Lectrosonics IFBT5 - Manual (Page 10)

FREQUENCY BLOCKS AND RANGES
The table below lists the factory designated frequency
ranges available for the T5 IFB Transmitter.
Each T5 transmitter is built to cover a pre-selected range
of frequencies (a “block”) as shown below. The transmit­
ter will tune to any of 256 different frequencies within this
factory assigned block.
The block number is determined by this formula:
25.6 × Freq. (MHz) = Lowest freq. (MHz) in the block
To determine a block number from a frequency:
Freq. (MHz) divided by 25.6 = Block number
It is handy to remember these formulas, in case you do
not have a copy of the table. For example, suppose you
need to know which block covers 685.500 MHz, without
using the table:
685.500 divided by 25.6 = 26.77734375
FREQUENCY
BLOCK RANGE
The first two digits left of the decimal are the block
number. In this case, 685.500 MHz falls within block 26.
The T5 IFB transmitter antennas are color coded to
indicate the frequency block that they operate within.
The length of the antenna varies with the frequency
block. The actual length of the antenna is not as critical
as it might appear in the table below. The usable band­
width of the A6U antennas are +/- 50 MHz from the
center frequency, so it is acceptable to use an antenna
from an adjacent block above or below the operating
frequency is some loss in range can be tolerated.
The color of the antenna sleeve is in keeping with
standard resistor value color codes for the second digit
of the block number.
ANT SLEEVE ANTENNA
COLOR WHIP LENGTH
21 537.600 - 563.100 Brown 4.74"
22 563.200 - 588.700 Red 4.48"
23 588.800 - 614.300 Orange 4.24”
24 614.400 - 639.900 Yellow 4.01"
25 640.000 - 665.500 Green 3.81"
26 665.600 - 691.100 Blue 3.62"
27 691.200 - 716.700 Violet (Pink) 3.46"
28 716.800 - 742.300 Grey 3.31"
29 742.400 - 767.900 White 3.18"
30 768.000 - 793.500 Orange/Black 3.08"
31 793.600 - 819.100 Orange/Brown 2.99”
32 819.200 - 844.700 Orange/Red 2.92”
33 844.800 - 865.000 Orange/Orange 2.87”
REPLACEMENT PARTS and ACCESSORIES
Part No. Description
21586 DC16A Pigtail power cable, LZR to strip & tin
A500 RA B(block #) Antenna, flex
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