KX2 and KX3 manuals provide no quick practical process to translate the
ATU.DATA display into L and C values.
EXISTING KX2 [KX3 (errata C5-3)] TEXT:
In the ATU.DATA and ATU MD menu entries, tapping ATU shows the present values
of L (inductance), C (capacitance) and N (L-network configuration). This
applies only to the internal ATU (KXAT2[3]). The displayed data format is
LxxCxxNy. <xx> is a 2-digit hexadecimal value that, when converted to binary,
shows which ATU L or C relays are engaged. <y> shows which side of the
L-network the capacitance is on: Nt = TX side, and NA = antenna side.
---
The above process requires the ATU schematic for L and C values (not included
in manual), hexadecimal number conversion to binary, determining which ATU
relays and associated L and C values are active, and summing those values.
Almost all of that is avoided with a value lookup table that uses directly
those four displayed hexadecimal numbers.
SUGGESTED KX2 MANUAL REVISION:
In the ATU.DATA and ATU MD menu entries, tapping ATU shows KXAT2 status for
inductance L, capacitance C, and L-network configuration n. The display format
is Lde.Cfg.nh. When those two-digit hexadecimal values are translated per the
table below, <de> yields L in uH and <fg> yields C in pF. Value <h> shows
L-network capacitance connection as t (transmitter side) or A (antenna side).
The KXAT2 is capable of 32764 unique configurations.
d e f g
hex Ld Le Cf Cg
0 - 0 0 0 0
1 - 1 .05 164 10
2 - 2 .10 330 18
3 - 3 .15 494 28
4 - 4 .23 680 39
5 - 5 .28 844 49
6 - 6 .33 1010 57
7 - 7 .38 1174 67
8 - * .50 * 82
9 - * .55 * 92
A - * .60 * 100
B - * .65 * 110
C - * .73 * 121
D - * .78 * 131
E - * .83 * 139
F - * .88 * 149
* Not applicable to KXAT2
L = Ld + Le C = Cf + Cg
Examples:
L4F.C2B.nA represents L= 4.88 uH, C= 440 pF, C on antenna side
L51.C67.nt represents L= 5.05 uH, C=1077 pF, C on transmitter side
---
SUGGESTED KX3 MANUAL REVISION:
In the ATU l.DATA and ATU MD menu entries, tapping ATU shows KXAT3 status for
inductance L, capacitance C, and L-network configuration n. The display format
is Lde.Cfg.nh. When those two-digit hexadecimal values are translated per the
table below, <de> yields L in uH and <fg> yields C in pF. Value <h> shows
L-network capacitance connection as t (transmitter side) or A (antenna side).
The KXAT3 is capable of 131068 unique configurations.
d e f g
hex Ld Le Cf Cg
0 - 0 0 0 0
1 - 1 .06 164 10
2 - 2 .12 330 18
3 - 3 .18 494 28
4 - 4 .25 680 39
5 - 5 .31 844 49
6 - 6 .37 1010 57
7 - 7 .43 1174 67
8 - 8 .50 1360 82
9 - 9 .56 1524 92
A - 10 .62 1690 100
B - 11 .68 1854 110
C - 12 .75 2040 121
D - 13 .81 2200 131
E - 14 .87 2370 139
F - 15 .93 2534 149
L = Ld + Le C = Cf + Cg
Examples:
L4F.C2B.nA represents L= 4.93 uH, C= 440 pF, C on antenna side
L51.C67.nt represents L= 5.06 uH, C=1077 pF, C on transmitter side
LDA.CE9.nA represents L=13.62 uH, C=2462 pF, C on antenna side
---
Perhaps a future firmware release will report ATU.DATA L and C directly. Until
then, this process determines L and C in a matter of seconds by simple table
inspection.
Mike / KK5F
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