User's Manual

TDFM-136B Installation Instructions 08RE398
B. Determine if the image frequency for the VHF Comm falls within the range of the TDFM-136B. If so,
select a set of frequencies that will cause the TDFM-136B 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-136B 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 L.O. 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-136B to 142.8000 MHz.
Frequencies Results
VHF #1 TDFM-136B Pass Fail
135.975 MHz 138.0000 MHz
121.150 MHz 157.5000 MHz
131.250 MHz 157.5000 MHz
Image
Frequencies Results
VHF #2 TDFM-136B Pass Fail
135.975 MHz 138.0000 MHz
121.150 MHz 157.5000 MHz
131.250 MHz 157.5000 MHz
Image
NOTES:
Technisonic Industries Ltd. 3-5