Texas Instruments 2000 series, Reference Manual

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February 2002 Associated Antenna Systems
35
Table 15: Tuning Range Settings
Jumper Setting C_tunb
(nF)
C_deviation
(nF)
Tuning Range
(uH)
Cable Length
(Meter)
V-RF_max
(V)
JP2 16.5 +/- 0.5 800 Vpp
JP2, JP11 21.5 +/- 0.7 800 Vpp
JP2, JP8 23.5 +/- 1 800 Vpp
JP2, JP5 33 +/- 1.5 800 Vpp
JP2, JP5, JP11 38 +/- 2.3 800 Vpp
JP2, JP5, JP8, JP11 45.5 +/- 3 27 5 to 40 800 Vpp
JP3, JP4 66 +/- 7 560 Vpp
JP2, JP4, JP7, JP10 74.5 +/- 7 16 5 to 40 560 Vpp
JP1, JP3, JP5 82.5 +/- 10 560 Vpp
JP1, JP3, JP5, JP10 92.5 +/- 12 560 Vpp
JP1, JP3, JP4, JP7, JP10 124 +/- 20 8 5 to 120 560 Vpp
The column ‘C_tunb’ is the capacity which is adjusted on the Antenna Tuning
Board. ‘C_deviation’ is the allowed tolerance within which the corresponding
jumper setting is valid.
The columns ‘Tuning Range’ and ‘Cable Length’ show some examples of jumper
settings for a particular antenna inductance and length. The cable length can be
between 5 and 120 meters. The column ‘V-RF_max’ shows the maximum
allowable resonance voltage at the antenna terminals.
In order to calculate C_tunb, use the following formula:
C_res. = ( µH/nF)
C_tunb. = C_res. – C_cable – 2.2 (nF)
(Default setting is 45.5 nF for 27µH and cable length up to 40 meters)
Recommended Cable: Twinax
Characteristic impedance: 100 to 105 Ohm
Capacitance: 50.9 pF/meter
Diameter: 8.4 mm
1406.45
L_ant. + 3