this avoids having to set the test level every time it is used.
3.8 Input Level Minimum input level for sequences Sequence input level Sequence failure FSK failure
The LA102 looks for FSK signals at a nominal level of 0dBu, being intended for direct
connection to professional line levels, but a wide range of levels should give satisfactory
operation (-30 to +20dBu). Below this level the FSK may not be received, especially if
the system is noisy, but see section 3.13 for direct triggering using a separate channel.
Loudspeaker testing can be carried out using a measuring microphone with a suitable pre-
amplifier, provided that this has the necessary gain. The actual measurements use
autoranging techniques, so they are independent of input level.
3.9 Ch
oosing a Sequence
Choosing a sequence Sequences − default Default sequences Tape machines
Although the LA101 has the capacity to store 250 sequence definitions, of which 110 are
currently defined as listed in table 3.1, many engineers find the Lindos Default sequences
are appropriate for nearly all their testing requirements.
The sequences are arranged in up to 25 sequence banks. Each bank contains 10 sequences
and the banks are listed in table 3.14. The default sequence bank is Bank 0.
Bank 0 is different from the others because the sequences therein are editable (see chapter
4). By default, Bank 0 contains the Lindos default sequences, and after option 4 is chosen
from the reset menu any user defined sequences in Bank 0 will be replaced by the Lindos
default sequences. Bank 1 also contains the Lindos default sequences, but this bank
cannot be edited. The other banks contain sequences written either by Lindos or third
parties.
Bank Sequences Allocation
B0 1-10 User sequences. These are held in RAM and can be edited
B1 11-20 Lindos default sequences
B2 21-30 Tape test sequences
B3 31-40 Speaker test sequences
B4 41-50 Filter test sequences
B5 51-60 Meter tone bursts
B6 61-70 Utilities
B7 71-80 BBC sequences
B8 81-90 BT lines/links sequences
B9 91-100 Telecom Australia sequences
B10 101-110 SAPO (South African Post Office) sequences
Table 3.14 Allocation of Sequence Banks in LA100 V6.5 Software
To select a particular sequence, first press
Subsequently each press of will
display the first 5 sequences of the next bank in succession. Pressing
will step back
a bank. Pressing
to will run the corresponding sequence. To view sequence 6 to 10
47
3. Sequence Testing
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