TECHNISONIC INDUSTRIES LIMITED
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TDFM-136A Installation Instructions
Page A-3
TiL 09RE404 Rev C Issue 1
B.
Determine if the image frequency for the VHF COMM falls within the range of the TDFM-136A. If
so, select a set of frequencies that will cause the TDFM-136A to be set as close as possible to
the image frequency. Any one of the many possible sets will suffice. Record those values in the
spaces provided in the following chart. Modulate the TDFM-136A transmitter on the following
frequencies for at least 20 seconds. Listen for any noise or detected audio signals on the VHF
Comm.
EXAMPLE:
Bendix/King KY 196A.
The first IF frequency is 11.4 MHz. The LO is above the receive frequency (high side injection).
Therefore, the image frequency is 22.8 MHz above the selected frequency. Set the KY 196A to
120.000 MHz and the TDFM-136A to 142.8000 MHz.
FREQUENCIES RESULTS
VHF #1
TDFM-136A
PASS
FAIL
135.975 MHz
135.975 MHz
121.150 MHz
121.150 MHz
131.250 MHz
131.250 MHz
Image
FREQUENCIES RESULTS
VHF #2
TDFM-136A
PASS
FAIL
138.0000 MHz
138.0000 MHz
157.5000 MHz
157.5000 MHz
157.5000 MHz
157.5000 MHz
Image
NOTES:
