[Elecraft] KX1 sn 379

[Ron D'Eau Claire]

I haven't tried to adjust the KX1 the way you did. You might be right =
about
the coupling causing the rough note. You should be okay as long as the
signal on the auxiliary receiver isn't abnormally-strong (less than =
S-9).=20

The ELECRAFT specs for the KX1 provide for all spurious emissions, =
including
harmonics, to be at least -30 dB down (the manual says -30 to -40 dB =
down).
This agrees with the FCC requirements for transmitters with a "mean" =
power
out of less than 5 watts which says "the attenuation must be at least 30
dB." (Part 97.307 paragraph d).

I suggest adjusting the turns on L2 as described on page 59 of the =
manual so
the output on 20 meters is somewhere between 0.3 and 0.6 watts below 40
meters, and then see how the signal sounds. I've not run into anyone who =
had
a rough note that was controlled by the spacing of the turns. I agree, =
it
sounds like a parasitic since you can adjust it with small changes in =
the
inductance.=20

Be sure the source power is "clean" when you check the note. Batteries =
are a
good idea, just to be sure something funny isn't happening with the =
power
source when you xmit.=20

Ron AC7AC


-----Original Message-----
Hi, Ron.

Well, yes, but not exactly as described.  I adjusted the toroid with the
xmitter connected to a dummy load, while listening to the signal on =
another
receiver. Frankly, the signal sounded bad, as though it was being =
modulated,
so I adjusted the toroid until I had a clean-sounding signal.  There is =
no
doubt in my mind this is the reason the power is low.

The question in my mind is whether or not the sound of the signal is
indicative of not enough spur suppression or some artifact from too =
tight of
a coupling between the receiver and transmitter when I was making the
adjustment.=20
(I had a
receive wire laying across the coax going to the load during the test.)=20
I'm
thinking about borrowing the spec analyzer from work in a couple of days =
to
look at the output while I try adjusting it again.  Could you remind me =
what
the spec's are for harmonic suppression?  I can't remember them =
off-hand.

Rick Hampton, WD8KEL