Attachment #1 shows the schematic of the test setup. Signal generator (Marconi) was used to supply the RF input. We observed the IF output in the following three test conditions.

1. Observed the spectrum with FM modulation (fcarrier of 40 MHz and fmod of 221 Hz )- a peak at 221 Hz was observed.
2. Observed the noise spectrum without FM modulation.
3. Observed the noise spectrum after disconnecting the delayed output of the delay line. 

• It is observed that the broad band noise level is higher without FM modulation (2) compared to that we observed after disconnecting the delayed output of the delay line (3).
• It is also observed that the noise level is increasing with increase in RF input power. 
• We need to find the reason for increase in broad band noise .