[KX2, KX3] Quick Translation of ATU.DATA To L And C Values

[Mike Morrow-3]

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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