Specifications
WFM 90 and WFM 91 Service Manual 1–7Table 1–1: Vertical deflection system (Cont.)
Category Description
DC Input Impedance
(Unterminated) REQ: 15 kW.
REF: With input switch in the HIZ position.
Video Input Return Loss REF: 40 dB from 50 kHz to 6 MHz with 75 W termination on.
Video Out Return Loss (75W)REF: 30 dB from 50 kHz to 6 MHz.
Video Out Differential Gain (50% APL) REF: Within 1% with a 140 IRE (1.0 V PAL) unit display.
Video Out Differential Phase (50% APL) REF: Within 1° with a 140 IRE (1.0 V PAL) unit display.
Table 1–2: DC restoration
Category Description
DC Restorer Clamp Time REF: Back Porch.
Frequency Response at
60 Hz (50 Hz PAL) REQ: Attenuation of 60 Hz (50 Hz PAL) on Input Signal:
Slow Mode: 20%.
Fast Mode: 90%.
REF: Blanking Level Shift with 10% to 90% APL Change:
APL changes from 50% to either 10% or 90% will cause blanking level
shift of 1 IRE unit (7.14 mV PAL) or less.
REF: Blanking Level Shift Due to Presence or Absence of Burst:
1 IRE unit (7.14 mV) or less shift from no color burst to presence of
color burst.
Table 1–3: Audio mode
Category Description
Reference Levels REQ: –10 dBu, 0 dBu, +4 dBu, +8 dBu.
REF: Nominal MIC Reference: –50 dBu.
Measurement Accuracy REQ: 0.5 dB at 1 kHz.
Frequency Response REQ: 0.5 dB from 50 Hz to 20 kHz.
Maximum Input Level Amplitude REF: +18 dBu.
DC Input Impedance REF: 15 kW.
Audio Output Connector REF: Mini stereo headphone jack.
Maximum Power Output REF: 250 mW.