Grundig GSS HRM 325, Assembly Instruction Manual

Page: 8 / 10

- 8 - HRM 325
4 s
etting the Cassette
In order to prevent interference, too high signal levels, e. g. of local transmit-
ters, can be reduced by absorption circuits.
• Switch on the head-end station.
Box 1 FM
87 – 108 MHz UKW
—> The display shows the following indica-
tion for the FM amplifier.
• Connect a spectrum analyser to the RF output of the head-end station.
• Set ” input level regulator ” to the mechanical centre.
+
Traps
4 … 6
Traps
1 … 3
Input level
regulator
• If necessary tune the absorption circuit groups ” Traps 1 … 3 ” and
” Traps 4 … 6 ” to the frequencies to be lowered.
—> You can lower 3 interfering frequencies each with the absorption cir-
cuit groups ” Traps 1 … 3 ” and ” Traps 4 … 6 ”. If the adjustment range
of an absorption circuit, for example from group ” Traps 1 … 3 ” is inad- is inad-
equate, you can lower the frequencies even further with an absorption
circuit that is tuned to the same frequency from group ”
Traps 4 … 6 ”.
Example of the progression of the tunable acceptor circuits
0 db
-4 db
-8 db
-12 db
-16 db
8 0 1 4 0 1 5 , 1 9 5 , 7 8
-14 db
-17 db
in MHz
Frequency