Frequency Meters

Specifications	Model 369	Model 4991
Accuracy MIL-M-23167	0.2 HZ @ 398-402 Hz – 0.4 Hz Elsewhere on Dial	0.2 HZ @ 398-402 Hz – 0.4 Hz Elsewhere on Dial
Accuracy MIL-M- 16125	NA	3% of Frequency Span on Dial
Resolution	0.2 Hz / Scale Division	0.1 Hz per Scale Division
Insulation Resistance	2600 Megohms Minimum	2600 Megohms Minimum
Over-Voltage	135% of Rated Voltage 15 Minutes	135% of Rated Voltage 15 Minutes
Burden	5 Volt-Amperes	5 Volt-Amperes
Storage	-65°C to +100°C	-65°C to +100°C
Scale Arc	90°	250°
Meter Movement Specification	MIL-PRF-10304	MIL-DTL-16034
Vibration	MIL-STD-167	MIL-STD-167
Shock	MIL-S-901	MIL-S-901

Scale Range (Hz)	Voltage Input Range (VAC)	Model Number (Military Designation)		MIL Spec.	Configuration
		3½” Panel	4½” Panel
395-405	120 ± 6	369-037 (MR38W41AFH)	4991-001 (MR49W41AFH)	MIL-M-23167	Self-Contained
395-405	450 ± 12	369-038 (MR38W42AFH)	4991-002 (MR49W42AFH)	MIL-M-23167	Self-Contained
395-405	208 ± 10	369-039 (MR38W43AFH)	4991-003 (MR49W43AFH)	MIL-M-23167	Self-Contained
395-405	220 ± 11	369-040 (MR38W44AFH)	4991-004 (MR49W44AFH)	MIL-M-23167	Self-Contained
395-405	440 ± 22	369-041 (MR38W45AFH)	4991-005 (MR49W45AFH)	MIL-M-23167	Self-Contained
59-61	120 ± 6	-	4991-010 (MR49W60AH)	MIL-M-16125	Self-Contained
55-65	120 ± 6	-	4991-008 (MR49W60BH)	MIL-M-16125	Self-Contained
350-450	120 ± 6	-	4991-012 (MR4W400DH)	MIL-M-16125	Self-Contained
55-65	120 ± 6	-	4991-006 * †	MIL-M-16125	Self-Contained
55-65	120 ± 6	-	4991-001 ** †	MIL-M-16125	Self-Contained
* Equivalent to GE P/N 50-101354APAP4 ** Equivalent Westinghouse 291B270A1 †The internal transducer can and circuitry are identical to A&M Model 4991-008