Description
AT&T ML17939 2-Line Corded Speakerphone – Caller ID & 12-Min Answering
A front desk that juggles a main number and a second line does not need a full phone system to stay organized. The AT&T ML17939 is a two-line corded speakerphone with caller ID/call waiting and a built-in digital answering system. ClearSpeak dial-in-base speakerphone lets our customers talk hands-free, and each line stores about 12 minutes of announcements, messages, memos, and two-way recordings. It is built for small offices, reception desks, and home businesses that still run analog lines and want one black desk set that covers both.
The Telecom Spot Take
The ML17939 fits our customers who need two analog lines on one desk without adding extra handsets. Facilities managers and office owners get line-status lights, automatic line selection, and a three-party conference across both lines. Each line has its own mailbox, so a sales line and an office line do not share one pile of messages. Caller ID and call waiting need a subscription from the phone company. The base needs the included power adapter for the display and answering system. With three AA alkaline batteries installed (sold separately), the phone keeps working in a power outage except for display lighting. With no batteries, line 1 still places and answers calls from the handset.
Key Features
- Two-line operation with line-status indicators so staff can see which line is ringing, in use, or on hold before they pick up.
- Automatic line selection answers the ringing line and uses the primary line (line 1 by default) for outgoing calls. The primary line can be changed in the menu.
- Three-party conferencing joins both lines into one call. Put one line on hold, connect the other, then press conference.
- ClearSpeak dial-in-base speakerphone supports hands-free talk and lets more than one person join from the desk. Preferred mode can be set to speakerphone or a corded headset.
- Digital answering on each line stores up to 99 messages. Total recording time per line is about 12 minutes for the announcement, messages, memos, and two-way recording. Message length can be set to 1, 2, or 4 minutes (default is 1 minute).
- Call screening is on by default, so staff can hear the greeting and the message as it records, then pick up to intercept.
- Remote access uses a three-digit code (default 500) from any touch-tone phone. Toll saver answers after 2 rings when new messages are waiting and after 4 rings when the mailbox is clear.
- Caller ID/call waiting shows name, number, time, and date while the phone rings, including waiting calls when that service is subscribed. The call log stores the last 99 incoming calls.
- Directory holds up to 100 names and numbers (16 characters for the name, 32 digits for the number). Eighteen speed-dial locations store up to 24 digits each.
- 2.5 mm headset jack for a corded headset (sold separately). If no headset is plugged in, the phone uses the speakerphone.
- Data port uses line 2 only, so a computer modem or similar device can share that line.
- Hold, mute, chain dialing, display dial, redial of the last five numbers, and separate volume controls for the receiver, speakerphone, and ringer.
- Selectable ringer tones and English, Spanish, or French setup menus.
- Hearing aid compatible for use with most T-coil hearing aids and cochlear implants.
- Desktop or wall mount. The package includes a mounting bracket for a standard dual-stud wall plate.
- Optional backup power uses three AA alkaline batteries (not included).
Technical Specifications
| Item | Detail |
|---|---|
| Model | ML17939 |
| Type | Two-line corded telephone / answering system with caller ID/call waiting |
| Color | Black |
| Lines | 2 |
| Speakerphone | ClearSpeak dial-in-base speakerphone |
| Conferencing | 3-party (both lines) |
| Directory | Up to 100 entries; 16 characters name, 32 digits number |
| Speed dial | 18 locations; up to 24 digits each |
| Caller ID history | Last 99 incoming calls |
| Answering system | One mailbox per line; up to 99 messages per line |
| Recording time | About 12 minutes per line (announcement, messages, memos, two-way recording) |
| Message length | 1, 2, or 4 minutes (default 1 minute) |
| Rings before answer | 2, 4, 6, or toll saver (default 4) |
| Remote access code | 3 digits, 000–999 (default 500); can be turned off |
| Headset jack | 2.5 mm (headset sold separately) |
| Data port | Yes; uses line 2 only |
| Display | LCD with backlight (can be turned on or off) |
| Menu languages | English, Spanish, French |
| Hearing aid | Hearing aid compatible (TIA-1083) |
| Dial mode | Tone or pulse |
| Power adapter | Input 100–120V AC 60Hz; output 6V DC 400mA (included) |
| Backup batteries | 3 AA alkaline, 1.5V (not included) |
| Operating temperature | 32°F–122°F (0°C–50°C) |
| Mounting | Tabletop or wall (mounting bracket included) |
| Warranty | 1-year limited warranty |
In the box: telephone base, handset with coiled cord, clear 2-conductor line cord, black 4-conductor line cord, power adapter, mounting bracket, replacement directory card, user’s manual, and quick start guide.
Comparison at a Glance
| Need | AT&T ML17939 | Basic one-line corded desk phone | Multi-handset cordless system |
|---|---|---|---|
| Lines on one set | 2, with status lights and auto line selection | Usually 1 | Often 1 or 2, shared across handsets |
| Built-in answering | About 12 minutes and up to 99 messages per line | Often none | Sometimes a base mailbox only |
| Hands-free | ClearSpeak base speakerphone plus 2.5 mm headset jack | Handset only on many models | Handset speakerphone; base speaker varies |
| Power loss | Line 1 handset still works with no batteries; fuller use with 3 AA batteries | Often line-powered | Usually needs base power or battery packs |
| Best fit | One desk, two analog lines, local message taking | Single number, light calling | Staff who walk away from the desk |
FAQ
Does caller ID work without a phone-company subscription?
No. Caller ID and caller ID with call waiting are subscription services. The phone still makes and receives calls, uses the directory, and runs the answering system without that subscription.
How much message time does each line get?
Each line stores up to 99 messages. Total space per line for the greeting, messages, memos, and two-way recording is about 12 minutes. You can cap each incoming message at 1, 2, or 4 minutes.
What happens if the power goes out?
With three AA alkaline batteries installed, all functions work except display lighting. With no batteries, you can still make and answer calls on line 1 with the handset. Redial and speed dial still work. The screen is dimmer.
Can I use a headset?
Yes. The base has a 2.5 mm jack for a corded telephone headset, sold separately. Preferred mode can be set to headset. If nothing is plugged in, the phone uses the speakerphone.
Do I need a filter if the office has DSL?
Yes. If high-speed internet runs on the phone line, install a DSL filter between each line cord and the wall jack. That helps prevent noise and caller ID problems.
Is the one-year warranty for business use?
The limited warranty covers defects in material and workmanship for one year from purchase. The manufacturer’s warranty text excludes products used for commercial or institutional purposes, including rental use. Check the warranty section in the user’s manual before you buy for an office.