13
4
Default settings
The modulators are supplied with the following default settings:
sec. 1 (preset
0.0
)
sec. 2 (preset
00.
)
Out. ch.
36 (preset
36
, indicator
S
does not
glow) 38 (preset
38
, indicator
S
does not
glow)
dF
0 MHz
0 MHz
P/S
16 dB (preset
1.6
)
16 dB (preset
16.
)
Video test
off (preset
n.o
)
off (preset
no.
)
RF on/off
on (preset
o.n
)
on (preset
on.
)
RF level
0 dB (preset
.0
)
0 dB (preset
0.
)
A. level
0 dB (preset
.0
)
0 dB (preset
0.
)
A. mode (mt420C)
mono (preset
A.-
)
mono (preset
A-.
)
TV std.
B/G (preset
b.3
)
B/G (preset
b3.
)
The last selected parameters will remain in memory if the power is interrupted.
OPERATING
Changing of settings
The modulator has two modes of operating:
1. normal: sets after switch on;
Output channel can be selected in normal mode by pressing buttons ▼
or
▲
(see tables 2-8).
2. setting: to enter the setting mode press and hold
▼
and
▲
buttons simultaneously for 1 second, to exit setting mode press
and hold
▼
and
▲
buttons simultaneously for 1 second.
Section 1 or 2 can be selected in normal mode by pressing button "Enter" (for example:
6.5
- 1 section, output channel 65;
69.
- 2 section, output channel 69), see Figure 7:
Position of glowing dot means which section is activated.
Figure
7.
Select necessary to change parameter by pressing button
▼
and set necessary mode by pressing
▲
button.
Can be change the following settings in the setting mode:
1. TV system setting:
a) after switching settings mode, indicator displays current TV system (see tables 2-8);
b) set necessary TV system by pressing
▲
button (see tables 2-8);
c) after TV system changing, modulator sets to first channel of selected TV system (see tables 2-8), other settings
remains unchanged.
2. fine tuning of video carrier frequency:
a) press button
▼
;
b) shift video carrier frequency by pressing button
▲
(see table 9).
3. picture/sound ratio switching:
a) press button
▼
;
b) switching between 12 dB and 16 dB by pressing button
▲
.
4. test pattern generator:
a) press
▼
button;
b) switching between OFF and ON by pressing button ▲
,
“no”
- test pattern generator OFF,
“t5”
- test pattern generator ON.
5. output signal switching:
a) press button
▼
;
b) switching between RF ON and RF OFF by pressing button ▲
,
“on”
- RF ON,
“oF”
- RF OFF.
6. RF output signal level adjustment:
a) press button
▼
;
b) RF signal level is changed from 0 to -10 dB by 1 dB step by pressing button
▲
.
7. audio signal level:
a) press button
▼
;
b) audio signal level is changed from +6 dB up to -6 dB by 2 dB step by pressing button
▲
.
8. audio processing mode (for mt420C only):
a) press button
▼
;
b) switching between
A-
(mono),
AS
(stereo),
Ad
(dual) by pressing button
▲
.
LOCKING THE FRONT PANEL CONTROLS
To prevent unauthorized access press buttons
▼
and
▲
simultaneously twice in 0.5 sec.
"
LO
"
will briefly be displayed.
To revert to normal operation, repeat above procedure.
"
UL
"
will briefly be displayed. The symbol
"
LO
"
appears, if you try
to change settings in locked mode.
Range frequenza
110-862 MHz
TV standard
B/G/D/K/I/L/Au
B/G/D/K/Au stereo A2
RF output
Livello/impedenza
90 dB
µ
V/ 75
Ω
Stabilità livello uscita
±
2
dB
Regolazione livello di uscita
0
÷
-10 dB (by 1 dB step)
Stabilità portanti
±
20 kHz
Regolazione rapporto portanti
10/16 dB
Stabilità rapporto portanti
±
3 dB
IMD2/IMD3 livello spurie
< -60 dB
Level spacing (PC/SC2*)
- 20
±
3 dB
C/N ratio
≥
55 dB
Range miscelazione RF
47-2150 MHz
Passaggio DC, tensione (max.)
0.3 A 24 V
Attenuazione passaggio Terr/SAT
1.5/2.5 dB
Return loss
≥
10 dB
Video
Livello di ingresso
1
±
0.1 Vp-p
Impedenza di ingresso
75
Ω
Banda video
20 Hz
÷
6 MHz
Guadagno differenziale
8 %
Fase differenziale
≤
6
о
Risposta in frequenza del canale
±
1.5 dB (0.5 MHz
÷
5 MHz)
K-factor (2T pulse)
≤
4 %
Rapporto S/N, ponderato
≥
55 dB
Audio
Range frequenza
40 Hz
÷
15 kHz
Impedenza di ingresso
> 10 k
Ω
Preenfasi
50
µ
s
Regolazione livello audio
+6
÷
-6 dB (by 2 dB step)
Risposta in frequenza (ref. to 1 kHz)
±
2 dB
Rapporto S/N FM (fm=1 kHz:
+
f=50 kHz), peso
≥
50 dB
Rapporto S/N AM (fm=1 kHz: m=60 %), standard L
≥
47 dB
-
Comuni
Alimentazione
+12 V
±
1 V
Consumo
450 mA
470 mA
Temperatura di esercizio
0
÷
50
о
С
Connettore RF
F
Connettore audio, video
RCA socket
Dimensioni/Peso
198x107.5x36 mm/0.9 kg
Specifiche tecniche
Tabella 1
Tipo
mt420 mt420C
pr.
pr.
pr.
* PC - portante immagine
SC2 - seconda portante audio
indica una funzione modificabile via software
pr.