SYMEK FSK-9601, Руководство пользователя

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FSK 9601 Page 6
As long as the transmitter is keyed (by TNC command or by jumper 2), the modem-transmitter is NOT muted.
(DIN-Connector) (Trimmer) 4 3 2 1
• • • •
• • • •
permanent transmit ON
FSK / GMSK switch (jumper 3)
With jumper 3, the transmit characteristic can be switched from the usual FSK-modulation to GMSK. Both modulation types
are alike, if there is not much noise present, you will find no difference. For best results, use the FSK-filter (jumper not in-
stalled).
(DIN-Connector) (Trimmer) 4 3 2 1
• • • •
• • • •
GMSK-Filter enabled
Filter-select switch (jumper 4)
The filter-EPROM can store up to four different sets of filter coefficients. Standard is FSK and GMSK-operation. Two addi-
tional filter curves may be selected by installing jumper 4. With the standard modem, this has no effect (future use)
(DIN-Connector) (Trimmer)
4 3 2 1
• • • •
• • • •
Optional filter enabled (future use)
Solder programmable jumpers in modem FSK9601
For special applications, there are some solder jumpers on the bottom side of the FSK9601 board. To open soldered jumpers,
carefully remove the solder with desolderung wick. J6 and J17 are closed by a copper trace, which has to be cut' with a small
sharp knife.
Bottom side (solder side) of the printed circuit board FSK9601-C
Watchdog (solder jumper 16)
The FSK9601 modem will key a transmitter only for a limited time. If the watchdog timer (approx. 15 seconds) is expired, the
PTT is released and the transceiver returns to receive mode, even when the TNC keeps the PTT-control line to 'low'. So, it
can be made sure, that the TNC does not key up the transmitter permanently, even in case of a software malfunction. This
circuit is called
Watchdog.
For full duplex or digipeater use, this watchdog function may be disabled by soldering jumper J16. This may be also useful for
some tests, if the transmitter is to be keyed up for longer periods. With jumper 2 (see above), the transmitter may be keyed up
independantly from the watchdog setting.
Jumper J17 "RX-muting"
In receive mode, the transmitter (modulation output) of the modem is muted. (Jumper MUTE installed). If a signal has to be
generated even in receive mode, the trace J17 has to be removed.