301-A

The General Radio 301-A Series Rheostats was introduced in Catalog G1 (1932) and remained available through Catalog N (1954).

The Type 301-A series are general purpose rheostats with 3 to 4 watt dissipation depending on the model. As seen below different types of wire is used dependant on resistance required. All are equipped with a ¼ inch stainless steel shaft and KNSP-6 knob. All the members of the series share the same type number, they differ by the code word.

Specifications

• Maximum Dissipation: 4 w without protection strip and 3 w with protection strip
• Winding Length: 3¾ inches
• Useful Angle of Rotation: 255°
• Shaft: ¼ inch stainless steel
• Wire Code
  • A: Copper Nickel (Constantan), 294 Ω per foot
  • L: Copper Nickel, 60 Ω per foot
  • N: Nickel-Chromium-Iron, 675 Ω per foot
  • R: Chromium-Aluminum-Iron, 800 Ω per foot

Type 301-A Series of Rheostats

Type	Maximum Resistance	Maximum Current	Approx. Turns	Wire	Code Word
301-A	5 Ω	900 ma	140	L	PALSY
301-A	10 Ω	630 ma	180	L	REMIT
301-A	20 Ω	450 ma	225	L	RENEW
301-A	50 Ω	280 ma	190	A	RIFLE
301-A	100 Ω	200 ma	235	A	RIGID
301-A	200 Ω	140 ma	300	A	REBUS
301-A	500 Ω	90 ma	375	A	RIVAL
301-A	1000 Ω	65 ma	475	A	RAVEL
# 301-A	2000 Ω	39 ma	580	A	READY
# 301-A	5000 Ω	24 ma	630	N	ROMAN
# 301-A	10 kΩ	17 ma	780	N	CURRY
# 301-A	20 kΩ	12 ma	840	R	CRUMB

• # Supplied with linen-phenolic protecting Strip

Photos

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  Mechanical Drawing