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Wednesday, December 25, 2013

KX3 Filter Settings for SSB, CW and Data

While setting up for the AWA '29 QSO Party I started playing more with the KX3 filtering and audio response....mostly because 80 meters seemed particularly noisy that night. I found something that really helped me see the interaction of the various receive selectivity options: Rcv Audio Equalization, Notch, APF, Data/RTTY mode, Passband Width, Passband Shift and Passband Hi/Low Cut.

I downloaded DigiPan from (Freeware) onto my laptop, not for the PSK31 function but for the waterfall. I then configured DigiPan to use my laptop built-in mic as the audio input/source. With my laptop sitting next to my KX3 I tuned to a unpopulated but white noisy frequency. This may require the preamp to be turned on. While watching the white noise on the DigiPan waterfall I tweaked the various filter settings. The white noise waterfall display changes to reflect the filter settings, clearly showing me the impact of what I was doing. SSB, CW and data signals can even be tuned in and viewed as the various selectivity options are changed. The KX3 CWT Aid and the Filter Passband Graphic show some of this but not to the detail of the DigiPan waterfall.

For example here's a sample waterfall showing the impact of narrowing the KX3 bandwidth setting followed by adding the Audio Peak Filter (APF). The horizontal scale is frequency (in Hz) and time is the vertical scale.  The CW signal of interest is the yellow streak at 520Hz. Interference is the yellow (stronger) and blue (weaker) around the 520Hz signal.

Friday, December 20, 2013

1929 BK QSO Party

The past two weekends I spent 4-5 hours operating in the BK. I had 16 QSOs
and worked five states including NC, MT, MI and ME. Background noise levels were pretty high but even with about 2 watts out I still made contacts.

I'm not pleased with the way my TNT transmitter sounds on 40. After an initial excursion into that band on Dec 7 and then critically listening to my own signal I decided to stick to 80.

Friday, December 6, 2013

1929 BK QSO Party

I'm set up for the AWA Bruce Kelley 1929 QSO Party. This year I'm using my TNT transmitter with two 45 triodes in push-pull .  This transmitter has an output of only 2-3 watts with 10 watts input, about typical for self excited oscillators like this connected directly to the antenna. At first I thought I'd also use a vintage receiver but I switched to my KX3.

Tonight I did work KK4HCF in TN and WA1KPD in CT  heard me so there is hope for the QSO Party.