The correct peak level of the stereo program applied to the stereo encoder sometimes
depends on the number of subcarriers in use. Some regulatory authorities require that total
baseband modulation be maintained within specified limits. Thus the level of the stereo main
and subchannel must be reduced when a subcarrier is turned on.
The 8200’s remote control feature allows you to reduce the stereo main and sub-channel
level by connecting an on/off signal from your subcarrier generator (See page 2-14). You
define the amount of reduction in % on the SYSTEM SETUP
I/O CALIB
screen (See
page 2-60). See page 2-74 for information on programming the remote control.
Ultrastable Pilot for the 8200 Stereo Encoder
This section explains how the OPTIMOD 8200 Stereo Encoder Board can be modified to
generate a pilot with ultrastable frequency.
This modification will allow a station’s carrier frequency to be maintained within 100Hz of
the assigned channel frequency when using the 8200’s stereo pilot as a reference. With a
100MHz carrier, this requires a stability of 1 part per million (ppm). This stability can only
be realized with a Temperature Compensated Crystal Oscillator (TCXO).
The 8200 Stereo Encoder Board has four unused pads that are spaced for a certain TCXO
package to be soldered into place. Four components also have to be removed from the Stereo
Encoder Board to make room for the TCXO. They are R102, Y1, C40 and C41.
We have found three different TCXOs that can be used on the 8200 Stereo Encoder Board.
They are:
Manufacturer
Model
Frequency
Stability
Monitor Products
7402 Series, Model B
4.864MHz
±
1.5ppm (
−
25
°
C to +60
°
C)
Raltron
TF69100-4.864
4.864MHz
±
1ppm (0
°
C to +50
°
C)
RXD
621B
4.864MHz
±
1ppm (
−
10
°
C to +50
°
C)
As we do not have a Retrofit Kit available at the time this manual was printed, you will need
to contact the manufacturer’s representative directly to place an order. Addresses for the
manufacturers and their reps are listed below.
Monitor Products
Raltron
RXD
502 Via Del Monte
2315 NW 107th Ave.
P.O. Box 1494
Oceanside, CA 92054
Miami, FL 33172
Norfolk, NE 68701
(619) 433-4510/434-0255 (fax)
(305) 593-6033/594-3973 (fax)
(402) 379-0112/379-3074 (fax)
DLDI
Kelex Electronics
California Capacitor
13455 Ventura Blvd #220
16631 Milliken Ave.
1579 Centre Pointe Dr.
Sherman Oaks, CA 91423
Irvine, CA 92714
Milpitas, CA 95035
(408) 496-6996/(818) 995-6451 (fax)
(714) 863-1230/474-1231 (fax)
(408) 262-6000/262-0272 (fax)
OPTIMOD-FM 8200
INTRODUCTION
1-9
