[Elecraft] K3 and MT63: XMIT Non-Copy

[Don Wilhelm]

Dan,

I think your statement about ALC=0 is the key..  With the K3, increase 
the audio drive until ALC= 4 bars (with the 5th bar flickering) for 
normal audio drive.  With that done, the K3 will propery transmit at the 
level set on the Power knob.  The onset of ALC in the K3 is at the the 
5th bar on the ALC meter - so you did not have sufficient audio drive.

It should make no difference between DATA A and SSB mode - except that 
in DATA A mode, the Compression is automatically set to zero.  Since you 
said you had compression set to zero, SSB mode should work just fine.

73,
Don W3FPR

On 11/2/2011 10:26 PM, Dan Sherwood wrote:
> I am trying to get my K3 to properly transmit in the MT63 digital mode, (1K,
> max interleave), on a USAF MARS net.  Frequency just above 4 MHZ.  The KBPF3
> module is installed.  I was running MIXW2.2, using the same installation and
> settings that used to run perfectly on my TS-940S.  Our net is standardized
> so everyone runs USB with the MT63 1K channel centered exactly 1 KHZ above
> dial frequency.  I use the line input/output on the K3.  In USB mode I set
> computer sound card output in s/w so that with power out set to 100W, and
> line-in level at 10, the rig produces 50W and absolutely no ALC.
> Compression was backed down to zero.  Using TX TEST and headphones, the
> transmit audio sounds clean and distortion free.  Transmit EQ settings are
> factory default.
>
> Comments from net members are the audio sounds clean, and well centered on
> frequency, (+ 3HZ within tolerance).  With live transmit, monitoring the
> signal has no evidence of distortion.  The problem is the print is
> double-spaced, with long strings of blanks, and all characters are lower
> case.  Also much garble not evident on the TS-940S.  I realize the guys
> recommend using DATA mode, but this net mixed voice and data ­ kind of tough
> to be switching back and forth.
>
> My copy on receive is as good as ever, just transmit.  I¹m thinking there¹s
> some kind of DSP issue going on here, even though compression is at 0.
>