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Digital communications with a USB sound card - dumb mistake #ubitx


Bo Barry
 

Whoops, a USB sound card gives you stereo sound output. Plugged into the mike connector for digital work it activates the PTT line with the audio!
The CAT interface works find for PTT and frequency control.
It took me forever to realize the orange PTT wire needs to be disconnected for digital work.

I made a bit of progress, getting a copyable RTTY signal with fldigi on my nearby rig. I couldn't get FT8 to copy. Experimenting with proper audio levels is driving me crazy but I'll figure it out.

The receiver surprised me, with me copying PA & NY on FT8 WHILE CONNECTED TO A DUMMY LOAD. I hope my transmitted signals didn't get out too.

I happened to have a 5v fan that fit the 3d printed panels I bought. I used a 7805 to drop the voltage down. Kinda noisy, going to drop it down to 3 volts. or so.

One awkwardness - the rig runs off of 12 volts which runs thru the power switch. However the usb interface activates the LCD whenever it is plugged in. How many times have I scratched my head with it when it wouldn't transmit even tho the display said it was, because the power switch was off. A solution would be to cut the +5v lead in a USB cable I guess.

In the meantime, a simple CW QSO is in order.
Bo W4GHV

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