I am building K2 s/n 4759. I apologize my poor English skills. Let's
hope you can help me.
The first test with control and front panel board was OK. Only "problem"
was agc voltage which didn't reach 3.80V but 3.79V. According to several
similar reports I decided to forget it.
Alignment and Test, Part II aroused some questions to my mind.
1) 4 MHz oscillator calibration didn't succeed.
I used the second method mentioned in manual: "use a calibrated
short-wave receiver". I found K2's oscillator frequency using my Yaesu
857 as a receiver. However, I didn't manage to set the frequency
exactly. My frequency display is about 1 kHz too high. Is it possible
use WWV signal in Europe to calibrate RX later? When adjusting C22 in
future to do the calibration do I have to do some other adjustments as
well? PLL oscillator? BFO alignment? VFO linearization? Other?
2) PLL Reference Oscillator Range Test failed.
I got 12100.35 kHz as high frquency and 12090.65 kHz as a low. Range is
9.7 kHz. Manual says "range must be between 9.8 and 15 kHz". However,
some postings in this list in past days says I could let it be as it is.
What is current opinion.? Especially which ranges other builders have
got lately. I believe there are many with pretty similar serial numbers
on the air.
3) BFO test "failed"
I got BFO high frequency 4917.23 kHz and 4912.95 kHz as low. Range is
4.28 kHz. Manual says range should be at least 3.6 kHz. Bfo low freq.
limit is 4912.7 kHz according to manual. Should I make something to this
one?
4) BFO alignment was not easy to do. My understanding is a bit of
defective what come's to "making ssb sidebands" with BFO. I set filter
and BFO settings to cw and ssb. Maybe it was a mistake. When listening
AM broadcasting station in 7 MHz BC-band I can't switch between LSB/USB
sidebands to listen AM signal. I have to adjust frequency when switching
between lsb and usb.
For an example. When listening 7145.10 Khz USB I get clean audio. When
switching to LSB I have to tune to 7146.06 kHz to get good audio. Why?
Other basic functions seems to be working OK. There were holyland
contest guys in the 40m band in the evening. K2 receiver is much more
better than I was waiting. You can listen weak signals during a contest
when very strong stations a driving their 1.5 kW to beams. Interferences
from adjacent frquencies were pretty minimal compared to my other mobile
tranceiver. It was a pleasure to listen so clean band.
Rolf Moberg
oh6kxl
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