One morning, while chatting with several friends on 75
Meters, we got to talking about how nice it would be to have a wireless
audio interface with our HF transceivers. It would provide freedom to
wander around the shack, or go refill our coffee cup in the kitchen, without
having to miss anything. Isn’t it amazing that none of the
transceiver manufacturers are providing a wireless interface?|
After searching on the “Net”, Ed, K6ED found the
Jabra A-210, which is an “off-the-shelf” Bluetooth interface, designed
to provide Bluetooth capability for non-Bluetooth equipped cell phones. They
are readily available, but the best price was found on Ebay (Typically
We initially tried a couple different conventional cell
phone headsets; the ones that have a small microphone that rests alongside
your cheek. They worked OK, but seemed to pick up a lot of room noise,
and sound a little “boomy”. Digging a little further, we found the
VXI Blue Parrott B-150, which resembled a more conventional headset, had an
adjustable boom microphone, and was equipped with an effective noise
canceling circuit. Since writing this article, the B150 headset has
been replaced with a B250, which is supposed to have twice the battery life
and range. Several reviews indicated that it’s performance and audio
quality, were very good, so Ed, K6ED and I decided to bite the bullet, and
For the A-210 to ICOM adapter, I purchased an 8-Pin
Microphone connector and 3/32” stereo jack from Radio Shack for about $7.
Refer to you transceiver’s instruction manual, and wire the Mic Input,
Receiver audio output, and ground leads to the 3/32 jack, so the Jabra A-210
can be plugged into it. I used some heatshrink to dress things up a
little. (See the picture below.)
The 3/32” Plug on the Jabra
A-210 is wired as follows:
Tip = Bluetooth Audio Out (Goes to Xcvr Mic Input - Pin
1 on IC-756/IC-7700 Mic connector)
Ring = Bluetooth Audio In (Goes to Xcvr Audio out –
Pin 8 on IC-756/IC-7700 Mic connector)
Sleeve = Ground. (Pin 7 on IC-756/IC-7700 Mic
After assembling your adapter, Plug the A210 into the
3/32” jack, and plug the 8-Pin connector into your radio. “Pair” the
A210 with your Bluetooth headset, put your radio in VOX Mode, and adjust the
VOX Gain, Anti-Trip, and Delay to suit your operating style.
There is a small 3-position switch at one end of the
Jabra A-210, which controls the audio output level towards your transceiver.
I found that Position 2 worked great for the IC-756 Pro III / IC-7000 /
IC-7700. Position 1 is less and Position 3 is more. Put your radio in
VOX mode, and you’re ready to go. Adjust the AF gain on your radio
from a comfortable listening level.
How does it work?
From initial tests, this arrangement works well up to
50 feet from the transceiver. . The noise canceling works amazingly
well. Stations I was talking with were unable to detect any background noise
at all. There was a slight difference in transmit audio between the desk
microphone and a wired Heil headset, but not enough to require any
This afternoon, I connected the Bluetooth adapter to my
mobile rig (an IC-7000). It is installed in a 4-wheel drive 1999 Dodge
diesel pickup, which is a relatively noisy environment. I called a local
friend, Forrest, K7OCR for some on-the-air tests. Sitting in the driveway
with both windows open, and engine idling, he was unable to hear any engine
noise whatsoever. He said the audio quality was as good as if I was inside
the house sitting in front of my IC-756 Pro III. Since this seemed to
work so well, I decided to take a little drive and see what would happen
with both windows down at 60 MPH. I was amazed when Forrest said he still
could not hear ANY background noise! In addition, the VOX in the
IC-7000 worked perfect, and never tripped from any background noise.
The VXI Bluetooth headset worked unbelievably well.
I would be interested in hearing from anyone else who
decides to try this. Please let me know what headset you try, and how
well it works for you. I am sure there are many excellent noise
canceling headsets out there.