Keene RF Modulator Operating Instructions Manual

Keene Electronics

RF Modulator

Operating instructions

Overview

By converting video and audio
signals to an RF signal, the Keene RF
Modulator allows the AV output of a
camcorder or other device to be fed
to a standard television receiver
through its aerial socket.

Typical applications include the
connection of a camcorder, video
recorder or SAT receiver to a
television set which has only a
standard aerial input; it can also be used to feed the signal from
a TV surveillance camera into a domestic cable installation.

The Keene RF Modulator will handle VHS, VHS-C and video 8
signals, as well as composite colour signals, with mono sound.

Connection and operation

• Make sure all devices are switched off before connecting.

• Connect the ‘audio’ output (often a black/white RCA phono
socket) of the source (output) device to the ‘audio in’ (RCA
phono socket) of the RF Modulator. If the output device
provides stereo audio, ie there are two audio out sockets,
connect the left (L) audio channel only.

• Connect the ‘video’ output (normally a yellow RCA phono
socket) of the source device to the ‘video in’ (RCA phono
socket) of the RF Modulator.

• Connect the ‘RF out’ lead of the RF modulator to the TV aerial
socket. If a TV aerial is to be connected simultaneously, then
a selector adaptor will be required.

1

Keene RF through modulator

Designed to be put in-line with aerial in and out connections, the
video and audio signal can then be put into any UHF channel
(from 30 – 40) desired. Ideal
for use with CCTV security
cameras and VCRs without RF
output. Supplied complete
with either UK style mains
adaptor (order code KRFT) or
Euro style mains adaptor
(order code KRFTE).

5

Keene distribution amplifier

4 way composite or S-video plus audio, each output
indistinguishable from the input, ideal for making up to four
simultaneous multiple copies. Uniquely the Keene Distribution
Amp also has a
switchable line drive
feature, giving the
ability to send audio
and/or video over
much longer cable runs
than normally possible
(up to 100m dependant
on cable). It works by
applying a signal boost
with emphasis on higher frequencies and
use of wideband ICs with very low output
impedance. Supplied complete with either
UK style mains adaptor (order code KDA)
or Euro style mains adaptor (order code
KDAE).

6

Keene wideband through modulator

Our RF wideband modulator enables a camcorder, security
camera, VCR or other device with AV (audio video) output to be
connected to the aerial socket of a TV. If required, it can be
permanently connected into the RF aerial downlead. The AV
signal can be positioned on any vacant RF channel between 21
and 69. This means, for example, that the signal from a security
camera could be introduced into the aerial lead and viewed in
the same way, and as easily, as any normal broadcast signal. An
additional feature of the Keene unit is that because it uses dip
switches, the settings will be saved in the event of a power
failure. Supplied
complete with clip-in
bracket for skirting
board/loft mounting and
either UK style mains
adaptor (order code
KRFTW) or Euro style
mains adaptor (order
code KRFTWE).

Keene Scart Distribution Amplifier

One input to five outputs, fully buffered using broadcast grade
video amplification ICs. Pin 8 is routed through (if the input goes
high all the outputs go high) and every pin connection is carried
through making it suitable for composite, S-video and even
RGB. Supplied in a robust metal case this is ideal for displaying
one signal on multiple TVs or for making up to five
simultaneous copies
from one source.
Supplied complete
with either UK style
mains adaptor (order
code SDA) or Euro
style mains adaptor
(order code SDAE).

Other video products from Keene Electronics

• Ensure that the RF Modulator has a suitable power supply (see
next section), switch it on, and check that the unit’s ‘power’
LED is illuminated.

• Switch on the camcorder (or other device) and put into ‘play’
mode.

• Switch on the TV, select a vacant channel, and tune until the
picture from the output device becomes clear (refer to TV
instruction manual for correct procedure). If the TV already has
a channel tuned to your VCR, or a spare channel designated
specifically for use with a VCR, best results will be obtained by
using that channel. When tuned, make a note of the channel
number and store for future reference.

Powering the RF Modulator

The RF Modulator will work with any power source supplying
4–15V DC @ 25mA. This includes an internal battery, the source
camcorder or a suitable mains to DC transformer.
Internal battery. Place a 9V PP3 type battery in the battery of
the RF Modulator. Ensure correct polarity.
Camcorder battery. Most camcorders feature a ‘DC out’ jack
socket, usually located between the video and audio connections.
Use the power cable supplied with the RF Modulator to connect
this to the ‘DC in’ socket of the RF Modulator. Note that if using
this method for powering the device, the ‘power’ LED will not
illuminate until both the RF Modulator and the camcorder are
switched on.
Mains/DC adaptor. The RF Modulator ‘DC in’ connection is a

2.1mm DC jack socket. The unit will work with any input voltage

from 4–15V DC @ 25mA, for example as output by the Keene KT5
(with 3 x ‘square’ pin mains input connector) or the Keene KT5E
(2 x round pin Euro-style mains input connector) mains adaptors.

2

Typical connection of the RF Modulator with
camcorder as output device.

Connecting cables

If all connections are as described earlier (ie phono socket to
phono socket video plus phono socket to phono socket audio,
then a 2 x phono plugs to 2 x phono plugs (video + audio) cable
such as Keene Electronics KLD44 will be required. If the output
device has other types of connection for video and/or audio
output, see below:

Source machine Keene Electronics
AV output cable code

3 x RCA phono sockets KLD44

2.5mm AV jack KLD68
Scart socket KLD5
8-pin mini socket KLD17
BNC socket (video) + 2 x phono sockets (audio) KLD44 + KA115

3

VIDEO IN

TV AERIAL

POWER

Troubleshooting

Power LED doesn’t light.

Is the RF Modulator switched on?
Is there a power supply connected?
If battery, is the battery correctly installed, and fresh?
If power from camcorder, are the video, audio and power
leads connected correctly, and is the camcorder switched on
(many camcorders have auto shutdown function)?
If mains/DC convertor, is it plugged in and switched on?

No picture on TV

Are all devices correctly connected (in particular have the
audio and video connections between camcorder and RF
Modulator got reversed)?
Is the correct TV channel selected?

Technical data

Input: Video 1 Vpp/75 ohm
Output: PAL I (UK, Hong Kong and South Africa

Black & white or colour with audio

Factory preset UHF channel 36
Modulation depth: 75%
Dimensions: approx 110 x 70 x 25mm
Weight: approx 200g

4

Manufactured in England by Keene Electronics Ltd
Unit 9 Old Hall Mills Business Park, Little Eaton, Derbyshire DE21 5DN UK
Tel [phone] Fax [phone] Web: http://www.keene.co.uk