The Packet Radio
“
2 N 1
”
Handbook
by
Buck Rogers
K4ABT
Section 1
;
Packet Radio “The Basics
”
Section 2
;
The X1J4 System Node Operator’s (SNO) Handbook
Section II
;
TheNET X1J4 System Node Operators Handbook
__ Page 39
To interconnect three or more TNCs as a multi-frequency node-stack, you should build a diode-matrix coupler. A
schematic for a four-frequency coupler is shown below. It uses 24 diodes (1N4148, 1N914 or equivalent).
Configuring a multi-frequency TheNET
X1
node for three or more frequencies is almost as easy as dual-frequency
operation. A TNC2 with TheNET
X1J4 EPROM
installed is used for each frequency. Once again, the TNCs are
interconnected via their RS232 ports. Interconnecting three or more TNCs requires nothing more elaborate than some
isolation diodes between the RS-232 ports.