The SR-3 portable is the main product manufactured and marketed by Spectratek Systems Limited.

The SR-3 HF/SSB Portable

Designed by TR Systems and developed and marketed as a joint venture with Spectratek, the SR-3 HF Handheld Portable has been specifically designed for use in New Zealand’s mountainous and outback regions.

Various versions of the SR-3 have been developed to suit specific customer requirements.

The Standard SR-3

The standard SR-3 handheld portable is built in a lightweight cast aluminium case designed to withstand the harshest of outdoor environments and weighs in at under 700 grams (not including internal AA dry cell batteries). The SR-3 has become the standard HF/SSB portable throughout New Zealand for many forms of outdoor pursuits including;

• Trekking/Tramping and Hunting Parties,


• Forestry and Wilderness Conservation,


• Emergency Services,


• Search and Rescue,


• Safety and Health,


• Para-Military and Law Enforcement.

The entry level SR-3 can be supplied with up to six channels (nine channels optional) for basic two way HF/SSB voice communications. Normally a high-powered base station would need to be established to provide a communications network to field deployed SR-3 portables. A useful range of up to 500 kms is achievable depending on frequency selection and propagation characteristics.

The SelCall SR-3

A selective calling (selcall) telephone interconnect capability can be provided on the SR-3 to allow field parties to connect automatically to the Public Switched Telephone Network (PSTN) via an automated Telephone Interconnect Base Station. This is a powerful tool in the field in the event of emergency or safety concerns. A field operator can use the SR-3 to make telephone calls to emergency services, police or seek medical assistance from almost anywhere in the wilderness via a Telephone Interconnect equipped base station.

Selcall Options include:

• Internal send only Selcall to allow fully compatible interoperability with Barrett or Codan Telephone Interconnect base stations.
• An external Selcall/Telcall microphone microphone can be fitted to provide both send and receive Selcall and Telcall protocol between Barrett and Codan Telephone Interconnect base stations.
• An internal electret microphone is provided as standard to allow the SR-3 to operate as a completely stand-alone HF transceiver. As an 'open channel' transceiver the SR-3 requires only connection to an aerial system to be fully operational in the field.

The Pelican SR-3P

The SR-3P version of the radio is electronically identical to the standard SR-3 handheld, but repackaged in a waterproof Pelican Case. This unit is completely self-contained with a compartment containing the selcall microphone and broadband aerial spool. The SR-3P also has greater battery capacity, provided by eight internally installed “C” cells and an external DC input for mains or external battery operation. An audio ‘scrambler’ option can be fitted to deter the casual eavesdropper.

All SR-3 versions can be supplied with a resonant dipole ‘bobbin’ type aerial for up to three frequencies, or the specially designed EFB-LT lightweight broadband aerial system; which does not require tuning, traps or links for selection of different frequencies.

Specifications For The SR-3 HF/SSB Portable Transceiver

A. General

Frequency Range: 2.000 to 7.995 MHz (Broadband - no tuning required).

Mode: A3J - SSB Simplex. USB Standard, USB/LSB Optional.

Number of Channels: 6 Standard, 9 Optional. (Crystal controlled).

Operating Voltage: 10.5 to 15.5 V DC at 750ma peak.

Power Supply: 12 V DC Internal Batteries (8 x AA or C), 13.8V DC External Supply.

Frequency Stability: < +/- 100 Hz for -10 C to +50C.

Operating Temp Range: -30C to +60C.

Aerial Impedance: 50 ohms - BNC or 450 ohms - Terminal Posts.

Physical: Die-cast Aluminium Case; dimensions: 153 x 84 x 72mm, weight: <700g (no batteries).

Physical: Pelican Case; dimensions 270 x 240 x 125mm, weight: < 2.6 Kg (inc Aerial & Mic).

B. Transmitter

Type: Crystal Controlled, Filter method of SSB generation.

RF Power Output: Adjustable from 0.5W to 4.0W PEP.

Supply Current: 300mA – 450ma average for speech.

Spurious Emissions: > 40 dB down wrt 4W PEP Output.

Timeout Timer: 60 Second Tx timeout, reset by releasing PTT button.

Selcall: Internal send only - CCIR-493 format

C. Receiver:

Type: Crystal Controlled, Single Conversion, 10.7 MHz IF.

Sensitivity: >12 dB SINAD for –121dBm (0.2 uv).

AGC Characteristics: <3 dB change from -110 to +10 dBm.

Supply Current: 40 ma Average.

Audio Output: 500 mW into 8 ohms.

D. Controls and Indicators

• Rotary Volume.
• Channel Select.
• PTT Button.
• Aerial Terminals for dipole connection.
• Optional BNC Coax Connector.
• Battery Indicator LED.
• Transmit Indicator LED.
• Internal Microphone and Speaker.
• Optional External DC input socket.
• Optional Input Sockets:Tx Audio (for external microphone), Rx Audio, 12 V DC output, PTT and Spare.

Specifications subject to change without notice.