[Elecraft] K2 Problem in NAQP

[Don Wilhelm]

  Jim,

I suspect you have the sidebands inverted in your RTTY filter set.

Do the following with the K2 set to a band lower than 15 meters,

First set the FL1 filter to use the OP1 filter on the KSB2 board, and 
that filter along with its BFO settings will be used for transmit.  Set 
RTTY the same as your SSB FL1 settings - the BFO setting for RTTY should 
be the same as LSB, and the RTTYr BFO should be the same as USB.

The other filters are created from the variable bandwidth filter.  I 
usually set FL2 to 1.00, FL3 to 0.70, FL4 to 0.40, and center these 3 
filters at 1000 Hz. - use Spectrogram
MMTTY mark frequency is set at 915 Hz to be compatible.

Check the BFO frequencies for RTTY and RTTYr - normally the RTTY BFO 
frequency will be in the vicinity of 4914.xx and the RTTYr BFO will be 
near 4912.xx if you are using 1000 Hz as the center frequency.

Higher center frequencies may be possible, but you may run into 
difficulty with limits of the BFO range for RTTYr.

The K2 reverses its mixing scheme on 15 meters and above - below 15 
meters the VFO and BFO subtract while on 15 and above the VFO and BFO 
add.  The K2 automatically swaps sidebands for you, but it will not come 
out right on all bands if the sidebands have been inverted in the filter 
settings.

73,
Don W3FPR



On 7/17/2011 11:14 AM, Jim Harris wrote:
> Hi Folks,
>
> I ran into a problem during the just completed NAQP RTTY contest with my Elecraft K2.  To make a very long and frustrating story short, on at least 20 and 40 meters it receives on the lower side band but transmits on the upper sideband.   On 15 meters it receives and transmits on the same sideband which appears to be the lower sideband.  The only way I was able to get it to transmit on the same sideband on the two bands mentioned was to put the radio into RTTY reverse (with CW REV) and then operate MMTTY in REV.  As a result of the problem I lost about three hours in the contest while troubleshooting the problem.  If someone can shed (and I'm sure they can) some light on this perplexity, I would very much appreciate it.
>
> This was my first serious attempt to do SO2R.  I used my K3 for the right radio and the K2 for the left.  I had aligned the RTTY filters in the K2 using the procedures found on the internet and used Spectogram.  I tried to be careful to set them on the correct sideband.  I can accept that maybe I didn't get that done right and will recheck them.  But, I don't understand why the upper band is correct and the lower bands are not.
>
>