USB Interface II

USB Interface II

Price: $185.00

Model: MH-USB II
Manufacturer: microHAM
Availability: IN STOCK

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Interface II Features

Interface II block diagram

The new microHAM USB Interface II interface includes full optical isolation of all control signals (radio control, CW, PTT and Squelch) and high quality audio isolation transformers with level trimmers (screwdriver adjust) to permit connecting a computer sound card to your radio’s rear panel audio input and constant level audio output for use with digital mode software or echolink.

  • No COM or LPT port necessary, just one USB port and sound card
  • Complete “Computer &lt-> Radio” electrical isolation

– bidirectional transformer isolation of sound card and rig
– optical isolation of

digital signals -> Radio Control, CW, 2xPTT, FSK, PA from USB port

  • Integrated computer control port for all radios CI-V, FIF-232, IF-232, RS-232

– fully supported Icom, Kenwood, Ten Tec, Yaesu and other radios
– no separate level converter required

  • Squelch input for signaling to computer

– two inputs, on is activated when is closed to ground, second when senses 5-8V power

  • No external power adapter

– Computer part is powered from USB
– Radio part is powered from transceiver or transceiver power supply

  • Strong RFI immunity

– integrated chokes and filters for best RFI immunity
– advanced shielding and circuit design for RFI product supression

  • Quick change connectors

– USB, Sound Card – 2 x 3.5mm (1/8″)
– Radio – DB15

  • LEDs for easy visual feedback of CAT, CW, PTT, SQL
  • Metal/Aluminum case, powder coated and silk screened


USB: USB 2.0 Full speed, USB 1.1 compatible

Radio Port: RxD, TxD max. 57600Bd

CW: open collector, driven from DTR, max 30V/400mA

PTT: open collector, driven from RTS, max 30V/400mA

FSK: open collector, driven from DTR (requires EXTFSK from MMTTY)

SQL: input, close to ground or high (two inputs) to activate. Wired to CTS

Dimensions: W 60mm (2.4″) x H 25mm (1″) x D 80mm (3.2″)

Weight: 500g

Rear Panel

Interface II rear spec

      1. LINE IN: 3.5mm (1/8″) jack – connects to sound card Line In
        TIP – Signal, RING – NC, SHELL – Signal Ground
      2. LINE OUT: 3.5mm (1/8″) jack – connects to sound card Line Out
        TIP – Signal, RING – NC, SHELL – Signal Ground
      3. RADIO: DB15F connector for radio interconnection – a detailed description is in Appendix A
      4. USB: USB B connector for computer connection. Connect a standard USB A-B cable.

Front Panel

Interface II front spec

      1. CONTROL: RED color indicates when radio sends data to computer
      2. CONTROL: GREEN color indicates when computer sends data to radio
      3. PTT: RED color indicates when PTT is active
      4. CW: RED color indicates when CW is active
      5. SQL: GREEN color indicates when squelch is active
      6. POWER: YELLOW color indicates when unit is powered

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