[Elecraft] K2 no. 3417

[dcoleman]

Greetings to the collective,

Today, K2 no. 3417 lathered the ether for the first time and I enjoyed quite a 
nice QSO

with G0WKW on 20M CW.  Tonight I have been working DX on 40 meters and am 
again amazed what 5 watts and a vertical can do.  The K2 undoubtedly is the 
best CW rig that I have ever had and I enjoyed the construction project 
immensely.  The construction went well and have had only a few problems with 
the testing phase.

One problem I had was that the 4.000 MHz crystal a bit high in frequency and 
would not net correctly, so I replaced it with a low-profile unit from my 
private stock. That one set correctly and appears stable, but I do not know 
what its drift characteristics are like. That is a loose end to be 
investigated on a rainy weekend.

The VCO alignment required a little trial and error.  Initially, the VCO 
voltage range was excessive, out both ends of the specified 1.5-7.5 volt 
range.  The components were correct, so transformer T5 was rewound with 17 
turns instead of the specified 16 turns. The result was a VCO voltage range 
within spec, but only by 30 millivolts inside both limits.  I am curious what 
sort of ranges that other builders have seen.

The transmitter alignment went okay and on most bands the spurs are 40-50 dB 
down, as measured with a Tektronix spectrum analyzer.  One exception is 17 
meters, with the second harmonic down only 36 dB.  I will revisit the 
alignment and see if I can improve that figure a bit. I just installed the 160 
meter module and noise blanker and will do a precise alignment of the entire 
rig in the next week or so.

I am having a little problem High Current messages that appears to be 
associated with stray RF getting into the monitoring circuit. A little 
bypassing should fix that.

There is one physical anomaly to my K2 that has me a little perplexed, and it 
involves the LCD display.  Mine does not look quite like face-on photos of 
other K2's that I have seen.  Mine showns a black edge along the top and left 
side of the LCD display and frankly looks a but ugly.  It appears that the 
rectangular opening in the front panel is actually too large.  The opening in 
my panel measures about 0.635" x 2.645".  Is that about what it should be or 
should it actually be a little smaller to hide the black border of the LCD?

I am very impressed with the K2. It is beyond doubt the best CW rig that I 
have ever used. I anticipate not just the great operating with this rig, but 
also many happy hours with tweaks and mods to get it just so.  The design of 
the rig has an exceptional number of clever circuits and of course the the 
quality and support is is top notch.  Well done Elecraft!

73,
Steve
AB4I
CW Forever