DANIELS
ELECTRONICS LTD.
TM
VHF Enhanced Extra Wideband Receiver Instruction Manual IM10-VR3H040-AB
4-1
4
RECEIVER ALIGNMENT
4.1
General
Receiver alignment is simplified by using an M-3 subrack, SM-3 system monitor, and RF
extender card/cable to provide receiver power and signal interconnection. Alternatively, +9.5
Vdc may be applied directly to a receiver module through positive connection to pins B6 / Z6,
and negative connection to pins B30 / Z30 / B32 / Z32. Receiver balanced audio (600
Ω
) is
available at pins B26 and Z26.
Throughout the alignment procedure reference is made to a "standard signal level". This refers
to an external generator signal source with FM modulation, 1 kHz tone, and 60% system
deviation connected to the receiver RF input type N connector (if a carrier frequency is not
given, it can be assumed to be the selected receiver channel frequency). All audio distortion
measurements are made at 1 kHz, and band limited from 300 Hz to 3.4 kHz.
Before proceeding with receiver alignment, check that the appropriate jumpers are installed. The
standard jumper configuration given in section 5 is normally employed for receiver alignment.
The extruded receiver case should be removed to expose all receiver circuitry. In addition, the
removal of the Front End is required for C130 second local oscillator frequency adjustment . All
jumpers and test points are clearly marked. All adjustments to the IF / Audio Main Board, with
the exception of C130, are made on the surface mount component side of the IF / Audio Main
Board.
4.2
Repair Note
All radio modules employ a high percentage of surface mount components which should not be
removed or replaced using an ordinary soldering iron. Removal and replacement of surface
mount components should be performed only with specifically designed surface mount rework
and repair stations complete with Electro Static Dissipative (ESD) protection.
When removing Surface Mount Solder Jumpers, it is recommended to use clean solder wick
braid in place of vacuum type desoldering tools. When connecting Surface Mount Solder
Jumpers, use a minimal amount of solder on the pads. These precautions will help prevent
damage to the circuit boards.
