Bluetooth PSK31/WSJT/Digital interface for Yaesu FT817 (and a tablet/PC)

I used a bluetooth CAT control with my Yaesu FT817 for quite awhile ($14 on ebay) and was generally happy with it. There is a small lag but one can get used to it. The advantage is no wires between a laptop and transceiver. Also, I could use my HP Stream tablet with it (Win 8) this way.

Given this success, I entertained an idea of making a digital (soundcard) interface wireless too. As the connection would be simplex and mono (1 channel), a regular bluetooth phone headset seemed up to the job.

I happened to have one laying around without much use so the first step was to prove the concept which was very easy. Once paired with the laptop / tablet, the headset became available as a soundcard in HRD DM780 settings. I tried sending some RTTY to it and it worked. I guess now I understand what Alexander Graham Bell felt like when his first phone worked (hi hi).

However, receiving (listening) from the headset did not work. After some googling, I found a hint – set bluetooth headset soundcard as a Default device in the Control Panel -> Sound -> Recording Devices settings. That helped right away so the next step was wiring the headset to the transceiver.

After disassembling the headset, I removed existing battery, speaker and mic and soldered new thin wires to the connecting pads.

Headset with wires

 

For TX (audio out) – I added a 1:25 resistive divider to decrease the output voltage off the speaker wires and to match the voltage requirements of Yaesu; and soldered the speakers wires to it. For RX (audio in), I needed to match Yaesu output to the headset mic. After some experimentation, a combination of two SMD capacitors to both pins and a small resistor in series to avoid overloading and to provide DC isolation finally worked.

Finally, I added a new bigger OEM Li-Ion battery (insulated with black tape) and a USB charger PCB with a switch to improve on portable operation time of the headset.

Li-Ion battery with a charger PCB

The headset, battery, charger, and the existing CAT BT control PCB all managed to fit into a small plastic enclosure. Some hot glue helped to secure them in place.

The boards sit on top of the battery / charger; to isolate the layer I cut a small sheet off a thick polyethylene water jug.

IMG_0789

The enclosure is secured with two small strips of a velcro tape. The battery can be charged via a USB connector; the switch turns on/off the bluetooth headset.

IMG_0788

The PTT is controlled by the software via the CAT control. Now to chase DX with WSJT QRP mode!

 

About va3paw
Ham radio enthusiast, software developer

5 Responses to Bluetooth PSK31/WSJT/Digital interface for Yaesu FT817 (and a tablet/PC)

  1. poglad2011 says:

    Impressive – I need one of these!

    • Michael Burley says:

      can you give the model number for the bluetooth, or a picture. Mike

      • va3paw says:

        Hi Michael, sorry for the delay. That was some no-name headset just laying around so sorry no model number / picture left.
        If I re-do this project again, I would explore other / newer options available: XS3868 / OVC3860 BT Audio modules using HSP (headset) profile.

  2. Michael Burley says:

    can you do voice

    • va3paw says:

      You can definitely play something from your PC / tablet or do recordings. To use a BT headset in place of a regular mic / headset, you’d need a BT receiver matched to the radio.
      73!

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