes (zones), and points, in all QSOs as required. The information shown in the Summary Score window is correct at all times. Just try this on any other contest logger - and see the difference for yourself.

SD is the only contest logger to offer these features, in real-time, as you type individual callsign characters. There's no need to touch another key or memorise Ctrl-This or Alt-That.

  • Dupe checking
  • Country/Band analysis
  • Check Partial by prefix
  • Beam headings
  • Advance flagging of potential multipliers
  • Band/Mode analysis by callsign
  • Linked database display
  • Auto data insert (Zones and area codes)
  • Countries Worked/Wanted by Continent

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IOTA Contest

SD supports the IOTA contest directly, and includes all the custom features that make it so efficient compared to other loggers. To do well in IOTA, you must work island stations because they're worth many times more than other QSOs. For the first fourteen years of the IOTA contest, from 1993 to 2006 inclusive, SD was the leading logger. Here are some stats.

SD sets the standard for instantly showing your band/mode status for island stations, for highlighting multiplier slots, and for ease of data entry of island references. Other loggers can't do this! IOTA is special, it needs the extra features that only SD offers.

SD identifies country and call-area, as you type individual callsign letters, and give you a real-time summary of IOTA islands (if any) worked and wanted for that country or call-area - for the current band and mode. When the country is an IOTA island with a single reference, SD auto-fills the reference.

SD gives you a worked/wanted analysis for all bands and modes when you type an IOTA reference in the callsign field - there's no need to touch another key or remember function keys or multiple keystrokes.

SD is ready now for the 2019 IOTA Contest

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IOTA Contest Results

2018 : 2017 : 2016 : 2015 : 2014 : 2013 : 2012 : 2011 : 2010 : 2009 : 2008 : 2007 : 2006 : 2005 : 2004 : 2003 : 2002 : 2001 : 2000 : 1999 : 1998 : 1997 : 1996 :

Soapbox comments about SD/SDI for -
2011 : 2010 : 2009 : 2008 : 2007 : 2006 : 2005

Please add a link from your website to
"SD by EI5DI" at

    Paul EI5DI -

    Paul O'Kane EI5DI