all
Bands
2008
Introduced
Frequencyn/a
PowerA USB sound-card interface for digital modes, not a radio. It passes transmit and receive audio and keys the transmitter; it does not generate RF.
ModesAll sound-card digital modes (FT8, FT4, JS8Call, PSK31, RTTY, SSTV, CW, JT65, WSPR, VARA, MT-63, Olivia, EchoLink, and more), Also supports digital voice modes (FreeDV)
Weight200 g (7.1 oz) - Approximate; Tigertronics does not publish a weight.
Year2008
Connectors
usbUSB-B to the computer (the SignaLink contains its own built-in USB sound card); USB bus-powered, no external supply
radioRJ-45 jack to a removable, radio-specific cable; an internal jumper block (six pre-cut jumpers) or a plug-in module configures it for your radio
aux speakerRear-panel Aux speaker/headphone jack (3.5 mm) to keep hearing receive audio when the unit is attached to the radio's external-speaker jack
power reqUSB bus-powered; no external power supply or batteries.
Digital-mode interface with its own built-in USB sound card, so it does not use the computer's sound card and frees it for other uses Handles audio and push-to-talk only: it keys the radio with a built-in VOX circuit and does NOT do CAT/rig frequency control (add a separate CAT cable for that) Full RF isolation: transmit and receive audio are transformer-isolated and PTT is switched by a sealed relay, which removes ground loops and hum Three front-panel knobs (TX audio level, RX audio level and transmit delay) adjustable without opening the case USB bus-powered, with no drivers needed; it appears as a standard USB audio device on Windows, Mac, Linux and Raspberry Pi Radio side connects through a removable radio-specific cable plus an internal jumper block (six pre-cut jumpers) or a no-solder plug-in module Cables and modules are available for nearly every transceiver (Icom, Yaesu, Kenwood, Elecraft, Xiegu, Ten-Tec, Baofeng and more) Rear Aux speaker/headphone jack (3.5 mm) lets you monitor receive audio when the SignaLink is connected to the radio's external-speaker jack Connects to the radio's mic, data or accessory port, so the microphone can usually stay plugged in FCC Part 15(B) Class B; made in the USA (Grants Pass, Oregon), with free telephone tech support
Strengths

A widely used digital-mode interface. The built-in sound card removes any dependence on the computer's sound card and simplifies setup, and full RF isolation through audio transformers and a relay PTT keeps out the ground loops and hum that plague homebrew cables. Front-panel knobs set TX/RX audio and PTT delay without opening the case, no drivers are needed on any common OS, and cables or plug-in modules exist for nearly every radio. Free US phone support and made in the USA.

Weaknesses

It is an external box plus a radio-specific cable, while many current radios (IC-7300, IC-705, FTDX10, QDX) have USB audio built in and need nothing extra. It does audio and VOX-PTT only, so CAT frequency/mode control needs a separate cable, the radio cable is an added cost if not bundled, the VOX hang time adds slight latency, and the computer connector is legacy USB-B rather than USB-C. New stock is now hard to find at major dealers.

Verdict

The Tigertronics SignaLink USB is a sound-card interface that puts a radio on the digital modes (FT8, PSK31, RTTY and the rest) through a single USB cable, with its own sound card and full RF isolation that set it apart from a homebrew cable. It is still useful for any radio without built-in USB audio, which is a large installed base; operators with a modern radio that already has USB audio do not need it, and new units have become scarce.

The Tigertronics SignaLink USB is a small interface box that connects a radio to a computer for digital modes such as FT8, PSK31, RTTY, JS8 and SSTV. It became popular because it contains its own USB sound card. Older interfaces, including Tigertronics' own SL-1+, relied on the computer's sound card and several audio cables; the SignaLink USB puts the sound card inside the box, so one USB cable carries the transmit and receive audio, fully isolated from the radio by transformers to keep out hum and ground loops.

One thing to understand up front: it handles audio and push-to-talk only. It keys the transmitter with a built-in VOX circuit triggered by the transmit audio, and you set the hang time with a front-panel knob. It does not do CAT, so it cannot read or change the radio's frequency or mode; if you want rig control you add a separate CAT cable. The front panel has three knobs (transmit level, receive level and delay), the unit is powered entirely from the USB port, and it needs no drivers on Windows, Mac, Linux or Raspberry Pi. A rear Aux jack lets you plug in a speaker or headphones to keep hearing receive audio when the SignaLink is connected to the radio's external-speaker jack.

The radio side connects through a removable, radio-specific cable, and inside is a small jumper block you either wire yourself (six pre-cut jumpers are supplied) or fit with a ready-made plug-in module for your radio. Tigertronics offers cables and modules for nearly every transceiver, which is much of its appeal: it works with almost anything that has a mic, data or accessory jack, and the radio can usually keep its microphone plugged in.

Its role has narrowed as radios arrived with the sound card already built in: an Icom IC-7300, or a purpose-built digital rig like the QRP Labs QDX, needs no external interface. But for the large number of older radios without USB audio, the SignaLink remains a simple, well-isolated way onto the digital modes, though new stock has become hard to find at the major dealers.