Fig. 2-7. Changing band C Coaxial Mixer to Wave Guide Adapter,

Signal input power to the analyzer should not exceed -30

dBm. Signal above this level will overload the 1st mixer and/

or the 1st IF stage and generate spurious signals on the dis-

play. Add at least 10 dB of attenuation to the input when

the signal begins to compress (no increase of signal amplitude

with an increase of signal level). A conversion chart (Fig.

2-8) may be used to calculate input signal level.

CAUTION

Signals stronger than +15 dBm applied to the

input or mixer will damage or burn out the mixer

diodes.

Mismatches between the signal source and the RF INPUT

connectors may be caused by signal source output imped-

ance, long coaxial cables, etc. These mismatches will ad-

versely affect display flatness. When optimum flatness is

desired and signal strength is adequate, a 50 Ω attenuator

pad of approximately 6 to 10 dB should be added between

the signal source and the input to the mixer. The addition

of the attenuator will minimize reflections and optimize dis-

play flatness.

Fig. 2-7. Changing band C Coaxial Mixer to Wave Guide Adapter,

Three attenuator pads, 10 dB, 20 dB and 40 dB are sup-

The Mixer Adapter or Coaxial Mixer may be removed from

plied with the accessories kit, These three attenuators may

the input receptacle by turning the retainer ring in either

be stacked on the N type connector to provide up to 70 dB

direction. See Fig. 2-7. To replace either assembly, push the

attenuation. A support should be provided however, if

adapter or coaxial mixer against the spring until the flange

more than 2 attenuators and an N to BNC adapter are

bottoms, then turn until the latch snaps to hold the unit in

stacked on the band A connector. The attenuators are rated

place.

at 2 watts (average).

Ω

Fig. 2-8. Volts-dBm-Watts conversion chart for 50

impedance.

2-9