[Elecraft] K1 - Problem

Ken H k9fv at highstream.net
Fri Dec 31 16:07:56 EST 2004


Thank you Jim - I'll also post this to the group as well just to keep them informed about where I'm at with testing.  IF I can't get this thing aligned completely, I may have to resort to bothering you with it "next year" when I get back to Mobile.

I did the following tests and re-checked the transmitter offset adjustment again.  That didn't seem to change much of anything.  As the two tones came together, there was kind of a "waver" in the sound.  when I continued to move past that point, the waver would disappear, then appear again.  I then moved the adjustment between those two points.  Is that correct?

> a problem with the 30 Meter HetrodyeOscillator Crystal.  It sounds like it 
> is not oscillating.  If you have a general coverage receiver you can tune to 
> the freq of the crystal and see you can hear it.

I tuned my 756Pro with CW filter set to 100hz with a coax jumper connected to the antenna SO-239.  With the K1-4 just turned on, no antenna connected and in receive mode with other end of coax held close to J6, pin #4 I get:
40 meter band = 15,003.96Mhz with a nice tone (15.00 Crystal?)
30 meter band = 18,097.78 Mhz with a nice tone (18.100 Crystal?)
20 meter band = 21.996.83Mhz with a nice tone (22.00 Crystal?)
40 meter band = 26,046.64Mhz with a nice tone (26.05 Crystal?)

The 30 meter signal was as strong as the other bands, but I am surprised at the offset from the stated filter freq.  OR is this normal and why we must do the Freq offset calibration for each band?

Now when I transmit with the K1-4 into a dummy load (an old Health Cantenna) and tune in the signal on the 756Pro, I get the following:

K1 transmits at 7040.0 = 756Pro receives at 7040.67 (K1 receives same freq 756Pro transmits)
K1 transmits at 10,130.0 = 756Pro receives at 10,130.00 (but K1 receives 600 hz off.)
K1 transmits at 14,030.0 = 756Pro receives at 14,030.63 (K1 receives same freq 756Pro transmits)
K1 transmits at 18,090.0 = 756Pro receives at 18,090.62 (K1 receives same freq 756Pro transmits)

On 30 meters the K1-4 only transmits in the milliwatt range too small to see on my wattmeter.  The K1-4 seems to receive pretty good on 30 meters when connected to outside antenna.  A weak signal on the 756Pro is still received on the K1-4, but a bit weaker.  It the signal is received on the 756Pro at 10,30.00, the K1-4 will receive it about 10,130.6.  It really seems like the K1-4 is receiving ok on 30 meters, just no power output.

I also re-melted solder on all the L1-L2-L3 inductor wires and the capacitors around it.  I counted the number of turns on each of the inductors to be sure it was correct and checked the spacing around the torrid core.

Thank you for the help,

Ken





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