DE
DANIELS
ELECTRONICS
3-2
Enhanced AM/FM Synthesizer Instruction Manual OS(R/T)-3(A/H) 29 - 470 MHz
The corresponding internal synthesizer jumper settings are:
Digital Board
•
Jumper JU2
not installed
9.6/10 MHz reference frequency, 9.6 MHz selected
•
Jumper JU1
installed
AM Multichannel mode selected
Analog Board
•
Jumper JU1:
'B' position
Internal/External reference. Internal selected
•
Jumper JU2
not installed
Internal/External reference. Internal selected
3.5
OS(R/T)-3(A/H) Synthesizer Alignment
3 . 5 . 1
General
Under normal circumstances, synthesizer alignment is accomplished without removing the
synthesizer from the MT-3 Receiver IF/Audio Board or the MT-3 Transmitter Main Board.
Alignment simply involves setting the internal TCXO reference frequency (if one is installed and
the internal reference option enabled). This step is described in "Reference Frequency Alignment"
of section 3.5.5.5. A change in synthesizer operating frequency greater than the maximum tuning
range for a particular model (Refer to Specifications section 1.3) from an initial factory setting
requires a slightly more involved alignment procedure as described in sections 3.5.2 to 3.5.5. To
convert a synthesizer with an internal reference source to a synthesizer requiring an external
reference signal or vice-versa is done through the appropriate selection of jumper JU1 A or B, and
JU2 (Refer to section 3.5.6).
3 . 5 . 2
Synthesizer Test Points
Analog
Board
Component
Layout
(Top)
Common to all synthesizer family members.
TP1
+8.0 ± 0.3 Vdc. U6 positive regulator output.
TP2
+5.0 ± 0.1 Vdc. U7 positive regulator output.
TP3
+5.0 ± 0.1 Vdc. U8 positive regulator output (always on).
TP4
PLL error voltage. Ranges from +1.0 to +7.0 Vdc depending on frequency.
Nominally adjusted (C24) to +4.5 Vdc for tuned center channel. UHF/VHF
versions employing integrated VCO modules (OSR-3H440, OST-3H440, OSR-
3A149, OST-3A128) require no adjustment.
Digital
Board
Component
Layout
(Bottom)
TP1
+5.0 ± 0.1 Vdc. U2 positive regulator output (controlled via pin P2-4).
TP2
Microcontroller E clock. 2 MHz logic level square wave.
