Voice Keyer Setup for SSB Contests: Messages, Levels and Keys
Call CQ on SSB once every fifteen seconds for 48 hours and you will have said “CQ contest” something like ten thousand times. No voice survives that, and no operator should try. A voice keyer, also called a digital voice keyer or DVK, plays recorded messages at the press of a key: your CQ, your callsign, the exchange, “thanks” and “again please”. It keeps the rate steady while your voice rests, it makes every CQ sound the same, and it leaves your hands free for logging. This guide covers the two main kinds of voice keyer, how to record messages that sound natural and are easy to copy, how to set the audio levels so the recorded voice matches your live voice, how to map the messages to keys, and the mistakes that make a station sound like a machine.
Two Kinds of Voice Keyer
Built into the radio
Most current HF transceivers include a voice memory keyer with several slots, usually recorded through the microphone with a menu or a front-panel button. Playback keys the transmitter automatically and the audio goes straight into the modulator, so the levels are consistent and there is no external audio chain to adjust. The limitations are the number of slots, which can be as few as four or five, the recording length per slot, and the fact that triggering playback from the logging software requires either a CAT command the radio supports or a separate keying interface. Some radios also offer a repeat function that plays the CQ message again after a pause until a station answers, which is useful when you are running on a quiet band.
From the logging software
The contest loggers play audio files from the computer through the sound card into the radio’s audio input, and key the transmitter through the usual PTT interface. The advantage is flexibility: unlimited messages, one audio file per message, variable content such as the serial number assembled from pre-recorded digits, and a single key press that plays the message and advances the logging program to the right state. The cost is an audio interface between computer and radio, with the attendant level setting and isolation issues. The N1MM Logger documentation describes its voice keyer features in detail, and the other major contest loggers have equivalents. Our N1MM setup guide for a first contest covers the basic configuration that the voice keyer builds on.
External hardware keyers
Dedicated voice keyer boxes, with their own memory and a microphone input, sit between the microphone and the radio. They were common before radios had voice memories built in and still have a place in multi-operator stations where the keyer must be independent of any one computer.
Comparing the Options
| Type | Message count | Logger integration | Audio quality | Setup effort | Best for |
|---|---|---|---|---|---|
| Radio memory keyer | Usually 4 to 8 slots | Via CAT command or a key line, radio dependent | Consistent, no external chain | Low | Casual contesting, portable operation |
| Logger playback through sound card | Unlimited | Full: message plays and logger advances | Depends on interface and level setting | Medium | Serious single-operator and multi-op stations |
| External hardware keyer | Typically 4 to 8 | Via key lines from the logger | Good, dedicated audio path | Medium | Multi-op stations wanting independence from the PC |
Recording Messages That Work
The recordings are heard thousands of times during a weekend, so spend an hour getting them right before the contest rather than regretting them during it.
- Record with the contest microphone and headset. If the message was recorded on a desk microphone and your live voice comes from a headset boom, the two will sound different and the station will sound like two operators.
- Speak at a normal contest pace. Not slowly: a slow CQ lowers the rate. Not rushed: a callsign that is hard to copy generates “again?” requests and costs more time than it saved.
- Use standard phonetics in the callsign. The ITU phonetic alphabet is understood everywhere, and a consistent callsign recording is one of the main reasons voice keyers improve rate. Our guide to the phonetic alphabet in pileups discusses when to vary it, which should be the exception.
- Keep the CQ short. “CQ contest, callsign, callsign, contest” is enough. Long CQs let other stations call on top of you and waste the seconds that add up to hundreds of contacts over a weekend.
- Record the exchange separately from the callsign. A contest where the exchange is a fixed zone or section needs one recording; a serial-number contest needs the digits recorded individually and assembled by the logger.
- Trim the silence. Half a second of dead air at the start of every message is half a second during which the station you are calling may give up. Edit the files to start immediately.
- Record a few utility messages. “Again please”, “thanks, callsign”, “QRZ” and “you are 59” with the exchange. The complete set of messages replaces nearly everything you would say in a routine contact.
Setting the Audio Levels
The goal is for the recorded voice and the live voice to produce the same transmitter drive, so that stations hear the same signal whether the keyer or the operator is speaking. With a radio memory keyer this is largely automatic, because the recording passes through the same microphone gain. With logger playback it has to be set by hand, and the sequence is:
- Set the microphone gain and speech processing for your live voice first, watching the ALC meter so that the ALC just reaches the top of its range on speech peaks and the processor adds a few decibels of compression without distortion.
- Play a recorded message and watch the same meters. Adjust the sound card output level, or the level in the logger’s audio settings, until the meters move the same way as with the live voice. Do not touch the radio’s microphone gain to make the recording fit, because the live voice will then be wrong.
- Listen to both on a monitor receiver or ask a nearby station to compare them. A recording that is a little quieter than the live voice is better than one that is louder and distorted.
- Check for hum, buzz and RF feedback on the recorded path. A ground loop between computer and radio shows up as hum in the transmitted audio only when the keyer is playing, and an isolation transformer in the audio line cures it.
Some radios have separate input selections for the front microphone and the rear data or accessory jack, with independent gain settings for each. Playing the keyer through the rear input and the live voice through the front then lets you set each level without disturbing the other, and the logger or a small switch box selects which one is active. The headset, footswitch and microphone arrangements that make this comfortable are described in our contest headset and footswitch guide.
Mapping Messages to Keys
The loggers use function keys for messages, and the convention is widely shared: one key for CQ, one for the exchange, one for the callsign, one for “thanks” and so on. The important part is that the same key does the same job in run mode and in search-and-pounce mode, and that a single press performs the whole step: play the message, and move the cursor or the logger state to what comes next. Enter Sends Message, or its equivalent, goes further by making the Enter key play whichever message is appropriate for the current state of the contact, so that a routine run contact becomes a sequence of callsign typed, Enter, exchange typed, Enter. Learn the sequence before the contest with a few practice contacts; an operator fumbling for keys is slower than one speaking live. Our article on where rate comes from shows why those saved seconds matter.
A footswitch or a key on the keyboard should interrupt any message instantly. When a station calls in the middle of your CQ, you want to stop the recording and answer, not wait for it to finish.
Using the Keyer Well
A voice keyer does the routine work; the operator does the listening, and the major contest rules, such as the CQ WW rules, require an operator to be in control of the station at all times. Use the recorded CQ and exchange when the band is steady and the contacts are routine, and switch to the live voice when something needs judgement: a weak station that needs the callsign a little slower, a request for a repeat, a station that sent an unexpected exchange. Avoid playing the CQ into an empty band for hours with the repeat function and no one listening; check the band map and the cluster, move if the band has died, and remember that a running station still needs to notice when a multiplier appears.
In a multi-operator station, keep one set of recordings per operator so that each voice matches its own live voice, and store them under the operator’s name in the logger. The first time a new operator sits down, play the messages back through the monitor to confirm the levels, because a different voice and microphone technique will drive the processor differently.
Serial Numbers and Variable Exchanges
Contests with a fixed exchange are easy for a keyer: one recording covers every contact. Serial-number contests are where logger playback earns its place. The logger holds a recording of each digit, or of each number from one to a hundred and the digits beyond, and builds the exchange on the fly from the next serial number in the log. Record the digits in the same session, at the same pace and distance from the microphone, so that an assembled number such as “five nine, one two three” does not sound like three different people. Many operators record the numbers both as single digits and as common pairs, because “twelve” is copied more reliably than “one two” by some ears and worse by others; the logger settings choose which style is used. Play the assembled exchange back through the monitor before the contest starts and fix any digit that sounds clipped or quieter than the rest, because that one digit will be the one asked to repeat all weekend.
Common Problems
Recorded voice sounds muffled or distant. The file was recorded at too low a level and then boosted, or through the wrong microphone. Re-record with the contest headset at a proper level.
Transmitter keys but no audio. The sound card output is going to the wrong device, or the radio is set to the wrong audio input. Check the device selection in the logger and the input selection on the radio.
Hum only during playback. A ground loop in the audio line between computer and radio. Add an isolation transformer or use a USB audio interface with isolation.
Messages cut off at the start. The PTT asserts a fraction later than the audio begins. Add a short lead-in of silence, or set the PTT lead time in the logger.
Voice quality changes between live and recorded. Levels or microphone mismatch. Reset the radio for the live voice first, then match the recording to it.
The Bottom Line
A voice keyer is the difference between an SSB contest that is fun on Sunday afternoon and one that ends with no voice at all. Choose the radio’s memory keyer for simplicity or logger playback for full integration, record short clear messages with the same headset you will use live, match the levels to your voice rather than the other way around, learn the key sequence until it is automatic, and stay in charge of the listening. The keyer carries the routine; you carry the contest.
Frequently Asked Questions
What is a voice keyer in ham radio?
A device or software function that plays pre-recorded voice messages such as CQ, your callsign and the contest exchange through the transmitter at the press of a key, so the operator does not have to speak every one.
Is it legal to use a voice keyer in contests?
Yes, recorded messages are standard practice in SSB contesting and permitted by the major contest rules. Fully automatic unattended operation is not; an operator must be in control of the station.
Should I use the radio’s built-in voice memory or the logger?
The built-in memory is simpler and has consistent audio. Logger playback integrates with the contact flow and has unlimited messages, including assembled serial numbers. Many contesters use the logger for single-operator entries and the radio memory for portable operation.
How do I make the recorded voice sound the same as my live voice?
Record with the same headset microphone, set the radio for your live voice first, then adjust the playback level so the ALC and power meters move the same way during playback.
How long should a contest CQ recording be?
A few seconds: “CQ contest, callsign, callsign, contest” is enough. Shorter CQs mean more CQs per minute and fewer stations calling over the end of a long one.
Why is there hum on my recorded messages but not my live voice?
The playback path from computer to radio has a ground loop. An audio isolation transformer or an isolated USB audio interface removes it.