[Elecraft] K2 headphone audio for sound card PSK31?

[Don Wilhelm]

Cathy,

I really have not had any problem using the headphone output - I have always
found that the AF Gain control on the K2 could be advanced sufficiently to
overdrive the sound card line-in.

You may want to look at something like the K2 Fixed Audio Output that I have
on my website http://w3fpr.qrpradio.com . I have a few boards left, but no
kits.

As for setting up the RTTY filters, my recommendation is to set FL1 just
like the SSB filter, FL2 at 1.00, FL3 at 0.70 and FL4 at 0.40.  Center FL2
thru FL4 on 1000 Hz.  In operation, you use the VFO to place the desired
signal near 1000 Hz, then you can narrow the filters if a strong signal
comes into the passband and activates the AGC - reducing the receiver
sensitivity.  Running PSK31 with AGC off is often a better way to operate.
BTW - lock the transmit frequency in your software if you use other than the
FL1 filter to keep the QSO from creeping up or down the band due to slight
differences in the audio pitch between filters.

73,
Don W3FPR

> -----Original Message-----
>
> I ran some tests this evening with my K2 and my computer sound card and
> HamScope software.  80 meters was not great, but it was open and there
> were a number of QSOs going on.
>
> The K2 was able to pick up signals and decode them quite well, and the
> narrow filters really help block QRM.  (My RTTY filter bandpasses are
> all over the place, though; I don't think I ever finished setting them
> up after getting Spectrogram going.  Have to revisit that!)
>
> However, the audio drive from the K2 is much less than from the DX-70TH
> that I use as my primary digital mode rig.  Although the signals decoded
> well, the traces on the waterfall barely showed even at fairly high
> soundcard record volume settings.  With the DX-70TH plugged into the
> sound card instead, the same signals were brilliant yellow and easily
> found by eye.
>
> What can I do to increase the audio output level of the K2 for sound
> card purposes?
>
> Cathy
> N5WVR
>