Technical Manual

Table Of Contents

Tuning Procedure

For North America (FCC), only the portion 460 to 470 MHz will be used; therefore,

a single device model A733-46 having the switching range between 460 and 470

MHz will be submitted for testing.

3.3.3. Tuning Procedure

The A431 modules are to be tuned by mounting them on a test ﬁxture consisting of

a specially modiﬁed A733 motherboard. The modiﬁcation refers to certain mechan-

ical aspects, in order to provide an easy plug in and out of the control connector (P2)

as well as to the TP1 and TP2 test points.

The alignment operation must differentiate between following classes of units:

• Band 1: from 430 to 440 MHz

• Band 2: from 440 to 450 MHz

• Band 3: from 450 to 460 MHz

• Band 4: from 460 to 470 MHz

Note: The boards differ only through the FL1 and FL2, in that Band 1 and 2 use

models TOKO 493S-1071A and 492S-1056A while Band 3 and 4 use models

TOKO 493S-1075A and 492S-1060A, respectively. In addition, the tuning pro-

cedure and some software parameters differ. The differences are clearly stat-

ed in the following paragraphs, where applicable.

3.3.4. Setting Up the Default Parameters

The tuning procedure is not possible without ﬁrst conﬁguring some default param-

eters for the A733 motherboard used in the testing ﬁxture. This is done via the serial

interface of the motherboard by using a communication terminal program (e.g. Hy-

perterminal, in Microsoft® Windows™ 95). The terminal program must be conﬁg-

ured as follows:

• 19200 Baud

• 1 Stop bit

• No parity

• No protocol (neither hardware, nor software)

To check if the communication is operational, press the

ENTER key. An

nnnn 0

prompt should appear on the terminal screen (

nnnn

is the actual ID of the unit that

is printed on its label). The following default parameters must be pre-loaded (for

more information about the meaning of the commands, consult the section “Com-

mands” on page 48):

RxD

TxD

Ground

Battery

Ext Power