609
Functional Tests
Second Harmonic Distortion (SHD)
Second Harmonic Distortion (SHD) 
Test Limits
This test checks the second harmonic distortion of the signal analyzer by 
tuning to twice the input frequency and examining the level of the distortion 
product. A low pass filter is inserted between the source and the signal 
analyzer to prevent the source second harmonic from artificially raising the 
second harmonic product displayed on the analyzer.
The power level at the input mixer is 20 dB higher than specified to allow the 
distortion product to be seen. For example, the instrument specification may 
state that with a –15 dBm signal at the input mixer, the distortion product 
should be suppressed by > –60 dBc. 
The equivalent Second Harmonic Intercept (SHI) is 45 dBm 
(–15 dBm + 60 dBc). This test is performed with –10 dBm at the mixer and 
verifies the distortion product is suppressed by –55 dBc. This ensures the SHI is 
also 45 dBm (–10 dBm + 55 dBc).
Applied Frequency Mixer Level Distortion
40 MHz –10 dBm < –55 dBc
Item
Critical Specifications
(for this test)
Recommended 
Keysight Model
Adapter, Type-N(m) to 
BNC(f)
Frequency: 10 MHz to 80 MHz 
VSWR: < 1.05:1
1250-1476
Adapter, BNC(f) to SMA(m) Frequency: 40 to 80 MHz 1250-1200
Adapter, 
3.5 mm(f) to 3.5 mm(f)
Frequency: 10 MHz to 80 MHz 
VSWR: < 1.1:1
83059B
Cable, BNC 120 cm (2 
required)
Frequency: 10 to 40 MHz 10503A
Filter, 50 MHz Low Pass Cutoff Frequency: 50 MHz
Rejection at 65 MHz: > 40 dB
Rejection at 75 MHz: > 60 dB
0955-0306
Synthesized Sweeper Frequency: 50 MHz
Spectral Purity: Better than –30 dBc
PSG