User's Manual

PINEAPPLE TECHNOLOGY, INC VII. DTXPRO-800VH THEORY OF OPERATION
DTXPRO-800VH OPERATING AND SERVICE MANUAL
THE INFORMATION PROVIDED HEREIN IS PINEAPPLE TECHNOLOGY INCORPORATED PROPRIETARY INFORMATION AND
CANNOT BE COPIED OR DISTRIBUTED WITHOUT PRIOR AUTHORIZATION
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VII -- DTXPRO-800VH THEORY OF OPERATION (Continued)
The rotary switch on the ADP1000 is the detail selector for the multi-meter. The various
positions are defined as follows:
PA5 Reads PA Driver device currents as selected
Typical reading in INHIBIT MODE 1.5 to 2.5 A.
Typical reading in normal transmitter operation approximately 1 to 2
amps.
PA1 to 4 Reads the individual drain currents on each device located on the
pallets located on the left and right side of the Power Amp selected.
Typical reading in normal transmitter operation is approximately 7
to14 amps.
PA6 Not used
PS VOLTS Reads DC voltage applied to PA stages Typical reading for 50 VDC
would be the center of the meter, in the green zone.
P FWRD Not Used (See Exciter)
P RFLD Not Used (See Exciter)
AUX 1 & AUX 2 Not used in this configuration.
E. DXDPRO-10VH EXCITER
The heart of any TV Transmitter is the Exciter. This equipment receives the ASI (or SMPTE)
digital stream from the source, changes the format to ATSC 8VSB and up converts the IF signal
to the specific ―on-channel‖ RF broadcast frequency.
The DXDPRO-10VH provides adaptive linear and non-linear correction and consists of a ProTV
core modulator assembly and a 15 VDC power supply. In addition, the DXDPRO-10VH Exciter
has an internal 10W driver, Automatic Level Control, Power Detector and Logical Measurement
and Control.
The DXDPRO-10VH has provision for accepting a pre mask filter RF monitoring sample and a
post mask filter RF monitoring sample. These samples are used by the internal modulator
assembly to make linear and non-linear corrections on-the-fly.
The DXDPRO-10VH has provision for accepting a transmitter forward output power sample and
reflected output power sample. These values can be read on the exciter front panel as a percent
of specified operating power levels.