[Elecraft] Connecting a KX2 to a Laptop--RESOLVED

[ke1b at richseifert.com]

Did a little testing, did a little thinking…

First, I verified that the audio output from the KX2 was working; it drove a pair of headphones just fine.

Then I verified that the external mic input to the computer was working; I connected a real microphone and was able to record audio using Audacity.

Then I thought about it, and realized that the KX2 output is STEREO, whereas the computer mic input is MONO. So I tried a MONO 3.5mm cable instead of the stereo cable, and voila! Audio going from the KX2 to the computer, verified by making a couple of FT8 contacts.

Thanks to all that responded.

FYI, this is a real minimal configuration. The “computer” is an Asus Transformer, 1 lb tablet running Windows 10, and the radio is a KX2. I can carry the whole shebang in one hand. Plan to use this with a Buddistick from French Polynesia, going to Moorea and Bora Bora next year. Probably won’t be able to work many NA with only QRP and a Buddistick, but I’ll see what I can do.

Rich KE1B


> On Sep 14, 2018, at 8:58 AM, Jack Brindle <jackbrindle at me.com> wrote:
> 
> Hey Rich!
> 
> What make of computer? Is the port selected for input? If a Mac, the normal selection would be the internal microphone, so you would need to go into the System Preferences/sound panel => Input tabard select the external microphone port.
> Interesting that my MacBook Pro doesn’t show such a port, so I’m not really sure what it takes to get it to show up.
> 
> You also posted to the N1MM list, so I suspect you are using a Windows machine. I can’t help you there, but look for some sort of input port sound selection.
> 
> Hope you get the issue solved quickly!
> 
> 73,
> Jack, W6FB
> 
> 
>> On Sep 14, 2018, at 8:48 AM, ke1b at richseifert.com wrote:
>> 
>> 
>> I am trying to connect a KX2 (which has a standard headphone output and microphone input on separate 3.5mm jacks) to a laptop that has an integrated (4 pin TRRS) microphone input and sound output. I have the adapter than converts the 4-pin 3.5 mm jack to two separate jacks, for a microphone input (to the laptop) and sound out (from the laptop). I connected those jacks to the corresponding jacks on the KX2, using stereo cables. This is the exact configuration as shown in Frank Cady’s KX2 book.
>> 
>> On transmit, everything works fine. I can key the radio from N1MM, send CW (via KY commands), and send digital data (e.g., FT8) to the radio and the radio transmits everything fine. All levels can be adjusted to perfection.
>> 
>> On receive, I’ve got nada. I can’t see any audio coming from the radio into the laptop. If I disconnect the external input, I can actually decode digital data with audio from the radio’s speaker, through the air, to the laptop’s internal microphone. Now, I can deal with the differences in levels, if necessary, but I’m not getting ANY audio from the radio to the laptop via the cabling. What am I missing? I’m hoping to make this work without lots of little adapter boxes, USB hubs, external codecs, etc. for very-portable operation.
>>