Graupner GmbH & Co. KG MC-20 用户手册

42

The Graupner HoTT system theoretically permits 
simultaneous operation of more than 200 models. 
However, because of the interspersed radio-
frequency utilization permitted by certifi cation for the 
2.4 GHz ISM band, this number is signifi cantly lower 
in practical application. Nevertheless, in general 
more models can be operated simultaneously in the 
2.4 GHz band than would be the case in conventional 
35 or 40 MHz frequency bands. The real limiting 
factor is – as often before –  is still likely to be the 
size of available operating space (i.e. airspace for 
aircraft). Alone the fact that it is no longer necessary 
to coordinate transmitting frequencies with other 
pilots in the vicinity (which is sometimes quite diffi cult 
in broken landscapes, such as on hillside slopes) 
represents an enormous boost for remote control 
operating security.

Battery charged?
Since the transmitter is delivered with an empty (not 
charged) battery, the battery must fi rst be charged 
according to the charging instructions on page 16. 
Otherwise a warning tone will be sounded and an 
appropriate message will be blended into the basic 
display if the low voltage threshold set in the 
"Battery warning" line of the 
»General basic settings« menu 
(see page 260) is underrun. 

After being switched on, the message shown below 
will appear in the transmitter's screen for about two 
seconds. 

OFF

ON

Please select

RF on/off?

Within this brief period there is an opportunity to switch 
RF transmission off by using the 

c or f key of the 

right touch pad to shift the position of the fi eld shown 
in inverse video to the right so that ON is in standard 
video and 

 is presented in inverse video.

ON

Please select

RF on/off?

OFF

Now switch the RF module off by tapping on the 
center

 key of the right touch pad. 

The telemetry display just below the antenna socket 
will then briefl y show the message …

… and in parallel to this, the transmitter's basic 
display will appear similar to that shown below:

#01

0:00h

Stop watch

Flight tim

0:00.0

4.1V

0:00.0

0

0

0

0

00:00h

M

The symbol combination   means that the currently 
active model memory has already "bonded " with a 

Batt. must
be re-
charged!!

Preliminary remarks about the 

mc-20

 HoTT transmitter

Graupner-HoTT receiver but there is no connection 
to that receiver at the moment. (In this example, 
RF transmission has been switched off.) 
If, however, the transmitter is switched on without
switching RF transmission off, the symbolic antenna 
mast will blink. At the same time, an acoustic warning 
will sound until a connection is established with the 
respective receiver. As soon as the connection is 
established, the "X" at the base of the symbolic antenna 
will be replace with a fi eld strength indicator, for 
example 

, and the visual and acoustic warnings will 

cease. 
If a telemetry connection has also been established 
for the incoming signal, that is output by the receiver 
in the model, then the right side of this same screen 
line will display a similar indication of signal strength 
for this reception of the receiver's transmitted signal 
(M

) as well as the current voltage of the receiver's 

power supply. 
On the other hand, if the symbol combination 

6

appears in in the display and the front display shows 
the message "Can't receive data" then the currently 
active model memory is not "bound" to any receiver 
at the moment.

Under-voltage warning
If the transmitter's voltage drops below a certain 
value set in the »General basic settings« menu 
(page 260), 4.7 V by default, there will be visual and 
acoustic under-voltage warnings issued.