K2 Transmitter Alignment Inductor Settings?

[Fred (FL)]

We're feeling good about K2 # 5422 operation - it
seems to receive well, on a good day on the ham bands.
 I've
gone over the "Transmitter Alignment" page 77 several
times.  And we have an analog-meter MFJ AT on order.

I'm wondering if I haven't gotten some of the
variable-L's, like L3, L4, ......, L12, and L13 -
off tuned and their cores too high or too low, putting
them in false peaks?

When going thru the page 77 K2 "Transmitter Alignment"
steps - some of the coils have very minimal peak areas
- perhaps it will become more evident when I get an
analog meter in the dummy load coax line.

QUESTION 1:  IS THERE A KNOWN DISTANCE, "inches", that
all of these RF Board "Toko Variable Inductor"
E690002, and E690001 inductor cores are set - from
factory?  1/4", 1/8", top, bottom, center?

1 or 2 of the inductors - I believe we have the core
screwed very high up near the top of the little can.

For something as serious as receiver/transmitter
alignment of my new K2 - I'd have a better feeling,
knowing I really have the whole circuitry peaked
correctly.  And just "looking at a varying output
wattage level" (which jumps up significantly
sometimes,
and then settles back down, on tune/no tune) - on LCD
doesn't give me a warm fuzzy.

QUESTION 2:  If I install the SSB Option NOW, will
that mess up my ability, to repeat the
receiver/transmitter alignment steps?  I did install
the NOISE BLANKER
yesterday.

Thanks,
Fred N3CSY
K2 # 5422 --- 40/20 sounded great on CW yesterday.

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[Don Wilhelm-3]

Fred,

Answer to 1: The exact position will vary with the precise value of the
fixed capacitors in the bandpass filter - there will be some variation due
to component tolerances.  It is sufficient to say that the slugs on all the
cans should be nearer the top rather than screwed down near the bottom.

As far as I know, there are no false peaks to contend with.

The fact that the power goes up significantly in some cases does not
indicate any problem - it does indicate that you are getting near a peak.
The point of going out of TUNE and back in if the power increases
significantly is only to allow the power leveling circuits in the K2 to
settle the output near 2 watts (the normal action of the power leveling
controls is modified during TUNE so you can see the peak - this is NOT a
problem).  The inductor (and trimmer cap) peak sensitivity is greater at low
power levels, and that is why you should do this alignment at 2 watts.

You do not have to completely re-do 'finding the peak' after dropping the
power back to 2 watts - know that it is already near the peak and adjust the
slug only a small amount to find the peak center.

While an analog meter may allow you to observe the peak more quickly, the
digital display is entirely adequate if you adjust the slug slowly giving
the display time to respond.  Even with an analog display, it is possible to
overshoot the peak because there is some mechanical damping (and overshoot)
in the meter movement, so the proper answer (and solution) is ADJUST SLOWLY,
no matter what indicator you may be using.  If you have already adjusted
near a peak (you actually did that during the receive pre-alignment), you
need only adjust a small amount, likely a quarter turn or even less for the
inductor slugs and only a few degrees for the trimmer capacitors.

Answer to 2:  The addition of options will not have any effect on the
bandpass filter alignment - with 2 exceptions: the K160RX can change the
setting of the 160/80 meter bandpass, and the K60XV can change the alignment
of the 40/60 meter bandpass - if you add these options, you need only to
adjust the filter that is effected, not the entire set.  The bandpass filter
of one pair of bands does not effect the other band pairs.

The addition of the KSB2 will require changes in your SSB filter alignment
(CAL FIL), but this is separate and independent from all other adjustments.

It is not all that complex - just follow the instructions in order and you
will have a properly aligned K2.
For the filter and dial calibration adjustments, I recommend the use of
Spectrogram to provide an easy to observe analog display should you want to
adjust the filters for optimum reception.  You can find full instructions in
the K2 Dial Calibration article on my website http://w3fpr.qrpradio.com

73,
Don W3FPR

> -----Original Message-----
>
> We're feeling good about K2 # 5422 operation - it
> seems to receive well, on a good day on the ham bands.
>  I've
> gone over the "Transmitter Alignment" page 77 several
> times.  And we have an analog-meter MFJ AT on order.
>
> I'm wondering if I haven't gotten some of the
> variable-L's, like L3, L4, ......, L12, and L13 -
> off tuned and their cores too high or too low, putting
> them in false peaks?
>
> When going thru the page 77 K2 "Transmitter Alignment"
> steps - some of the coils have very minimal peak areas
> - perhaps it will become more evident when I get an
> analog meter in the dummy load coax line.
>
> QUESTION 1:  IS THERE A KNOWN DISTANCE, "inches", that
> all of these RF Board "Toko Variable Inductor"
> E690002, and E690001 inductor cores are set - from
> factory?  1/4", 1/8", top, bottom, center?
>
> 1 or 2 of the inductors - I believe we have the core
> screwed very high up near the top of the little can.
>
> For something as serious as receiver/transmitter
> alignment of my new K2 - I'd have a better feeling,
> knowing I really have the whole circuitry peaked
> correctly.  And just "looking at a varying output
> wattage level" (which jumps up significantly
> sometimes,
> and then settles back down, on tune/no tune) - on LCD
> doesn't give me a warm fuzzy.
>
> QUESTION 2:  If I install the SSB Option NOW, will
> that mess up my ability, to repeat the
> receiver/transmitter alignment steps?  I did install
> the NOISE BLANKER
> yesterday.
>
> Thanks,
> Fred N3CSY
> K2 # 5422 --- 40/20 sounded great on CW yesterday.
>

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