Skanti TRP 5000, Инструкция по эксплуатации

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When the BAND switch is turned into the 2182 kHz position, terminal 11
receives a LOW level signal which, via 3/4
IC6, activates the ripple
blanking outputs of IC12, and IC19. The displays are then blanked, but
the original Frequency No. is stored.
If a HIGH level is applied to terminal 13 (Disable) or a LOW level to
terminal 14 (Programmed Frequency No.), the Blanking Oscillator
consisting of IC3 and associated components starts a 1Hz oscillation and
the Key-line is inhibited. Thus the displays, via 3/4
IC6 and IC12,
IC14, and IC19, will start to flash with a frequency of 1 Hz. However,
if the BAND switch is turned to its 2182 kHz position, the levels of
terminals 13 and 14 do not affect the Key-line.
5.4.9 /240\ MASTER OSCILLATOR
The oscillator itself is a sealed unit containing a highly stable
temperature compensated crystal oscillator, TCXO, at 11.2 MHz. The
output signal of the TCXO is amplified in the transistors TRI to TR3 and
fed to the binary counter IC1 that divides the input frequency by 8. The
1.4 MHz square wave signal is filtered in a tuned Circuit C6, T1, and
the re-suiting sine wave signal is fed to the output terminals.
TCXO's of two different manufactures may be used. In both cases crystal
oscillator ageing is very small (less than 10-11 per anum)and will be
greatest during the first few years. Ageing will normally cause an
increase in frequency, which in the one case can be compensated for by
introducing the connection indicated by the dotted line in the circuit
diagram (this will reduce the frequency by approx. 2*10-6)
and in the
other case by changing the factory selected resistor.
The resistor should be selected at 25°C ambient temperature to give a
TCXO output frequency offset from the nominal frequency (11.2 MHz) by
the amount marked on the can.
Frequency adjustment should be carried out only if a high quali ty coun-
ter is available for control of the frequency. It must be ensured that
the accuracy of the counter at the time of use is better than 10-7.
5.4.10 /241\ PROGRAMMING UNIT (Optional)
The purpose of this printed circuit board is to make it possible to
program manually the PROM’s used as building blocks in the MEMORY /238\.
The only types of PROM’S, which can be programmed by means of the
PROGRAMMING UNIT are the TI-types shown in table 3.11.1. Three PROM’s
together can contain the information of 32 different Frequency No’s. The
three PROM’s are placed in SK1, SK2 and SK3. Their input word address is
chosen by means of the key-board on the front panel, thus selecting
one of the 32 possible words in each of the three PROM’S.
A programmed output will be greater than 2V (HIGH), an un-programmed
output will be less than 0.8V (LOW). To prevent an attempt being made,
by mistake, to program new information into a word which has already
been programmed once, one bit location, pin 9 of the PROM placed in S K1,
must always be programmed if the rest of
the bit locations of a
Frequency No. have been correctly programmed.
Half of IC4 is always sensing the voltage level on pin 9 of SK1. If this
voltage level is HIGH, pin 5 of IC4 will also become HIGH after the
first positive transition of the clock pulse at pin 3, thus disabling
IC2 and thereby IC6 and IC8 from being activated by the key S1.
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