DANIELS
ELECTRONICS LTD.
TM
2-2
IM10-VR3H040-AB VHF Enhanced Extra Wideband Receiver Instruction Manual
2.2
Frequency Selection
Receiver channel selection is achieved by setting a decimal number on four BCD frequency
select switches, FSW1 through FSW4. These rotary switches are located on the FM IF/Audio
Main Board and are made accessible by removing the outer receiver cover. The switch settings
are scanned by the synthesizer module when the receiver is first powered up, and the desired
local oscillator frequency is generated. Refer to the following equations or the channel
designation manual for simplified channel number and frequency information.
VR-3H035-S and VR-3H045-S (29 - 50 MHz) with:
• 5 kHz channel increments (BCD settings from 0000 to 4999):
CHNL#=
Rx
frequency
−
29 MHz
5 kHz
or
Rx
frequency
= CHNL#
×
5 kHz
[
]
+
29 MHz
• 6.25 kHz channel increments (BCD settings from 5000 to 9999):
CHNL #=
Rx
frequency
−
29 MHz
6.25 kHz
+ 5000
or
Rx
frequency
= CHNL# -5000
(
)
×
6.25 kHz
[
]
+
29 MHz
Alternatively, a frequency and channel lookup table is available in the 'Channel Designation
Table' manual for the VR-3H040.
A channel can be selected from a set of 15 (maximum possible) factory programmed channels by
the four channel select lines available at the rear 'F' connector on the Receiver Main Board. A
single user selectable channel is set by switches located on the Receiver Main Board. See the
Receiver Main Board Manual for details.