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Is there a way to use a Bluetooth headset with my transceiver to eliminate all the wires, like a Bluetooth adapter? It seems like all the Bluetooth applications require a smartphone in the loop somewhere, and I don't have one.

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  • $\begingroup$ What's the make and model of your transceiver? $\endgroup$ – Mike Waters Oct 6 '17 at 22:52
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Cobra makes a very adaptable Bluetooth headset/microphone that has a 10 hour talk time. The radio side of the device has a four pin connector that is easily adapted for most amateur radios. It comes with a remote PTT switch but if your radio supports VOX operation, it will typically work with that also.

A real bonus with this device is that it can simultaneously mate with your phone via BT and you can switch between the phone and the radio from the headset. This is completely optional as the headset can be used directly with the radio without requiring the use of a BT phone.

These are widely used in the trucking industry and have a very good track record. It is regularly available on the Internet for $70.

Cobra CA BTCB4

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I'm pretty certain you can find wireless headphones in the market that have "standard" analog plugs (like 3.5mm" headphone or RCA plugs). This feels like there's a huge market for callcenters and generally, people that regularly have to make phone calls.

Whether or not these headphones use Bluetooth or something else for wireless communication between headset and plug is a different question.

Generally, what these devices (probably) all do is the following:

  1. Take the analog signal from the audio output of the device you want to use with your headset, digitize it
  2. Send it to the headset part using a digital modulation in some ISM band
  3. In the headset part, convert the digital signal received to an analog signal for the actual headphones
  4. Take the analog signal from the mic, digitize them
  5. send them, digitally, to the device-side part, using the same ISM band
  6. convert them to analog for the line input of the device

Bluetooth specifies how to do the digital link part of a headset connection using its "Headset Profile" HSP. That way, any bluetooth headset will be able to talk to any Bluetooth master (e.g. a smart phone) that speaks the same profile. (And, since that's only a software thing, many devices can).

Now, you can build something like that yourself rather easily! You just need a PC, a laptop, or a single-board computer with a bluetooth adapter. Adapters cost lest than ten bucks. What ever computer you use needs to have an analog line out and an analog line in. If it doesn't, you'd need to spend another hand full of dollars on a USB sound card.

What you'd then do is connect the computer to your headset via bluetooth (that's usually a five to ten click procedure), then tell the audio system to monitor the analog line in on the audio output on the headset, and vice versa, monitor the audio input from the headset on the analog output of the computer.

Cable your computer to your rig; how to do that exactly depends on the analog line in and out interface your rig has.

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Some rigs (e.g. Yaesu's FTM-100 and FTM-400 VHF/UHF radios) will accept an optional Bluetooth module that will allow you to connect any Bluetooth headset.

In practice I'm not sure I'm happy with how Bluetooth headsets work with ham radios. With HF rigs I tend to prefer to wear a wired headset and use a foot pedal for push-to-talk.

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  • $\begingroup$ On the Icom side, the 2730, 5100 and 4100 have bluetooth modules. I use 2730 and have similar experience. It's often hard to find out if a headset is going to work fine with the radio, volume and gain adjustments are complicated and need significant changes.between bluetooth and regular speaker and microphone. $\endgroup$ – AndrejaKo Oct 15 '17 at 20:58
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I am not sure if this should be a comment or an answer because I only cover part of the question. First, as others have said, it is possible to use Bluetooth and trivial for listening as there are all sorts of audio adapters that plug into headphones jack and create a Bluetooth signal carrying the audio (just search on Amazon, that is where I bought mine).

I was not interested in voice because I am virtually all CW (aka Morse Code), so the voice mic input part of the problem was not something I was concerned about. So this comment is about BT and CW.

It does not work. Well, it works but the delay that Bluetooth causes creates havoc with sending CW and especially at faster speeds and in particular with fast-break-in operation. I tried for about an hour to train my head to copy while sending and not make mistakes. I had to slow down to about 5 wpm on a straight key before I could do this and that was with slow-break-in only. At 20 wpm and greater, no way could I send. I hear the dit for a letter for the first time by the time I finish the letter such as I, S, or H.

Although I never tried BT with voice but if you do try with voice, make sure you are not listening to yourself by any monitor feedback system. That will probably even mess you up with voice -- like an echo chamber.

Update

There is an active discussion about CW copy and Bluetooth headsets right now on the Elecraft forum. The big issue of course is the delay caused by the BT latency. But, there may be improvements. I quote the following from a post on Elecraft forum:

OK, I did some digging and found marketing info from Avantree. When they say “no” latency, they mean “some” - on the order of 40 msec when used with a transmitter that supports low-latency aptx codec mode. This sounds reminiscent of a Monty Python sketch.

40 msec is about one dit at 30 wpm, which would probably throw me off. I’ve tried to listen to my own sending via various SDRs, and it’s agonizing.

I never did make actual measurements with my setup but I would guess it was probably at least one full dit and a half delay at 10 wpm. Close to 2 dits at 20 wpm.

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  • $\begingroup$ this is technologically very interesting! Point is that 40ms does sound like a lot, but reasonable for a packeted radio protocol. What kind of device are we talking about here? Unlike headsets, there's no Bluetooth profile for "morse keying", so, is this a keyboard/HID profile, or some serial profile? $\endgroup$ – Marcus Müller Oct 8 '17 at 21:40
  • $\begingroup$ @MarcusMüller -- I think you misunderstood the application. The headset is for listening only, keying (at least in my situation) is with a Begali Paddle using my Elecraft built-in keyer. No keyboard, no computer is involved. This is audio only, not sure what you mean by serial profile. $\endgroup$ – K7PEH Oct 8 '17 at 23:58
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    $\begingroup$ aaaah, sorry, I thought you had a wireless paddle! Yeah, for audio, 40ms is pretty much a lower boundary, considering in that time you need to gather a bluetooth packet worth of audio samples, process and compress them, interleave, symbol map and mix them to the Bluetooth frequency hopping spectrum, and do the reverse in the receiver. That's kind of impossible to do with extremely low latency – and that's the reason why stage microphone systems, for example, are analog or employ trade-secret level proprietary digital modes $\endgroup$ – Marcus Müller Oct 9 '17 at 8:29

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