Some ICOM mobile rigs have support for Bluetooth headsets, this is especially useful when driving and operating a rig but even in the shack, it would be nice to have the freedom to move around, at least without being tied to the rig via the headphones cable!
Is this feature able to be added? Well not inside the rig without some surgery which most people will not be interested in. It is possible however to add a very small Bluetooth transmitter to the 3.5mm headphone jack and then use a pair of Bluetooth headphones around the shack. These units are often sold to support Bluetooth headphones getting audio from a TV set so that a show can be watched without disturbing others.
It is VERY important that you find a device designed for the transmit function as may “adapters” only work as the receive end of a link – every Bluetooth device transmits and receives at least control data but in this case the “role” is important. For example the Logitech Bluetooth adapter has the receiver functions and is meant to be used to feed amplified speakers so that music from a smart phone, tablet or PC can be sent to the speakers without needing to run wires.
There are Bluetooth adapters that can perform both the transmit and receive function. These are often micro-controller equipped and such a device might enable the use of a complete Bluetooth headset (i.e. microphone as well as headphones) to work with a rig. In my case however I was only looking to have the headphones remote – when I want to transmit I will return to the rig and it’s microphone.
Here is the cheap (eBay) unit that I am using to plug into the IC-7300 headphone jack:
Bluetooth Transmitter Audio 4.0 H366T Wireless Sender Adapter A2DP TV Stereo
As you can see the unit is very small – it only has a micro-USB socket to charge the internal battery and a 3.5mm socket for the audio input. Cables are supplied for both these functions (i.e. a 3.5mm stereo to 3.5mm stereo lead and a micro-USB to normal USB-A plug for charging). There is no PSU supplied as the small “hockey puck” shaped unit can be charged off a PC USB socket or a smart phone charger.
All operations are completed via the one button on the top of the puck. Basically, you only need two functions – turn on and turn off – both of these are achieved by pressing the button for 2 seconds.
Sequence is important. Your Bluetooth headphones need to be turned on prior to turning the “puck” on, so that when it is turned on it sees the headphones and pairs with them. In fact the unit can pair with two devices at the same time – so two pairs of headphones or one pair of Bluetooth headphones and a Bluetooth speaker for example.
WIRELESS BLUETOOTH STEREO HEADSET HEADPHONES+MIC FM
There are several very similar Bluetooth headphones available on eBay ranging in price from €12 to €50 or more. It is personal choice however I would say any pair in the range of €12 – €20 will be fine. My €14.50 ones are comfortable and the sound from them is good.
This pair actually also has an FM radio and media player (add your own micro-SD card) in them. These headphones, like the “Puck”, are charged via a micro-USB to USB-A cable which is supplied. If you ever wanted to, you could cable connect the headphones (that cable is not supplied but is a simple 3.5mm to 3.5mm cable).
When the headphones are turned on a very Chinese accented voice says in English – “The Bluetooth device is ready to pal”, after this you should turn on the “Puck” and the same Chinese voice will say – “The Bluetooth device is er.. connected successfully”. When closing down – reverse the process – turn off the “Puck” and then the same “The Bluetooth device is ready to pal” message will be played in the headphones, which is your indication to turn the headphones off.
The stated range for both the “puck” and the headphones is the standard for Bluetooth, 10 metres however I have found I can wander everywhere around my house and still hear the audio from the IC-7300 through the Bluetooth headphones.
Should someone want to try to make Bluetooth in the opposite direction work, (so that transmission using VOX on the IC-7300 may be possible) there is a microphone in these headphones (but may not be in all Bluetooth headphones). Some extra work at the rig end will be needed – possibly connecting up one of the micro-controller equipped Bluetooth transmitter/receiver units to the AUX socket on the back of the IC-7300 rather than the front Mic socket, because of the bias (aka Phantom) voltage on pin 1 of the Mic input on the rig.
All in all for around €20 I am quite happy with this small addition to my IC-7300’s capabilities. the option to simply roll over to the computer keyboard with having to worry what happens with the headphone cable is great!
Stage 2 – Second headset.
Adding a second headset (using the same BT sender “puck”)is straight forward – after connecting the first headset a double click on the “puck” connects the second device (in this case another pair of headphones) and both headsets receive the same audio stream. Choice of bright colours in case I use these on a field day / contest one day and want to see them in reduced light levels.
Of note is the fact that both the headsets and the puck run their batteries down quite quickly. 2 hours usage if that seems to be all, that they can hold, so the charger cable (micro-USB for all devices), needs to be close by – in fact the “puck” could stay always connected to a 5V supply.