Revision A
T-48 90 008 026
2-7
1. Connect the TSP-1A directly to the
ANTENNA CONNECTOR
located on the front panel of
the T-48 Test Set.
2. Maintain a 15-100 ft. separation from the Test Set and the aircraft under test, and a clear
unobstructed path from the antenna and the Test Set (Figure 2-4).
3. Ensure the transponder that you are testing is significantly closer to the Test Set than another
operating transponder equipped aircraft. Otherwise, an undesired reply may occur or
erroneous indications might result.
4. DME and transponder antennas are similar in shape and appearance. Have positive
identification of the correct antenna as to adhere to the 15-100 ft. range.
5. If the aircraft you are testing is dual transponder equipped, ensure the correct antenna and
transponder is selected.
6. If unfavorable results occur when utilizing the Omni Antenna, move closer to the transponder
antenna and re-test. Aircraft external fuel tanks, pods, and landing gear doors may interfere
with the Test Set reception.
Omni Antenna
Maintain 15-100 ft.
Unobstructed Distance
T-
48
15-100 ft.
Omni Antenna Limitations
Figure 2-4
2.9.2
Antenna Couplers TAP-135, 10 and 50 ft lengths
The Antenna Coupler provides transponder power, frequency, sensitivity, and diversity measurements. The
Antenna Couplers can only be utilized on blade type antennas. When using the Antenna Coupler, be sure
you have selected the correct antenna to test. The TAP-135 is interchangeable with The T-49C MOD 3 Test
Set.
1. Remove the TAP-135 from the Test Set front cover, unwind the cable and connect the cable
to the
ANTENNA
connector on the front panel of the T-48 Test Set.
