Symec TNC2h - Front

DESCRIPTION G3RUH PACKET RADIO MODEM
In the TNC2H a G3RUH modem is used in the form improved by DF9IC. The circuit was adapted in co-operation with G3RUH, James Miller, for the TNC2H and is optimal regarding sensitivity and signal figuration of the send signals. It guarantees a small bandwidth with high data transmission rate.

CURRENT CONSUMPTION
The device operates with 12 V of DC voltage 9 to 16 Volt, a polarity protection is inserted. Power input of approx. 160 mA. The TNC2H is to a large extent equipped with MCOcS BUILDING BLOCKS.

OPERATE ALSO WITHOUT COMPUTER
For the operation of the TNC2S not constantly a computer is necessary. As long as the computer is switched off or is used for other purposes, the TNC operates independently as Digipeater, can become connected and stores detailed messages.

MODEM DISCONNECT PLUG FOR EXTENSIONS
In the TNC2H is a 20-pin plug-in connection for additional modems. The plug is occupied after the DF9IC High Speed Modem Disconnect. All external modems with the appropriate plug allocation can be attached. Symek offers among other things with the AFSK1200 a modem, with which the TNC2H for 1200 Baud AFSK operation can be extended.

OPERATION FROM THE FRONT PANEL
The control elements (DIP switches for terminal Baud rate, software switching) are operated from the front panel, the device need not to be screwed on.

MANUAL AND DOCUMENTATION
The TNC2H is supplied with a very detailed German manual with glossary. On 60 pages for also for the beginner one explains exactly, how the TNC2H is used in 9600 Baud operation. Additionally a 60-seitiges FSK manual is supplied, which in detail describes the 9600 Baud FSK technique and in that the conversion instructions for approximately 100 different radio types is contained. Of course a complete diagram with bill of material is contained. The TNC2H manual is available also in English and French language. Current information is published in the Internet.

BATTERY SUPPORTED MEMORY
The RAM memory of the TNC2H is supplied by a lithium battery, as long as the TNC is not attached to a voltage supply. Thus all adjustments (parameters) are preserved. Ram offers 32 KB to storage space.

ALSO FOR SATELLITE OPERATION
Operation over OSCAR satellites with 9600 Baud G3RUH-Modulation is problem free possible with the TNC2H. If the satellite communication program the OCN STATUS on pin 9 of the serial interface needs: The signal is available in the TNC2H, the necessary interface driver is in series inserted.

RELIABLE RESET CIRCUIT
A external Reset circuit prevents the fact that the TNC2H falls with short voltage drops uncontrolled or that is lost to data in the RAM. When restarting supply voltage the microprocessor of the TNC is started reliably.

EMI FILTERS IN ALL ACCESS LINES
In the access lines to the radio, to the computer and for current supply L-C-L filters are inserted against unwanted HF radiation or against outside HF influence. The filters are so select that the effect on the amateur frequencies is optimal.

CPU WITH 9,8 MC/S CLOCK
The clock frequency of the TNC2H of processor amounts to 9.8 mc/s, it components is used, which can operate with up to 10 mc/s clock frequency.

DAMA MODE
The TF firmware TF27, used in the TNC2H, is DAMA able. Standard radio link with 5-pin DIN socket. The link of the radio is made by a 5-pin DIN socket. The allocation of the socket corresponds to the standard usual for TNC2 (pin 1: Modulator, pin 4: Demodulator, pin 3: PTT, pin 2: Mass, pin 5: freely.

RS232 INTERFACE
The link of the TNC been made by a 25-pin Sub d socket with a 1:1 wired serial cable to the computer. The TNC2H possesses a genuine RS232 interface with +-10 V of voltage levels. Except TxD and RxD depending upon software also CTS, RTS of signals are supported.

19200 BAUD OPERATION
The TNC2H is applicable with most EPROM Software also for 19200 Baud. To the change prepared cable links must be switched, additionally the filter condensers have to be replaced after manual by other values.

9600 BAUD OPERATION AFTER G3RUH STANDARD
The TNC2H produces signals in accordance with in the amateur radio usual, of James Miller G3RUH the suggested standard. This standard was developed originally for satellite operation, is however meanwhile also usual on all terrestrial radio data transmission distances.

SWITCHABLE TNC SOFTWARE
With a DIL switch at the front plate one can select between two TNC2-Firmwares. In the TNC2H-EPROM is u.A. the most current TF2.7 von Nord >< links contained.

KISS MODE FOR TCP AND IP
The software in the EPROM contains the KISS mode or SMACK, a compatible, extended KISS mode with check total generator for RS232-Uebertragung. With special PC programs WAMPES, NOS, etc. can thereby packets in the PC be produced and by the TNC sent unchanged. All received packages are sent without modification to the PC. Thus the transfer is possible e.g. from TCP/IP log packages.

FIRM HOUSING
The TNC2H is inserted in a sturdy housing from anodized aluminum. 8 terminals of Baud advice to 38400 Baud adjustable. The Baud rate between computers and TNC can be adjusted by the front side. 8 of Baud advice is available: 150, 600, 1200, 2400, 4800, 9600, 19200 and 38400 Baud.

WATCHDOG
A reliable Watchdog circuit in the TNC2H prevents that also in the case of a malfunctioning of the TNC software of the transmitters remains continuously groped. After approx.. the protection circuit the transmitter switches 20 seconds off.

LIGHT EMITTING DIODES TO THE OPERATIONAL STATUS INDICATOR
With five light emitting diodes at the front plate the operating conditions are displayed: Power TNC is switched on, PTT transmitter palpation, DCD channel is occupied, CON connection to remote station exists, STA data to remote station are still on the way. To keep it special Low Current light emitting diodes used around the current consumption small.

FIR FILTER AFTER G3RUH
The transmitter signal is produced by a EPROM-CONTROLLED FIR filter. In the EPROM 16 different tables are stored for signal generation. Depending upon used radio one can select so the most favorable signal cam shape with the DIL switch at the front plate.

SENSITIVE, HIGH IMPEDANCE NF INPUT
The NF input of the TNC2H loads the demodulator output only minimum, since a high impedance preamplifier ensures a high impedance input impedance as buffer. Signals with only few millivolts are decoded perfectly by the TNC2H.

CLAMPING CIRCUIT IN THE INPUT
During the switching of transmitting on receipt strong DC voltage branches at the demodulator output occur with most radio's, which the input of the usual modems for some - zig milliseconds override and thus to a clear delay the ready to receive shank lead. In the TNC2H the link condenser in the input are loaded with over regulation by a clamping circuit very fast and the correct bias point is rapidly achieved.

LOW IMPEDANCE NF OUTPUT WITH HIGH OUTPUT VOLTAGE
Some radios need a relatively high NF voltage around sufficient FM stroke to produce. For this purpose the TNC2H possesses an NF output amplifier, which supplies up to approx. 5 V EFF. In as delivered condition the output voltage amounts to approx. 0.5 V of EFF. The output resistance of the TNC2H is low impedance by the amplifier, thus long, capacity-afflicted inlets are uncritical to the modulator.

TRANSMITTER WITH VMOS FET TRANSISTOR
The transmitter of the radio is groped by a VMOS FET transistor in the TNC. The max. current on contact is 400 mA. The reliable palpation of the radios is guaranteed by the low ON resistance of this transistors. The transmitter palpation with hand radios with common PTT and microphone line is problem free possible, since the necessary nF Link condenser is in series inserted.

STANDARD PRINTED CIRCUIT BOARD FORMAT
The printed circuit board has the European format of 100 x 160 mm. On this surface the packing CONTROLLER and the G3RUH-Modem are accommodated. The installation as 19 inch plug-in card is possible, a contact strip is however intended. Options and modifications of the TNC2H

5 VOLT SUPPLY
The circuit of the TNC2S operates internally with 5 V of DC voltage. If the voltage regulator is bridged, the TNC2H can be supplied also directly from 5 V a voltage supply.

LOW POWER OPTION
The TNC2H contains 7805 voltage regulators. As option a switched voltage regulator is applicable, instead of that the 7805 to be used can and the power input with 12 V bisected. The TNC operates then in the voltage range from 6 to 16 V. The major part of the current the GALs uses. Here zero power GALs are available as option, which reduce the current consumption strongly. Standard the TNC2H needs approx. 160 mA with 12 V. Become the zero power GALS or the bias-reducing potential automatic controller assigned, then the current reduces to approximately 80 mA. If both current economy measures are used, then the current consumption amounts to with 13.5 V only approx. 35 mA.

ALIGNMENT
An alignment is not necessary with the TNC2H. All signals are digitally synthesized and decoded. The amplitude of the output voltage is only stopped.

MAILBOX OPERATION
A mailbox EPROM for TNC2 is available. The TNC2H can be operated as small personal mailbox, into which each message can pick placing out and from the each message.

CURRENT SUPPLY LINK FROM COMPUTER OR RADIO
The TNC2H is supplied via a current supply plug with 12 V. The supply over the RS232 cable or over the 5-pin DIN socket is likewise possible.

OPERATION WITH COMBINED 1200 TO 9600 BAUD DIGIPEATER
The DCD channel occupies recognition OF the TNC2H CAN linked with the DCD circuits of other Symek TNC's. To make the operation more over combined 1200 Baud to 9600 Baud Digipeater is necessary it to recognize and win with a or circuit the combined DCD signal both modulation sort. 1200 Baud DCD can be built easily additionally in the TNC2H.

HANDBOOK
For the TNC2H is a alternative Handbook in the English and French language.

Symec TNC2h - Back

TECHNICAL DATA POWER SUPPLY
12 Volt DC min. 9 V, max. 16 V, typ. 160 mA Option: 70 or 35 mA, internal supply: 5 Volt. Regulator: standard regulator 7805 Option low-power: MAX738

PHYSICAL DIMENSIONS
Approx. B=105, T=170, H=42mm, 4 x 6.7 x 1.6 inch, weight approx. 450 gr.

COMPUTER INTERFACE
RS232 +/- 10 Volt, 25-pin Sub-D receptacle with UNC-nut bolts. Baudrate: 150; 300; 1200; 2400; 4800; 9600; 19200; 38400 Baud Parity: none word length 8 Bit may be configured by software outputs: data out Pin 3, CTS Pin 5 optional: DCD Pin 9 and DSR Pin 6 inputs: data in Pin 2, RTS Pin 4 optional DTR Pin 20

MODEM INTERFACE
CMOS -level 5 volt. TX Data, TX Clock, RX Data, RX Clock, RTS CTS, DCD, + 5 Volt, Reset, ground. The TNC2H may supply up to 200 mA for a external modem, connected to the 20 pin modem connector. Connection of additional modems to the TNC2H digital controller via 20 pin ribbon cable and connector. Assignment of the 20 pin modem connector according to the recommendation of DF9IC for high speed modem disconnect connections.

LED DISPLAY
Power 5 Volt, STA, CON, PTT, DCD.

MICROPROCESSOR
Z80 Toshiba TMPZ84C00-10 CPU, 9,8 MHz clock, 8 bit data bus.

PROGRAM STORAGE EPROM
2 x 32 kb containing 2 software programs, selectable by DIP-switch. Data Storage CMOS RAM: with battery backup 32 KB, about 24 kb available for data.

REALTIME CLOCK
Software clock, depends on the software. Not supplied by the battery.

DIP SWITCHES
9 switches for selection of software-options, terminal-baudrate and modem transmit filter. Reset and Watch dog circuit: MAX 691 reset and power supervisory circuit

BATTERY
3 Volt lithium battery with automatic switch over by MAX691. Calculated lifetime: 8 years.

MORE INFO ABOUT THE SYMEK PACKET RADIO MODEMS YOU CAN FIND AT:  HTTP://WWW.SYMEK.DE