Austron 1250A Crystal Frequency Standard

Physical Specifications

Height 3.5 in.
Width 17 in (19 in with furnished rack mount adapters).
Depth 11.68 in behind the rack panel, 13.75 in overall.
Weight 20 lbs 12 oz.
Output terminals 5 MHz, 1 MHz and 100 kHz front and rear BNC type. Clock and external electrical tuning, rear BNC type.

Electrical Specifications

Input voltage 115/230 Vac ±10 percent, 48 Hz to 420 Hz. 17 Vdc to 35 Vdc negative ground. 12 W maximum.
Standby Internal NiCad battery pack provides ten hours of standby power at 25° C.
Battery recharge 14 to 16 hours.

Operating Specifications

Output frequency 5 MHz, 1 MHz, 100 kHz and 1 MHz clock drive sinusoidal.
Output voltage ≥ 1 Vrms into 50 ohms, clock drive ≥ 0.5 Vrms into 1 kilohm.
Alarm output Contact closure on primary failure. Contacts rated 5A 120 Vac.
Frequency Adjustments:
Fine Adjustments
≥ 90 x 10-9 with digital dial having 5000 divisions.
Coarse Adjustments ≥ 300 x 10-9.
External Adjustments ≥ 5 x 10-8 with 5 Vdc to -5 Vdc applied.
 
Long term stability 5 x 10-10 after 24 hours, 1 x 10-10 / day after 30 days.
Ultimate drift is typically 5 x 10-11 / day after 90 days.
Medium term stability 1 x 10-11 rms for a 120 second averaging time.
Short term stability 5 x 10-12 rms for a 1 second averaging time.
Retrace 1 x 10-9 after 2 hours warm-up following a 24 hour off-time.
 
Ambient ≤ ± 2 x 10-9 from -10° C to 50° C.
Load ≤ ± 1 x 10-11 for open, 50 ohm load.
Supply ≤ ± 5 x 10-11 for 17 Vdc to 35 Vdc or 114/230 Vac ±10 percent.
 
Harmonic distortion 5 MHz, 1 MHz, 100 kHz down more than 40 dB from rated output.
Non-harmonically related outputs 5 MHz, 1 MHz, 100 kHz down more than 80 dB from rated output.
Storage temperature -55° C to 75° C without batteries.
-40° C to 50° C with batteries.
Operating temperature -40° C to 50° C (batteries cannot be charged below -17° C).
Humidity 0 to 95 percent.

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