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it is either an error or an informational message. To retrieve the menu
display, just press any key.
7) LORAN
Output
This BNC outputs the amplified and filtered antenna signal. This may
be used in conjunction with the rear panel GRI SYNC and GATE
outputs to view the receiver's tracking point. The output is about 6 V
pk-pk and will drive a high impedance load.
8) Frequency Output
This connector can be set to output a TTL level signal (2.5 V into 50
ohms) at a frequency between 0.01 Hz and 10 MHz in a 1, 2.5, 5
sequence. This output may be terminated into 50 ohms.
9) Oscillator Input
This is the input to the FS700's internal phasemeter. The input signal to
the phasemeter should have the same frequency as the FREQUENCY
OUTPUT. The input has a 1 kohm input impedance and requires a
signal level of about 300 mV pk-pk. This input is protected to 100 VDC
and 40 VAC.
10) Phase Output
This is the phasemeter analog output. The output voltage is
proportional to the phase difference between the OSCILLATOR INPUT
and the FREQUENCY OUTPUT with a coefficient of proportionality of
0.01 V/degree. This output has a range of ±360 degrees (±3.6 V) and
expects a high impedance load.
Rear Panel Features
1) Power Entry Module
The power entry module contains the FS700's fuse and the line voltage
selection card. Be sure that the fuse rating matches that listed on the
rear panel and that the line voltage is set to the local value. To set the
line voltage: remove the power cord, remove the fuse, remove the
voltage selector card from the power entry module, insert the voltage
selector card so that the desired line voltage is visible through the clear
plastic window, replace the fuse with a correct rated fuse for the line
voltage selected, and reconnect the power cord.
2) IEEE-488 Connector
This connector can be used with any standard IEEE-488 (GPIB) cable
to allow computer control of the FS700.
3) GRI SYNCH Output
These two outputs may be used in conjunction with the front panel
Gate Output
LORAN OUTPUT to view the FS700's tracking point. Both outputs
provide TTL level outputs and may have a 50 ohm termination. The
GRI SYNC output provides a negative going pulse at the start of each
GRI. When the receiver is in LOCK (LOCK LED on) this pulse occurs
500 ±5 ms before the receiver tracking point, and the GATE output
brackets the third zero crossing point with a negative going pulse.
These outputs may be used with an averaging digital oscilloscope (such
as HP 54501A) to view the Loran pulse tracking point. This procedure
is detailed in the tracking section of this manual.
