FireFox Synthesizer User Manual
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© 2006 Jackson-Labs
3.2.3 How long does the FireFox system take to warm up?
The FireFox system typically warms up to within 10-8 within 15 minutes. Its specified operating
parameters and GPS lock are typically achieved in less than 5 hours from a cold start when receiving
satellites in position hold mode.
3.2.4 Why is there no power switch on the FireFox?
The FireFox is designed for permanent power-on to achieve its rated accuracy. Cold power-on
requires ca. 5 hours of operation to achieve UTC lock, and the unit is kept operating to avoid this
initial delay. In order to stay locked to UTC, the OCXO oscillator receives constant drift corrections
from the GPS timing receiver. Over time the drift errors of the OCXO and the GPS receiver will
decrease, and the system errors that need to be corrected will thus decrease as well. The unit only has
to lock to UTC once after power-up, and will remain locked as long as GPS signals are received and
power is supplied. Power consumption is typically low at 18W when operating from 110V AC, and
less than 10W when running from a 12V DC supply.
3.3 Application/Usage FAQs
The following FAQs give useful hints in operating the FireFox Signal Generators.
3.3.1 What is the difference between the FireFox Desktop unit
and the FireFox OEM PCB?
The FireFox Desktop unit uses the same FireFox OEM board that is also sold separately. The desktop
unit includes a Swiss-made enclosure, a power supply, an LCD Display, a Keypad, and external
connectors for all the I/O connections available on the FireFox OEM board. The FireFox OEM board
is typically installed into a user enclosure, and statically set to a fixed frequency, or controlled via the
built-in RS-232 serial port.
3.3.2 What applications is the FireFox Synthesizer designed
for?
The FireFox synthesizer has five independent outputs to allow it to be used in almost any application
that requires a highly stable and accurate analog sine-wave signal, or digital clock signal. It combines
a function generator, signal generator, and GPS Disciplined frequency reference into one small unit.
As a bonus, the unit also includes a generic, non-dedicated 2GHz mixer usable for building receivers,
or up/down-converters.
The units’ outputs are optimized for the following uses:
* High-power HCMOS 3.3V/5Vpp digital output signal, DC to 390MHz. This signal is a typical
CMOS output signal that can drive an un-terminated 50 Ohm transmission line at either 5V or 3.3V
peak (selectable via switch on the back panel). The output driver is strong enough to also drive 50
Ohm resistor end-terminated transmission lines up to 2.4V (5Vpp setting), which is enough
signal-level to switch typical 3.3V CMOS logic or TTL inputs. The rise and fall times of this output
are typically less than 1ns. The output can typically provide 32mA of drive current. This signal can
Summary of Contents for FireFox
Page 1: ...FireFox Synthesizer User Manual Document 0012008 Version 004 Date 10 April 2008...
Page 2: ...FireFox Synthesizer User Manual Copyright 2008 Jackson Labs...
Page 34: ...FireFox Synthesizer User Manual 28 2006 Jackson Labs...
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