Arcam Delta 150 NICAM - Manual (Page 10)

Delta 150 NICAM stereo TV tuner handbook
Front panel functions
DELTA 150 MONITOR STANDARD TV TUNER
STORE TUNE
V A
STEREO LI L2 CHANNEL NICAM
V Л
POWER
l_l
I I
NICAM STEREO DIGITAL DECODING
Store and Tune buttons (up & down)
These controls are not for everyday use. They are needed to
tune the Delta 150 to the required TV channels in your area. By pressing
down one of the 'tune' buttons all the available TV channels from 21 to
69 are scanned in a period of approximately one minute, after which the
cycle repeats itself.
Most people will wish to assign BBC I to preset I on the
Delta 150, BBC2 to preset 2, ITV to preset 3 and so on. To do this
speedily when first setting up the Delta 150 proceed as follows:
Use the set up procedure described on page 7 to tune your
TV into the remodulated output of the Delta 150. Then use the TV
normally to check the programme content of a desired station (e.g.
Channel 4). Now use the Delta I50's channel buttons or remote control
to select preset number 4, shown by the display on the front panel.
Switch the TV back to channel 5 (displaying the Delta 150's remodulated
output), and hold down one of the tune buttons on the Delta 150 until
the same programme appears on the TV screen. When the picture is
tuned in as clearly as possible, press the 'store' button on the Delta 150.
Preset number 4 on the Delta 150 is now assigned to your local Channel
4 transmitter.
Repeat the procedure for as many other channels as you
wish, up to 8.
Please note that the Delta 150 employs a powerful
Automatic Frequency Control (AFC). This circuitry is used to compensate
for minor tuning drift with time and temperature. The AFC function is
defeated during tuning and remains defeated for approximately
1 second after a channel has been tuned.
The effects of this are noticeable as the Delta 150 will 'pull in'
a slightly mistuned programme back into the optimum position.
This means that it is possible to obtain a good picture on a
programme that is badly tuned in. When tuning the programme in, care
should be taken to ensure that the initial effects of the AFC are
minimised: this is done by tuning the programme in and waiting for
about I second for the AFC function to be enabled. If the picture does
not change when the AFC is enabled, then the programme will be close
to its optimum tuning point.
To achieve precise tuning you may find it helpful to use two
fingers to 'rock' between the tune up and down buttons. If this is done
quickly then the AFC remains disabled, making it easy to see when
optimum tuning (i.e. the best picture) has been achieved.