[Elecraft] NaP3 and the KX3

Lyle Johnson kk7p4dsp at gmail.com
Mon Apr 1 20:50:35 EDT 2013


Paul,

Usually the "big center spike" is due to a so-called ground loop between 
the computer_plus_soundcard and the KX3_plus_power source.

The two ways to cure this are:
1) bond everything together with low-resistance, low-inductance straps, or
2) use audio isolation transformers.  There have been lots of posts here 
about candidate isolation transformers.

I have no idea what the "two side traces" might be.  How far apart are 
they from the center spike?  Are they symmetrical on either side of it?  
What is their amplitude?  Do they get masked by band noise when you have 
a tuned-up antenna attached to the radio?

Apart from the three spikes, is the panadapter otherwise working on your 
computer?

73,

Lyle KK7P

> I've been struggling with HDSDR and a Griffin audio device to bring the audio
> from the the Elecraft RX I/Q cable in via USB. I get a big center spike in
> the display with two side traces.



More information about the Elecraft mailing list