[Elecraft] odds and ends...

[Richard Ferch]

Jeff,

In addition to the cable, you will also need to be sure that your 
laptop's sound card accepts stereo input. Panadapter software requires 
stereo input (I and Q channels). Some laptop input jacks will only 
accept mono signals, even though the laptop's sound card itself is 
stereo. My newest laptop, for example, has a TRRS jack for the sound 
card with a single input line, two stereo output lines, and ground.
I have no way to get stereo input into this sound card. An older laptop 
I have has separate input and output jacks, but while the output jack is 
stereo, the input jack is mono. If your laptop is like either of these, 
your only recourse may be to get an external USB sound card with stereo 
inputs.

The sound card's maximum sampling rate will determine how wide your 
panadapter display can be (in kHz); for example, a sound card capable of 
sampling at 48 kHz can display slightly less than 48 kHz of spectrum. If 
you want a wider display, you will have to ensure that your sound card 
can sample at higher rates.

Note that if you need to use an external (e.g. USB) sound card, it may 
or may not have 3.5mm inputs. For example, I have one with dual RCA 
phono jacks for its line inputs. With one of these cards, you would need 
to go from 2.5mm stereo for the KX3's RX I/Q jack to two separate RCA 
phono plugs for the sound card's input.

I don't know whether Radio Shack has the specific cable you would need, 
but I am sure that they have cables and adapters that could be combined 
to achieve the desired result.

73,
Rich VE3KI


WW6L wrote:

> Per the manual Iit looks like I would need one of these
>
> A cable with a 2.5 mm (3/32") plug on one end and
> a plug that matches your sound card input on the
> other end (typically 3.5 mm [1/8"] stereo) is
> required.
>
> If I want to see a panadapter display on my laptop.
>
> Where do I get it?