14
Testing FM Systems with FONIX 6500-CX Analyzers
1.2.4 Test FM system with high-level input — EFM90
1. Set up the FM system for testing according to the FM setup in Section 1.1.3. The FM
receiver should be set to receive FM-only signals.
2.
Press [START] to begin the pure-tone sweep. The response will be stored in the
Multi-Curve stack when the measurement is complete. For instruments without the
Multi-Curve option, press [CRT] to print a hardcopy.
3.
This response will be referred to as the Electroacoustic FM Saturation Response or
EFM90.
Figure 1.2.4
Comparison of EHA90 (CRV2), the hearing aid response at 90 dB
SPL with EFM90 (CRV1), the FM response at 90 dB
4.
To view both curves on the same screen requires the Multi-Curve Option:
a. Press
[MULTI].
b. Highlight
MULTIPLE
CURVES.
c. Press
[START].
d. If necessary, use [<, >] to display CRV 1 in the first slot. This curve is EFM90.
e. Use
[
∨
] to select the second slot.
f. If necessary, use [<, >] to display CRV 2 in the second slot. This curve is EHA90.
