Operators Handbook and Service Manual TEKK KS-960 (KS-900N) Crystal Controlled Digital Data Radio This Manual is intended for use by both the Operator and the Service Technician and is therefore divided into two logical parts. The operation chapter presents all the necessary information to connect, adjust and place the radio in operation. The service chapter provides all the necessary information and data to test, align, and repair the radio. This document was included with the order of the KS-960.
Introduction The KS-960 Series is available in a Low and High Band configuration. The suffix L and H indicate Low and High respectively. The Low Band radio is intended for operation between 430 and 450 MHz. The High Band version for operation between 450 and 470 MHz. Because there are a number of component differences between the Low and High Band Radios it is not generally feasible to use a Low Band Radio on a High Band Frequency. The opposite case also being true.
Sensitivity Selectivity Spurious Rejection Frequency Stability Audio Response Audio Distortion Audio Output Receiver Recovery Time to Stable D Current Drain, Squelched <0.35 uV for 12 dB SINAD 70dB 60dB +/- 5ppm Flat < 5% 750 mV RMS < 8 mS 20 mA Transmitter Power Output Duty Cycle Spurious Radiation Harmonic Radiation Modulation Attack Time to Stable Data Audio Response Distortion Data Modulation Level for 3.5KHz Deviation Approximate Current Drain at 2 Watts 2 Watts at 9.6 Volts 2 min.
The KS-960 is a Half-Duplex UHF Transceiver with crystals controlling the Transmit and Receives Frequencies. Half-Duplex indicates that the radio can transmit on a frequency that is different from the receive frequency but can not RECEIVE and TRANSMIT at the same time. For the single channel KS-960 there is no limit to the separation of the Transmit and Receive frequencies as long as both are in the same, high or low band. There is no limit to the separation of the receive and transmit frequencies.
In many Modems, the Data Out Signal used to Modulate the KS-960 is a fixed level. To allow for proper modulation of the KS-960 a level or deviation control, VR1, has been included. If the Modem used also has a level control It should be set so that the level of the output signal is approximately 50 mV. The final adjustment for proper deviation should be made with VR1 using suitable test equipment as described in the Service Chapter Step 8.
A Microampmeter may be connected directly to Pin 8 to indicate the relative strength of the received signal. The circuit has a dynamic range of about 60 dB with a scale factor of approximately 0.8uA per dB. A meter with a 50 uA movement will provide a suitable indication of the signal strength. The Meter may be left connected at all times. Once installed and placed in operation, a correctly adjusted and aligned KS-960 should provide years of trouble free operation.
The input, Pin 16, of IC1 is connected directly to the internal mixer. Pins 1 and 2 are the frequency controlling pins of the internal oscillator. A 20.945 MHz crystal is connected to Pin 1. When the 21.4 MHz signal is mixed with the 20.945MHz crystal signal frequencies of 910 and 455KHz are produced. The 455 KHz signal out of the mixer, Pin 3, is selected by the 4 pole filter F3. After filtering the signal is reinserted via Pin 5, to the input of the internal high gain main IF amplifier and limiter.
All of the receiver stages are supplied with a constant +B voltage from the regulator transistor Q10. This voltage can be checked at TP11. The base of Q10 is fixed at 6.2 volts via the Zener Diode D10. To insure very fast receiver recovery, the receiver +B buss is not switched off during transmit. TRANSMITTER, GENERAL The transmitter is a straight forward direct modulated FM transmitter delivering approximately 2 watts to a 50 Ohm load.
The base voltage of Q8 is held constant by the Zener Diode D9. The emitter voltage of Q8 is then a constant value around 5 volts. This 5 volts (T5) is used to supply the oscillator, multipliers and drivers as well as the modulation amplifier IC2.
2) Adjust the signal generator to receive frequency and set the output level to 1mV. Adjust the modulation to 1000 Hz(*) with a deviation of 3.5 KHz (*) Note: If the distortion analyzer uses a frequency other then 1000 Hz, adjust the modulation to that frequency. 3) If the test jig meter or the SINAD er indicates that the signal is passing through the receiver, adjust the trimmer TC1 for an indicating of minimum distortion on the distortion analyzer.
12) While observing the wave form on the oscilloscope, change the output voltage of the power supply between 8 volts and 12 volts and note that there is no noticable change in the wave form. THIS COMPLETES THE RECEIVER ALIGNMENT Transmitter Alignment 1) Connect the KS-960 to the test jig and to the 20dB directional coupler, notch filter, spectrum analyzer, counter and 50 Ohm power meter. 2) Close the PTT switch and note if transmitter output is indicated.
6) Connect the spectrum analyzer between the radio and the 50 ohm power meter. Set the Spectrum analyzer to display a frequency spectrum from zero to 3GHz. Adjust the Notch filter connected in front of the spectrum analyzer to notch out the transmitter carrier. 7) Make the final adjustment of T7, T8, T9, T10, T11, and the trimmers TC3, TC4, TC5, TC6 for maximum power output 8) Modulate the transmitter with a 1KHz signal with an amplitude of 50mV. Adjust VR1 to produce 3.
