DANIELS
ELECTRONICS LTD.
TM
VHF Enhanced Extra Wideband Receiver Instruction Manual IM10-VR3H040-AB
4-5
4.6
Front End Tuning
•
Attach the front-end assembly to the main board and solder the red wire to the 9.5V
line (J6-2).
•
Use a spectrum analyzer with Tracking Generator. Connect the generator O/P of the
spectrum analyzer to the RF I/P of the front end. Connect the IF O/P of the front end
to the analyzer I/P. Apply power to the Rx. Note that the LO input of front end must
be disconnected.
•
Spectrum analyzer set up: Generate a level of -30dBm and put -30dBm on the top of
the y-axis using “RF ATTEN” key. Set the scan width to 10MHz/div. Enter in your
Rx frequency.
•
Tune the five variable inductors CCW, on the side of the front end, until they are
within a few turns of being flush with the top. You should see a shape on the display
that resembles a ‘volcano.’ Using the five variable inductors adjust the position of
the ‘volcano’ until its center is aligned with the Rx frequency. The shape should look
like this:
-110
-30
-40
-50
-60
-70
-80
-90
-100
SCAN
WIDTH
FREQUENCY
300 kHz
0 dB ATT
GEN -30
20 mS
•
Connect the IF output of the front end to the IF input on the main board. Connect the
LO input of front end to synthesizer output.
