K3 Contest configurations, software and hardware

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w0yk.jpg

W0YK - SSB Contesting

On receive, I used the 1.8kHz crystal filter with the same DSP bandwidth, although signals were quite intelligible down to 1.2kHz and at 1.5kHz there wasn't much degradation from 1.8kHz. As yet, the K3 filter center frequencies are not settable in the CONFIG menu, but I found that an IF SHIFT of -500Hz to work well with the 1.8kHz filter. (That's an FC of 1.10kHz.) For now, this results in a pass band icon in the display that is skewed to the left. I set up Presets I & II to be the 2.8 and 1.8kHz filters respectively and switching between them results in virtually the same desired audio, but with most of the undesired audio stripped off with the narrower filter ... just what you'd want. There is no sense of audio constriction, just absence of noise and other distractions in the pass band. Whenever I've used narrow SSB filters in the past with other radios, there was always a audio quality compromise that took my brain several hours of listening to get accustomed to. Intelligibility was severely compromised. The K3 is a whole different experience because all that happens with the narrower filter is you lose the fatigue-building sounds.

Just like on the other modes, the problem in using the K3 is that you can operate so much closer to others that the stations you are working have problems unless they, too, are using the K3. I've never had so many occurrences of people asking me to move a bit further away from their transmit frequency. I predict that we will soon have a sense of signal spacing for K3s that much denser than other radios. This only works if both ends of the circuit are using K3s ... fortunate for Elecraft and hopefully motivating for other radio manufacturers.

On transmit, I used a Heil headset with the HC4 element that is shaped for punch in crowded and/or weak signal conditions, rather than hi-fidelity. I strongly recommend you get with someone on the air to listen to you and give critical feedback as you adjust things. I set the K3 TX equalizer with the bottom three bands (50, 100 and 200) at -16dB, the 2.4kHz at +2dB and 3.2kHz at +4dB. Adding more at the high end is not generally needed with this mic element but my natural voice is weighted low in frequency so a bit more high emphasis is crisper. Compression was set to max at 30 and a lot of testing was done at other settings to determine that no ill effects were heard at the higher settings. However, signal quality was sensitive to Mic level. I found that when the Mic level was increased such that the K3's CMP meter kicked up above 10dB that clipping of voice peaks occurred. This is a bit backward from how one would normally adjust Mic and CMP, but it worked much better to ignore the ALC meter and just watch CMP when running the compressor wide open. Mic level was 15 on the 'L' range for both K3s.

The biggest thing I learned from all this was that it is very easy to overdo the K3 mic gain and get peak clipping. Follow Wayne's section in the Owner's Manual exactly. Follow the text but don't try to duplicate his pictorials of CMP and ALC. An initial mistake I did was to increase mic gain to get more compression bars lit up on the K3 LCD. That resulted in the undesired clipping. I've come to not trust the ALC and CMP meters with whatever peak-sensing and hang time are programmed into them.

One anecdotal measure of improved TX audio quality was the number of repeats that I was asked for ... virtually none and those were only when a nearby strong signal was covering my own. In particular, in past Phone Sweepstakes I was asked every other QSO for a repeat on my Check (62) but this time it was no more asked for than other parts of the exchange. I was surprised at the number of unsolicited comments about "nice audio", which is a challenge to produce with high compression.

VOX--another delightful story. I just never used VOX before the K3 because it was impractical, especially in a contest. The VOX and antiVOX settings were tricky to adjust and never worked well enough to allow comfortable use of it. I always felt like VOX was some kind of lab experiment that sort of worked but wasn't ready for prime time. Well, enter the K3 and all is changed. I ran with VOX the entire 24 hours and never even thought about it. The experience was totally transparent, and I mean that literally, much like the exceptional QSK on CW. I set VOX at 70, ANTIVOX at 0 and DELAY at 15. I started with DELAY at 5 as N0SS has noted and it worked fine but one critic noticed the transitions between words so I compromised at 15msec. I think it was more a "new experience" for my listener than an actual problem. Before the K3, there hasn't been a VOX (that I'm aware of) which operated so responsively. 5msec would have avoided a couple instances where the other station came back so fast that I missed part of the first letter of his call.

AE6Y - DXing

I was listening to a very weak J5C last night on 80 next to his pileup. On the K3 I could factor in some noise reduction and pull him out. On my 756 PRO2, when I turned on the NR, I got various clicks and pops on his frequency due to the pileup and couldn't read him. I'm normally skeptical when anyone says they can hear a signal on one radio and not on another, but this was a case where it was true. The K3 passband is completely free from digital artifacts, even with the NR on.

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