[Elecraft] K2 and RTTY - a few questions

[Bill Coleman]

On Feb 11, 2013, at 11:54 PM, "Andy, KU7T" <ku7t at ku7t.org> wrote:

> Question 1: My frequency is 1000Hz off compared to what DX cluster spots
> show.  When I see  a spot at 14.077 it, is for at 14.078. This must have to
> do with the fact that the filters centers at 1000Hz, but is there a way to
> compensate somewhere for this? Would be nice to be able to use the band map
> of my contest program to jump to stations I would like to work.

If you use the N!MM contesting software, you can program an offset. Generally, the frequency of the spot should be the Mark frequency, so your offset should be the value of your mark frequency.

> Question 2: I noticed that 15m and up, I had to put both MTTY and the K2 in
> RTTY reverse.  Is this correct? I happen to remember that the switch to USB
> from LSB happens on 20m. Now I am wondering if this is something special for
> RTTY or not.

I would double-check that you have the sidebands correct on your RTTY mode BFO settings. It sounds to me like you have both sides tuned to the same sideband. Member RTTY and RTTY REV should correspond to LSB and USB, respectively, much like the CW and CW REV modes.

The K2 does an internal inversion on 15m and up, but it picks the opposite sideband, so it all comes out the same. However, you've got to have the BFO settings right.

I've got a blog posting about how I set up my K2/100 filters here:
http://boringhamradiopart.blogspot.com/2010/02/configuring-elecraft-k2-crystal-filters.html

There's several tips in this posting. Note that I opted for a RTTY center frequency of 1500 Hz, which required a slight modification to the BFO oscillator to get enough range. It's in the article.

The K2/100 works pretty well on RTTY. My only complaint is that the transmitter gain varies wildly from band to band, so you have to carefully adjust the audio input level when you change bands.

Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Web: http://boringhamradiopart.blogspot.com
Quote: "Not within a thousand years will man ever fly!"
           -- Wilbur Wright, 1901