Q: How can I connect an analog S-meter to the TRX4S?
A:
You have to open the cover and add a wire to the RSSI-signal line. You can
access this at the CPU U800 (18 pin socket) pin 8 or at U260 pins 2 and 6 or at
U261 pins 2 or 3 (recommended).
Here you find the RSSI for wideband and narrow band mode according to the
programming.
The RSSI signals for narrow mode only can be found on point M260 and for wide at
M261 (both located between the 7-segment display and the 3 blue electrolytic
capacitors).
The Instrument should have 100 kOhm or more internal resistance. Voltage range is 0 to 5 volt. The voltage (minus offset) is nearly proportional to the logarithm of the input signal strength.
Q: Which is the real advantage of such short tx-rx switching delay?
A: At 9600 Baud, it takes approx. 0,8 ms to transmit a byte. While a normal fm transceiver switches from receive to transmit (100 ms), the TRX4S is able to transmit a complete packet of 100 Byte length. With 153600 Baud, a full data packet is only 5 ms long, the tx-delay should be less than 0.2 ms.
Q: Are there special versions of TRX4S available (rx only, tx only, lower transmit power, kit ...)?
A: There exists only one type of TRX4S. Other frequency ranges (other than 430-440) are possible. The version TRX2S is for 2m amateur band. We can produce versions from 140 up to 500 MHz upon request. If you have very special requirements, you should talk to our engineers about a special development.
Q: Could the TRX4S be used for higher data rates (over 153 kbaud)?
A: No. IF-filter wider than 300 kHz are not available, the speed is limited to 153 kbit/s (binary fsk).
Q: Which parts come with the TRX4S?
A: Transceiver, power cable, rs232-cable with 9 pin sub-d connector, cable to TNC (6 pin mini-DIN), diskette, complete manual with schematics (German or English language, you can download it here). No microphone.
Q: Which software is necessary for programming the TRX4S?
A: Just a simple terminal-programm (TERM, Telix, TERMINAL/Windows,
HyperTerm/Win95 etc.)
Examples and a special PC program are supplied on a 3 1/2 inch disk to configure
the TRX4S.
(frequencies, power, mode, calibration etc.).
Q: Which frequencies can I program?
A: With the German TRX4TERM software, frequency input is limited to 430 to 440 MHz. The international (English) TRXTERMG allows input of any frequency. However, the user has to observe not to program frequencies which are outside the specified frequency range. If you attempt to use suchfrequencies, the specified sensitivity and output power are not valid and the oscillators may unlock.