Instruction Manual

FREQUENCY BLOCKS AND RANGES
The table below lists the factory designated frequency ranges
available for the UDR200B receiver. For convenience, the
table includes information about the UM200B belt-pack trans-
mitter antennas as well.
Each UDR200B receiver is built to cover a pre-selected range
of frequencies (a “block”) as shown below. The receiver 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
The first two digits left of the decimal are the block number. In
FREQUENCY ANT SLEEVE ANTENNA
BLOCK RANGE COLOR
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”
this case, 685.500 MHz falls within block 26.
These factory defined "blocks" of frequencies should not be
confused with the user defined "groups" that can be stored in
the receiver memory.
Four user defined groups of frequencies can be stored in the
receiver memory. The groups are numbered 1 through 4 as
depicted on the Receiver Setup Panel (see the section on
COMPUTER INTERFACE). Each frequency in a group can be
individually named for convenience.
The UM200B belt-pack transmitter antennas (model A6U) 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 bandwidth 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.
The color of the antenna sleeve is in keeping with standard
resistor value color codes for the second digit of the block
number. Block 23 is not used since it covers a 608 to 614 MHz
band that is illegal for use with wireless microphones.
WHIP LENGTH
14