User's Guide

3-6 Enhanced AM/FM Synthesizer Instruction Manual OS(R/T)-3(A/H) 29 - 935 MHz
3.5.5.4 UHF OS(R/T)-3H 406 - 470 MHz VCO Alignment
Refer to the
"OS(R/T)-3H 406 - 470 MHz Analog Board Component Layout" diagram and the
"OS(R/T)-3H 406 - 470 MHz Analog Board Schematic Diagram" on pages 4-13, 4-14 and 4-15
of this manual.
Using a high impedance (10 MΩ) DC Voltmeter, measure the PLL control voltage at TP4
located on the synthesizer module analog board (top).
Access to TP4 is available through the
synthesizer top cover.
The UHF synthesizers operating in the 406 - 470 MHz frequency range
employ integrated VCO modules having no external frequency adjustment capability.
The
OST-3H418, OST-3H460 and OSR-3H440 models cover frequencies from 406 - 430 MHz,
450 - 470 MHz and 427.4 - 451.4 MHz respectively and provide full band coverage without
tuning adjustment.
For the OST-3H418, measured PLL control voltages below approximately
+0.5 Vdc and above approximately +4.5 Vdc will indicate an “out of lock” condition. For the
OSR-3H440 and the OST-3H460, measured PLL control voltages below approximately
+1.0 Vdc and above approximately +7.0 Vdc will indicate an “out of lock” condition.
It is important to check the loop control voltage at TP4 when multiple synthesizer channels have
been programmed.
All channel selections should result in a TP4 voltage within the +0.5 to
+4.5 Vdc range for the OST-3H418. The TP4 voltage for the OSR-3H440 and the OST-3H460
should be within the +1.0 to +7.0 Vdc range. Channel selections beyond the tuning range
capability of the synthesizer will result in unlocked operation.
The tuning range capability of all
synthesizer models is listed in the Specifications section of this manual.
3.5.5.5 UHF OS(R/T)-3H 928 - 935 MHz VCO Alignment
Refer to the
"OS(R/T)-3H 928 -935 MHz Analog Board Component Layout" diagram and the
"OS(R/T)-3H 928 - 935 MHz Analog Board Schematic Diagram" on pages 4-17, 4-18 and 4-19
of this manual.
Using a high impedance (10 MΩ) DC Voltmeter, measure the PLL control voltage at TP4
located on the synthesizer module analog board (top).
Access to TP4 is available through the
synthesizer top cover.
The UHF synthesizers operating in the 928 - 935 MHz frequency range
employ integrated VCO modules having no external frequency adjustment capability.
The
OST-3H932 model covers frequencies from 928 - 935 MHz and provides full band coverage
without tuning adjustment. For the OST-3H932, measured PLL control voltages below
approximately +0.5 Vdc and above approximately +4.5 Vdc will indicate an “out of lock”
condition.
It is important to check the loop control voltage at TP4 when multiple synthesizer channels have
been programmed.
All channel selections should result in a TP4 voltage within the +0.5 to
+4.5 Vdc range for the OST-3H932. Channel selections beyond the tuning range capability of