Pineapple Technology Inc. XL1000-PRO Manuale Utente
XL1000Pro
Retrofit Instructions
XL1000Pro
PREPARATORY MEASUREMENTS AND ADJUSTMENTS:
The following adjustments are recommended to insure that the transmitter is
working properly before any changes are made.
working properly before any changes are made.
1.
Apply video signal composed of blanking level with sync and color burst to
the modulator and connect the output of the driver to a separate watt meter and 50
ohm load. Measure the output power of the driver. It should be about 3.0 to 4.0
watts. The front panel Power adjustment knob should vary the power by +1 to -4
dB. If the output power is capable of greater than +1 dB power increase, adjust
the variable resistor (see the XL1000 instruction Manual) to ensure a limit of 5.5
watts is maintained. This is important to protect the power amplifier from damage
by overdrive. Overdrive damage to the XL1000-PRO is not covered by warranty.
ohm load. Measure the output power of the driver. It should be about 3.0 to 4.0
watts. The front panel Power adjustment knob should vary the power by +1 to -4
dB. If the output power is capable of greater than +1 dB power increase, adjust
the variable resistor (see the XL1000 instruction Manual) to ensure a limit of 5.5
watts is maintained. This is important to protect the power amplifier from damage
by overdrive. Overdrive damage to the XL1000-PRO is not covered by warranty.
2.
Connect a directional coupler in the main RF path before the wattmeter and
load. Connect the forward sample port to a spectrum analyzer, after ensuring the
RF level at the sample port is less than the maximum input level for the spectrum
analyzer. Using the modulator controls, adjust the aural/visual ratio to -13 dB (5%)
as measured on the spectrum analyzer. This is a typical setting for most
applications, however, the power amplifier can be used at higher levels if
necessary with only minor degradation in performance.
RF level at the sample port is less than the maximum input level for the spectrum
analyzer. Using the modulator controls, adjust the aural/visual ratio to -13 dB (5%)
as measured on the spectrum analyzer. This is a typical setting for most
applications, however, the power amplifier can be used at higher levels if
necessary with only minor degradation in performance.
3.
Measure the purity of the driver output signal on the spectrum analyzer.
This measurement is made to ensure that the mixing products are at least -45dBc
or better. The solid state power amplifier that will be installed later is broadband
and will amplify these unwanted signals making filtering necessary if they are out
of specs to start with. If the mixing products are not –45 dBc relative to the visual
carrier, consult the instruction manual or equipment supplier to achieve this.
or better. The solid state power amplifier that will be installed later is broadband
and will amplify these unwanted signals making filtering necessary if they are out
of specs to start with. If the mixing products are not –45 dBc relative to the visual
carrier, consult the instruction manual or equipment supplier to achieve this.