public address amplifier

Datecirca 1936

Inventory NumberRS0105

ClassificationAmplifier

Subject

Maker Cruft Laboratory, Harvard University founded 1914

Maker David P. Wheatland 1898 - 1993

Maker Atomic Instrument Company 1947 - 1956

User Harvard Cyclotron Laboratory 1937 - 2002

Associate Name(designer) Emory Leon Chaffee 1885 - 1975

Associate Name(designer) Frederick Vinton Hunt 1905 - 1972

Maker(meters) Western Electric Company 1869 - 1995

Cultural Region

Place of Origin

Dimensions175 x 52 x 42 cm (68 7/8 x 20 1/2 x 16 9/16 in.)

Material

Signedetched and white filled on top panel: CATHODE-RAY OSCILLOGRAPH No 8 / CRUFT LABORATORY etched and white filled on panel 2nd from the top: 4-POS. - 2 CHAN. / MIXER AMP. / CRUFT LABORATORY etched and white filled on panel 3nd from the top: REFLEX / VACUUM TUBE VOLTMETER / NOVEMBER 1933 DW etched and white filled on panel 4th from the top: 100 KC FREQUENCY SHIFTER / CRUFT LAB. HARVARD UNIV. / DECEMBER 1955 etched and white filled on panel 3rd from the bottom: DRACO FREQUENCY CODER / CRUFT LABORATORY HARVARD UNIVERSITY etched and white filled on panel 2nd from the bottom: LINEAR AMPLIFIER / MODEL 204-B SERIAL NO. 240 etched and white filled on panel on bottom: SCALE OF 64 / ATOMIC (logo) Instrument Company / BOSTON, MASS / MODEL 101-A SERIAL NO. 484 on face of meter, top panel: PAT. 1,579,849 1,661,214 1,714,065 / AMPERES A.C. / WESTON ELECTRICAL INSTRUMENT CORP., NEWARK, N.J., U.S.A. / MODEL 476 NO. 134151 on face of top meter, panel 2nd from the top: - DECIBLES + / RECTIFIER TYPE / ZERO POWER LEVEL / 6 MILLIWATTS 500 OHMS / WESTON ELECTRICAL INSTRUMENT CORP., NEWARK, N.J., U.S.A. / MODEL 301 HS-1 NO. 1172971 / PAT. 1,640,335 1,746,935 on face of lower meter, panel 2nd from the top: D.C. / MILLIAMPERES / TRIPLETT / MODEL 221 PAT. APLD. FOR / TRIPLETT ELECTRIC CO. / BLU(obscured) OHIO, U.S.A. on face of left meter on panel, 3rd from the top: VOLTS D.C. / 62 / OHMS PER VOLT / WESTON ELECTRICAL INSTRUMENT CORP., NEWARK, N.J., U.S.A. / MODEL 301 NO. 101540 on face of right meter on panel, 3rd from the top: PAT. 1,579,849 1,597,256 1,635,595 1,661,214 / MILLIAMPERES D.C. / WESTON ELECTRICAL INSTRUMENT CORP., NEWARK, N.J., U.S.A. / MODEL 600 NO. 235

Inscribedplate on panel 2nd from the bottom: HARVARD UNIVERSITY / GOVERNMENT PROPERTY / 00076 D00392 stamped in yellow on panel 2nd from the top: CRUFT in white on panel 4th from the top: P in red on panel 2nd from the bottom: 5 in red on panel on bottom: 1-2 in red on panel on bottom: KS; label 1: COUNTER / SCALE OF 64 / 1952 / Atomic Instrument / Co Boston 14 Mass / Model 101 A Ser484 / (over) / used with the / 2nd Harvard / Cyclotron / from Andy Kohler / of Cyclotron / 4/16/68 / DW label 2: LINE AMPLIFIER / for COUNTER / 1952 / Atomic Instrument / Co Boston 14 Mass / Linear Amplifier / Model 204-B / Ser. 240 / (over) / Harvard Uniov / Govt Project / 76 D 392 / Received from / Andy Kohler of the / Cyclotron 4/16/68 / DW label 3: V.T. VOLTMETER / 1933 / Designed and / built by DD / Wheatland / from schematic / by EL Chaffee / (see his book) / (over) / Meter (Micro amp) / range switch / designed by DW / to maintain / consistant circuit / resistance - / however resist / coils are not / heavy enough / for the last / 2 ranges 10 m2 / %50 W-2 label 4: TERCENTENARY / PUBLIC ADDRESS / AMPLIFIER / 1936 / marked: / "MIXER-AMP. / CRUFT LABORATORY / 4 POS.- 2 CHAN. "/ (over) / This amplifier / was designed / by Prof. F.V. Hunt / and built in the / Cruft shop / expressly for the / Tercentenary exer- / cises in the / Harvard Yard / June 1936. / Harvard Sci. Instr- / Presented by Prof. / Hunt Sep. 23 1969

Functionfor use with cathode-ray oscillograph

Example: A helium-filled ionization chamber connected to a linear amplifier served as a detector for fast neutrons. The ionization pulses of the chamber were observed visually by means of a cathode-ray oscillograph and were recorded by the usual counting arrangement.

http://www.fdrlibrary.marist.edu/psf/box5/t64h02.html