A log is your station’s record of who you talked to, when, and how. It also unlocks confirmations: QSL cards and Logbook of The World both depend on two stations recording the same contact. This guide covers what to write down, the file format logging programs exchange, and the ways a contact gets confirmed.
Why keep a log
The ARRL groups the reasons into three kinds: legal, because a log of your transmissions helps if you are ever part of an interference complaint; operational, because it tells you what you need when a QSL card arrives months later; and personal, as a record of the people and places you have talked to (ARRL). The rules require the station licensee to make the station and its records available for inspection when an FCC representative asks (47 CFR 97.103(c); Technician pool question T1F01), and many amateurs keep a log so they can reply if the FCC requests information about their station (General pool question G2D08). Some records are named in the rules; for example, a 60 m station using an antenna other than a dipole must keep its gain data (47 CFR 97.313(i)).
What to record
The ARRL suggests recording, for your own station, the date, frequency, mode and power, and for the station you contact, its call sign, the times the contact started and ended, its signal report, the operator’s name and their location (ARRL).
Paper works, and so does a computer. Logging programs keep UTC straight automatically, and many can export a log to send to Logbook of The World (ARRL).
ADIF, the format logs share
Logging programs, Logbook of The World and Parks on the Air exchange logs in ADIF, the Amateur Data Interchange
Format. An ADIF text file, with the extension .adi, holds one record per contact. Each piece of data is written as
a field name, the length of the data, and the data itself, and each record ends with <EOR>
(ADIF 3.1.7).
<STATION_CALLSIGN:6>KE7ZZZ<CALL:5>W1ZZZ<QSO_DATE:8>20261012<TIME_ON:4>2215<BAND:3>10m<FREQ:6>28.405<MODE:3>SSB<RST_SENT:2>59<RST_RCVD:2>57<EOR>
In <CALL:5>W1ZZZ the field name is CALL, the number 5 is how many characters of data follow, and W1ZZZ is the data. <EOR> ends the record.
STATION_CALLSIGN- Your call sign, as sent on the air
CALL- The station you contacted
QSO_DATE- Date the contact started, UTC, as YYYYMMDD
TIME_ON- Time it started, UTC, as HHMM or HHMMSS
BAND- Band, from the list in the specification
FREQ- Frequency in megahertz
MODE- Mode, from the list in the specification
RST_SENT- Signal report you gave
RST_RCVD- Signal report you received
Sources: ADIF Specification 3.1.7 (ADIF Developers Group); FSD-220 time conversion chart (ARRL); Daylight Saving Time (NIST)
The specification leaves it to each program to decide which fields make up a contact, but suggests at least the date, the start time, the band or frequency, the mode and the other station’s call sign (ADIF 3.1.7). Logbook of The World needs the same core items: your partner’s call sign, the date and start time in UTC, the band and the mode (ARRL). Parks on the Air requires ADIF for activation logs (POTA).
QSL cards
A QSL card is a postcard that confirms a contact between two hams (ARRL glossary). You can mail a card directly to the other station, or send cards for stations in other countries through the QSL bureaus:
- Incoming bureaus in the US are run by volunteers for each call area and act as clearing houses for cards from other countries. ARRL membership is not required. You claim your cards by keeping self-addressed stamped envelopes or money credit on file with the bureau for your call area. Do not send cards for US stations through the bureaus, and expect cards from overseas to take months; many are more than a year old when they arrive (ARRL).
- The ARRL Outgoing QSL Service sends members’ cards to other countries’ bureaus, for a fee: priced by the number of cards for up to 20 cards, and by weight for larger shipments (ARRL).
Logbook of The World
Logbook of The World (LoTW) is the ARRL’s online system for submitting electronic logs and receiving confirmations, which count toward awards such as DXCC, for confirmed contacts with 100 countries, and Worked All States. ARRL membership is not required. Getting a certificate, uploading contacts and viewing confirmations are free; a fee applies only when you submit confirmed contacts for award credit (ARRL).
Install TQSL
Download the free TQSL program and use it to request a Callsign Certificate.
Wait for the postcard
For a US call sign, the ARRL mails an 8-digit password to the postal address on your FCC license. Enter it online; your certificate arrives by email.
Describe your station location
In TQSL, set up a Station Location with the details of where you operate, such as your grid square and US state.
Sign and upload contacts
Your logging program, or TQSL itself, signs an ADIF or Cabrillo log with your certificate and sends it.
Match
When the other station uploads the same contact (matching call signs and band, the same mode or mode group, start times within 30 minutes), both accounts show it as confirmed.
Sources: Getting Started with LoTW (ARRL); Submitting QSOs to LoTW (ARRL); Key Terms and Concepts (ARRL); About Logbook of The World (ARRL)
A contact is confirmed when both uploads agree: each lists the other’s call sign as signed by its certificate, the start times are within 30 minutes of each other, the band matches, and the modes match exactly or fall in the same mode group, such as AM, FM and SSB in the phone group (ARRL). If your FCC postal address is out of date, fix it in ULS before you request a certificate, because that is where the postcard goes (ARRL).
The HF operating guide describes awards and other confirmation services, and the parks and summits guide explains how activators submit their logs.