15
Troubleshooting
If the ATU menu parameter shows "
- - -
" at all times,
make sure you have revision 109 or later of the
K1 main processor firmware. Other possibilities include a connector shifted by one position, an unsoldered
pin, etc. Check the ATU PC board for shorts to ground, solder bridges, and unsoldered connections. Verify
that the microcontroller is fully seated in its socket and is not plugged in backwards.
If you don’t see
r 8 . 5
when doing TUNE with the ATU in
F x . x
mode,
digital SWR data is not being
sent correctly across the RFDET/DATA line. Check U2 and D3 for proper orientation. Also look for a short
anywhere around U2 or related components.
If the ATU menu parameter becomes "
- - -
" after doing a tune-up,
it may be due to very high RF
feedback into the transceiver. Turn power off and back on, then re-test the ATU using a dummy load or a
different antenna. If it functions correctly on a dummy load but not on your antenna, try using a balun.
If the SWR isn’t <
r 1 . 2
with a 50-ohm load,
C9's setting may be incorrect. On the highest bands the
SWR may be slightly higher than 1.0:1 due to stray reactances in the tuner, even when the ATU is in
C L S
mode.
If the power indicated is always about 0 watts,
the windings of T1 may be reversed, or one or more leads
of T1 or L1-L4 may not be properly stripped.
If you see
P
L O
on the display during any mode that should display SWR,
you probably have power set
too low to obtain a stable SWR reading. Power is automatically reduced to 1.5 watts in all SWR-reading
modes, so there’s usually no need to set power below this level manually, unless you’re operating “QRPp”
(very low power). In this case, set the power to about 1 to 2 watts for tune-up purposes, then decrease it for
operation.
If the ATU shows an error message (
E x x
in the menu where
x x
is between 1 and 49),
you may have a
defective microcontroller.
E x x
numbers 50-99 are used for tune-up algorithm tracking, and do not indicate
a problem.
If SWR is not displayed during TUNE with the ATU in
C L S
,
T U N
, or a status mode,
you may have
high RF feedback into the transceiver. Reduce power to 0.5 watts using the
O U T
menu entry. If this cures
the problem, you may need to improve your ground system, move the antenna farther away, or use a balun.
If the tuner is unable to achieve a low SWR on some bands,
even with several different antennas, you
could have a single defective relay or component on the L-C board. Start by slowly scrolling through ATU
menu parameters
L 0
through
L 4
,
C 0
through
C 5
,
N 1
, and
N 2
. At each setting you should hear relays
switching. If you find one that doesn't, this may pinpoint a bad relay. If the relays are all working but you
suspect an inductor or capacitor, you can test each L and C by noting their effect on SWR, one at a time.
Start on the highest band. Connect a 50-ohm dummy load to one of the antenna jacks, select
L 0
, do TUNE,
and note the SWR reading. Then select
L 1
and do TUNE again; the SWR should change by a small
amount.
L 2
should have a larger effect, etc. When the inductance selections cause the SWR to go off the
scale (
9 . 9
), switch to a lower band, go back to
L 0
, then test the remaining inductors. Similarly, you can
test all five capacitors, starting on the highest band with
C 0
,
C 1
, etc. You'll know you have found the bad
component if it has too large or small an effect (or no effect) on SWR, in relation to the others tested.
