VIDEO OUT
AUDIO OUT
RF IN
DC INPUT
+5V
+12V
GND
CH
0
4
AUDIO
OFF AIR
CATV
PWR
CATV
+
100
DMM 806
TV ANTENNA
OR
CATV FEED
AC POWER
CORD
DC POWER CABLE
F1
F2
F3
F4
INSTALLATION 3
2
FRONT PANEL DESCRIPTION REAR PANEL DESCRIPTION
R.L. DRAKE COMPANY
230 INDUSTRIAL DRIVE
FRANKLIN, OHIO 45005 U.S.A.
CUSTOMER SERVICE AND PARTS TELEPHONE:
+1 (937) 746-6990
TELEFAX:
+1 (937) 743-4576
WORLD WIDE WEB SITE: http://www.rldrake.com
®
Figure 1 Figure 2
R1
R2
R3
R4
SYSTEM OUT
RF COMBINER
F1 - POWER Indicator
Lights when the unit is connected to the
required source of DC power via the rear
panel DC INPUT connector.
F2- Channel Number Switch
Sets the received channel number for off-air
TV channels 02 through 69 or for CATV
channels 02 through 125. See also Item F3
which sets the type of channel (Off-Air or
CATV) and sets the leading “1” for CATV
channels 100 through 125.
F3 - Mode Switch
Sets the type of channel, Off-Air or CATV.
The third position sets a leading “1” for
CATV channels from 100 through 125. See
also Item F2 for setting the channel number.
For example:
For example:
Setting for CATV
Setting for CATV
channel "25"-
channel "125"-
CH
5
2
OFF AIR
CATV
CATV
+
100
CH
5
2
OFF AIR
CATV
CATV
+
100
F4 - AUDIO Output Level Control
This screwdriver adjustment permits setting
the audio output level over a range of
approximately 0.5 to 1.5 Vp-p.
R1 - VIDEO OUTPUT Connector
This is the 75 Ohm baseband video output at
a fixed, nominal 1.0 Vp-p level.
R2 - AUDIO OUTPUT Connector
This is the unbalanced, audio output which is
adjustable with the front panel AUDIO control
over a range of approximately ± 10 dB from
the nominal output level of 300 mV rms.
NOTE: An internal jumper defeats the audio
de-emphasis for stereo capability, if required.
R3 - DC INPUT Connector
This 3-pin connector (Male) accepts the
appropriate mating DC power cable.
Observe proper orientation and wiring.
R4 - RF INPUT Connector
This is the 75 Ohm input to the demodulator
circuits from an off-air television receiving
antenna or from a CATV cable input.
CONNECTIONS and CONTROLS
All connections to and from the DMM 806 are
made through the rear panel. Figure 3
illustrates the use of the DMM 806 as an off-
air channel processor. For this purpose, the
feed from a television antenna is connected
via a 75 Ohm coaxial cable to the RF IN
connector of the DMM 806. The front panel
switches are set for “OFF-AIR” and the
received TV channel number is set for 02
through 69 as required. The VIDEO OUT
and AUDIO OUT signals are connected to
the VIDEO IN and AUDIO IN connectors
respectively of an adjacently located Video
Modulator, such as a Drake Mini-rack Video
Modulator, operating on the desired cable TV
channel. Alternatively, cable TV channels
can be processed by connecting the 75 Ohm
coaxial cable of a CATV feed to the DMM 806
RF IN connector and setting the front panel
switches for “CATV” or “CATV +100” and the
received cable channel number 02 through
125 as required. Additional channels can be
processed by adding combinations of
DMM 806 units with Drake Mini-rack Video
Modulator units.
RACK MOUNTING
Adequate ventilation is very important in
multi-channel installations. Units should be
spaced apart by at least one panel height
wherever possible, and some air movement
is advisable in enclosed rack cabinets.
Excessive heat will shorten component life
and system performance will be degraded
without proper cooling.
Figure 3
Illustration of Channel Processing using DMM 806 and a Drake Mini-rack Video Modulator.
DMM 806
Audio - Flat
Audio De-emphasis
(factory setting)
INTERNAL
JUMPER
Front
Panel
DRAKE MINI-RACK
VIDEO MODULATOR