Initial comparison of K3 #84 to K2 #3135

[konigsburg]

I received the kit form of the 100W K3 on 27 Nov 07. I had some troubles
getting the firmware to load and those were resolved by using the only
comm port on the computer. I also had some error messages that went away
when I reseated the front panel and DSP boards. The K3 support folks
were very helpful. The rig was operational on 13 Dec 07.

In addition to the stock filter, the K3 has the 6.0 KHz, 500 Hz, and 200
Hz filter. It also has the antenna tuner, the transverter interface and
the general receive module.

I also have built the 100W version of the K2 #3135. I have been using
the K2 since March of 2004. I like to play in contests, both SSB and CW.
I have only wire antennas and they are low – only 10 meters up in trees.
So I just S&P in the contests.

The first few times I used the rig, I could not tell much difference
between the K2 and the K3. When the bands were not crowded, both radios
were equally good for moderate or stronger signals. The K3 noise
reduction and stereo receive did seem better to me for weak signals.

This past weekend, I used the K3 in the North America QSO Party CW
contest. I had obligations and could operate for only 4.5 hours (78
QSOs) during daylight hours on the 10m, 15m, 20m and 40m bands. During
this contest, I could tell that the K3 was superior to the K2.


Ergonomically:
- having the filter controls on the front panel made a huge difference
- rather than cycling through the filters I could adjust them more finely
- holding one button quickly reset the filtering to a more normal setting
- the main tuning knob is much more comfortable (this S&P operator uses
it a lot)

Selectivity:
- In the crowded bands the K3 could hear the station and the K2 would not
- I could finely narrow the bandwidth of the filter – much too coarse in
the K2
- the shift allowed me to keep the pitch of the signal I wanted to hear
- sometimes I had to do both – adjust the bandwidth and the shift
- in one case there were two strong signals and a weak one. I initially
heard what sounded like machine gun fire. When I narrowed the filter,
and the tighter roofing filter kicked in, the machine gun sounds went
away, and I was able to copy and work the weak signal. AGC is set to fast.
- There was some ringing when I selected the narrowest filters. However,
I believe this has been corrected in the latest firmware.

Miscellaneous:
- The CW decoding did not work in the crowded conditions. I only tried
once or twice.
- The CW Tuning indicator worked. I found my ears did as good a job.
- The antenna tuner could only get a 1.3:1 match on 15m; the K2 (with
KAT100) was able to get a better match on this same antenna/feedline.
- The transmit/receive switching seemed to be quicker in the K3. I had
it set for QSK.
- The fan in the K3 is much quieter than the fan in K2.

I am still learning to use this radio and am looking forward to an SSB
contest


:) PK (Paul - K3MZ K2 #3135 K3 #84)
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